reconcile merge

Signed-off-by: Huamin Chen <hchen@redhat.com>

vendor/google.golang.org/appengine/datastore/datastore.go

@@ -0,0 +1,407 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+
+	"github.com/golang/protobuf/proto"
+	"golang.org/x/net/context"
+
+	"google.golang.org/appengine"
+	"google.golang.org/appengine/internal"
+	pb "google.golang.org/appengine/internal/datastore"
+)
+
+var (
+	// ErrInvalidEntityType is returned when functions like Get or Next are
+	// passed a dst or src argument of invalid type.
+	ErrInvalidEntityType = errors.New("datastore: invalid entity type")
+	// ErrInvalidKey is returned when an invalid key is presented.
+	ErrInvalidKey = errors.New("datastore: invalid key")
+	// ErrNoSuchEntity is returned when no entity was found for a given key.
+	ErrNoSuchEntity = errors.New("datastore: no such entity")
+)
+
+// ErrFieldMismatch is returned when a field is to be loaded into a different
+// type than the one it was stored from, or when a field is missing or
+// unexported in the destination struct.
+// StructType is the type of the struct pointed to by the destination argument
+// passed to Get or to Iterator.Next.
+type ErrFieldMismatch struct {
+	StructType reflect.Type
+	FieldName  string
+	Reason     string
+}
+
+func (e *ErrFieldMismatch) Error() string {
+	return fmt.Sprintf("datastore: cannot load field %q into a %q: %s",
+		e.FieldName, e.StructType, e.Reason)
+}
+
+// protoToKey converts a Reference proto to a *Key. If the key is invalid,
+// protoToKey will return the invalid key along with ErrInvalidKey.
+func protoToKey(r *pb.Reference) (k *Key, err error) {
+	appID := r.GetApp()
+	namespace := r.GetNameSpace()
+	for _, e := range r.Path.Element {
+		k = &Key{
+			kind:      e.GetType(),
+			stringID:  e.GetName(),
+			intID:     e.GetId(),
+			parent:    k,
+			appID:     appID,
+			namespace: namespace,
+		}
+		if !k.valid() {
+			return k, ErrInvalidKey
+		}
+	}
+	return
+}
+
+// keyToProto converts a *Key to a Reference proto.
+func keyToProto(defaultAppID string, k *Key) *pb.Reference {
+	appID := k.appID
+	if appID == "" {
+		appID = defaultAppID
+	}
+	n := 0
+	for i := k; i != nil; i = i.parent {
+		n++
+	}
+	e := make([]*pb.Path_Element, n)
+	for i := k; i != nil; i = i.parent {
+		n--
+		e[n] = &pb.Path_Element{
+			Type: &i.kind,
+		}
+		// At most one of {Name,Id} should be set.
+		// Neither will be set for incomplete keys.
+		if i.stringID != "" {
+			e[n].Name = &i.stringID
+		} else if i.intID != 0 {
+			e[n].Id = &i.intID
+		}
+	}
+	var namespace *string
+	if k.namespace != "" {
+		namespace = proto.String(k.namespace)
+	}
+	return &pb.Reference{
+		App:       proto.String(appID),
+		NameSpace: namespace,
+		Path: &pb.Path{
+			Element: e,
+		},
+	}
+}
+
+// multiKeyToProto is a batch version of keyToProto.
+func multiKeyToProto(appID string, key []*Key) []*pb.Reference {
+	ret := make([]*pb.Reference, len(key))
+	for i, k := range key {
+		ret[i] = keyToProto(appID, k)
+	}
+	return ret
+}
+
+// multiValid is a batch version of Key.valid. It returns an error, not a
+// []bool.
+func multiValid(key []*Key) error {
+	invalid := false
+	for _, k := range key {
+		if !k.valid() {
+			invalid = true
+			break
+		}
+	}
+	if !invalid {
+		return nil
+	}
+	err := make(appengine.MultiError, len(key))
+	for i, k := range key {
+		if !k.valid() {
+			err[i] = ErrInvalidKey
+		}
+	}
+	return err
+}
+
+// It's unfortunate that the two semantically equivalent concepts pb.Reference
+// and pb.PropertyValue_ReferenceValue aren't the same type. For example, the
+// two have different protobuf field numbers.
+
+// referenceValueToKey is the same as protoToKey except the input is a
+// PropertyValue_ReferenceValue instead of a Reference.
+func referenceValueToKey(r *pb.PropertyValue_ReferenceValue) (k *Key, err error) {
+	appID := r.GetApp()
+	namespace := r.GetNameSpace()
+	for _, e := range r.Pathelement {
+		k = &Key{
+			kind:      e.GetType(),
+			stringID:  e.GetName(),
+			intID:     e.GetId(),
+			parent:    k,
+			appID:     appID,
+			namespace: namespace,
+		}
+		if !k.valid() {
+			return nil, ErrInvalidKey
+		}
+	}
+	return
+}
+
+// keyToReferenceValue is the same as keyToProto except the output is a
+// PropertyValue_ReferenceValue instead of a Reference.
+func keyToReferenceValue(defaultAppID string, k *Key) *pb.PropertyValue_ReferenceValue {
+	ref := keyToProto(defaultAppID, k)
+	pe := make([]*pb.PropertyValue_ReferenceValue_PathElement, len(ref.Path.Element))
+	for i, e := range ref.Path.Element {
+		pe[i] = &pb.PropertyValue_ReferenceValue_PathElement{
+			Type: e.Type,
+			Id:   e.Id,
+			Name: e.Name,
+		}
+	}
+	return &pb.PropertyValue_ReferenceValue{
+		App:         ref.App,
+		NameSpace:   ref.NameSpace,
+		Pathelement: pe,
+	}
+}
+
+type multiArgType int
+
+const (
+	multiArgTypeInvalid multiArgType = iota
+	multiArgTypePropertyLoadSaver
+	multiArgTypeStruct
+	multiArgTypeStructPtr
+	multiArgTypeInterface
+)
+
+// checkMultiArg checks that v has type []S, []*S, []I, or []P, for some struct
+// type S, for some interface type I, or some non-interface non-pointer type P
+// such that P or *P implements PropertyLoadSaver.
+//
+// It returns what category the slice's elements are, and the reflect.Type
+// that represents S, I or P.
+//
+// As a special case, PropertyList is an invalid type for v.
+func checkMultiArg(v reflect.Value) (m multiArgType, elemType reflect.Type) {
+	if v.Kind() != reflect.Slice {
+		return multiArgTypeInvalid, nil
+	}
+	if v.Type() == typeOfPropertyList {
+		return multiArgTypeInvalid, nil
+	}
+	elemType = v.Type().Elem()
+	if reflect.PtrTo(elemType).Implements(typeOfPropertyLoadSaver) {
+		return multiArgTypePropertyLoadSaver, elemType
+	}
+	switch elemType.Kind() {
+	case reflect.Struct:
+		return multiArgTypeStruct, elemType
+	case reflect.Interface:
+		return multiArgTypeInterface, elemType
+	case reflect.Ptr:
+		elemType = elemType.Elem()
+		if elemType.Kind() == reflect.Struct {
+			return multiArgTypeStructPtr, elemType
+		}
+	}
+	return multiArgTypeInvalid, nil
+}
+
+// Get loads the entity stored for k into dst, which must be a struct pointer
+// or implement PropertyLoadSaver. If there is no such entity for the key, Get
+// returns ErrNoSuchEntity.
+//
+// The values of dst's unmatched struct fields are not modified, and matching
+// slice-typed fields are not reset before appending to them. In particular, it
+// is recommended to pass a pointer to a zero valued struct on each Get call.
+//
+// ErrFieldMismatch is returned when a field is to be loaded into a different
+// type than the one it was stored from, or when a field is missing or
+// unexported in the destination struct. ErrFieldMismatch is only returned if
+// dst is a struct pointer.
+func Get(c context.Context, key *Key, dst interface{}) error {
+	if dst == nil { // GetMulti catches nil interface; we need to catch nil ptr here
+		return ErrInvalidEntityType
+	}
+	err := GetMulti(c, []*Key{key}, []interface{}{dst})
+	if me, ok := err.(appengine.MultiError); ok {
+		return me[0]
+	}
+	return err
+}
+
+// GetMulti is a batch version of Get.
+//
+// dst must be a []S, []*S, []I or []P, for some struct type S, some interface
+// type I, or some non-interface non-pointer type P such that P or *P
+// implements PropertyLoadSaver. If an []I, each element must be a valid dst
+// for Get: it must be a struct pointer or implement PropertyLoadSaver.
+//
+// As a special case, PropertyList is an invalid type for dst, even though a
+// PropertyList is a slice of structs. It is treated as invalid to avoid being
+// mistakenly passed when []PropertyList was intended.
+func GetMulti(c context.Context, key []*Key, dst interface{}) error {
+	v := reflect.ValueOf(dst)
+	multiArgType, _ := checkMultiArg(v)
+	if multiArgType == multiArgTypeInvalid {
+		return errors.New("datastore: dst has invalid type")
+	}
+	if len(key) != v.Len() {
+		return errors.New("datastore: key and dst slices have different length")
+	}
+	if len(key) == 0 {
+		return nil
+	}
+	if err := multiValid(key); err != nil {
+		return err
+	}
+	req := &pb.GetRequest{
+		Key: multiKeyToProto(internal.FullyQualifiedAppID(c), key),
+	}
+	res := &pb.GetResponse{}
+	if err := internal.Call(c, "datastore_v3", "Get", req, res); err != nil {
+		return err
+	}
+	if len(key) != len(res.Entity) {
+		return errors.New("datastore: internal error: server returned the wrong number of entities")
+	}
+	multiErr, any := make(appengine.MultiError, len(key)), false
+	for i, e := range res.Entity {
+		if e.Entity == nil {
+			multiErr[i] = ErrNoSuchEntity
+		} else {
+			elem := v.Index(i)
+			if multiArgType == multiArgTypePropertyLoadSaver || multiArgType == multiArgTypeStruct {
+				elem = elem.Addr()
+			}
+			if multiArgType == multiArgTypeStructPtr && elem.IsNil() {
+				elem.Set(reflect.New(elem.Type().Elem()))
+			}
+			multiErr[i] = loadEntity(elem.Interface(), e.Entity)
+		}
+		if multiErr[i] != nil {
+			any = true
+		}
+	}
+	if any {
+		return multiErr
+	}
+	return nil
+}
+
+// Put saves the entity src into the datastore with key k. src must be a struct
+// pointer or implement PropertyLoadSaver; if a struct pointer then any
+// unexported fields of that struct will be skipped. If k is an incomplete key,
+// the returned key will be a unique key generated by the datastore.
+func Put(c context.Context, key *Key, src interface{}) (*Key, error) {
+	k, err := PutMulti(c, []*Key{key}, []interface{}{src})
+	if err != nil {
+		if me, ok := err.(appengine.MultiError); ok {
+			return nil, me[0]
+		}
+		return nil, err
+	}
+	return k[0], nil
+}
+
+// PutMulti is a batch version of Put.
+//
+// src must satisfy the same conditions as the dst argument to GetMulti.
+func PutMulti(c context.Context, key []*Key, src interface{}) ([]*Key, error) {
+	v := reflect.ValueOf(src)
+	multiArgType, _ := checkMultiArg(v)
+	if multiArgType == multiArgTypeInvalid {
+		return nil, errors.New("datastore: src has invalid type")
+	}
+	if len(key) != v.Len() {
+		return nil, errors.New("datastore: key and src slices have different length")
+	}
+	if len(key) == 0 {
+		return nil, nil
+	}
+	appID := internal.FullyQualifiedAppID(c)
+	if err := multiValid(key); err != nil {
+		return nil, err
+	}
+	req := &pb.PutRequest{}
+	for i := range key {
+		elem := v.Index(i)
+		if multiArgType == multiArgTypePropertyLoadSaver || multiArgType == multiArgTypeStruct {
+			elem = elem.Addr()
+		}
+		sProto, err := saveEntity(appID, key[i], elem.Interface())
+		if err != nil {
+			return nil, err
+		}
+		req.Entity = append(req.Entity, sProto)
+	}
+	res := &pb.PutResponse{}
+	if err := internal.Call(c, "datastore_v3", "Put", req, res); err != nil {
+		return nil, err
+	}
+	if len(key) != len(res.Key) {
+		return nil, errors.New("datastore: internal error: server returned the wrong number of keys")
+	}
+	ret := make([]*Key, len(key))
+	for i := range ret {
+		var err error
+		ret[i], err = protoToKey(res.Key[i])
+		if err != nil || ret[i].Incomplete() {
+			return nil, errors.New("datastore: internal error: server returned an invalid key")
+		}
+	}
+	return ret, nil
+}
+
+// Delete deletes the entity for the given key.
+func Delete(c context.Context, key *Key) error {
+	err := DeleteMulti(c, []*Key{key})
+	if me, ok := err.(appengine.MultiError); ok {
+		return me[0]
+	}
+	return err
+}
+
+// DeleteMulti is a batch version of Delete.
+func DeleteMulti(c context.Context, key []*Key) error {
+	if len(key) == 0 {
+		return nil
+	}
+	if err := multiValid(key); err != nil {
+		return err
+	}
+	req := &pb.DeleteRequest{
+		Key: multiKeyToProto(internal.FullyQualifiedAppID(c), key),
+	}
+	res := &pb.DeleteResponse{}
+	return internal.Call(c, "datastore_v3", "Delete", req, res)
+}
+
+func namespaceMod(m proto.Message, namespace string) {
+	// pb.Query is the only type that has a name_space field.
+	// All other namespace support in datastore is in the keys.
+	switch m := m.(type) {
+	case *pb.Query:
+		if m.NameSpace == nil {
+			m.NameSpace = &namespace
+		}
+	}
+}
+
+func init() {
+	internal.NamespaceMods["datastore_v3"] = namespaceMod
+	internal.RegisterErrorCodeMap("datastore_v3", pb.Error_ErrorCode_name)
+	internal.RegisterTimeoutErrorCode("datastore_v3", int32(pb.Error_TIMEOUT))
+}

vendor/google.golang.org/appengine/datastore/doc.go

@@ -0,0 +1,361 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+/*
+Package datastore provides a client for App Engine's datastore service.
+
+
+Basic Operations
+
+Entities are the unit of storage and are associated with a key. A key
+consists of an optional parent key, a string application ID, a string kind
+(also known as an entity type), and either a StringID or an IntID. A
+StringID is also known as an entity name or key name.
+
+It is valid to create a key with a zero StringID and a zero IntID; this is
+called an incomplete key, and does not refer to any saved entity. Putting an
+entity into the datastore under an incomplete key will cause a unique key
+to be generated for that entity, with a non-zero IntID.
+
+An entity's contents are a mapping from case-sensitive field names to values.
+Valid value types are:
+  - signed integers (int, int8, int16, int32 and int64),
+  - bool,
+  - string,
+  - float32 and float64,
+  - []byte (up to 1 megabyte in length),
+  - any type whose underlying type is one of the above predeclared types,
+  - ByteString,
+  - *Key,
+  - time.Time (stored with microsecond precision),
+  - appengine.BlobKey,
+  - appengine.GeoPoint,
+  - structs whose fields are all valid value types,
+  - slices of any of the above.
+
+Slices of structs are valid, as are structs that contain slices. However, if
+one struct contains another, then at most one of those can be repeated. This
+disqualifies recursively defined struct types: any struct T that (directly or
+indirectly) contains a []T.
+
+The Get and Put functions load and save an entity's contents. An entity's
+contents are typically represented by a struct pointer.
+
+Example code:
+
+	type Entity struct {
+		Value string
+	}
+
+	func handle(w http.ResponseWriter, r *http.Request) {
+		ctx := appengine.NewContext(r)
+
+		k := datastore.NewKey(ctx, "Entity", "stringID", 0, nil)
+		e := new(Entity)
+		if err := datastore.Get(ctx, k, e); err != nil {
+			http.Error(w, err.Error(), 500)
+			return
+		}
+
+		old := e.Value
+		e.Value = r.URL.Path
+
+		if _, err := datastore.Put(ctx, k, e); err != nil {
+			http.Error(w, err.Error(), 500)
+			return
+		}
+
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		fmt.Fprintf(w, "old=%q\nnew=%q\n", old, e.Value)
+	}
+
+GetMulti, PutMulti and DeleteMulti are batch versions of the Get, Put and
+Delete functions. They take a []*Key instead of a *Key, and may return an
+appengine.MultiError when encountering partial failure.
+
+
+Properties
+
+An entity's contents can be represented by a variety of types. These are
+typically struct pointers, but can also be any type that implements the
+PropertyLoadSaver interface. If using a struct pointer, you do not have to
+explicitly implement the PropertyLoadSaver interface; the datastore will
+automatically convert via reflection. If a struct pointer does implement that
+interface then those methods will be used in preference to the default
+behavior for struct pointers. Struct pointers are more strongly typed and are
+easier to use; PropertyLoadSavers are more flexible.
+
+The actual types passed do not have to match between Get and Put calls or even
+across different calls to datastore. It is valid to put a *PropertyList and
+get that same entity as a *myStruct, or put a *myStruct0 and get a *myStruct1.
+Conceptually, any entity is saved as a sequence of properties, and is loaded
+into the destination value on a property-by-property basis. When loading into
+a struct pointer, an entity that cannot be completely represented (such as a
+missing field) will result in an ErrFieldMismatch error but it is up to the
+caller whether this error is fatal, recoverable or ignorable.
+
+By default, for struct pointers, all properties are potentially indexed, and
+the property name is the same as the field name (and hence must start with an
+upper case letter).
+
+Fields may have a `datastore:"name,options"` tag. The tag name is the
+property name, which must be one or more valid Go identifiers joined by ".",
+but may start with a lower case letter. An empty tag name means to just use the
+field name. A "-" tag name means that the datastore will ignore that field.
+
+The only valid options are "omitempty" and "noindex".
+
+If the options include "omitempty" and the value of the field is empty, then the field will be omitted on Save.
+The empty values are false, 0, any nil interface value, and any array, slice, map, or string of length zero.
+Struct field values will never be empty.
+
+If options include "noindex" then the field will not be indexed. All fields are indexed
+by default. Strings or byte slices longer than 1500 bytes cannot be indexed;
+fields used to store long strings and byte slices must be tagged with "noindex"
+or they will cause Put operations to fail.
+
+To use multiple options together, separate them by a comma.
+The order does not matter.
+
+If the options is "" then the comma may be omitted.
+
+Example code:
+
+	// A and B are renamed to a and b.
+	// A, C and J are not indexed.
+	// D's tag is equivalent to having no tag at all (E).
+	// I is ignored entirely by the datastore.
+	// J has tag information for both the datastore and json packages.
+	type TaggedStruct struct {
+		A int `datastore:"a,noindex"`
+		B int `datastore:"b"`
+		C int `datastore:",noindex"`
+		D int `datastore:""`
+		E int
+		I int `datastore:"-"`
+		J int `datastore:",noindex" json:"j"`
+	}
+
+
+Structured Properties
+
+If the struct pointed to contains other structs, then the nested or embedded
+structs are flattened. For example, given these definitions:
+
+	type Inner1 struct {
+		W int32
+		X string
+	}
+
+	type Inner2 struct {
+		Y float64
+	}
+
+	type Inner3 struct {
+		Z bool
+	}
+
+	type Outer struct {
+		A int16
+		I []Inner1
+		J Inner2
+		Inner3
+	}
+
+then an Outer's properties would be equivalent to those of:
+
+	type OuterEquivalent struct {
+		A     int16
+		IDotW []int32  `datastore:"I.W"`
+		IDotX []string `datastore:"I.X"`
+		JDotY float64  `datastore:"J.Y"`
+		Z     bool
+	}
+
+If Outer's embedded Inner3 field was tagged as `datastore:"Foo"` then the
+equivalent field would instead be: FooDotZ bool `datastore:"Foo.Z"`.
+
+If an outer struct is tagged "noindex" then all of its implicit flattened
+fields are effectively "noindex".
+
+
+The PropertyLoadSaver Interface
+
+An entity's contents can also be represented by any type that implements the
+PropertyLoadSaver interface. This type may be a struct pointer, but it does
+not have to be. The datastore package will call Load when getting the entity's
+contents, and Save when putting the entity's contents.
+Possible uses include deriving non-stored fields, verifying fields, or indexing
+a field only if its value is positive.
+
+Example code:
+
+	type CustomPropsExample struct {
+		I, J int
+		// Sum is not stored, but should always be equal to I + J.
+		Sum int `datastore:"-"`
+	}
+
+	func (x *CustomPropsExample) Load(ps []datastore.Property) error {
+		// Load I and J as usual.
+		if err := datastore.LoadStruct(x, ps); err != nil {
+			return err
+		}
+		// Derive the Sum field.
+		x.Sum = x.I + x.J
+		return nil
+	}
+
+	func (x *CustomPropsExample) Save() ([]datastore.Property, error) {
+		// Validate the Sum field.
+		if x.Sum != x.I + x.J {
+			return nil, errors.New("CustomPropsExample has inconsistent sum")
+		}
+		// Save I and J as usual. The code below is equivalent to calling
+		// "return datastore.SaveStruct(x)", but is done manually for
+		// demonstration purposes.
+		return []datastore.Property{
+			{
+				Name:  "I",
+				Value: int64(x.I),
+			},
+			{
+				Name:  "J",
+				Value: int64(x.J),
+			},
+		}, nil
+	}
+
+The *PropertyList type implements PropertyLoadSaver, and can therefore hold an
+arbitrary entity's contents.
+
+
+Queries
+
+Queries retrieve entities based on their properties or key's ancestry. Running
+a query yields an iterator of results: either keys or (key, entity) pairs.
+Queries are re-usable and it is safe to call Query.Run from concurrent
+goroutines. Iterators are not safe for concurrent use.
+
+Queries are immutable, and are either created by calling NewQuery, or derived
+from an existing query by calling a method like Filter or Order that returns a
+new query value. A query is typically constructed by calling NewQuery followed
+by a chain of zero or more such methods. These methods are:
+  - Ancestor and Filter constrain the entities returned by running a query.
+  - Order affects the order in which they are returned.
+  - Project constrains the fields returned.
+  - Distinct de-duplicates projected entities.
+  - KeysOnly makes the iterator return only keys, not (key, entity) pairs.
+  - Start, End, Offset and Limit define which sub-sequence of matching entities
+    to return. Start and End take cursors, Offset and Limit take integers. Start
+    and Offset affect the first result, End and Limit affect the last result.
+    If both Start and Offset are set, then the offset is relative to Start.
+    If both End and Limit are set, then the earliest constraint wins. Limit is
+    relative to Start+Offset, not relative to End. As a special case, a
+    negative limit means unlimited.
+
+Example code:
+
+	type Widget struct {
+		Description string
+		Price       int
+	}
+
+	func handle(w http.ResponseWriter, r *http.Request) {
+		ctx := appengine.NewContext(r)
+		q := datastore.NewQuery("Widget").
+			Filter("Price <", 1000).
+			Order("-Price")
+		b := new(bytes.Buffer)
+		for t := q.Run(ctx); ; {
+			var x Widget
+			key, err := t.Next(&x)
+			if err == datastore.Done {
+				break
+			}
+			if err != nil {
+				serveError(ctx, w, err)
+				return
+			}
+			fmt.Fprintf(b, "Key=%v\nWidget=%#v\n\n", key, x)
+		}
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		io.Copy(w, b)
+	}
+
+
+Transactions
+
+RunInTransaction runs a function in a transaction.
+
+Example code:
+
+	type Counter struct {
+		Count int
+	}
+
+	func inc(ctx context.Context, key *datastore.Key) (int, error) {
+		var x Counter
+		if err := datastore.Get(ctx, key, &x); err != nil && err != datastore.ErrNoSuchEntity {
+			return 0, err
+		}
+		x.Count++
+		if _, err := datastore.Put(ctx, key, &x); err != nil {
+			return 0, err
+		}
+		return x.Count, nil
+	}
+
+	func handle(w http.ResponseWriter, r *http.Request) {
+		ctx := appengine.NewContext(r)
+		var count int
+		err := datastore.RunInTransaction(ctx, func(ctx context.Context) error {
+			var err1 error
+			count, err1 = inc(ctx, datastore.NewKey(ctx, "Counter", "singleton", 0, nil))
+			return err1
+		}, nil)
+		if err != nil {
+			serveError(ctx, w, err)
+			return
+		}
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		fmt.Fprintf(w, "Count=%d", count)
+	}
+
+
+Metadata
+
+The datastore package provides access to some of App Engine's datastore
+metadata. This metadata includes information about the entity groups,
+namespaces, entity kinds, and properties in the datastore, as well as the
+property representations for each property.
+
+Example code:
+
+	func handle(w http.ResponseWriter, r *http.Request) {
+		// Print all the kinds in the datastore, with all the indexed
+		// properties (and their representations) for each.
+		ctx := appengine.NewContext(r)
+
+		kinds, err := datastore.Kinds(ctx)
+		if err != nil {
+			serveError(ctx, w, err)
+			return
+		}
+
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		for _, kind := range kinds {
+			fmt.Fprintf(w, "%s:\n", kind)
+			props, err := datastore.KindProperties(ctx, kind)
+			if err != nil {
+				fmt.Fprintln(w, "\t(unable to retrieve properties)")
+				continue
+			}
+			for p, rep := range props {
+				fmt.Fprintf(w, "\t-%s (%s)\n", p, strings.Join(rep, ", "))
+			}
+		}
+	}
+*/
+package datastore // import "google.golang.org/appengine/datastore"

