ceph-csi/vendor/github.com/google/cel-go/cel/io.go

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// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package cel
import (
"errors"
"fmt"
"reflect"
"google.golang.org/protobuf/proto"
"github.com/google/cel-go/common"
"github.com/google/cel-go/common/ast"
"github.com/google/cel-go/common/types"
"github.com/google/cel-go/common/types/ref"
"github.com/google/cel-go/common/types/traits"
"github.com/google/cel-go/parser"
exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
anypb "google.golang.org/protobuf/types/known/anypb"
)
// CheckedExprToAst converts a checked expression proto message to an Ast.
func CheckedExprToAst(checkedExpr *exprpb.CheckedExpr) *Ast {
checked, _ := CheckedExprToAstWithSource(checkedExpr, nil)
return checked
}
// CheckedExprToAstWithSource converts a checked expression proto message to an Ast,
// using the provided Source as the textual contents.
//
// In general the source is not necessary unless the AST has been modified between the
// `Parse` and `Check` calls as an `Ast` created from the `Parse` step will carry the source
// through future calls.
//
// Prefer CheckedExprToAst if loading expressions from storage.
func CheckedExprToAstWithSource(checkedExpr *exprpb.CheckedExpr, src Source) (*Ast, error) {
checkedAST, err := ast.CheckedExprToCheckedAST(checkedExpr)
if err != nil {
return nil, err
}
return &Ast{
expr: checkedAST.Expr,
info: checkedAST.SourceInfo,
source: src,
refMap: checkedAST.ReferenceMap,
typeMap: checkedAST.TypeMap,
}, nil
}
// AstToCheckedExpr converts an Ast to an protobuf CheckedExpr value.
//
// If the Ast.IsChecked() returns false, this conversion method will return an error.
func AstToCheckedExpr(a *Ast) (*exprpb.CheckedExpr, error) {
if !a.IsChecked() {
return nil, fmt.Errorf("cannot convert unchecked ast")
}
cAst := &ast.CheckedAST{
Expr: a.expr,
SourceInfo: a.info,
ReferenceMap: a.refMap,
TypeMap: a.typeMap,
}
return ast.CheckedASTToCheckedExpr(cAst)
}
// ParsedExprToAst converts a parsed expression proto message to an Ast.
func ParsedExprToAst(parsedExpr *exprpb.ParsedExpr) *Ast {
return ParsedExprToAstWithSource(parsedExpr, nil)
}
// ParsedExprToAstWithSource converts a parsed expression proto message to an Ast,
// using the provided Source as the textual contents.
//
// In general you only need this if you need to recheck a previously checked
// expression, or if you need to separately check a subset of an expression.
//
// Prefer ParsedExprToAst if loading expressions from storage.
func ParsedExprToAstWithSource(parsedExpr *exprpb.ParsedExpr, src Source) *Ast {
si := parsedExpr.GetSourceInfo()
if si == nil {
si = &exprpb.SourceInfo{}
}
if src == nil {
src = common.NewInfoSource(si)
}
return &Ast{
expr: parsedExpr.GetExpr(),
info: si,
source: src,
}
}
// AstToParsedExpr converts an Ast to an protobuf ParsedExpr value.
func AstToParsedExpr(a *Ast) (*exprpb.ParsedExpr, error) {
return &exprpb.ParsedExpr{
Expr: a.Expr(),
SourceInfo: a.SourceInfo(),
}, nil
}
// AstToString converts an Ast back to a string if possible.
//
// Note, the conversion may not be an exact replica of the original expression, but will produce
// a string that is semantically equivalent and whose textual representation is stable.
func AstToString(a *Ast) (string, error) {
expr := a.Expr()
info := a.SourceInfo()
return parser.Unparse(expr, info)
}
// RefValueToValue converts between ref.Val and api.expr.Value.
// The result Value is the serialized proto form. The ref.Val must not be error or unknown.