vendor/google.golang.org/appengine/datastore/key.go

@@ -0,0 +1,396 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/gob"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+	"golang.org/x/net/context"
+
+	"google.golang.org/appengine/internal"
+	pb "google.golang.org/appengine/internal/datastore"
+)
+
+type KeyRangeCollisionError struct {
+	start int64
+	end   int64
+}
+
+func (e *KeyRangeCollisionError) Error() string {
+	return fmt.Sprintf("datastore: Collision when attempting to allocate range [%d, %d]",
+		e.start, e.end)
+}
+
+type KeyRangeContentionError struct {
+	start int64
+	end   int64
+}
+
+func (e *KeyRangeContentionError) Error() string {
+	return fmt.Sprintf("datastore: Contention when attempting to allocate range [%d, %d]",
+		e.start, e.end)
+}
+
+// Key represents the datastore key for a stored entity, and is immutable.
+type Key struct {
+	kind      string
+	stringID  string
+	intID     int64
+	parent    *Key
+	appID     string
+	namespace string
+}
+
+// Kind returns the key's kind (also known as entity type).
+func (k *Key) Kind() string {
+	return k.kind
+}
+
+// StringID returns the key's string ID (also known as an entity name or key
+// name), which may be "".
+func (k *Key) StringID() string {
+	return k.stringID
+}
+
+// IntID returns the key's integer ID, which may be 0.
+func (k *Key) IntID() int64 {
+	return k.intID
+}
+
+// Parent returns the key's parent key, which may be nil.
+func (k *Key) Parent() *Key {
+	return k.parent
+}
+
+// AppID returns the key's application ID.
+func (k *Key) AppID() string {
+	return k.appID
+}
+
+// Namespace returns the key's namespace.
+func (k *Key) Namespace() string {
+	return k.namespace
+}
+
+// Incomplete returns whether the key does not refer to a stored entity.
+// In particular, whether the key has a zero StringID and a zero IntID.
+func (k *Key) Incomplete() bool {
+	return k.stringID == "" && k.intID == 0
+}
+
+// valid returns whether the key is valid.
+func (k *Key) valid() bool {
+	if k == nil {
+		return false
+	}
+	for ; k != nil; k = k.parent {
+		if k.kind == "" || k.appID == "" {
+			return false
+		}
+		if k.stringID != "" && k.intID != 0 {
+			return false
+		}
+		if k.parent != nil {
+			if k.parent.Incomplete() {
+				return false
+			}
+			if k.parent.appID != k.appID || k.parent.namespace != k.namespace {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// Equal returns whether two keys are equal.
+func (k *Key) Equal(o *Key) bool {
+	for k != nil && o != nil {
+		if k.kind != o.kind || k.stringID != o.stringID || k.intID != o.intID || k.appID != o.appID || k.namespace != o.namespace {
+			return false
+		}
+		k, o = k.parent, o.parent
+	}
+	return k == o
+}
+
+// root returns the furthest ancestor of a key, which may be itself.
+func (k *Key) root() *Key {
+	for k.parent != nil {
+		k = k.parent
+	}
+	return k
+}
+
+// marshal marshals the key's string representation to the buffer.
+func (k *Key) marshal(b *bytes.Buffer) {
+	if k.parent != nil {
+		k.parent.marshal(b)
+	}
+	b.WriteByte('/')
+	b.WriteString(k.kind)
+	b.WriteByte(',')
+	if k.stringID != "" {
+		b.WriteString(k.stringID)
+	} else {
+		b.WriteString(strconv.FormatInt(k.intID, 10))
+	}
+}
+
+// String returns a string representation of the key.
+func (k *Key) String() string {
+	if k == nil {
+		return ""
+	}
+	b := bytes.NewBuffer(make([]byte, 0, 512))
+	k.marshal(b)
+	return b.String()
+}
+
+type gobKey struct {
+	Kind      string
+	StringID  string
+	IntID     int64
+	Parent    *gobKey
+	AppID     string
+	Namespace string
+}
+
+func keyToGobKey(k *Key) *gobKey {
+	if k == nil {
+		return nil
+	}
+	return &gobKey{
+		Kind:      k.kind,
+		StringID:  k.stringID,
+		IntID:     k.intID,
+		Parent:    keyToGobKey(k.parent),
+		AppID:     k.appID,
+		Namespace: k.namespace,
+	}
+}
+
+func gobKeyToKey(gk *gobKey) *Key {
+	if gk == nil {
+		return nil
+	}
+	return &Key{
+		kind:      gk.Kind,
+		stringID:  gk.StringID,
+		intID:     gk.IntID,
+		parent:    gobKeyToKey(gk.Parent),
+		appID:     gk.AppID,
+		namespace: gk.Namespace,
+	}
+}
+
+func (k *Key) GobEncode() ([]byte, error) {
+	buf := new(bytes.Buffer)
+	if err := gob.NewEncoder(buf).Encode(keyToGobKey(k)); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func (k *Key) GobDecode(buf []byte) error {
+	gk := new(gobKey)
+	if err := gob.NewDecoder(bytes.NewBuffer(buf)).Decode(gk); err != nil {
+		return err
+	}
+	*k = *gobKeyToKey(gk)
+	return nil
+}
+
+func (k *Key) MarshalJSON() ([]byte, error) {
+	return []byte(`"` + k.Encode() + `"`), nil
+}
+
+func (k *Key) UnmarshalJSON(buf []byte) error {
+	if len(buf) < 2 || buf[0] != '"' || buf[len(buf)-1] != '"' {
+		return errors.New("datastore: bad JSON key")
+	}
+	k2, err := DecodeKey(string(buf[1 : len(buf)-1]))
+	if err != nil {
+		return err
+	}
+	*k = *k2
+	return nil
+}
+
+// Encode returns an opaque representation of the key
+// suitable for use in HTML and URLs.
+// This is compatible with the Python and Java runtimes.
+func (k *Key) Encode() string {
+	ref := keyToProto("", k)
+
+	b, err := proto.Marshal(ref)
+	if err != nil {
+		panic(err)
+	}
+
+	// Trailing padding is stripped.
+	return strings.TrimRight(base64.URLEncoding.EncodeToString(b), "=")
+}
+
+// DecodeKey decodes a key from the opaque representation returned by Encode.
+func DecodeKey(encoded string) (*Key, error) {
+	// Re-add padding.
+	if m := len(encoded) % 4; m != 0 {
+		encoded += strings.Repeat("=", 4-m)
+	}
+
+	b, err := base64.URLEncoding.DecodeString(encoded)
+	if err != nil {
+		return nil, err
+	}
+
+	ref := new(pb.Reference)
+	if err := proto.Unmarshal(b, ref); err != nil {
+		return nil, err
+	}
+
+	return protoToKey(ref)
+}
+
+// NewIncompleteKey creates a new incomplete key.
+// kind cannot be empty.
+func NewIncompleteKey(c context.Context, kind string, parent *Key) *Key {
+	return NewKey(c, kind, "", 0, parent)
+}
+
+// NewKey creates a new key.
+// kind cannot be empty.
+// Either one or both of stringID and intID must be zero. If both are zero,
+// the key returned is incomplete.
+// parent must either be a complete key or nil.
+func NewKey(c context.Context, kind, stringID string, intID int64, parent *Key) *Key {
+	// If there's a parent key, use its namespace.
+	// Otherwise, use any namespace attached to the context.
+	var namespace string
+	if parent != nil {
+		namespace = parent.namespace
+	} else {
+		namespace = internal.NamespaceFromContext(c)
+	}
+
+	return &Key{
+		kind:      kind,
+		stringID:  stringID,
+		intID:     intID,
+		parent:    parent,
+		appID:     internal.FullyQualifiedAppID(c),
+		namespace: namespace,
+	}
+}
+
+// AllocateIDs returns a range of n integer IDs with the given kind and parent
+// combination. kind cannot be empty; parent may be nil. The IDs in the range
+// returned will not be used by the datastore's automatic ID sequence generator
+// and may be used with NewKey without conflict.
+//
+// The range is inclusive at the low end and exclusive at the high end. In
+// other words, valid intIDs x satisfy low <= x && x < high.
+//
+// If no error is returned, low + n == high.
+func AllocateIDs(c context.Context, kind string, parent *Key, n int) (low, high int64, err error) {
+	if kind == "" {
+		return 0, 0, errors.New("datastore: AllocateIDs given an empty kind")
+	}
+	if n < 0 {
+		return 0, 0, fmt.Errorf("datastore: AllocateIDs given a negative count: %d", n)
+	}
+	if n == 0 {
+		return 0, 0, nil
+	}
+	req := &pb.AllocateIdsRequest{
+		ModelKey: keyToProto("", NewIncompleteKey(c, kind, parent)),
+		Size:     proto.Int64(int64(n)),
+	}
+	res := &pb.AllocateIdsResponse{}
+	if err := internal.Call(c, "datastore_v3", "AllocateIds", req, res); err != nil {
+		return 0, 0, err
+	}
+	// The protobuf is inclusive at both ends. Idiomatic Go (e.g. slices, for loops)
+	// is inclusive at the low end and exclusive at the high end, so we add 1.
+	low = res.GetStart()
+	high = res.GetEnd() + 1
+	if low+int64(n) != high {
+		return 0, 0, fmt.Errorf("datastore: internal error: could not allocate %d IDs", n)
+	}
+	return low, high, nil
+}
+
+// AllocateIDRange allocates a range of IDs with specific endpoints.
+// The range is inclusive at both the low and high end. Once these IDs have been
+// allocated, you can manually assign them to newly created entities.
+//
+// The Datastore's automatic ID allocator never assigns a key that has already
+// been allocated (either through automatic ID allocation or through an explicit
+// AllocateIDs call). As a result, entities written to the given key range will
+// never be overwritten. However, writing entities with manually assigned keys in
+// this range may overwrite existing entities (or new entities written by a separate
+// request), depending on the error returned.
+//
+// Use this only if you have an existing numeric ID range that you want to reserve
+// (for example, bulk loading entities that already have IDs). If you don't care
+// about which IDs you receive, use AllocateIDs instead.
+//
+// AllocateIDRange returns nil if the range is successfully allocated. If one or more
+// entities with an ID in the given range already exist, it returns a KeyRangeCollisionError.
+// If the Datastore has already cached IDs in this range (e.g. from a previous call to
+// AllocateIDRange), it returns a KeyRangeContentionError. Errors of other types indicate
+// problems with arguments or an error returned directly from the Datastore.
+func AllocateIDRange(c context.Context, kind string, parent *Key, start, end int64) (err error) {
+	if kind == "" {
+		return errors.New("datastore: AllocateIDRange given an empty kind")
+	}
+
+	if start < 1 || end < 1 {
+		return errors.New("datastore: AllocateIDRange start and end must both be greater than 0")
+	}
+
+	if start > end {
+		return errors.New("datastore: AllocateIDRange start must be before end")
+	}
+
+	req := &pb.AllocateIdsRequest{
+		ModelKey: keyToProto("", NewIncompleteKey(c, kind, parent)),
+		Max:      proto.Int64(end),
+	}
+	res := &pb.AllocateIdsResponse{}
+	if err := internal.Call(c, "datastore_v3", "AllocateIds", req, res); err != nil {
+		return err
+	}
+
+	// Check for collisions, i.e. existing entities with IDs in this range.
+	// We could do this before the allocation, but we'd still have to do it
+	// afterward as well to catch the race condition where an entity is inserted
+	// after that initial check but before the allocation. Skip the up-front check
+	// and just do it once.
+	q := NewQuery(kind).Filter("__key__ >=", NewKey(c, kind, "", start, parent)).
+		Filter("__key__ <=", NewKey(c, kind, "", end, parent)).KeysOnly().Limit(1)
+
+	keys, err := q.GetAll(c, nil)
+	if err != nil {
+		return err
+	}
+	if len(keys) != 0 {
+		return &KeyRangeCollisionError{start: start, end: end}
+	}
+
+	// Check for a race condition, i.e. cases where the datastore may have
+	// cached ID batches that contain IDs in this range.
+	if start < res.GetStart() {
+		return &KeyRangeContentionError{start: start, end: end}
+	}
+
+	return nil
+}

vendor/google.golang.org/appengine/datastore/key_test.go

@@ -0,0 +1,204 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"bytes"
+	"encoding/gob"
+	"encoding/json"
+	"testing"
+
+	"golang.org/x/net/context"
+
+	"google.golang.org/appengine/internal"
+)
+
+func TestKeyEncoding(t *testing.T) {
+	testCases := []struct {
+		desc string
+		key  *Key
+		exp  string
+	}{
+		{
+			desc: "A simple key with an int ID",
+			key: &Key{
+				kind:  "Person",
+				intID: 1,
+				appID: "glibrary",
+			},
+			exp: "aghnbGlicmFyeXIMCxIGUGVyc29uGAEM",
+		},
+		{
+			desc: "A simple key with a string ID",
+			key: &Key{
+				kind:     "Graph",
+				stringID: "graph:7-day-active",
+				appID:    "glibrary",
+			},
+			exp: "aghnbGlicmFyeXIdCxIFR3JhcGgiEmdyYXBoOjctZGF5LWFjdGl2ZQw",
+		},
+		{
+			desc: "A key with a parent",
+			key: &Key{
+				kind:  "WordIndex",
+				intID: 1033,
+				parent: &Key{
+					kind:  "WordIndex",
+					intID: 1020032,
+					appID: "glibrary",
+				},
+				appID: "glibrary",
+			},
+			exp: "aghnbGlicmFyeXIhCxIJV29yZEluZGV4GIChPgwLEglXb3JkSW5kZXgYiQgM",
+		},
+	}
+	for _, tc := range testCases {
+		enc := tc.key.Encode()
+		if enc != tc.exp {
+			t.Errorf("%s: got %q, want %q", tc.desc, enc, tc.exp)
+		}
+
+		key, err := DecodeKey(tc.exp)
+		if err != nil {
+			t.Errorf("%s: failed decoding key: %v", tc.desc, err)
+			continue
+		}
+		if !key.Equal(tc.key) {
+			t.Errorf("%s: decoded key %v, want %v", tc.desc, key, tc.key)
+		}
+	}
+}
+
+func TestKeyGob(t *testing.T) {
+	k := &Key{
+		kind:  "Gopher",
+		intID: 3,
+		parent: &Key{
+			kind:     "Mom",
+			stringID: "narwhal",
+			appID:    "gopher-con",
+		},
+		appID: "gopher-con",
+	}
+
+	buf := new(bytes.Buffer)
+	if err := gob.NewEncoder(buf).Encode(k); err != nil {
+		t.Fatalf("gob encode failed: %v", err)
+	}
+
+	k2 := new(Key)
+	if err := gob.NewDecoder(buf).Decode(k2); err != nil {
+		t.Fatalf("gob decode failed: %v", err)
+	}
+	if !k2.Equal(k) {
+		t.Errorf("gob round trip of %v produced %v", k, k2)
+	}
+}
+
+func TestNilKeyGob(t *testing.T) {
+	type S struct {
+		Key *Key
+	}
+	s1 := new(S)
+
+	buf := new(bytes.Buffer)
+	if err := gob.NewEncoder(buf).Encode(s1); err != nil {
+		t.Fatalf("gob encode failed: %v", err)
+	}
+
+	s2 := new(S)
+	if err := gob.NewDecoder(buf).Decode(s2); err != nil {
+		t.Fatalf("gob decode failed: %v", err)
+	}
+	if s2.Key != nil {
+		t.Errorf("gob round trip of nil key produced %v", s2.Key)
+	}
+}
+
+func TestKeyJSON(t *testing.T) {
+	k := &Key{
+		kind:  "Gopher",
+		intID: 2,
+		parent: &Key{
+			kind:     "Mom",
+			stringID: "narwhal",
+			appID:    "gopher-con",
+		},
+		appID: "gopher-con",
+	}
+	exp := `"` + k.Encode() + `"`
+
+	buf, err := json.Marshal(k)
+	if err != nil {
+		t.Fatalf("json.Marshal failed: %v", err)
+	}
+	if s := string(buf); s != exp {
+		t.Errorf("JSON encoding of key %v: got %q, want %q", k, s, exp)
+	}
+
+	k2 := new(Key)
+	if err := json.Unmarshal(buf, k2); err != nil {
+		t.Fatalf("json.Unmarshal failed: %v", err)
+	}
+	if !k2.Equal(k) {
+		t.Errorf("JSON round trip of %v produced %v", k, k2)
+	}
+}
+
+func TestNilKeyJSON(t *testing.T) {
+	type S struct {
+		Key *Key
+	}
+	s1 := new(S)
+
+	buf, err := json.Marshal(s1)
+	if err != nil {
+		t.Fatalf("json.Marshal failed: %v", err)
+	}
+
+	s2 := new(S)
+	if err := json.Unmarshal(buf, s2); err != nil {
+		t.Fatalf("json.Unmarshal failed: %v", err)
+	}
+	if s2.Key != nil {
+		t.Errorf("JSON round trip of nil key produced %v", s2.Key)
+	}
+}
+
+func TestIncompleteKeyWithParent(t *testing.T) {
+	c := internal.WithAppIDOverride(context.Background(), "s~some-app")
+
+	// fadduh is a complete key.
+	fadduh := NewKey(c, "Person", "", 1, nil)
+	if fadduh.Incomplete() {
+		t.Fatalf("fadduh is incomplete")
+	}
+
+	// robert is an incomplete key with fadduh as a parent.
+	robert := NewIncompleteKey(c, "Person", fadduh)
+	if !robert.Incomplete() {
+		t.Fatalf("robert is complete")
+	}
+
+	// Both should be valid keys.
+	if !fadduh.valid() {
+		t.Errorf("fadduh is invalid: %v", fadduh)
+	}
+	if !robert.valid() {
+		t.Errorf("robert is invalid: %v", robert)
+	}
+}
+
+func TestNamespace(t *testing.T) {
+	key := &Key{
+		kind:      "Person",
+		intID:     1,
+		appID:     "s~some-app",
+		namespace: "mynamespace",
+	}
+	if g, w := key.Namespace(), "mynamespace"; g != w {
+		t.Errorf("key.Namespace() = %q, want %q", g, w)
+	}
+}

vendor/google.golang.org/appengine/datastore/load.go

@@ -0,0 +1,429 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"google.golang.org/appengine"
+	pb "google.golang.org/appengine/internal/datastore"
+)
+
+var (
+	typeOfBlobKey    = reflect.TypeOf(appengine.BlobKey(""))
+	typeOfByteSlice  = reflect.TypeOf([]byte(nil))
+	typeOfByteString = reflect.TypeOf(ByteString(nil))
+	typeOfGeoPoint   = reflect.TypeOf(appengine.GeoPoint{})
+	typeOfTime       = reflect.TypeOf(time.Time{})
+	typeOfKeyPtr     = reflect.TypeOf(&Key{})
+	typeOfEntityPtr  = reflect.TypeOf(&Entity{})
+)
+
+// typeMismatchReason returns a string explaining why the property p could not
+// be stored in an entity field of type v.Type().
+func typeMismatchReason(pValue interface{}, v reflect.Value) string {
+	entityType := "empty"
+	switch pValue.(type) {
+	case int64:
+		entityType = "int"
+	case bool:
+		entityType = "bool"
+	case string:
+		entityType = "string"
+	case float64:
+		entityType = "float"
+	case *Key:
+		entityType = "*datastore.Key"
+	case time.Time:
+		entityType = "time.Time"
+	case appengine.BlobKey:
+		entityType = "appengine.BlobKey"
+	case appengine.GeoPoint:
+		entityType = "appengine.GeoPoint"
+	case ByteString:
+		entityType = "datastore.ByteString"
+	case []byte:
+		entityType = "[]byte"
+	}
+	return fmt.Sprintf("type mismatch: %s versus %v", entityType, v.Type())
+}
+
+type propertyLoader struct {
+	// m holds the number of times a substruct field like "Foo.Bar.Baz" has
+	// been seen so far. The map is constructed lazily.
+	m map[string]int
+}
+
+func (l *propertyLoader) load(codec *structCodec, structValue reflect.Value, p Property, requireSlice bool) string {
+	var v reflect.Value
+	var sliceIndex int
+
+	name := p.Name
+
+	// If name ends with a '.', the last field is anonymous.
+	// In this case, strings.Split will give us "" as the
+	// last element of our fields slice, which will match the ""
+	// field name in the substruct codec.
+	fields := strings.Split(name, ".")
+
+	for len(fields) > 0 {
+		var decoder fieldCodec
+		var ok bool
+
+		// Cut off the last field (delimited by ".") and find its parent
+		// in the codec.
+		// eg. for name "A.B.C.D", split off "A.B.C" and try to
+		// find a field in the codec with this name.
+		// Loop again with "A.B", etc.
+		for i := len(fields); i > 0; i-- {
+			parent := strings.Join(fields[:i], ".")
+			decoder, ok = codec.fields[parent]
+			if ok {
+				fields = fields[i:]
+				break
+			}
+		}
+
+		// If we never found a matching field in the codec, return
+		// error message.
+		if !ok {
+			return "no such struct field"
+		}
+
+		v = initField(structValue, decoder.path)
+		if !v.IsValid() {
+			return "no such struct field"
+		}
+		if !v.CanSet() {
+			return "cannot set struct field"
+		}
+
+		if decoder.structCodec != nil {
+			codec = decoder.structCodec
+			structValue = v
+		}
+
+		if v.Kind() == reflect.Slice && v.Type() != typeOfByteSlice {
+			if l.m == nil {
+				l.m = make(map[string]int)
+			}
+			sliceIndex = l.m[p.Name]
+			l.m[p.Name] = sliceIndex + 1
+			for v.Len() <= sliceIndex {
+				v.Set(reflect.Append(v, reflect.New(v.Type().Elem()).Elem()))
+			}
+			structValue = v.Index(sliceIndex)
+			requireSlice = false
+		}
+	}
+
+	var slice reflect.Value
+	if v.Kind() == reflect.Slice && v.Type().Elem().Kind() != reflect.Uint8 {
+		slice = v
+		v = reflect.New(v.Type().Elem()).Elem()
+	} else if requireSlice {
+		return "multiple-valued property requires a slice field type"
+	}
+
+	// Convert indexValues to a Go value with a meaning derived from the
+	// destination type.
+	pValue := p.Value
+	if iv, ok := pValue.(indexValue); ok {
+		meaning := pb.Property_NO_MEANING
+		switch v.Type() {
+		case typeOfBlobKey:
+			meaning = pb.Property_BLOBKEY
+		case typeOfByteSlice:
+			meaning = pb.Property_BLOB
+		case typeOfByteString:
+			meaning = pb.Property_BYTESTRING
+		case typeOfGeoPoint:
+			meaning = pb.Property_GEORSS_POINT
+		case typeOfTime:
+			meaning = pb.Property_GD_WHEN
+		case typeOfEntityPtr:
+			meaning = pb.Property_ENTITY_PROTO
+		}
+		var err error
+		pValue, err = propValue(iv.value, meaning)
+		if err != nil {
+			return err.Error()
+		}
+	}
+
+	if errReason := setVal(v, pValue); errReason != "" {
+		// Set the slice back to its zero value.
+		if slice.IsValid() {
+			slice.Set(reflect.Zero(slice.Type()))
+		}
+		return errReason
+	}
+
+	if slice.IsValid() {
+		slice.Index(sliceIndex).Set(v)
+	}
+
+	return ""
+}
+
+// setVal sets v to the value pValue.
+func setVal(v reflect.Value, pValue interface{}) string {
+	switch v.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		x, ok := pValue.(int64)
+		if !ok && pValue != nil {
+			return typeMismatchReason(pValue, v)
+		}
+		if v.OverflowInt(x) {
+			return fmt.Sprintf("value %v overflows struct field of type %v", x, v.Type())
+		}
+		v.SetInt(x)
+	case reflect.Bool:
+		x, ok := pValue.(bool)
+		if !ok && pValue != nil {
+			return typeMismatchReason(pValue, v)
+		}
+		v.SetBool(x)
+	case reflect.String:
+		switch x := pValue.(type) {
+		case appengine.BlobKey:
+			v.SetString(string(x))
+		case ByteString:
+			v.SetString(string(x))
+		case string:
+			v.SetString(x)
+		default:
+			if pValue != nil {
+				return typeMismatchReason(pValue, v)
+			}
+		}
+	case reflect.Float32, reflect.Float64:
+		x, ok := pValue.(float64)
+		if !ok && pValue != nil {
+			return typeMismatchReason(pValue, v)
+		}
+		if v.OverflowFloat(x) {
+			return fmt.Sprintf("value %v overflows struct field of type %v", x, v.Type())
+		}
+		v.SetFloat(x)
+	case reflect.Ptr:
+		x, ok := pValue.(*Key)
+		if !ok && pValue != nil {
+			return typeMismatchReason(pValue, v)
+		}
+		if _, ok := v.Interface().(*Key); !ok {
+			return typeMismatchReason(pValue, v)
+		}
+		v.Set(reflect.ValueOf(x))
+	case reflect.Struct:
+		switch v.Type() {
+		case typeOfTime:
+			x, ok := pValue.(time.Time)
+			if !ok && pValue != nil {
+				return typeMismatchReason(pValue, v)
+			}
+			v.Set(reflect.ValueOf(x))
+		case typeOfGeoPoint:
+			x, ok := pValue.(appengine.GeoPoint)
+			if !ok && pValue != nil {
+				return typeMismatchReason(pValue, v)
+			}
+			v.Set(reflect.ValueOf(x))
+		default:
+			ent, ok := pValue.(*Entity)
+			if !ok {
+				return typeMismatchReason(pValue, v)
+			}
+
+			// Recursively load nested struct
+			pls, err := newStructPLS(v.Addr().Interface())
+			if err != nil {
+				return err.Error()
+			}
+
+			// if ent has a Key value and our struct has a Key field,
+			// load the Entity's Key value into the Key field on the struct.
+			if ent.Key != nil && pls.codec.keyField != -1 {
+
+				pls.v.Field(pls.codec.keyField).Set(reflect.ValueOf(ent.Key))
+			}
+
+			err = pls.Load(ent.Properties)
+			if err != nil {
+				return err.Error()
+			}
+		}
+	case reflect.Slice:
+		x, ok := pValue.([]byte)
+		if !ok {
+			if y, yok := pValue.(ByteString); yok {
+				x, ok = []byte(y), true
+			}
+		}
+		if !ok && pValue != nil {
+			return typeMismatchReason(pValue, v)
+		}
+		if v.Type().Elem().Kind() != reflect.Uint8 {
+			return typeMismatchReason(pValue, v)
+		}
+		v.SetBytes(x)
+	default:
+		return typeMismatchReason(pValue, v)
+	}
+	return ""
+}
+
+// initField is similar to reflect's Value.FieldByIndex, in that it
+// returns the nested struct field corresponding to index, but it
+// initialises any nil pointers encountered when traversing the structure.
+func initField(val reflect.Value, index []int) reflect.Value {
+	for _, i := range index[:len(index)-1] {
+		val = val.Field(i)
+		if val.Kind() == reflect.Ptr {
+			if val.IsNil() {
+				val.Set(reflect.New(val.Type().Elem()))
+			}
+			val = val.Elem()
+		}
+	}
+	return val.Field(index[len(index)-1])
+}
+
+// loadEntity loads an EntityProto into PropertyLoadSaver or struct pointer.
+func loadEntity(dst interface{}, src *pb.EntityProto) (err error) {
+	ent, err := protoToEntity(src)
+	if err != nil {
+		return err
+	}
+	if e, ok := dst.(PropertyLoadSaver); ok {
+		return e.Load(ent.Properties)
+	}
+	return LoadStruct(dst, ent.Properties)
+}
+
+func (s structPLS) Load(props []Property) error {
+	var fieldName, reason string
+	var l propertyLoader
+	for _, p := range props {
+		if errStr := l.load(s.codec, s.v, p, p.Multiple); errStr != "" {
+			// We don't return early, as we try to load as many properties as possible.
+			// It is valid to load an entity into a struct that cannot fully represent it.
+			// That case returns an error, but the caller is free to ignore it.
+			fieldName, reason = p.Name, errStr
+		}
+	}
+	if reason != "" {
+		return &ErrFieldMismatch{
+			StructType: s.v.Type(),
+			FieldName:  fieldName,
+			Reason:     reason,
+		}
+	}
+	return nil
+}
+
+func protoToEntity(src *pb.EntityProto) (*Entity, error) {
+	props, rawProps := src.Property, src.RawProperty
+	outProps := make([]Property, 0, len(props)+len(rawProps))
+	for {
+		var (
+			x       *pb.Property
+			noIndex bool
+		)
+		if len(props) > 0 {
+			x, props = props[0], props[1:]
+		} else if len(rawProps) > 0 {
+			x, rawProps = rawProps[0], rawProps[1:]
+			noIndex = true
+		} else {
+			break
+		}
+
+		var value interface{}
+		if x.Meaning != nil && *x.Meaning == pb.Property_INDEX_VALUE {
+			value = indexValue{x.Value}
+		} else {
+			var err error
+			value, err = propValue(x.Value, x.GetMeaning())
+			if err != nil {
+				return nil, err
+			}
+		}
+		outProps = append(outProps, Property{
+			Name:     x.GetName(),
+			Value:    value,
+			NoIndex:  noIndex,
+			Multiple: x.GetMultiple(),
+		})
+	}
+
+	var key *Key
+	if src.Key != nil {
+		// Ignore any error, since nested entity values
+		// are allowed to have an invalid key.
+		key, _ = protoToKey(src.Key)
+	}
+	return &Entity{key, outProps}, nil
+}
+
+// propValue returns a Go value that combines the raw PropertyValue with a
+// meaning. For example, an Int64Value with GD_WHEN becomes a time.Time.
+func propValue(v *pb.PropertyValue, m pb.Property_Meaning) (interface{}, error) {
+	switch {
+	case v.Int64Value != nil:
+		if m == pb.Property_GD_WHEN {
+			return fromUnixMicro(*v.Int64Value), nil
+		} else {
+			return *v.Int64Value, nil
+		}
+	case v.BooleanValue != nil:
+		return *v.BooleanValue, nil
+	case v.StringValue != nil:
+		if m == pb.Property_BLOB {
+			return []byte(*v.StringValue), nil
+		} else if m == pb.Property_BLOBKEY {
+			return appengine.BlobKey(*v.StringValue), nil
+		} else if m == pb.Property_BYTESTRING {
+			return ByteString(*v.StringValue), nil
+		} else if m == pb.Property_ENTITY_PROTO {
+			var ent pb.EntityProto
+			err := proto.Unmarshal([]byte(*v.StringValue), &ent)
+			if err != nil {
+				return nil, err
+			}
+			return protoToEntity(&ent)
+		} else {
+			return *v.StringValue, nil
+		}
+	case v.DoubleValue != nil:
+		return *v.DoubleValue, nil
+	case v.Referencevalue != nil:
+		key, err := referenceValueToKey(v.Referencevalue)
+		if err != nil {
+			return nil, err
+		}
+		return key, nil
+	case v.Pointvalue != nil:
+		// NOTE: Strangely, latitude maps to X, longitude to Y.
+		return appengine.GeoPoint{Lat: v.Pointvalue.GetX(), Lng: v.Pointvalue.GetY()}, nil
+	}
+	return nil, nil
+}
+
+// indexValue is a Property value that is created when entities are loaded from
+// an index, such as from a projection query.
+//
+// Such Property values do not contain all of the metadata required to be
+// faithfully represented as a Go value, and are instead represented as an
+// opaque indexValue. Load the properties into a concrete struct type (e.g. by
+// passing a struct pointer to Iterator.Next) to reconstruct actual Go values
+// of type int, string, time.Time, etc.
+type indexValue struct {
+	value *pb.PropertyValue
+}