func RefValueToValue(res ref.Val) (*exprpb.Value, error) {
switch res.Type() {
case types.BoolType:
return &exprpb.Value{
Kind: &exprpb.Value_BoolValue{BoolValue: res.Value().(bool)}}, nil
case types.BytesType:
return &exprpb.Value{
Kind: &exprpb.Value_BytesValue{BytesValue: res.Value().([]byte)}}, nil
case types.DoubleType:
return &exprpb.Value{
Kind: &exprpb.Value_DoubleValue{DoubleValue: res.Value().(float64)}}, nil
case types.IntType:
return &exprpb.Value{
Kind: &exprpb.Value_Int64Value{Int64Value: res.Value().(int64)}}, nil
case types.ListType:
l := res.(traits.Lister)
sz := l.Size().(types.Int)
elts := make([]*exprpb.Value, 0, int64(sz))
for i := types.Int(0); i < sz; i++ {
v, err := RefValueToValue(l.Get(i))
if err != nil {
return nil, err
}
elts = append(elts, v)
}
return &exprpb.Value{
Kind: &exprpb.Value_ListValue{
ListValue: &exprpb.ListValue{Values: elts}}}, nil
case types.MapType:
mapper := res.(traits.Mapper)
sz := mapper.Size().(types.Int)
entries := make([]*exprpb.MapValue_Entry, 0, int64(sz))
for it := mapper.Iterator(); it.HasNext().(types.Bool); {
k := it.Next()
v := mapper.Get(k)
kv, err := RefValueToValue(k)
if err != nil {
return nil, err
}
vv, err := RefValueToValue(v)
if err != nil {
return nil, err
}
entries = append(entries, &exprpb.MapValue_Entry{Key: kv, Value: vv})
}
return &exprpb.Value{
Kind: &exprpb.Value_MapValue{
MapValue: &exprpb.MapValue{Entries: entries}}}, nil
case types.NullType:
return &exprpb.Value{
Kind: &exprpb.Value_NullValue{}}, nil
case types.StringType:
return &exprpb.Value{
Kind: &exprpb.Value_StringValue{StringValue: res.Value().(string)}}, nil
case types.TypeType:
typeName := res.(ref.Type).TypeName()
return &exprpb.Value{Kind: &exprpb.Value_TypeValue{TypeValue: typeName}}, nil
case types.UintType:
return &exprpb.Value{
Kind: &exprpb.Value_Uint64Value{Uint64Value: res.Value().(uint64)}}, nil
default:
any, err := res.ConvertToNative(anyPbType)
if err != nil {
return nil, err
}
return &exprpb.Value{
Kind: &exprpb.Value_ObjectValue{ObjectValue: any.(*anypb.Any)}}, nil
}
}
var (
typeNameToTypeValue = map[string]ref.Val{
"bool": types.BoolType,
"bytes": types.BytesType,
"double": types.DoubleType,
"null_type": types.NullType,
"int": types.IntType,
"list": types.ListType,
"map": types.MapType,
"string": types.StringType,
"type": types.TypeType,
"uint": types.UintType,
}
anyPbType = reflect.TypeOf(&anypb.Any{})
)
// ValueToRefValue converts between exprpb.Value and ref.Val.
func ValueToRefValue(adapter types.Adapter, v *exprpb.Value) (ref.Val, error) {
switch v.Kind.(type) {
case *exprpb.Value_NullValue:
return types.NullValue, nil
case *exprpb.Value_BoolValue:
return types.Bool(v.GetBoolValue()), nil
case *exprpb.Value_Int64Value:
return types.Int(v.GetInt64Value()), nil
case *exprpb.Value_Uint64Value:
return types.Uint(v.GetUint64Value()), nil
case *exprpb.Value_DoubleValue:
return types.Double(v.GetDoubleValue()), nil
case *exprpb.Value_StringValue:
return types.String(v.GetStringValue()), nil
case *exprpb.Value_BytesValue:
return types.Bytes(v.GetBytesValue()), nil
case *exprpb.Value_ObjectValue:
any := v.GetObjectValue()
msg, err := anypb.UnmarshalNew(any, proto.UnmarshalOptions{DiscardUnknown: true})
if err != nil {
return nil, err
}
return adapter.NativeToValue(msg), nil
case *exprpb.Value_MapValue:
m := v.GetMapValue()
entries := make(map[ref.Val]ref.Val)
for _, entry := range m.Entries {
key, err := ValueToRefValue(adapter, entry.Key)
if err != nil {
return nil, err
}
pb, err := ValueToRefValue(adapter, entry.Value)
if err != nil {
return nil, err
}
entries[key] = pb
}
return adapter.NativeToValue(entries), nil
case *exprpb.Value_ListValue:
l := v.GetListValue()
elts := make([]ref.Val, len(l.Values))
for i, e := range l.Values {
rv, err := ValueToRefValue(adapter, e)
if err != nil {
return nil, err
}
elts[i] = rv
}
return adapter.NativeToValue(elts), nil
case *exprpb.Value_TypeValue:
typeName := v.GetTypeValue()
tv, ok := typeNameToTypeValue[typeName]
if ok {
return tv, nil
}
return types.NewObjectTypeValue(typeName), nil
}
return nil, errors.New("unknown value")
}