vendor/google.golang.org/appengine/datastore/load_test.go

@@ -0,0 +1,656 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"reflect"
+	"testing"
+
+	proto "github.com/golang/protobuf/proto"
+	pb "google.golang.org/appengine/internal/datastore"
+)
+
+type Simple struct {
+	I int64
+}
+
+type SimpleWithTag struct {
+	I int64 `datastore:"II"`
+}
+
+type NestedSimpleWithTag struct {
+	A SimpleWithTag `datastore:"AA"`
+}
+
+type NestedSliceOfSimple struct {
+	A []Simple
+}
+
+type SimpleTwoFields struct {
+	S  string
+	SS string
+}
+
+type NestedSimpleAnonymous struct {
+	Simple
+	X string
+}
+
+type NestedSimple struct {
+	A Simple
+	I int64
+}
+
+type NestedSimple1 struct {
+	A Simple
+	X string
+}
+
+type NestedSimple2X struct {
+	AA NestedSimple
+	A  SimpleTwoFields
+	S  string
+}
+
+type BDotB struct {
+	B string `datastore:"B.B"`
+}
+
+type ABDotB struct {
+	A BDotB
+}
+
+type MultiAnonymous struct {
+	Simple
+	SimpleTwoFields
+	X string
+}
+
+var (
+	// these values need to be addressable
+	testString2 = "two"
+	testString3 = "three"
+	testInt64   = int64(2)
+
+	fieldNameI         = "I"
+	fieldNameX         = "X"
+	fieldNameS         = "S"
+	fieldNameSS        = "SS"
+	fieldNameADotI     = "A.I"
+	fieldNameAADotII   = "AA.II"
+	fieldNameADotBDotB = "A.B.B"
+)
+
+func TestLoadEntityNestedLegacy(t *testing.T) {
+	testCases := []struct {
+		desc string
+		src  *pb.EntityProto
+		want interface{}
+	}{
+		{
+			"nested",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name: &fieldNameX,
+						Value: &pb.PropertyValue{
+							StringValue: &testString2,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameADotI,
+						Value: &pb.PropertyValue{
+							Int64Value: &testInt64,
+						},
+					},
+				},
+			},
+			&NestedSimple1{
+				A: Simple{I: testInt64},
+				X: testString2,
+			},
+		},
+		{
+			"nested with tag",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name: &fieldNameAADotII,
+						Value: &pb.PropertyValue{
+							Int64Value: &testInt64,
+						},
+					},
+				},
+			},
+			&NestedSimpleWithTag{
+				A: SimpleWithTag{I: testInt64},
+			},
+		},
+		{
+			"nested with anonymous struct field",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name: &fieldNameX,
+						Value: &pb.PropertyValue{
+							StringValue: &testString2,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameI,
+						Value: &pb.PropertyValue{
+							Int64Value: &testInt64,
+						},
+					},
+				},
+			},
+			&NestedSimpleAnonymous{
+				Simple: Simple{I: testInt64},
+				X:      testString2,
+			},
+		},
+		{
+			"nested with dotted field tag",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name: &fieldNameADotBDotB,
+						Value: &pb.PropertyValue{
+							StringValue: &testString2,
+						},
+					},
+				},
+			},
+			&ABDotB{
+				A: BDotB{
+					B: testString2,
+				},
+			},
+		},
+		{
+			"nested with dotted field tag",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name: &fieldNameI,
+						Value: &pb.PropertyValue{
+							Int64Value: &testInt64,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameS,
+						Value: &pb.PropertyValue{
+							StringValue: &testString2,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameSS,
+						Value: &pb.PropertyValue{
+							StringValue: &testString3,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameX,
+						Value: &pb.PropertyValue{
+							StringValue: &testString3,
+						},
+					},
+				},
+			},
+			&MultiAnonymous{
+				Simple:          Simple{I: testInt64},
+				SimpleTwoFields: SimpleTwoFields{S: "two", SS: "three"},
+				X:               "three",
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		dst := reflect.New(reflect.TypeOf(tc.want).Elem()).Interface()
+		err := loadEntity(dst, tc.src)
+		if err != nil {
+			t.Errorf("loadEntity: %s: %v", tc.desc, err)
+			continue
+		}
+
+		if !reflect.DeepEqual(tc.want, dst) {
+			t.Errorf("%s: compare:\ngot:  %#v\nwant: %#v", tc.desc, dst, tc.want)
+		}
+	}
+}
+
+type WithKey struct {
+	X string
+	I int64
+	K *Key `datastore:"__key__"`
+}
+
+type NestedWithKey struct {
+	N WithKey
+	Y string
+}
+
+var (
+	incompleteKey = newKey("", nil)
+	invalidKey    = newKey("s", incompleteKey)
+
+	// these values need to be addressable
+	fieldNameA     = "A"
+	fieldNameK     = "K"
+	fieldNameN     = "N"
+	fieldNameY     = "Y"
+	fieldNameAA    = "AA"
+	fieldNameII    = "II"
+	fieldNameBDotB = "B.B"
+
+	entityProtoMeaning = pb.Property_ENTITY_PROTO
+
+	TRUE  = true
+	FALSE = false
+)
+
+var (
+	simpleEntityProto, nestedSimpleEntityProto,
+	simpleTwoFieldsEntityProto, simpleWithTagEntityProto,
+	bDotBEntityProto, withKeyEntityProto string
+)
+
+func init() {
+	// simpleEntityProto corresponds to:
+	// Simple{I: testInt64}
+	simpleEntityProtob, err := proto.Marshal(&pb.EntityProto{
+		Key: keyToProto("", incompleteKey),
+		Property: []*pb.Property{
+			&pb.Property{
+				Name: &fieldNameI,
+				Value: &pb.PropertyValue{
+					Int64Value: &testInt64,
+				},
+				Multiple: &FALSE,
+			},
+		},
+		EntityGroup: &pb.Path{},
+	})
+	if err != nil {
+		panic(err)
+	}
+	simpleEntityProto = string(simpleEntityProtob)
+
+	// nestedSimpleEntityProto corresponds to:
+	// NestedSimple{
+	// 	A: Simple{I: testInt64},
+	// 	I: testInt64,
+	// }
+	nestedSimpleEntityProtob, err := proto.Marshal(&pb.EntityProto{
+		Key: keyToProto("", incompleteKey),
+		Property: []*pb.Property{
+			&pb.Property{
+				Name:    &fieldNameA,
+				Meaning: &entityProtoMeaning,
+				Value: &pb.PropertyValue{
+					StringValue: &simpleEntityProto,
+				},
+				Multiple: &FALSE,
+			},
+			&pb.Property{
+				Name:    &fieldNameI,
+				Meaning: &entityProtoMeaning,
+				Value: &pb.PropertyValue{
+					Int64Value: &testInt64,
+				},
+				Multiple: &FALSE,
+			},
+		},
+		EntityGroup: &pb.Path{},
+	})
+	if err != nil {
+		panic(err)
+	}
+	nestedSimpleEntityProto = string(nestedSimpleEntityProtob)
+
+	// simpleTwoFieldsEntityProto corresponds to:
+	// SimpleTwoFields{S: testString2, SS: testString3}
+	simpleTwoFieldsEntityProtob, err := proto.Marshal(&pb.EntityProto{
+		Key: keyToProto("", incompleteKey),
+		Property: []*pb.Property{
+			&pb.Property{
+				Name: &fieldNameS,
+				Value: &pb.PropertyValue{
+					StringValue: &testString2,
+				},
+				Multiple: &FALSE,
+			},
+			&pb.Property{
+				Name: &fieldNameSS,
+				Value: &pb.PropertyValue{
+					StringValue: &testString3,
+				},
+				Multiple: &FALSE,
+			},
+		},
+		EntityGroup: &pb.Path{},
+	})
+	if err != nil {
+		panic(err)
+	}
+	simpleTwoFieldsEntityProto = string(simpleTwoFieldsEntityProtob)
+
+	// simpleWithTagEntityProto corresponds to:
+	// SimpleWithTag{I: testInt64}
+	simpleWithTagEntityProtob, err := proto.Marshal(&pb.EntityProto{
+		Key: keyToProto("", incompleteKey),
+		Property: []*pb.Property{
+			&pb.Property{
+				Name: &fieldNameII,
+				Value: &pb.PropertyValue{
+					Int64Value: &testInt64,
+				},
+				Multiple: &FALSE,
+			},
+		},
+		EntityGroup: &pb.Path{},
+	})
+	if err != nil {
+		panic(err)
+	}
+	simpleWithTagEntityProto = string(simpleWithTagEntityProtob)
+
+	// bDotBEntityProto corresponds to:
+	// BDotB{
+	// 	B: testString2,
+	// }
+	bDotBEntityProtob, err := proto.Marshal(&pb.EntityProto{
+		Key: keyToProto("", incompleteKey),
+		Property: []*pb.Property{
+			&pb.Property{
+				Name: &fieldNameBDotB,
+				Value: &pb.PropertyValue{
+					StringValue: &testString2,
+				},
+				Multiple: &FALSE,
+			},
+		},
+		EntityGroup: &pb.Path{},
+	})
+	if err != nil {
+		panic(err)
+	}
+	bDotBEntityProto = string(bDotBEntityProtob)
+
+	// withKeyEntityProto corresponds to:
+	// WithKey{
+	// 	X: testString3,
+	// 	I: testInt64,
+	// 	K: testKey1a,
+	// }
+	withKeyEntityProtob, err := proto.Marshal(&pb.EntityProto{
+		Key: keyToProto("", testKey1a),
+		Property: []*pb.Property{
+			&pb.Property{
+				Name: &fieldNameX,
+				Value: &pb.PropertyValue{
+					StringValue: &testString3,
+				},
+				Multiple: &FALSE,
+			},
+			&pb.Property{
+				Name: &fieldNameI,
+				Value: &pb.PropertyValue{
+					Int64Value: &testInt64,
+				},
+				Multiple: &FALSE,
+			},
+		},
+		EntityGroup: &pb.Path{},
+	})
+	if err != nil {
+		panic(err)
+	}
+	withKeyEntityProto = string(withKeyEntityProtob)
+
+}
+
+func TestLoadEntityNested(t *testing.T) {
+	testCases := []struct {
+		desc string
+		src  *pb.EntityProto
+		want interface{}
+	}{
+		{
+			"nested basic",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name:    &fieldNameA,
+						Meaning: &entityProtoMeaning,
+						Value: &pb.PropertyValue{
+							StringValue: &simpleEntityProto,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameI,
+						Value: &pb.PropertyValue{
+							Int64Value: &testInt64,
+						},
+					},
+				},
+			},
+			&NestedSimple{
+				A: Simple{I: 2},
+				I: 2,
+			},
+		},
+		{
+			"nested with struct tags",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name:    &fieldNameAA,
+						Meaning: &entityProtoMeaning,
+						Value: &pb.PropertyValue{
+							StringValue: &simpleWithTagEntityProto,
+						},
+					},
+				},
+			},
+			&NestedSimpleWithTag{
+				A: SimpleWithTag{I: testInt64},
+			},
+		},
+		{
+			"nested 2x",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name:    &fieldNameAA,
+						Meaning: &entityProtoMeaning,
+						Value: &pb.PropertyValue{
+							StringValue: &nestedSimpleEntityProto,
+						},
+					},
+					&pb.Property{
+						Name:    &fieldNameA,
+						Meaning: &entityProtoMeaning,
+						Value: &pb.PropertyValue{
+							StringValue: &simpleTwoFieldsEntityProto,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameS,
+						Value: &pb.PropertyValue{
+							StringValue: &testString3,
+						},
+					},
+				},
+			},
+			&NestedSimple2X{
+				AA: NestedSimple{
+					A: Simple{I: testInt64},
+					I: testInt64,
+				},
+				A: SimpleTwoFields{S: testString2, SS: testString3},
+				S: testString3,
+			},
+		},
+		{
+			"nested anonymous",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name: &fieldNameI,
+						Value: &pb.PropertyValue{
+							Int64Value: &testInt64,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameX,
+						Value: &pb.PropertyValue{
+							StringValue: &testString2,
+						},
+					},
+				},
+			},
+			&NestedSimpleAnonymous{
+				Simple: Simple{I: testInt64},
+				X:      testString2,
+			},
+		},
+		{
+			"nested simple with slice",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name:     &fieldNameA,
+						Meaning:  &entityProtoMeaning,
+						Multiple: &TRUE,
+						Value: &pb.PropertyValue{
+							StringValue: &simpleEntityProto,
+						},
+					},
+					&pb.Property{
+						Name:     &fieldNameA,
+						Meaning:  &entityProtoMeaning,
+						Multiple: &TRUE,
+						Value: &pb.PropertyValue{
+							StringValue: &simpleEntityProto,
+						},
+					},
+				},
+			},
+			&NestedSliceOfSimple{
+				A: []Simple{Simple{I: testInt64}, Simple{I: testInt64}},
+			},
+		},
+		{
+			"nested with multiple anonymous fields",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name: &fieldNameI,
+						Value: &pb.PropertyValue{
+							Int64Value: &testInt64,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameS,
+						Value: &pb.PropertyValue{
+							StringValue: &testString2,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameSS,
+						Value: &pb.PropertyValue{
+							StringValue: &testString3,
+						},
+					},
+					&pb.Property{
+						Name: &fieldNameX,
+						Value: &pb.PropertyValue{
+							StringValue: &testString2,
+						},
+					},
+				},
+			},
+			&MultiAnonymous{
+				Simple:          Simple{I: testInt64},
+				SimpleTwoFields: SimpleTwoFields{S: testString2, SS: testString3},
+				X:               testString2,
+			},
+		},
+		{
+			"nested with dotted field tag",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name:    &fieldNameA,
+						Meaning: &entityProtoMeaning,
+						Value: &pb.PropertyValue{
+							StringValue: &bDotBEntityProto,
+						},
+					},
+				},
+			},
+			&ABDotB{
+				A: BDotB{
+					B: testString2,
+				},
+			},
+		},
+		{
+			"nested entity with key",
+			&pb.EntityProto{
+				Key: keyToProto("some-app-id", testKey0),
+				Property: []*pb.Property{
+					&pb.Property{
+						Name: &fieldNameY,
+						Value: &pb.PropertyValue{
+							StringValue: &testString2,
+						},
+					},
+					&pb.Property{
+						Name:    &fieldNameN,
+						Meaning: &entityProtoMeaning,
+						Value: &pb.PropertyValue{
+							StringValue: &withKeyEntityProto,
+						},
+					},
+				},
+			},
+			&NestedWithKey{
+				Y: testString2,
+				N: WithKey{
+					X: testString3,
+					I: testInt64,
+					K: testKey1a,
+				},
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		dst := reflect.New(reflect.TypeOf(tc.want).Elem()).Interface()
+		err := loadEntity(dst, tc.src)
+		if err != nil {
+			t.Errorf("loadEntity: %s: %v", tc.desc, err)
+			continue
+		}
+
+		if !reflect.DeepEqual(tc.want, dst) {
+			t.Errorf("%s: compare:\ngot:  %#v\nwant: %#v", tc.desc, dst, tc.want)
+		}
+	}
+}

vendor/google.golang.org/appengine/datastore/metadata.go

@@ -0,0 +1,78 @@
+// Copyright 2016 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import "golang.org/x/net/context"
+
+// Datastore kinds for the metadata entities.
+const (
+	namespaceKind = "__namespace__"
+	kindKind      = "__kind__"
+	propertyKind  = "__property__"
+)
+
+// Namespaces returns all the datastore namespaces.
+func Namespaces(ctx context.Context) ([]string, error) {
+	// TODO(djd): Support range queries.
+	q := NewQuery(namespaceKind).KeysOnly()
+	keys, err := q.GetAll(ctx, nil)
+	if err != nil {
+		return nil, err
+	}
+	// The empty namespace key uses a numeric ID (==1), but luckily
+	// the string ID defaults to "" for numeric IDs anyway.
+	return keyNames(keys), nil
+}
+
+// Kinds returns the names of all the kinds in the current namespace.
+func Kinds(ctx context.Context) ([]string, error) {
+	// TODO(djd): Support range queries.
+	q := NewQuery(kindKind).KeysOnly()
+	keys, err := q.GetAll(ctx, nil)
+	if err != nil {
+		return nil, err
+	}
+	return keyNames(keys), nil
+}
+
+// keyNames returns a slice of the provided keys' names (string IDs).
+func keyNames(keys []*Key) []string {
+	n := make([]string, 0, len(keys))
+	for _, k := range keys {
+		n = append(n, k.StringID())
+	}
+	return n
+}
+
+// KindProperties returns all the indexed properties for the given kind.
+// The properties are returned as a map of property names to a slice of the
+// representation types. The representation types for the supported Go property
+// types are:
+//   "INT64":     signed integers and time.Time
+//   "DOUBLE":    float32 and float64
+//   "BOOLEAN":   bool
+//   "STRING":    string, []byte and ByteString
+//   "POINT":     appengine.GeoPoint
+//   "REFERENCE": *Key
+//   "USER":      (not used in the Go runtime)
+func KindProperties(ctx context.Context, kind string) (map[string][]string, error) {
+	// TODO(djd): Support range queries.
+	kindKey := NewKey(ctx, kindKind, kind, 0, nil)
+	q := NewQuery(propertyKind).Ancestor(kindKey)
+
+	propMap := map[string][]string{}
+	props := []struct {
+		Repr []string `datastore:"property_representation"`
+	}{}
+
+	keys, err := q.GetAll(ctx, &props)
+	if err != nil {
+		return nil, err
+	}
+	for i, p := range props {
+		propMap[keys[i].StringID()] = p.Repr
+	}
+	return propMap, nil
+}

vendor/google.golang.org/appengine/datastore/prop.go

@@ -0,0 +1,330 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+	"unicode"
+)
+
+// Entities with more than this many indexed properties will not be saved.
+const maxIndexedProperties = 20000
+
+// []byte fields more than 1 megabyte long will not be loaded or saved.
+const maxBlobLen = 1 << 20
+
+// Property is a name/value pair plus some metadata. A datastore entity's
+// contents are loaded and saved as a sequence of Properties. An entity can
+// have multiple Properties with the same name, provided that p.Multiple is
+// true on all of that entity's Properties with that name.
+type Property struct {
+	// Name is the property name.
+	Name string
+	// Value is the property value. The valid types are:
+	//	- int64
+	//	- bool
+	//	- string
+	//	- float64
+	//	- ByteString
+	//	- *Key
+	//	- time.Time
+	//	- appengine.BlobKey
+	//	- appengine.GeoPoint
+	//	- []byte (up to 1 megabyte in length)
+	//	- *Entity (representing a nested struct)
+	// This set is smaller than the set of valid struct field types that the
+	// datastore can load and save. A Property Value cannot be a slice (apart
+	// from []byte); use multiple Properties instead. Also, a Value's type
+	// must be explicitly on the list above; it is not sufficient for the
+	// underlying type to be on that list. For example, a Value of "type
+	// myInt64 int64" is invalid. Smaller-width integers and floats are also
+	// invalid. Again, this is more restrictive than the set of valid struct
+	// field types.
+	//
+	// A Value will have an opaque type when loading entities from an index,
+	// such as via a projection query. Load entities into a struct instead
+	// of a PropertyLoadSaver when using a projection query.
+	//
+	// A Value may also be the nil interface value; this is equivalent to
+	// Python's None but not directly representable by a Go struct. Loading
+	// a nil-valued property into a struct will set that field to the zero
+	// value.
+	Value interface{}
+	// NoIndex is whether the datastore cannot index this property.
+	NoIndex bool
+	// Multiple is whether the entity can have multiple properties with
+	// the same name. Even if a particular instance only has one property with
+	// a certain name, Multiple should be true if a struct would best represent
+	// it as a field of type []T instead of type T.
+	Multiple bool
+}
+
+// An Entity is the value type for a nested struct.
+// This type is only used for a Property's Value.
+type Entity struct {
+	Key        *Key
+	Properties []Property
+}
+
+// ByteString is a short byte slice (up to 1500 bytes) that can be indexed.
+type ByteString []byte
+
+// PropertyLoadSaver can be converted from and to a slice of Properties.
+type PropertyLoadSaver interface {
+	Load([]Property) error
+	Save() ([]Property, error)
+}
+
+// PropertyList converts a []Property to implement PropertyLoadSaver.
+type PropertyList []Property
+
+var (
+	typeOfPropertyLoadSaver = reflect.TypeOf((*PropertyLoadSaver)(nil)).Elem()
+	typeOfPropertyList      = reflect.TypeOf(PropertyList(nil))
+)
+
+// Load loads all of the provided properties into l.
+// It does not first reset *l to an empty slice.
+func (l *PropertyList) Load(p []Property) error {
+	*l = append(*l, p...)
+	return nil
+}
+
+// Save saves all of l's properties as a slice or Properties.
+func (l *PropertyList) Save() ([]Property, error) {
+	return *l, nil
+}
+
+// validPropertyName returns whether name consists of one or more valid Go
+// identifiers joined by ".".
+func validPropertyName(name string) bool {
+	if name == "" {
+		return false
+	}
+	for _, s := range strings.Split(name, ".") {
+		if s == "" {
+			return false
+		}
+		first := true
+		for _, c := range s {
+			if first {
+				first = false
+				if c != '_' && !unicode.IsLetter(c) {
+					return false
+				}
+			} else {
+				if c != '_' && !unicode.IsLetter(c) && !unicode.IsDigit(c) {
+					return false
+				}
+			}
+		}
+	}
+	return true
+}
+
+// structCodec describes how to convert a struct to and from a sequence of
+// properties.
+type structCodec struct {
+	// fields gives the field codec for the structTag with the given name.
+	fields map[string]fieldCodec
+	// hasSlice is whether a struct or any of its nested or embedded structs
+	// has a slice-typed field (other than []byte).
+	hasSlice bool
+	// keyField is the index of a *Key field with structTag __key__.
+	// This field is not relevant for the top level struct, only for
+	// nested structs.
+	keyField int
+	// complete is whether the structCodec is complete. An incomplete
+	// structCodec may be encountered when walking a recursive struct.
+	complete bool
+}
+
+// fieldCodec is a struct field's index and, if that struct field's type is
+// itself a struct, that substruct's structCodec.
+type fieldCodec struct {
+	// path is the index path to the field
+	path    []int
+	noIndex bool
+	// omitEmpty indicates that the field should be omitted on save
+	// if empty.
+	omitEmpty bool
+	// structCodec is the codec fot the struct field at index 'path',
+	// or nil if the field is not a struct.
+	structCodec *structCodec
+}
+
+// structCodecs collects the structCodecs that have already been calculated.
+var (
+	structCodecsMutex sync.Mutex
+	structCodecs      = make(map[reflect.Type]*structCodec)
+)
+
+// getStructCodec returns the structCodec for the given struct type.
+func getStructCodec(t reflect.Type) (*structCodec, error) {
+	structCodecsMutex.Lock()
+	defer structCodecsMutex.Unlock()
+	return getStructCodecLocked(t)
+}
+
+// getStructCodecLocked implements getStructCodec. The structCodecsMutex must
+// be held when calling this function.
+func getStructCodecLocked(t reflect.Type) (ret *structCodec, retErr error) {
+	c, ok := structCodecs[t]
+	if ok {
+		return c, nil
+	}
+	c = &structCodec{
+		fields: make(map[string]fieldCodec),
+		// We initialize keyField to -1 so that the zero-value is not
+		// misinterpreted as index 0.
+		keyField: -1,
+	}
+
+	// Add c to the structCodecs map before we are sure it is good. If t is
+	// a recursive type, it needs to find the incomplete entry for itself in
+	// the map.
+	structCodecs[t] = c
+	defer func() {
+		if retErr != nil {
+			delete(structCodecs, t)
+		}
+	}()
+
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		// Skip unexported fields.
+		// Note that if f is an anonymous, unexported struct field,
+		// we will promote its fields.
+		if f.PkgPath != "" && !f.Anonymous {
+			continue
+		}
+
+		tags := strings.Split(f.Tag.Get("datastore"), ",")
+		name := tags[0]
+		opts := make(map[string]bool)
+		for _, t := range tags[1:] {
+			opts[t] = true
+		}
+		switch {
+		case name == "":
+			if !f.Anonymous {
+				name = f.Name
+			}
+		case name == "-":
+			continue
+		case name == "__key__":
+			if f.Type != typeOfKeyPtr {
+				return nil, fmt.Errorf("datastore: __key__ field on struct %v is not a *datastore.Key", t)
+			}
+			c.keyField = i
+		case !validPropertyName(name):
+			return nil, fmt.Errorf("datastore: struct tag has invalid property name: %q", name)
+		}
+
+		substructType, fIsSlice := reflect.Type(nil), false
+		switch f.Type.Kind() {
+		case reflect.Struct:
+			substructType = f.Type
+		case reflect.Slice:
+			if f.Type.Elem().Kind() == reflect.Struct {
+				substructType = f.Type.Elem()
+			}
+			fIsSlice = f.Type != typeOfByteSlice
+			c.hasSlice = c.hasSlice || fIsSlice
+		}
+
+		var sub *structCodec
+		if substructType != nil && substructType != typeOfTime && substructType != typeOfGeoPoint {
+			var err error
+			sub, err = getStructCodecLocked(substructType)
+			if err != nil {
+				return nil, err
+			}
+			if !sub.complete {
+				return nil, fmt.Errorf("datastore: recursive struct: field %q", f.Name)
+			}
+			if fIsSlice && sub.hasSlice {
+				return nil, fmt.Errorf(
+					"datastore: flattening nested structs leads to a slice of slices: field %q", f.Name)
+			}
+			c.hasSlice = c.hasSlice || sub.hasSlice
+			// If f is an anonymous struct field, we promote the substruct's fields up to this level
+			// in the linked list of struct codecs.
+			if f.Anonymous {
+				for subname, subfield := range sub.fields {
+					if name != "" {
+						subname = name + "." + subname
+					}
+					if _, ok := c.fields[subname]; ok {
+						return nil, fmt.Errorf("datastore: struct tag has repeated property name: %q", subname)
+					}
+					c.fields[subname] = fieldCodec{
+						path:        append([]int{i}, subfield.path...),
+						noIndex:     subfield.noIndex || opts["noindex"],
+						omitEmpty:   subfield.omitEmpty,
+						structCodec: subfield.structCodec,
+					}
+				}
+				continue
+			}
+		}
+
+		if _, ok := c.fields[name]; ok {
+			return nil, fmt.Errorf("datastore: struct tag has repeated property name: %q", name)
+		}
+		c.fields[name] = fieldCodec{
+			path:        []int{i},
+			noIndex:     opts["noindex"],
+			omitEmpty:   opts["omitempty"],
+			structCodec: sub,
+		}
+	}
+	c.complete = true
+	return c, nil
+}
+
+// structPLS adapts a struct to be a PropertyLoadSaver.
+type structPLS struct {
+	v     reflect.Value
+	codec *structCodec
+}
+
+// newStructPLS returns a structPLS, which implements the
+// PropertyLoadSaver interface, for the struct pointer p.
+func newStructPLS(p interface{}) (*structPLS, error) {
+	v := reflect.ValueOf(p)
+	if v.Kind() != reflect.Ptr || v.Elem().Kind() != reflect.Struct {
+		return nil, ErrInvalidEntityType
+	}
+	v = v.Elem()
+	codec, err := getStructCodec(v.Type())
+	if err != nil {
+		return nil, err
+	}
+	return &structPLS{v, codec}, nil
+}
+
+// LoadStruct loads the properties from p to dst.
+// dst must be a struct pointer.
+func LoadStruct(dst interface{}, p []Property) error {
+	x, err := newStructPLS(dst)
+	if err != nil {
+		return err
+	}
+	return x.Load(p)
+}
+
+// SaveStruct returns the properties from src as a slice of Properties.
+// src must be a struct pointer.
+func SaveStruct(src interface{}) ([]Property, error) {
+	x, err := newStructPLS(src)
+	if err != nil {
+		return nil, err
+	}
+	return x.Save()
+}

vendor/google.golang.org/appengine/datastore/prop_test.go

@@ -0,0 +1,672 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"reflect"
+	"sort"
+	"testing"
+	"time"
+
+	"google.golang.org/appengine"
+)
+
+func TestValidPropertyName(t *testing.T) {
+	testCases := []struct {
+		name string
+		want bool
+	}{
+		// Invalid names.
+		{"", false},
+		{"'", false},
+		{".", false},
+		{"..", false},
+		{".foo", false},
+		{"0", false},
+		{"00", false},
+		{"X.X.4.X.X", false},
+		{"\n", false},
+		{"\x00", false},
+		{"abc\xffz", false},
+		{"foo.", false},
+		{"foo..", false},
+		{"foo..bar", false},
+		{"☃", false},
+		{`"`, false},
+		// Valid names.
+		{"AB", true},
+		{"Abc", true},
+		{"X.X.X.X.X", true},
+		{"_", true},
+		{"_0", true},
+		{"a", true},
+		{"a_B", true},
+		{"f00", true},
+		{"f0o", true},
+		{"fo0", true},
+		{"foo", true},
+		{"foo.bar", true},
+		{"foo.bar.baz", true},
+		{"世界", true},
+	}
+	for _, tc := range testCases {
+		got := validPropertyName(tc.name)
+		if got != tc.want {
+			t.Errorf("%q: got %v, want %v", tc.name, got, tc.want)
+		}
+	}
+}
+
+func TestStructCodec(t *testing.T) {
+	type oStruct struct {
+		O int
+	}
+	type pStruct struct {
+		P int
+		Q int
+	}
+	type rStruct struct {
+		R int
+		S pStruct
+		T oStruct
+		oStruct
+	}
+	type uStruct struct {
+		U int
+		v int
+	}
+	type vStruct struct {
+		V string `datastore:",noindex"`
+	}
+	oStructCodec := &structCodec{
+		fields: map[string]fieldCodec{
+			"O": {path: []int{0}},
+		},
+		complete: true,
+	}
+	pStructCodec := &structCodec{
+		fields: map[string]fieldCodec{
+			"P": {path: []int{0}},
+			"Q": {path: []int{1}},
+		},
+		complete: true,
+	}
+	rStructCodec := &structCodec{
+		fields: map[string]fieldCodec{
+			"R": {path: []int{0}},
+			"S": {path: []int{1}, structCodec: pStructCodec},
+			"T": {path: []int{2}, structCodec: oStructCodec},
+			"O": {path: []int{3, 0}},
+		},
+		complete: true,
+	}
+	uStructCodec := &structCodec{
+		fields: map[string]fieldCodec{
+			"U": {path: []int{0}},
+		},
+		complete: true,
+	}
+	vStructCodec := &structCodec{
+		fields: map[string]fieldCodec{
+			"V": {path: []int{0}, noIndex: true},
+		},
+		complete: true,
+	}
+
+	testCases := []struct {
+		desc        string
+		structValue interface{}
+		want        *structCodec
+	}{
+		{
+			"oStruct",
+			oStruct{},
+			oStructCodec,
+		},
+		{
+			"pStruct",
+			pStruct{},
+			pStructCodec,
+		},
+		{
+			"rStruct",
+			rStruct{},
+			rStructCodec,
+		},
+		{
+			"uStruct",
+			uStruct{},
+			uStructCodec,
+		},
+		{
+			"non-basic fields",
+			struct {
+				B appengine.BlobKey
+				K *Key
+				T time.Time
+			}{},
+			&structCodec{
+				fields: map[string]fieldCodec{
+					"B": {path: []int{0}},
+					"K": {path: []int{1}},
+					"T": {path: []int{2}},
+				},
+				complete: true,
+			},
+		},
+		{
+			"struct tags with ignored embed",
+			struct {
+				A       int `datastore:"a,noindex"`
+				B       int `datastore:"b"`
+				C       int `datastore:",noindex"`
+				D       int `datastore:""`
+				E       int
+				I       int `datastore:"-"`
+				J       int `datastore:",noindex" json:"j"`
+				oStruct `datastore:"-"`
+			}{},
+			&structCodec{
+				fields: map[string]fieldCodec{
+					"a": {path: []int{0}, noIndex: true},
+					"b": {path: []int{1}},
+					"C": {path: []int{2}, noIndex: true},
+					"D": {path: []int{3}},
+					"E": {path: []int{4}},
+					"J": {path: []int{6}, noIndex: true},
+				},
+				complete: true,
+			},
+		},
+		{
+			"unexported fields",
+			struct {
+				A int
+				b int
+				C int `datastore:"x"`
+				d int `datastore:"Y"`
+			}{},
+			&structCodec{
+				fields: map[string]fieldCodec{
+					"A": {path: []int{0}},
+					"x": {path: []int{2}},
+				},
+				complete: true,
+			},
+		},
+		{
+			"nested and embedded structs",
+			struct {
+				A   int
+				B   int
+				CC  oStruct
+				DDD rStruct
+				oStruct
+			}{},
+			&structCodec{
+				fields: map[string]fieldCodec{
+					"A":   {path: []int{0}},
+					"B":   {path: []int{1}},
+					"CC":  {path: []int{2}, structCodec: oStructCodec},
+					"DDD": {path: []int{3}, structCodec: rStructCodec},
+					"O":   {path: []int{4, 0}},
+				},
+				complete: true,
+			},
+		},
+		{
+			"struct tags with nested and embedded structs",
+			struct {
+				A       int     `datastore:"-"`
+				B       int     `datastore:"w"`
+				C       oStruct `datastore:"xx"`
+				D       rStruct `datastore:"y"`
+				oStruct `datastore:"z"`
+			}{},
+			&structCodec{
+				fields: map[string]fieldCodec{
+					"w":   {path: []int{1}},
+					"xx":  {path: []int{2}, structCodec: oStructCodec},
+					"y":   {path: []int{3}, structCodec: rStructCodec},
+					"z.O": {path: []int{4, 0}},
+				},
+				complete: true,
+			},
+		},
+		{
+			"unexported nested and embedded structs",
+			struct {
+				a int
+				B int
+				c uStruct
+				D uStruct
+				uStruct
+			}{},
+			&structCodec{
+				fields: map[string]fieldCodec{
+					"B": {path: []int{1}},
+					"D": {path: []int{3}, structCodec: uStructCodec},
+					"U": {path: []int{4, 0}},
+				},
+				complete: true,
+			},
+		},
+		{
+			"noindex nested struct",
+			struct {
+				A oStruct `datastore:",noindex"`
+			}{},
+			&structCodec{
+				fields: map[string]fieldCodec{
+					"A": {path: []int{0}, structCodec: oStructCodec, noIndex: true},
+				},
+				complete: true,
+			},
+		},
+		{
+			"noindex slice",
+			struct {
+				A []string `datastore:",noindex"`
+			}{},
+			&structCodec{
+				fields: map[string]fieldCodec{
+					"A": {path: []int{0}, noIndex: true},
+				},
+				hasSlice: true,
+				complete: true,
+			},
+		},
+		{
+			"noindex embedded struct slice",
+			struct {
+				// vStruct has a single field, V, also with noindex.
+				A []vStruct `datastore:",noindex"`
+			}{},
+			&structCodec{
+				fields: map[string]fieldCodec{
+					"A": {path: []int{0}, structCodec: vStructCodec, noIndex: true},
+				},
+				hasSlice: true,
+				complete: true,
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		got, err := getStructCodec(reflect.TypeOf(tc.structValue))
+		if err != nil {
+			t.Errorf("%s: getStructCodec: %v", tc.desc, err)
+			continue
+		}
+		// can't reflect.DeepEqual b/c element order in fields map may differ
+		if !isEqualStructCodec(got, tc.want) {
+			t.Errorf("%s\ngot  %+v\nwant %+v\n", tc.desc, got, tc.want)
+		}
+	}
+}
+
+func isEqualStructCodec(got, want *structCodec) bool {
+	if got.complete != want.complete {
+		return false
+	}
+	if got.hasSlice != want.hasSlice {
+		return false
+	}
+	if len(got.fields) != len(want.fields) {
+		return false
+	}
+	for name, wantF := range want.fields {
+		gotF := got.fields[name]
+		if !reflect.DeepEqual(wantF.path, gotF.path) {
+			return false
+		}
+		if wantF.noIndex != gotF.noIndex {
+			return false
+		}
+		if wantF.structCodec != nil {
+			if gotF.structCodec == nil {
+				return false
+			}
+			if !isEqualStructCodec(gotF.structCodec, wantF.structCodec) {
+				return false
+			}
+		}
+	}
+
+	return true
+}
+
+func TestRepeatedPropertyName(t *testing.T) {
+	good := []interface{}{
+		struct {
+			A int `datastore:"-"`
+		}{},
+		struct {
+			A int `datastore:"b"`
+			B int
+		}{},
+		struct {
+			A int
+			B int `datastore:"B"`
+		}{},
+		struct {
+			A int `datastore:"B"`
+			B int `datastore:"-"`
+		}{},
+		struct {
+			A int `datastore:"-"`
+			B int `datastore:"A"`
+		}{},
+		struct {
+			A int `datastore:"B"`
+			B int `datastore:"A"`
+		}{},
+		struct {
+			A int `datastore:"B"`
+			B int `datastore:"C"`
+			C int `datastore:"A"`
+		}{},
+		struct {
+			A int `datastore:"B"`
+			B int `datastore:"C"`
+			C int `datastore:"D"`
+		}{},
+	}
+	bad := []interface{}{
+		struct {
+			A int `datastore:"B"`
+			B int
+		}{},
+		struct {
+			A int
+			B int `datastore:"A"`
+		}{},
+		struct {
+			A int `datastore:"C"`
+			B int `datastore:"C"`
+		}{},
+		struct {
+			A int `datastore:"B"`
+			B int `datastore:"C"`
+			C int `datastore:"B"`
+		}{},
+	}
+	testGetStructCodec(t, good, bad)
+}
+
+func TestFlatteningNestedStructs(t *testing.T) {
+	type DeepGood struct {
+		A struct {
+			B []struct {
+				C struct {
+					D int
+				}
+			}
+		}
+	}
+	type DeepBad struct {
+		A struct {
+			B []struct {
+				C struct {
+					D []int
+				}
+			}
+		}
+	}
+	type ISay struct {
+		Tomato int
+	}
+	type YouSay struct {
+		Tomato int
+	}
+	type Tweedledee struct {
+		Dee int `datastore:"D"`
+	}
+	type Tweedledum struct {
+		Dum int `datastore:"D"`
+	}
+
+	good := []interface{}{
+		struct {
+			X []struct {
+				Y string
+			}
+		}{},
+		struct {
+			X []struct {
+				Y []byte
+			}
+		}{},
+		struct {
+			P []int
+			X struct {
+				Y []int
+			}
+		}{},
+		struct {
+			X struct {
+				Y []int
+			}
+			Q []int
+		}{},
+		struct {
+			P []int
+			X struct {
+				Y []int
+			}
+			Q []int
+		}{},
+		struct {
+			DeepGood
+		}{},
+		struct {
+			DG DeepGood
+		}{},
+		struct {
+			Foo struct {
+				Z int
+			} `datastore:"A"`
+			Bar struct {
+				Z int
+			} `datastore:"B"`
+		}{},
+	}
+	bad := []interface{}{
+		struct {
+			X []struct {
+				Y []string
+			}
+		}{},
+		struct {
+			X []struct {
+				Y []int
+			}
+		}{},
+		struct {
+			DeepBad
+		}{},
+		struct {
+			DB DeepBad
+		}{},
+		struct {
+			ISay
+			YouSay
+		}{},
+		struct {
+			Tweedledee
+			Tweedledum
+		}{},
+		struct {
+			Foo struct {
+				Z int
+			} `datastore:"A"`
+			Bar struct {
+				Z int
+			} `datastore:"A"`
+		}{},
+	}
+	testGetStructCodec(t, good, bad)
+}
+
+func testGetStructCodec(t *testing.T, good []interface{}, bad []interface{}) {
+	for _, x := range good {
+		if _, err := getStructCodec(reflect.TypeOf(x)); err != nil {
+			t.Errorf("type %T: got non-nil error (%s), want nil", x, err)
+		}
+	}
+	for _, x := range bad {
+		if _, err := getStructCodec(reflect.TypeOf(x)); err == nil {
+			t.Errorf("type %T: got nil error, want non-nil", x)
+		}
+	}
+}
+
+func TestNilKeyIsStored(t *testing.T) {
+	x := struct {
+		K *Key
+		I int
+	}{}
+	p := PropertyList{}
+	// Save x as properties.
+	p1, _ := SaveStruct(&x)
+	p.Load(p1)
+	// Set x's fields to non-zero.
+	x.K = &Key{}
+	x.I = 2
+	// Load x from properties.
+	p2, _ := p.Save()
+	LoadStruct(&x, p2)
+	// Check that x's fields were set to zero.
+	if x.K != nil {
+		t.Errorf("K field was not zero")
+	}
+	if x.I != 0 {
+		t.Errorf("I field was not zero")
+	}
+}
+
+func TestSaveStructOmitEmpty(t *testing.T) {
+	// Expected props names are sorted alphabetically
+	expectedPropNamesForSingles := []string{"EmptyValue", "NonEmptyValue", "OmitEmptyWithValue"}
+	expectedPropNamesForSlices := []string{"NonEmptyValue", "NonEmptyValue", "OmitEmptyWithValue", "OmitEmptyWithValue"}
+
+	testOmitted := func(expectedPropNames []string, src interface{}) {
+		// t.Helper() - this is available from Go version 1.9, but we also support Go versions 1.6, 1.7, 1.8
+		if props, err := SaveStruct(src); err != nil {
+			t.Fatal(err)
+		} else {
+			// Collect names for reporting if diffs from expected and for easier sorting
+			actualPropNames := make([]string, len(props))
+			for i := range props {
+				actualPropNames[i] = props[i].Name
+			}
+			// Sort actuals for comparing with already sorted expected names
+			sort.Sort(sort.StringSlice(actualPropNames))
+			if !reflect.DeepEqual(actualPropNames, expectedPropNames) {
+				t.Errorf("Expected this properties: %v, got: %v", expectedPropNames, actualPropNames)
+			}
+		}
+	}
+
+	testOmitted(expectedPropNamesForSingles, &struct {
+		EmptyValue         int
+		NonEmptyValue      int
+		OmitEmptyNoValue   int `datastore:",omitempty"`
+		OmitEmptyWithValue int `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      1,
+		OmitEmptyWithValue: 2,
+	})
+
+	testOmitted(expectedPropNamesForSlices, &struct {
+		EmptyValue         []int
+		NonEmptyValue      []int
+		OmitEmptyNoValue   []int `datastore:",omitempty"`
+		OmitEmptyWithValue []int `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      []int{1, 2},
+		OmitEmptyWithValue: []int{3, 4},
+	})
+
+	testOmitted(expectedPropNamesForSingles, &struct {
+		EmptyValue         bool
+		NonEmptyValue      bool
+		OmitEmptyNoValue   bool `datastore:",omitempty"`
+		OmitEmptyWithValue bool `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      true,
+		OmitEmptyWithValue: true,
+	})
+
+	testOmitted(expectedPropNamesForSlices, &struct {
+		EmptyValue         []bool
+		NonEmptyValue      []bool
+		OmitEmptyNoValue   []bool `datastore:",omitempty"`
+		OmitEmptyWithValue []bool `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      []bool{true, true},
+		OmitEmptyWithValue: []bool{true, true},
+	})
+
+	testOmitted(expectedPropNamesForSingles, &struct {
+		EmptyValue         string
+		NonEmptyValue      string
+		OmitEmptyNoValue   string `datastore:",omitempty"`
+		OmitEmptyWithValue string `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      "s",
+		OmitEmptyWithValue: "s",
+	})
+
+	testOmitted(expectedPropNamesForSlices, &struct {
+		EmptyValue         []string
+		NonEmptyValue      []string
+		OmitEmptyNoValue   []string `datastore:",omitempty"`
+		OmitEmptyWithValue []string `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      []string{"s1", "s2"},
+		OmitEmptyWithValue: []string{"s3", "s4"},
+	})
+
+	testOmitted(expectedPropNamesForSingles, &struct {
+		EmptyValue         float32
+		NonEmptyValue      float32
+		OmitEmptyNoValue   float32 `datastore:",omitempty"`
+		OmitEmptyWithValue float32 `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      1.1,
+		OmitEmptyWithValue: 1.2,
+	})
+
+	testOmitted(expectedPropNamesForSlices, &struct {
+		EmptyValue         []float32
+		NonEmptyValue      []float32
+		OmitEmptyNoValue   []float32 `datastore:",omitempty"`
+		OmitEmptyWithValue []float32 `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      []float32{1.1, 2.2},
+		OmitEmptyWithValue: []float32{3.3, 4.4},
+	})
+
+	testOmitted(expectedPropNamesForSingles, &struct {
+		EmptyValue         time.Time
+		NonEmptyValue      time.Time
+		OmitEmptyNoValue   time.Time `datastore:",omitempty"`
+		OmitEmptyWithValue time.Time `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      now,
+		OmitEmptyWithValue: now,
+	})
+
+	testOmitted(expectedPropNamesForSlices, &struct {
+		EmptyValue         []time.Time
+		NonEmptyValue      []time.Time
+		OmitEmptyNoValue   []time.Time `datastore:",omitempty"`
+		OmitEmptyWithValue []time.Time `datastore:",omitempty"`
+	}{
+		NonEmptyValue:      []time.Time{now, now},
+		OmitEmptyWithValue: []time.Time{now, now},
+	})
+}

vendor/google.golang.org/appengine/datastore/query.go

@@ -0,0 +1,757 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"math"
+	"reflect"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+	"golang.org/x/net/context"
+
+	"google.golang.org/appengine/internal"
+	pb "google.golang.org/appengine/internal/datastore"
+)
+
+type operator int
+
+const (
+	lessThan operator = iota
+	lessEq
+	equal
+	greaterEq
+	greaterThan
+)
+
+var operatorToProto = map[operator]*pb.Query_Filter_Operator{
+	lessThan:    pb.Query_Filter_LESS_THAN.Enum(),
+	lessEq:      pb.Query_Filter_LESS_THAN_OR_EQUAL.Enum(),
+	equal:       pb.Query_Filter_EQUAL.Enum(),
+	greaterEq:   pb.Query_Filter_GREATER_THAN_OR_EQUAL.Enum(),
+	greaterThan: pb.Query_Filter_GREATER_THAN.Enum(),
+}
+
+// filter is a conditional filter on query results.
+type filter struct {
+	FieldName string
+	Op        operator
+	Value     interface{}
+}
+
+type sortDirection int
+
+const (
+	ascending sortDirection = iota
+	descending
+)
+
+var sortDirectionToProto = map[sortDirection]*pb.Query_Order_Direction{
+	ascending:  pb.Query_Order_ASCENDING.Enum(),
+	descending: pb.Query_Order_DESCENDING.Enum(),
+}
+
+// order is a sort order on query results.
+type order struct {
+	FieldName string
+	Direction sortDirection
+}
+
+// NewQuery creates a new Query for a specific entity kind.
+//
+// An empty kind means to return all entities, including entities created and
+// managed by other App Engine features, and is called a kindless query.
+// Kindless queries cannot include filters or sort orders on property values.
+func NewQuery(kind string) *Query {
+	return &Query{
+		kind:  kind,
+		limit: -1,
+	}
+}
+
+// Query represents a datastore query.
+type Query struct {
+	kind       string
+	ancestor   *Key
+	filter     []filter
+	order      []order
+	projection []string
+
+	distinct bool
+	keysOnly bool
+	eventual bool
+	limit    int32
+	offset   int32
+	count    int32
+	start    *pb.CompiledCursor
+	end      *pb.CompiledCursor
+
+	err error
+}
+
+func (q *Query) clone() *Query {
+	x := *q
+	// Copy the contents of the slice-typed fields to a new backing store.
+	if len(q.filter) > 0 {
+		x.filter = make([]filter, len(q.filter))
+		copy(x.filter, q.filter)
+	}
+	if len(q.order) > 0 {
+		x.order = make([]order, len(q.order))
+		copy(x.order, q.order)
+	}
+	return &x
+}
+
+// Ancestor returns a derivative query with an ancestor filter.
+// The ancestor should not be nil.
+func (q *Query) Ancestor(ancestor *Key) *Query {
+	q = q.clone()
+	if ancestor == nil {
+		q.err = errors.New("datastore: nil query ancestor")
+		return q
+	}
+	q.ancestor = ancestor
+	return q
+}
+
+// EventualConsistency returns a derivative query that returns eventually
+// consistent results.
+// It only has an effect on ancestor queries.
+func (q *Query) EventualConsistency() *Query {
+	q = q.clone()
+	q.eventual = true
+	return q
+}
+
+// Filter returns a derivative query with a field-based filter.
+// The filterStr argument must be a field name followed by optional space,
+// followed by an operator, one of ">", "<", ">=", "<=", or "=".
+// Fields are compared against the provided value using the operator.
+// Multiple filters are AND'ed together.
+func (q *Query) Filter(filterStr string, value interface{}) *Query {
+	q = q.clone()
+	filterStr = strings.TrimSpace(filterStr)
+	if len(filterStr) < 1 {
+		q.err = errors.New("datastore: invalid filter: " + filterStr)
+		return q
+	}
+	f := filter{
+		FieldName: strings.TrimRight(filterStr, " ><=!"),
+		Value:     value,
+	}
+	switch op := strings.TrimSpace(filterStr[len(f.FieldName):]); op {
+	case "<=":
+		f.Op = lessEq
+	case ">=":
+		f.Op = greaterEq
+	case "<":
+		f.Op = lessThan
+	case ">":
+		f.Op = greaterThan
+	case "=":
+		f.Op = equal
+	default:
+		q.err = fmt.Errorf("datastore: invalid operator %q in filter %q", op, filterStr)
+		return q
+	}
+	q.filter = append(q.filter, f)
+	return q
+}
+
+// Order returns a derivative query with a field-based sort order. Orders are
+// applied in the order they are added. The default order is ascending; to sort
+// in descending order prefix the fieldName with a minus sign (-).
+func (q *Query) Order(fieldName string) *Query {
+	q = q.clone()
+	fieldName = strings.TrimSpace(fieldName)
+	o := order{
+		Direction: ascending,
+		FieldName: fieldName,
+	}
+	if strings.HasPrefix(fieldName, "-") {
+		o.Direction = descending
+		o.FieldName = strings.TrimSpace(fieldName[1:])
+	} else if strings.HasPrefix(fieldName, "+") {
+		q.err = fmt.Errorf("datastore: invalid order: %q", fieldName)
+		return q
+	}
+	if len(o.FieldName) == 0 {
+		q.err = errors.New("datastore: empty order")
+		return q
+	}
+	q.order = append(q.order, o)
+	return q
+}
+
+// Project returns a derivative query that yields only the given fields. It
+// cannot be used with KeysOnly.
+func (q *Query) Project(fieldNames ...string) *Query {
+	q = q.clone()
+	q.projection = append([]string(nil), fieldNames...)
+	return q
+}
+
+// Distinct returns a derivative query that yields de-duplicated entities with
+// respect to the set of projected fields. It is only used for projection
+// queries.
+func (q *Query) Distinct() *Query {
+	q = q.clone()
+	q.distinct = true
+	return q
+}
+
+// KeysOnly returns a derivative query that yields only keys, not keys and
+// entities. It cannot be used with projection queries.
+func (q *Query) KeysOnly() *Query {
+	q = q.clone()
+	q.keysOnly = true
+	return q
+}
+
+// Limit returns a derivative query that has a limit on the number of results
+// returned. A negative value means unlimited.
+func (q *Query) Limit(limit int) *Query {
+	q = q.clone()
+	if limit < math.MinInt32 || limit > math.MaxInt32 {
+		q.err = errors.New("datastore: query limit overflow")
+		return q
+	}
+	q.limit = int32(limit)
+	return q
+}
+
+// Offset returns a derivative query that has an offset of how many keys to
+// skip over before returning results. A negative value is invalid.
+func (q *Query) Offset(offset int) *Query {
+	q = q.clone()
+	if offset < 0 {
+		q.err = errors.New("datastore: negative query offset")
+		return q
+	}
+	if offset > math.MaxInt32 {
+		q.err = errors.New("datastore: query offset overflow")
+		return q
+	}
+	q.offset = int32(offset)
+	return q
+}
+
+// BatchSize returns a derivative query to fetch the supplied number of results
+// at once. This value should be greater than zero, and equal to or less than
+// the Limit.
+func (q *Query) BatchSize(size int) *Query {
+	q = q.clone()
+	if size <= 0 || size > math.MaxInt32 {
+		q.err = errors.New("datastore: query batch size overflow")
+		return q
+	}
+	q.count = int32(size)
+	return q
+}
+
+// Start returns a derivative query with the given start point.
+func (q *Query) Start(c Cursor) *Query {
+	q = q.clone()
+	if c.cc == nil {
+		q.err = errors.New("datastore: invalid cursor")
+		return q
+	}
+	q.start = c.cc
+	return q
+}
+
+// End returns a derivative query with the given end point.
+func (q *Query) End(c Cursor) *Query {
+	q = q.clone()
+	if c.cc == nil {
+		q.err = errors.New("datastore: invalid cursor")
+		return q
+	}
+	q.end = c.cc
+	return q
+}
+
+// toProto converts the query to a protocol buffer.
+func (q *Query) toProto(dst *pb.Query, appID string) error {
+	if len(q.projection) != 0 && q.keysOnly {
+		return errors.New("datastore: query cannot both project and be keys-only")
+	}
+	dst.Reset()
+	dst.App = proto.String(appID)
+	if q.kind != "" {
+		dst.Kind = proto.String(q.kind)
+	}
+	if q.ancestor != nil {
+		dst.Ancestor = keyToProto(appID, q.ancestor)
+		if q.eventual {
+			dst.Strong = proto.Bool(false)
+		}
+	}
+	if q.projection != nil {
+		dst.PropertyName = q.projection
+		if q.distinct {
+			dst.GroupByPropertyName = q.projection
+		}
+	}
+	if q.keysOnly {
+		dst.KeysOnly = proto.Bool(true)
+		dst.RequirePerfectPlan = proto.Bool(true)
+	}
+	for _, qf := range q.filter {
+		if qf.FieldName == "" {
+			return errors.New("datastore: empty query filter field name")
+		}
+		p, errStr := valueToProto(appID, qf.FieldName, reflect.ValueOf(qf.Value), false)
+		if errStr != "" {
+			return errors.New("datastore: bad query filter value type: " + errStr)
+		}
+		xf := &pb.Query_Filter{
+			Op:       operatorToProto[qf.Op],
+			Property: []*pb.Property{p},
+		}
+		if xf.Op == nil {
+			return errors.New("datastore: unknown query filter operator")
+		}
+		dst.Filter = append(dst.Filter, xf)
+	}
+	for _, qo := range q.order {
+		if qo.FieldName == "" {
+			return errors.New("datastore: empty query order field name")
+		}
+		xo := &pb.Query_Order{
+			Property:  proto.String(qo.FieldName),
+			Direction: sortDirectionToProto[qo.Direction],
+		}
+		if xo.Direction == nil {
+			return errors.New("datastore: unknown query order direction")
+		}
+		dst.Order = append(dst.Order, xo)
+	}
+	if q.limit >= 0 {
+		dst.Limit = proto.Int32(q.limit)
+	}
+	if q.offset != 0 {
+		dst.Offset = proto.Int32(q.offset)
+	}
+	if q.count != 0 {
+		dst.Count = proto.Int32(q.count)
+	}
+	dst.CompiledCursor = q.start
+	dst.EndCompiledCursor = q.end
+	dst.Compile = proto.Bool(true)
+	return nil
+}
+
+// Count returns the number of results for the query.
+//
+// The running time and number of API calls made by Count scale linearly with
+// the sum of the query's offset and limit. Unless the result count is
+// expected to be small, it is best to specify a limit; otherwise Count will
+// continue until it finishes counting or the provided context expires.
+func (q *Query) Count(c context.Context) (int, error) {
+	// Check that the query is well-formed.
+	if q.err != nil {
+		return 0, q.err
+	}
+
+	// Run a copy of the query, with keysOnly true (if we're not a projection,
+	// since the two are incompatible), and an adjusted offset. We also set the
+	// limit to zero, as we don't want any actual entity data, just the number
+	// of skipped results.
+	newQ := q.clone()
+	newQ.keysOnly = len(newQ.projection) == 0
+	newQ.limit = 0
+	if q.limit < 0 {
+		// If the original query was unlimited, set the new query's offset to maximum.
+		newQ.offset = math.MaxInt32
+	} else {
+		newQ.offset = q.offset + q.limit
+		if newQ.offset < 0 {
+			// Do the best we can, in the presence of overflow.
+			newQ.offset = math.MaxInt32
+		}
+	}
+	req := &pb.Query{}
+	if err := newQ.toProto(req, internal.FullyQualifiedAppID(c)); err != nil {
+		return 0, err
+	}
+	res := &pb.QueryResult{}
+	if err := internal.Call(c, "datastore_v3", "RunQuery", req, res); err != nil {
+		return 0, err
+	}
+
+	// n is the count we will return. For example, suppose that our original
+	// query had an offset of 4 and a limit of 2008: the count will be 2008,
+	// provided that there are at least 2012 matching entities. However, the
+	// RPCs will only skip 1000 results at a time. The RPC sequence is:
+	//   call RunQuery with (offset, limit) = (2012, 0)  // 2012 == newQ.offset
+	//   response has (skippedResults, moreResults) = (1000, true)
+	//   n += 1000  // n == 1000
+	//   call Next     with (offset, limit) = (1012, 0)  // 1012 == newQ.offset - n
+	//   response has (skippedResults, moreResults) = (1000, true)
+	//   n += 1000  // n == 2000
+	//   call Next     with (offset, limit) = (12, 0)    // 12 == newQ.offset - n
+	//   response has (skippedResults, moreResults) = (12, false)
+	//   n += 12    // n == 2012
+	//   // exit the loop
+	//   n -= 4     // n == 2008
+	var n int32
+	for {
+		// The QueryResult should have no actual entity data, just skipped results.
+		if len(res.Result) != 0 {
+			return 0, errors.New("datastore: internal error: Count request returned too much data")
+		}
+		n += res.GetSkippedResults()
+		if !res.GetMoreResults() {
+			break
+		}
+		if err := callNext(c, res, newQ.offset-n, q.count); err != nil {
+			return 0, err
+		}
+	}
+	n -= q.offset
+	if n < 0 {
+		// If the offset was greater than the number of matching entities,
+		// return 0 instead of negative.
+		n = 0
+	}
+	return int(n), nil
+}
+
+// callNext issues a datastore_v3/Next RPC to advance a cursor, such as that
+// returned by a query with more results.
+func callNext(c context.Context, res *pb.QueryResult, offset, count int32) error {
+	if res.Cursor == nil {
+		return errors.New("datastore: internal error: server did not return a cursor")
+	}
+	req := &pb.NextRequest{
+		Cursor: res.Cursor,
+	}
+	if count >= 0 {
+		req.Count = proto.Int32(count)
+	}
+	if offset != 0 {
+		req.Offset = proto.Int32(offset)
+	}
+	if res.CompiledCursor != nil {
+		req.Compile = proto.Bool(true)
+	}
+	res.Reset()
+	return internal.Call(c, "datastore_v3", "Next", req, res)
+}
+
+// GetAll runs the query in the given context and returns all keys that match
+// that query, as well as appending the values to dst.
+//
+// dst must have type *[]S or *[]*S or *[]P, for some struct type S or some non-
+// interface, non-pointer type P such that P or *P implements PropertyLoadSaver.
+//
+// As a special case, *PropertyList is an invalid type for dst, even though a
+// PropertyList is a slice of structs. It is treated as invalid to avoid being
+// mistakenly passed when *[]PropertyList was intended.
+//
+// The keys returned by GetAll will be in a 1-1 correspondence with the entities
+// added to dst.
+//
+// If q is a ``keys-only'' query, GetAll ignores dst and only returns the keys.
+//
+// The running time and number of API calls made by GetAll scale linearly with
+// the sum of the query's offset and limit. Unless the result count is
+// expected to be small, it is best to specify a limit; otherwise GetAll will
+// continue until it finishes collecting results or the provided context
+// expires.
+func (q *Query) GetAll(c context.Context, dst interface{}) ([]*Key, error) {
+	var (
+		dv               reflect.Value
+		mat              multiArgType
+		elemType         reflect.Type
+		errFieldMismatch error
+	)
+	if !q.keysOnly {
+		dv = reflect.ValueOf(dst)
+		if dv.Kind() != reflect.Ptr || dv.IsNil() {
+			return nil, ErrInvalidEntityType
+		}
+		dv = dv.Elem()
+		mat, elemType = checkMultiArg(dv)
+		if mat == multiArgTypeInvalid || mat == multiArgTypeInterface {
+			return nil, ErrInvalidEntityType
+		}
+	}
+
+	var keys []*Key
+	for t := q.Run(c); ; {
+		k, e, err := t.next()
+		if err == Done {
+			break
+		}
+		if err != nil {
+			return keys, err
+		}
+		if !q.keysOnly {
+			ev := reflect.New(elemType)
+			if elemType.Kind() == reflect.Map {
+				// This is a special case. The zero values of a map type are
+				// not immediately useful; they have to be make'd.
+				//
+				// Funcs and channels are similar, in that a zero value is not useful,
+				// but even a freshly make'd channel isn't useful: there's no fixed
+				// channel buffer size that is always going to be large enough, and
+				// there's no goroutine to drain the other end. Theoretically, these
+				// types could be supported, for example by sniffing for a constructor
+				// method or requiring prior registration, but for now it's not a
+				// frequent enough concern to be worth it. Programmers can work around
+				// it by explicitly using Iterator.Next instead of the Query.GetAll
+				// convenience method.
+				x := reflect.MakeMap(elemType)
+				ev.Elem().Set(x)
+			}
+			if err = loadEntity(ev.Interface(), e); err != nil {
+				if _, ok := err.(*ErrFieldMismatch); ok {
+					// We continue loading entities even in the face of field mismatch errors.
+					// If we encounter any other error, that other error is returned. Otherwise,
+					// an ErrFieldMismatch is returned.
+					errFieldMismatch = err
+				} else {
+					return keys, err
+				}
+			}
+			if mat != multiArgTypeStructPtr {
+				ev = ev.Elem()
+			}
+			dv.Set(reflect.Append(dv, ev))
+		}
+		keys = append(keys, k)
+	}
+	return keys, errFieldMismatch
+}
+
+// Run runs the query in the given context.
+func (q *Query) Run(c context.Context) *Iterator {
+	if q.err != nil {
+		return &Iterator{err: q.err}
+	}
+	t := &Iterator{
+		c:      c,
+		limit:  q.limit,
+		count:  q.count,
+		q:      q,
+		prevCC: q.start,
+	}
+	var req pb.Query
+	if err := q.toProto(&req, internal.FullyQualifiedAppID(c)); err != nil {
+		t.err = err
+		return t
+	}
+	if err := internal.Call(c, "datastore_v3", "RunQuery", &req, &t.res); err != nil {
+		t.err = err
+		return t
+	}
+	offset := q.offset - t.res.GetSkippedResults()
+	var count int32
+	if t.count > 0 && (t.limit < 0 || t.count < t.limit) {
+		count = t.count
+	} else {
+		count = t.limit
+	}
+	for offset > 0 && t.res.GetMoreResults() {
+		t.prevCC = t.res.CompiledCursor
+		if err := callNext(t.c, &t.res, offset, count); err != nil {
+			t.err = err
+			break
+		}
+		skip := t.res.GetSkippedResults()
+		if skip < 0 {
+			t.err = errors.New("datastore: internal error: negative number of skipped_results")
+			break
+		}
+		offset -= skip
+	}
+	if offset < 0 {
+		t.err = errors.New("datastore: internal error: query offset was overshot")
+	}
+	return t
+}
+
+// Iterator is the result of running a query.
+type Iterator struct {
+	c   context.Context
+	err error
+	// res is the result of the most recent RunQuery or Next API call.
+	res pb.QueryResult
+	// i is how many elements of res.Result we have iterated over.
+	i int
+	// limit is the limit on the number of results this iterator should return.
+	// A negative value means unlimited.
+	limit int32
+	// count is the number of results this iterator should fetch at once. This
+	// should be equal to or greater than zero.
+	count int32
+	// q is the original query which yielded this iterator.
+	q *Query
+	// prevCC is the compiled cursor that marks the end of the previous batch
+	// of results.
+	prevCC *pb.CompiledCursor
+}
+
+// Done is returned when a query iteration has completed.
+var Done = errors.New("datastore: query has no more results")
+
+// Next returns the key of the next result. When there are no more results,
+// Done is returned as the error.
+//
+// If the query is not keys only and dst is non-nil, it also loads the entity
+// stored for that key into the struct pointer or PropertyLoadSaver dst, with
+// the same semantics and possible errors as for the Get function.
+func (t *Iterator) Next(dst interface{}) (*Key, error) {
+	k, e, err := t.next()
+	if err != nil {
+		return nil, err
+	}
+	if dst != nil && !t.q.keysOnly {
+		err = loadEntity(dst, e)
+	}
+	return k, err
+}
+
+func (t *Iterator) next() (*Key, *pb.EntityProto, error) {
+	if t.err != nil {
+		return nil, nil, t.err
+	}
+
+	// Issue datastore_v3/Next RPCs as necessary.
+	for t.i == len(t.res.Result) {
+		if !t.res.GetMoreResults() {
+			t.err = Done
+			return nil, nil, t.err
+		}
+		t.prevCC = t.res.CompiledCursor
+		var count int32
+		if t.count > 0 && (t.limit < 0 || t.count < t.limit) {
+			count = t.count
+		} else {
+			count = t.limit
+		}
+		if err := callNext(t.c, &t.res, 0, count); err != nil {
+			t.err = err
+			return nil, nil, t.err
+		}
+		if t.res.GetSkippedResults() != 0 {
+			t.err = errors.New("datastore: internal error: iterator has skipped results")
+			return nil, nil, t.err
+		}
+		t.i = 0
+		if t.limit >= 0 {
+			t.limit -= int32(len(t.res.Result))
+			if t.limit < 0 {
+				t.err = errors.New("datastore: internal error: query returned more results than the limit")
+				return nil, nil, t.err
+			}
+		}
+	}
+
+	// Extract the key from the t.i'th element of t.res.Result.
+	e := t.res.Result[t.i]
+	t.i++
+	if e.Key == nil {
+		return nil, nil, errors.New("datastore: internal error: server did not return a key")
+	}
+	k, err := protoToKey(e.Key)
+	if err != nil || k.Incomplete() {
+		return nil, nil, errors.New("datastore: internal error: server returned an invalid key")
+	}
+	return k, e, nil
+}
+
+// Cursor returns a cursor for the iterator's current location.
+func (t *Iterator) Cursor() (Cursor, error) {
+	if t.err != nil && t.err != Done {
+		return Cursor{}, t.err
+	}
+	// If we are at either end of the current batch of results,
+	// return the compiled cursor at that end.
+	skipped := t.res.GetSkippedResults()
+	if t.i == 0 && skipped == 0 {
+		if t.prevCC == nil {
+			// A nil pointer (of type *pb.CompiledCursor) means no constraint:
+			// passing it as the end cursor of a new query means unlimited results
+			// (glossing over the integer limit parameter for now).
+			// A non-nil pointer to an empty pb.CompiledCursor means the start:
+			// passing it as the end cursor of a new query means 0 results.
+			// If prevCC was nil, then the original query had no start cursor, but
+			// Iterator.Cursor should return "the start" instead of unlimited.
+			return Cursor{&zeroCC}, nil
+		}
+		return Cursor{t.prevCC}, nil
+	}
+	if t.i == len(t.res.Result) {
+		return Cursor{t.res.CompiledCursor}, nil
+	}
+	// Otherwise, re-run the query offset to this iterator's position, starting from
+	// the most recent compiled cursor. This is done on a best-effort basis, as it
+	// is racy; if a concurrent process has added or removed entities, then the
+	// cursor returned may be inconsistent.
+	q := t.q.clone()
+	q.start = t.prevCC
+	q.offset = skipped + int32(t.i)
+	q.limit = 0
+	q.keysOnly = len(q.projection) == 0
+	t1 := q.Run(t.c)
+	_, _, err := t1.next()
+	if err != Done {
+		if err == nil {
+			err = fmt.Errorf("datastore: internal error: zero-limit query did not have zero results")
+		}
+		return Cursor{}, err
+	}
+	return Cursor{t1.res.CompiledCursor}, nil
+}
+
+var zeroCC pb.CompiledCursor
+
+// Cursor is an iterator's position. It can be converted to and from an opaque
+// string. A cursor can be used from different HTTP requests, but only with a
+// query with the same kind, ancestor, filter and order constraints.
+type Cursor struct {
+	cc *pb.CompiledCursor
+}
+
+// String returns a base-64 string representation of a cursor.
+func (c Cursor) String() string {
+	if c.cc == nil {
+		return ""
+	}
+	b, err := proto.Marshal(c.cc)
+	if err != nil {
+		// The only way to construct a Cursor with a non-nil cc field is to
+		// unmarshal from the byte representation. We panic if the unmarshal
+		// succeeds but the marshaling of the unchanged protobuf value fails.
+		panic(fmt.Sprintf("datastore: internal error: malformed cursor: %v", err))
+	}
+	return strings.TrimRight(base64.URLEncoding.EncodeToString(b), "=")
+}
+
+// Decode decodes a cursor from its base-64 string representation.
+func DecodeCursor(s string) (Cursor, error) {
+	if s == "" {
+		return Cursor{&zeroCC}, nil
+	}
+	if n := len(s) % 4; n != 0 {
+		s += strings.Repeat("=", 4-n)
+	}
+	b, err := base64.URLEncoding.DecodeString(s)
+	if err != nil {
+		return Cursor{}, err
+	}
+	cc := &pb.CompiledCursor{}
+	if err := proto.Unmarshal(b, cc); err != nil {
+		return Cursor{}, err
+	}
+	return Cursor{cc}, nil
+}

vendor/google.golang.org/appengine/datastore/query_test.go

@@ -0,0 +1,584 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/golang/protobuf/proto"
+
+	"google.golang.org/appengine/internal"
+	"google.golang.org/appengine/internal/aetesting"
+	pb "google.golang.org/appengine/internal/datastore"
+)
+
+var (
+	path1 = &pb.Path{
+		Element: []*pb.Path_Element{
+			{
+				Type: proto.String("Gopher"),
+				Id:   proto.Int64(6),
+			},
+		},
+	}
+	path2 = &pb.Path{
+		Element: []*pb.Path_Element{
+			{
+				Type: proto.String("Gopher"),
+				Id:   proto.Int64(6),
+			},
+			{
+				Type: proto.String("Gopher"),
+				Id:   proto.Int64(8),
+			},
+		},
+	}
+)
+
+func fakeRunQuery(in *pb.Query, out *pb.QueryResult) error {
+	expectedIn := &pb.Query{
+		App:     proto.String("dev~fake-app"),
+		Kind:    proto.String("Gopher"),
+		Compile: proto.Bool(true),
+	}
+	if !proto.Equal(in, expectedIn) {
+		return fmt.Errorf("unsupported argument: got %v want %v", in, expectedIn)
+	}
+	*out = pb.QueryResult{
+		Result: []*pb.EntityProto{
+			{
+				Key: &pb.Reference{
+					App:  proto.String("s~test-app"),
+					Path: path1,
+				},
+				EntityGroup: path1,
+				Property: []*pb.Property{
+					{
+						Meaning: pb.Property_TEXT.Enum(),
+						Name:    proto.String("Name"),
+						Value: &pb.PropertyValue{
+							StringValue: proto.String("George"),
+						},
+					},
+					{
+						Name: proto.String("Height"),
+						Value: &pb.PropertyValue{
+							Int64Value: proto.Int64(32),
+						},
+					},
+				},
+			},
+			{
+				Key: &pb.Reference{
+					App:  proto.String("s~test-app"),
+					Path: path2,
+				},
+				EntityGroup: path1, // ancestor is George
+				Property: []*pb.Property{
+					{
+						Meaning: pb.Property_TEXT.Enum(),
+						Name:    proto.String("Name"),
+						Value: &pb.PropertyValue{
+							StringValue: proto.String("Rufus"),
+						},
+					},
+					// No height for Rufus.
+				},
+			},
+		},
+		MoreResults: proto.Bool(false),
+	}
+	return nil
+}
+
+type StructThatImplementsPLS struct{}
+
+func (StructThatImplementsPLS) Load(p []Property) error   { return nil }
+func (StructThatImplementsPLS) Save() ([]Property, error) { return nil, nil }
+
+var _ PropertyLoadSaver = StructThatImplementsPLS{}
+
+type StructPtrThatImplementsPLS struct{}
+
+func (*StructPtrThatImplementsPLS) Load(p []Property) error   { return nil }
+func (*StructPtrThatImplementsPLS) Save() ([]Property, error) { return nil, nil }
+
+var _ PropertyLoadSaver = &StructPtrThatImplementsPLS{}
+
+type PropertyMap map[string]Property
+
+func (m PropertyMap) Load(props []Property) error {
+	for _, p := range props {
+		if p.Multiple {
+			return errors.New("PropertyMap does not support multiple properties")
+		}
+		m[p.Name] = p
+	}
+	return nil
+}
+
+func (m PropertyMap) Save() ([]Property, error) {
+	props := make([]Property, 0, len(m))
+	for _, p := range m {
+		if p.Multiple {
+			return nil, errors.New("PropertyMap does not support multiple properties")
+		}
+		props = append(props, p)
+	}
+	return props, nil
+}
+
+var _ PropertyLoadSaver = PropertyMap{}
+
+type Gopher struct {
+	Name   string
+	Height int
+}
+
+// typeOfEmptyInterface is the type of interface{}, but we can't use
+// reflect.TypeOf((interface{})(nil)) directly because TypeOf takes an
+// interface{}.
+var typeOfEmptyInterface = reflect.TypeOf((*interface{})(nil)).Elem()
+
+func TestCheckMultiArg(t *testing.T) {
+	testCases := []struct {
+		v        interface{}
+		mat      multiArgType
+		elemType reflect.Type
+	}{
+		// Invalid cases.
+		{nil, multiArgTypeInvalid, nil},
+		{Gopher{}, multiArgTypeInvalid, nil},
+		{&Gopher{}, multiArgTypeInvalid, nil},
+		{PropertyList{}, multiArgTypeInvalid, nil}, // This is a special case.
+		{PropertyMap{}, multiArgTypeInvalid, nil},
+		{[]*PropertyList(nil), multiArgTypeInvalid, nil},
+		{[]*PropertyMap(nil), multiArgTypeInvalid, nil},
+		{[]**Gopher(nil), multiArgTypeInvalid, nil},
+		{[]*interface{}(nil), multiArgTypeInvalid, nil},
+		// Valid cases.
+		{
+			[]PropertyList(nil),
+			multiArgTypePropertyLoadSaver,
+			reflect.TypeOf(PropertyList{}),
+		},
+		{
+			[]PropertyMap(nil),
+			multiArgTypePropertyLoadSaver,
+			reflect.TypeOf(PropertyMap{}),
+		},
+		{
+			[]StructThatImplementsPLS(nil),
+			multiArgTypePropertyLoadSaver,
+			reflect.TypeOf(StructThatImplementsPLS{}),
+		},
+		{
+			[]StructPtrThatImplementsPLS(nil),
+			multiArgTypePropertyLoadSaver,
+			reflect.TypeOf(StructPtrThatImplementsPLS{}),
+		},
+		{
+			[]Gopher(nil),
+			multiArgTypeStruct,
+			reflect.TypeOf(Gopher{}),
+		},
+		{
+			[]*Gopher(nil),
+			multiArgTypeStructPtr,
+			reflect.TypeOf(Gopher{}),
+		},
+		{
+			[]interface{}(nil),
+			multiArgTypeInterface,
+			typeOfEmptyInterface,
+		},
+	}
+	for _, tc := range testCases {
+		mat, elemType := checkMultiArg(reflect.ValueOf(tc.v))
+		if mat != tc.mat || elemType != tc.elemType {
+			t.Errorf("checkMultiArg(%T): got %v, %v want %v, %v",
+				tc.v, mat, elemType, tc.mat, tc.elemType)
+		}
+	}
+}
+
+func TestSimpleQuery(t *testing.T) {
+	struct1 := Gopher{Name: "George", Height: 32}
+	struct2 := Gopher{Name: "Rufus"}
+	pList1 := PropertyList{
+		{
+			Name:  "Name",
+			Value: "George",
+		},
+		{
+			Name:  "Height",
+			Value: int64(32),
+		},
+	}
+	pList2 := PropertyList{
+		{
+			Name:  "Name",
+			Value: "Rufus",
+		},
+	}
+	pMap1 := PropertyMap{
+		"Name": Property{
+			Name:  "Name",
+			Value: "George",
+		},
+		"Height": Property{
+			Name:  "Height",
+			Value: int64(32),
+		},
+	}
+	pMap2 := PropertyMap{
+		"Name": Property{
+			Name:  "Name",
+			Value: "Rufus",
+		},
+	}
+
+	testCases := []struct {
+		dst  interface{}
+		want interface{}
+	}{
+		// The destination must have type *[]P, *[]S or *[]*S, for some non-interface
+		// type P such that *P implements PropertyLoadSaver, or for some struct type S.
+		{new([]Gopher), &[]Gopher{struct1, struct2}},
+		{new([]*Gopher), &[]*Gopher{&struct1, &struct2}},
+		{new([]PropertyList), &[]PropertyList{pList1, pList2}},
+		{new([]PropertyMap), &[]PropertyMap{pMap1, pMap2}},
+
+		// Any other destination type is invalid.
+		{0, nil},
+		{Gopher{}, nil},
+		{PropertyList{}, nil},
+		{PropertyMap{}, nil},
+		{[]int{}, nil},
+		{[]Gopher{}, nil},
+		{[]PropertyList{}, nil},
+		{new(int), nil},
+		{new(Gopher), nil},
+		{new(PropertyList), nil}, // This is a special case.
+		{new(PropertyMap), nil},
+		{new([]int), nil},
+		{new([]map[int]int), nil},
+		{new([]map[string]Property), nil},
+		{new([]map[string]interface{}), nil},
+		{new([]*int), nil},
+		{new([]*map[int]int), nil},
+		{new([]*map[string]Property), nil},
+		{new([]*map[string]interface{}), nil},
+		{new([]**Gopher), nil},
+		{new([]*PropertyList), nil},
+		{new([]*PropertyMap), nil},
+	}
+	for _, tc := range testCases {
+		nCall := 0
+		c := aetesting.FakeSingleContext(t, "datastore_v3", "RunQuery", func(in *pb.Query, out *pb.QueryResult) error {
+			nCall++
+			return fakeRunQuery(in, out)
+		})
+		c = internal.WithAppIDOverride(c, "dev~fake-app")
+
+		var (
+			expectedErr   error
+			expectedNCall int
+		)
+		if tc.want == nil {
+			expectedErr = ErrInvalidEntityType
+		} else {
+			expectedNCall = 1
+		}
+		keys, err := NewQuery("Gopher").GetAll(c, tc.dst)
+		if err != expectedErr {
+			t.Errorf("dst type %T: got error [%v], want [%v]", tc.dst, err, expectedErr)
+			continue
+		}
+		if nCall != expectedNCall {
+			t.Errorf("dst type %T: Context.Call was called an incorrect number of times: got %d want %d", tc.dst, nCall, expectedNCall)
+			continue
+		}
+		if err != nil {
+			continue
+		}
+
+		key1 := NewKey(c, "Gopher", "", 6, nil)
+		expectedKeys := []*Key{
+			key1,
+			NewKey(c, "Gopher", "", 8, key1),
+		}
+		if l1, l2 := len(keys), len(expectedKeys); l1 != l2 {
+			t.Errorf("dst type %T: got %d keys, want %d keys", tc.dst, l1, l2)
+			continue
+		}
+		for i, key := range keys {
+			if key.AppID() != "s~test-app" {
+				t.Errorf(`dst type %T: Key #%d's AppID = %q, want "s~test-app"`, tc.dst, i, key.AppID())
+				continue
+			}
+			if !keysEqual(key, expectedKeys[i]) {
+				t.Errorf("dst type %T: got key #%d %v, want %v", tc.dst, i, key, expectedKeys[i])
+				continue
+			}
+		}
+
+		if !reflect.DeepEqual(tc.dst, tc.want) {
+			t.Errorf("dst type %T: Entities got %+v, want %+v", tc.dst, tc.dst, tc.want)
+			continue
+		}
+	}
+}
+
+// keysEqual is like (*Key).Equal, but ignores the App ID.
+func keysEqual(a, b *Key) bool {
+	for a != nil && b != nil {
+		if a.Kind() != b.Kind() || a.StringID() != b.StringID() || a.IntID() != b.IntID() {
+			return false
+		}
+		a, b = a.Parent(), b.Parent()
+	}
+	return a == b
+}
+
+func TestQueriesAreImmutable(t *testing.T) {
+	// Test that deriving q2 from q1 does not modify q1.
+	q0 := NewQuery("foo")
+	q1 := NewQuery("foo")
+	q2 := q1.Offset(2)
+	if !reflect.DeepEqual(q0, q1) {
+		t.Errorf("q0 and q1 were not equal")
+	}
+	if reflect.DeepEqual(q1, q2) {
+		t.Errorf("q1 and q2 were equal")
+	}
+
+	// Test that deriving from q4 twice does not conflict, even though
+	// q4 has a long list of order clauses. This tests that the arrays
+	// backed by a query's slice of orders are not shared.
+	f := func() *Query {
+		q := NewQuery("bar")
+		// 47 is an ugly number that is unlikely to be near a re-allocation
+		// point in repeated append calls. For example, it's not near a power
+		// of 2 or a multiple of 10.
+		for i := 0; i < 47; i++ {
+			q = q.Order(fmt.Sprintf("x%d", i))
+		}
+		return q
+	}
+	q3 := f().Order("y")
+	q4 := f()
+	q5 := q4.Order("y")
+	q6 := q4.Order("z")
+	if !reflect.DeepEqual(q3, q5) {
+		t.Errorf("q3 and q5 were not equal")
+	}
+	if reflect.DeepEqual(q5, q6) {
+		t.Errorf("q5 and q6 were equal")
+	}
+}
+
+func TestFilterParser(t *testing.T) {
+	testCases := []struct {
+		filterStr     string
+		wantOK        bool
+		wantFieldName string
+		wantOp        operator
+	}{
+		// Supported ops.
+		{"x<", true, "x", lessThan},
+		{"x <", true, "x", lessThan},
+		{"x  <", true, "x", lessThan},
+		{"   x   <  ", true, "x", lessThan},
+		{"x <=", true, "x", lessEq},
+		{"x =", true, "x", equal},
+		{"x >=", true, "x", greaterEq},
+		{"x >", true, "x", greaterThan},
+		{"in >", true, "in", greaterThan},
+		{"in>", true, "in", greaterThan},
+		// Valid but (currently) unsupported ops.
+		{"x!=", false, "", 0},
+		{"x !=", false, "", 0},
+		{" x  !=  ", false, "", 0},
+		{"x IN", false, "", 0},
+		{"x in", false, "", 0},
+		// Invalid ops.
+		{"x EQ", false, "", 0},
+		{"x lt", false, "", 0},
+		{"x <>", false, "", 0},
+		{"x >>", false, "", 0},
+		{"x ==", false, "", 0},
+		{"x =<", false, "", 0},
+		{"x =>", false, "", 0},
+		{"x !", false, "", 0},
+		{"x ", false, "", 0},
+		{"x", false, "", 0},
+	}
+	for _, tc := range testCases {
+		q := NewQuery("foo").Filter(tc.filterStr, 42)
+		if ok := q.err == nil; ok != tc.wantOK {
+			t.Errorf("%q: ok=%t, want %t", tc.filterStr, ok, tc.wantOK)
+			continue
+		}
+		if !tc.wantOK {
+			continue
+		}
+		if len(q.filter) != 1 {
+			t.Errorf("%q: len=%d, want %d", tc.filterStr, len(q.filter), 1)
+			continue
+		}
+		got, want := q.filter[0], filter{tc.wantFieldName, tc.wantOp, 42}
+		if got != want {
+			t.Errorf("%q: got %v, want %v", tc.filterStr, got, want)
+			continue
+		}
+	}
+}
+
+func TestQueryToProto(t *testing.T) {
+	// The context is required to make Keys for the test cases.
+	var got *pb.Query
+	NoErr := errors.New("No error")
+	c := aetesting.FakeSingleContext(t, "datastore_v3", "RunQuery", func(in *pb.Query, out *pb.QueryResult) error {
+		got = in
+		return NoErr // return a non-nil error so Run doesn't keep going.
+	})
+	c = internal.WithAppIDOverride(c, "dev~fake-app")
+
+	testCases := []struct {
+		desc  string
+		query *Query
+		want  *pb.Query
+		err   string
+	}{
+		{
+			desc:  "empty",
+			query: NewQuery(""),
+			want:  &pb.Query{},
+		},
+		{
+			desc:  "standard query",
+			query: NewQuery("kind").Order("-I").Filter("I >", 17).Filter("U =", "Dave").Limit(7).Offset(42).BatchSize(5),
+			want: &pb.Query{
+				Kind: proto.String("kind"),
+				Filter: []*pb.Query_Filter{
+					{
+						Op: pb.Query_Filter_GREATER_THAN.Enum(),
+						Property: []*pb.Property{
+							{
+								Name:     proto.String("I"),
+								Value:    &pb.PropertyValue{Int64Value: proto.Int64(17)},
+								Multiple: proto.Bool(false),
+							},
+						},
+					},
+					{
+						Op: pb.Query_Filter_EQUAL.Enum(),
+						Property: []*pb.Property{
+							{
+								Name:     proto.String("U"),
+								Value:    &pb.PropertyValue{StringValue: proto.String("Dave")},
+								Multiple: proto.Bool(false),
+							},
+						},
+					},
+				},
+				Order: []*pb.Query_Order{
+					{
+						Property:  proto.String("I"),
+						Direction: pb.Query_Order_DESCENDING.Enum(),
+					},
+				},
+				Limit:  proto.Int32(7),
+				Offset: proto.Int32(42),
+				Count:  proto.Int32(5),
+			},
+		},
+		{
+			desc:  "ancestor",
+			query: NewQuery("").Ancestor(NewKey(c, "kind", "Mummy", 0, nil)),
+			want: &pb.Query{
+				Ancestor: &pb.Reference{
+					App: proto.String("dev~fake-app"),
+					Path: &pb.Path{
+						Element: []*pb.Path_Element{{Type: proto.String("kind"), Name: proto.String("Mummy")}},
+					},
+				},
+			},
+		},
+		{
+			desc:  "projection",
+			query: NewQuery("").Project("A", "B"),
+			want: &pb.Query{
+				PropertyName: []string{"A", "B"},
+			},
+		},
+		{
+			desc:  "projection with distinct",
+			query: NewQuery("").Project("A", "B").Distinct(),
+			want: &pb.Query{
+				PropertyName:        []string{"A", "B"},
+				GroupByPropertyName: []string{"A", "B"},
+			},
+		},
+		{
+			desc:  "keys only",
+			query: NewQuery("").KeysOnly(),
+			want: &pb.Query{
+				KeysOnly:           proto.Bool(true),
+				RequirePerfectPlan: proto.Bool(true),
+			},
+		},
+		{
+			desc:  "empty filter",
+			query: NewQuery("kind").Filter("=", 17),
+			err:   "empty query filter field nam",
+		},
+		{
+			desc:  "bad filter type",
+			query: NewQuery("kind").Filter("M =", map[string]bool{}),
+			err:   "bad query filter value type",
+		},
+		{
+			desc:  "bad filter operator",
+			query: NewQuery("kind").Filter("I <<=", 17),
+			err:   `invalid operator "<<=" in filter "I <<="`,
+		},
+		{
+			desc:  "empty order",
+			query: NewQuery("kind").Order(""),
+			err:   "empty order",
+		},
+		{
+			desc:  "bad order direction",
+			query: NewQuery("kind").Order("+I"),
+			err:   `invalid order: "+I`,
+		},
+	}
+
+	for _, tt := range testCases {
+		got = nil
+		if _, err := tt.query.Run(c).Next(nil); err != NoErr {
+			if tt.err == "" || !strings.Contains(err.Error(), tt.err) {
+				t.Errorf("%s: error %v, want %q", tt.desc, err, tt.err)
+			}
+			continue
+		}
+		if tt.err != "" {
+			t.Errorf("%s: no error, want %q", tt.desc, tt.err)
+			continue
+		}
+		// Fields that are common to all protos.
+		tt.want.App = proto.String("dev~fake-app")
+		tt.want.Compile = proto.Bool(true)
+		if !proto.Equal(got, tt.want) {
+			t.Errorf("%s:\ngot  %v\nwant %v", tt.desc, got, tt.want)
+		}
+	}
+}

vendor/google.golang.org/appengine/datastore/save.go

@@ -0,0 +1,333 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"reflect"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+
+	"google.golang.org/appengine"
+	pb "google.golang.org/appengine/internal/datastore"
+)
+
+func toUnixMicro(t time.Time) int64 {
+	// We cannot use t.UnixNano() / 1e3 because we want to handle times more than
+	// 2^63 nanoseconds (which is about 292 years) away from 1970, and those cannot
+	// be represented in the numerator of a single int64 divide.
+	return t.Unix()*1e6 + int64(t.Nanosecond()/1e3)
+}
+
+func fromUnixMicro(t int64) time.Time {
+	return time.Unix(t/1e6, (t%1e6)*1e3).UTC()
+}
+
+var (
+	minTime = time.Unix(int64(math.MinInt64)/1e6, (int64(math.MinInt64)%1e6)*1e3)
+	maxTime = time.Unix(int64(math.MaxInt64)/1e6, (int64(math.MaxInt64)%1e6)*1e3)
+)
+
+// valueToProto converts a named value to a newly allocated Property.
+// The returned error string is empty on success.
+func valueToProto(defaultAppID, name string, v reflect.Value, multiple bool) (p *pb.Property, errStr string) {
+	var (
+		pv          pb.PropertyValue
+		unsupported bool
+	)
+	switch v.Kind() {
+	case reflect.Invalid:
+		// No-op.
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		pv.Int64Value = proto.Int64(v.Int())
+	case reflect.Bool:
+		pv.BooleanValue = proto.Bool(v.Bool())
+	case reflect.String:
+		pv.StringValue = proto.String(v.String())
+	case reflect.Float32, reflect.Float64:
+		pv.DoubleValue = proto.Float64(v.Float())
+	case reflect.Ptr:
+		if k, ok := v.Interface().(*Key); ok {
+			if k != nil {
+				pv.Referencevalue = keyToReferenceValue(defaultAppID, k)
+			}
+		} else {
+			unsupported = true
+		}
+	case reflect.Struct:
+		switch t := v.Interface().(type) {
+		case time.Time:
+			if t.Before(minTime) || t.After(maxTime) {
+				return nil, "time value out of range"
+			}
+			pv.Int64Value = proto.Int64(toUnixMicro(t))
+		case appengine.GeoPoint:
+			if !t.Valid() {
+				return nil, "invalid GeoPoint value"
+			}
+			// NOTE: Strangely, latitude maps to X, longitude to Y.
+			pv.Pointvalue = &pb.PropertyValue_PointValue{X: &t.Lat, Y: &t.Lng}
+		default:
+			unsupported = true
+		}
+	case reflect.Slice:
+		if b, ok := v.Interface().([]byte); ok {
+			pv.StringValue = proto.String(string(b))
+		} else {
+			// nvToProto should already catch slice values.
+			// If we get here, we have a slice of slice values.
+			unsupported = true
+		}
+	default:
+		unsupported = true
+	}
+	if unsupported {
+		return nil, "unsupported datastore value type: " + v.Type().String()
+	}
+	p = &pb.Property{
+		Name:     proto.String(name),
+		Value:    &pv,
+		Multiple: proto.Bool(multiple),
+	}
+	if v.IsValid() {
+		switch v.Interface().(type) {
+		case []byte:
+			p.Meaning = pb.Property_BLOB.Enum()
+		case ByteString:
+			p.Meaning = pb.Property_BYTESTRING.Enum()
+		case appengine.BlobKey:
+			p.Meaning = pb.Property_BLOBKEY.Enum()
+		case time.Time:
+			p.Meaning = pb.Property_GD_WHEN.Enum()
+		case appengine.GeoPoint:
+			p.Meaning = pb.Property_GEORSS_POINT.Enum()
+		}
+	}
+	return p, ""
+}
+
+type saveOpts struct {
+	noIndex   bool
+	multiple  bool
+	omitEmpty bool
+}
+
+// saveEntity saves an EntityProto into a PropertyLoadSaver or struct pointer.
+func saveEntity(defaultAppID string, key *Key, src interface{}) (*pb.EntityProto, error) {
+	var err error
+	var props []Property
+	if e, ok := src.(PropertyLoadSaver); ok {
+		props, err = e.Save()
+	} else {
+		props, err = SaveStruct(src)
+	}
+	if err != nil {
+		return nil, err
+	}
+	return propertiesToProto(defaultAppID, key, props)
+}
+
+func saveStructProperty(props *[]Property, name string, opts saveOpts, v reflect.Value) error {
+	if opts.omitEmpty && isEmptyValue(v) {
+		return nil
+	}
+	p := Property{
+		Name:     name,
+		NoIndex:  opts.noIndex,
+		Multiple: opts.multiple,
+	}
+	switch x := v.Interface().(type) {
+	case *Key:
+		p.Value = x
+	case time.Time:
+		p.Value = x
+	case appengine.BlobKey:
+		p.Value = x
+	case appengine.GeoPoint:
+		p.Value = x
+	case ByteString:
+		p.Value = x
+	default:
+		switch v.Kind() {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			p.Value = v.Int()
+		case reflect.Bool:
+			p.Value = v.Bool()
+		case reflect.String:
+			p.Value = v.String()
+		case reflect.Float32, reflect.Float64:
+			p.Value = v.Float()
+		case reflect.Slice:
+			if v.Type().Elem().Kind() == reflect.Uint8 {
+				p.NoIndex = true
+				p.Value = v.Bytes()
+			}
+		case reflect.Struct:
+			if !v.CanAddr() {
+				return fmt.Errorf("datastore: unsupported struct field: value is unaddressable")
+			}
+			sub, err := newStructPLS(v.Addr().Interface())
+			if err != nil {
+				return fmt.Errorf("datastore: unsupported struct field: %v", err)
+			}
+			return sub.save(props, name+".", opts)
+		}
+	}
+	if p.Value == nil {
+		return fmt.Errorf("datastore: unsupported struct field type: %v", v.Type())
+	}
+	*props = append(*props, p)
+	return nil
+}
+
+func (s structPLS) Save() ([]Property, error) {
+	var props []Property
+	if err := s.save(&props, "", saveOpts{}); err != nil {
+		return nil, err
+	}
+	return props, nil
+}
+
+func (s structPLS) save(props *[]Property, prefix string, opts saveOpts) error {
+	for name, f := range s.codec.fields {
+		name = prefix + name
+		v := s.v.FieldByIndex(f.path)
+		if !v.IsValid() || !v.CanSet() {
+			continue
+		}
+		var opts1 saveOpts
+		opts1.noIndex = opts.noIndex || f.noIndex
+		opts1.multiple = opts.multiple
+		opts1.omitEmpty = f.omitEmpty // don't propagate
+		// For slice fields that aren't []byte, save each element.
+		if v.Kind() == reflect.Slice && v.Type().Elem().Kind() != reflect.Uint8 {
+			opts1.multiple = true
+			for j := 0; j < v.Len(); j++ {
+				if err := saveStructProperty(props, name, opts1, v.Index(j)); err != nil {
+					return err
+				}
+			}
+			continue
+		}
+		// Otherwise, save the field itself.
+		if err := saveStructProperty(props, name, opts1, v); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func propertiesToProto(defaultAppID string, key *Key, props []Property) (*pb.EntityProto, error) {
+	e := &pb.EntityProto{
+		Key: keyToProto(defaultAppID, key),
+	}
+	if key.parent == nil {
+		e.EntityGroup = &pb.Path{}
+	} else {
+		e.EntityGroup = keyToProto(defaultAppID, key.root()).Path
+	}
+	prevMultiple := make(map[string]bool)
+
+	for _, p := range props {
+		if pm, ok := prevMultiple[p.Name]; ok {
+			if !pm || !p.Multiple {
+				return nil, fmt.Errorf("datastore: multiple Properties with Name %q, but Multiple is false", p.Name)
+			}
+		} else {
+			prevMultiple[p.Name] = p.Multiple
+		}
+
+		x := &pb.Property{
+			Name:     proto.String(p.Name),
+			Value:    new(pb.PropertyValue),
+			Multiple: proto.Bool(p.Multiple),
+		}
+		switch v := p.Value.(type) {
+		case int64:
+			x.Value.Int64Value = proto.Int64(v)
+		case bool:
+			x.Value.BooleanValue = proto.Bool(v)
+		case string:
+			x.Value.StringValue = proto.String(v)
+			if p.NoIndex {
+				x.Meaning = pb.Property_TEXT.Enum()
+			}
+		case float64:
+			x.Value.DoubleValue = proto.Float64(v)
+		case *Key:
+			if v != nil {
+				x.Value.Referencevalue = keyToReferenceValue(defaultAppID, v)
+			}
+		case time.Time:
+			if v.Before(minTime) || v.After(maxTime) {
+				return nil, fmt.Errorf("datastore: time value out of range")
+			}
+			x.Value.Int64Value = proto.Int64(toUnixMicro(v))
+			x.Meaning = pb.Property_GD_WHEN.Enum()
+		case appengine.BlobKey:
+			x.Value.StringValue = proto.String(string(v))
+			x.Meaning = pb.Property_BLOBKEY.Enum()
+		case appengine.GeoPoint:
+			if !v.Valid() {
+				return nil, fmt.Errorf("datastore: invalid GeoPoint value")
+			}
+			// NOTE: Strangely, latitude maps to X, longitude to Y.
+			x.Value.Pointvalue = &pb.PropertyValue_PointValue{X: &v.Lat, Y: &v.Lng}
+			x.Meaning = pb.Property_GEORSS_POINT.Enum()
+		case []byte:
+			x.Value.StringValue = proto.String(string(v))
+			x.Meaning = pb.Property_BLOB.Enum()
+			if !p.NoIndex {
+				return nil, fmt.Errorf("datastore: cannot index a []byte valued Property with Name %q", p.Name)
+			}
+		case ByteString:
+			x.Value.StringValue = proto.String(string(v))
+			x.Meaning = pb.Property_BYTESTRING.Enum()
+		default:
+			if p.Value != nil {
+				return nil, fmt.Errorf("datastore: invalid Value type for a Property with Name %q", p.Name)
+			}
+		}
+
+		if p.NoIndex {
+			e.RawProperty = append(e.RawProperty, x)
+		} else {
+			e.Property = append(e.Property, x)
+			if len(e.Property) > maxIndexedProperties {
+				return nil, errors.New("datastore: too many indexed properties")
+			}
+		}
+	}
+	return e, nil
+}
+
+// isEmptyValue is taken from the encoding/json package in the standard library.
+func isEmptyValue(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+		// TODO(perfomance): Only reflect.String needed, other property types are not supported (copy/paste from json package)
+		return v.Len() == 0
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		// TODO(perfomance): Uint* are unsupported property types - should be removed (copy/paste from json package)
+		return v.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.Interface, reflect.Ptr:
+		return v.IsNil()
+	case reflect.Struct:
+		switch x := v.Interface().(type) {
+		case time.Time:
+			return x.IsZero()
+		}
+	}
+	return false
+}

vendor/google.golang.org/appengine/datastore/time_test.go

@@ -0,0 +1,65 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"testing"
+	"time"
+)
+
+func TestUnixMicro(t *testing.T) {
+	// Test that all these time.Time values survive a round trip to unix micros.
+	testCases := []time.Time{
+		{},
+		time.Date(2, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(23, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(234, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1000, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1600, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1700, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1800, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Unix(-1e6, -1000),
+		time.Unix(-1e6, 0),
+		time.Unix(-1e6, +1000),
+		time.Unix(-60, -1000),
+		time.Unix(-60, 0),
+		time.Unix(-60, +1000),
+		time.Unix(-1, -1000),
+		time.Unix(-1, 0),
+		time.Unix(-1, +1000),
+		time.Unix(0, -3000),
+		time.Unix(0, -2000),
+		time.Unix(0, -1000),
+		time.Unix(0, 0),
+		time.Unix(0, +1000),
+		time.Unix(0, +2000),
+		time.Unix(+60, -1000),
+		time.Unix(+60, 0),
+		time.Unix(+60, +1000),
+		time.Unix(+1e6, -1000),
+		time.Unix(+1e6, 0),
+		time.Unix(+1e6, +1000),
+		time.Date(1999, 12, 31, 23, 59, 59, 999000, time.UTC),
+		time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC),
+		time.Date(2006, 1, 2, 15, 4, 5, 678000, time.UTC),
+		time.Date(2009, 11, 10, 23, 0, 0, 0, time.UTC),
+		time.Date(3456, 1, 1, 0, 0, 0, 0, time.UTC),
+	}
+	for _, tc := range testCases {
+		got := fromUnixMicro(toUnixMicro(tc))
+		if !got.Equal(tc) {
+			t.Errorf("got %q, want %q", got, tc)
+		}
+	}
+
+	// Test that a time.Time that isn't an integral number of microseconds
+	// is not perfectly reconstructed after a round trip.
+	t0 := time.Unix(0, 123)
+	t1 := fromUnixMicro(toUnixMicro(t0))
+	if t1.Nanosecond()%1000 != 0 || t0.Nanosecond()%1000 == 0 {
+		t.Errorf("quantization to µs: got %q with %d ns, started with %d ns", t1, t1.Nanosecond(), t0.Nanosecond())
+	}
+}

vendor/google.golang.org/appengine/datastore/transaction.go

@@ -0,0 +1,96 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"errors"
+
+	"golang.org/x/net/context"
+
+	"google.golang.org/appengine/internal"
+	pb "google.golang.org/appengine/internal/datastore"
+)
+
+func init() {
+	internal.RegisterTransactionSetter(func(x *pb.Query, t *pb.Transaction) {
+		x.Transaction = t
+	})
+	internal.RegisterTransactionSetter(func(x *pb.GetRequest, t *pb.Transaction) {
+		x.Transaction = t
+	})
+	internal.RegisterTransactionSetter(func(x *pb.PutRequest, t *pb.Transaction) {
+		x.Transaction = t
+	})
+	internal.RegisterTransactionSetter(func(x *pb.DeleteRequest, t *pb.Transaction) {
+		x.Transaction = t
+	})
+}
+
+// ErrConcurrentTransaction is returned when a transaction is rolled back due
+// to a conflict with a concurrent transaction.
+var ErrConcurrentTransaction = errors.New("datastore: concurrent transaction")
+
+// RunInTransaction runs f in a transaction. It calls f with a transaction
+// context tc that f should use for all App Engine operations.
+//
+// If f returns nil, RunInTransaction attempts to commit the transaction,
+// returning nil if it succeeds. If the commit fails due to a conflicting
+// transaction, RunInTransaction retries f, each time with a new transaction
+// context. It gives up and returns ErrConcurrentTransaction after three
+// failed attempts. The number of attempts can be configured by specifying
+// TransactionOptions.Attempts.
+//
+// If f returns non-nil, then any datastore changes will not be applied and
+// RunInTransaction returns that same error. The function f is not retried.
+//
+// Note that when f returns, the transaction is not yet committed. Calling code
+// must be careful not to assume that any of f's changes have been committed
+// until RunInTransaction returns nil.
+//
+// Since f may be called multiple times, f should usually be idempotent.
+// datastore.Get is not idempotent when unmarshaling slice fields.
+//
+// Nested transactions are not supported; c may not be a transaction context.
+func RunInTransaction(c context.Context, f func(tc context.Context) error, opts *TransactionOptions) error {
+	xg := false
+	if opts != nil {
+		xg = opts.XG
+	}
+	readOnly := false
+	if opts != nil {
+		readOnly = opts.ReadOnly
+	}
+	attempts := 3
+	if opts != nil && opts.Attempts > 0 {
+		attempts = opts.Attempts
+	}
+	var t *pb.Transaction
+	var err error
+	for i := 0; i < attempts; i++ {
+		if t, err = internal.RunTransactionOnce(c, f, xg, readOnly, t); err != internal.ErrConcurrentTransaction {
+			return err
+		}
+	}
+	return ErrConcurrentTransaction
+}
+
+// TransactionOptions are the options for running a transaction.
+type TransactionOptions struct {
+	// XG is whether the transaction can cross multiple entity groups. In
+	// comparison, a single group transaction is one where all datastore keys
+	// used have the same root key. Note that cross group transactions do not
+	// have the same behavior as single group transactions. In particular, it
+	// is much more likely to see partially applied transactions in different
+	// entity groups, in global queries.
+	// It is valid to set XG to true even if the transaction is within a
+	// single entity group.
+	XG bool
+	// Attempts controls the number of retries to perform when commits fail
+	// due to a conflicting transaction. If omitted, it defaults to 3.
+	Attempts int
+	// ReadOnly controls whether the transaction is a read only transaction.
+	// Read only transactions are potentially more efficient.
+	ReadOnly bool
+}