vendor files

vendor/k8s.io/apimachinery/pkg/util/yaml/decoder.go

@@ -0,0 +1,346 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+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 yaml
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"strings"
+	"unicode"
+
+	"github.com/ghodss/yaml"
+	"github.com/golang/glog"
+)
+
+// ToJSON converts a single YAML document into a JSON document
+// or returns an error. If the document appears to be JSON the
+// YAML decoding path is not used (so that error messages are
+// JSON specific).
+func ToJSON(data []byte) ([]byte, error) {
+	if hasJSONPrefix(data) {
+		return data, nil
+	}
+	return yaml.YAMLToJSON(data)
+}
+
+// YAMLToJSONDecoder decodes YAML documents from an io.Reader by
+// separating individual documents. It first converts the YAML
+// body to JSON, then unmarshals the JSON.
+type YAMLToJSONDecoder struct {
+	reader Reader
+}
+
+// NewYAMLToJSONDecoder decodes YAML documents from the provided
+// stream in chunks by converting each document (as defined by
+// the YAML spec) into its own chunk, converting it to JSON via
+// yaml.YAMLToJSON, and then passing it to json.Decoder.
+func NewYAMLToJSONDecoder(r io.Reader) *YAMLToJSONDecoder {
+	reader := bufio.NewReader(r)
+	return &YAMLToJSONDecoder{
+		reader: NewYAMLReader(reader),
+	}
+}
+
+// Decode reads a YAML document as JSON from the stream or returns
+// an error. The decoding rules match json.Unmarshal, not
+// yaml.Unmarshal.
+func (d *YAMLToJSONDecoder) Decode(into interface{}) error {
+	bytes, err := d.reader.Read()
+	if err != nil && err != io.EOF {
+		return err
+	}
+
+	if len(bytes) != 0 {
+		err := yaml.Unmarshal(bytes, into)
+		if err != nil {
+			return YAMLSyntaxError{err}
+		}
+	}
+	return err
+}
+
+// YAMLDecoder reads chunks of objects and returns ErrShortBuffer if
+// the data is not sufficient.
+type YAMLDecoder struct {
+	r         io.ReadCloser
+	scanner   *bufio.Scanner
+	remaining []byte
+}
+
+// NewDocumentDecoder decodes YAML documents from the provided
+// stream in chunks by converting each document (as defined by
+// the YAML spec) into its own chunk. io.ErrShortBuffer will be
+// returned if the entire buffer could not be read to assist
+// the caller in framing the chunk.
+func NewDocumentDecoder(r io.ReadCloser) io.ReadCloser {
+	scanner := bufio.NewScanner(r)
+	scanner.Split(splitYAMLDocument)
+	return &YAMLDecoder{
+		r:       r,
+		scanner: scanner,
+	}
+}
+
+// Read reads the previous slice into the buffer, or attempts to read
+// the next chunk.
+// TODO: switch to readline approach.
+func (d *YAMLDecoder) Read(data []byte) (n int, err error) {
+	left := len(d.remaining)
+	if left == 0 {
+		// return the next chunk from the stream
+		if !d.scanner.Scan() {
+			err := d.scanner.Err()
+			if err == nil {
+				err = io.EOF
+			}
+			return 0, err
+		}
+		out := d.scanner.Bytes()
+		d.remaining = out
+		left = len(out)
+	}
+
+	// fits within data
+	if left <= len(data) {
+		copy(data, d.remaining)
+		d.remaining = nil
+		return len(d.remaining), nil
+	}
+
+	// caller will need to reread
+	copy(data, d.remaining[:left])
+	d.remaining = d.remaining[left:]
+	return len(data), io.ErrShortBuffer
+}
+
+func (d *YAMLDecoder) Close() error {
+	return d.r.Close()
+}
+
+const yamlSeparator = "\n---"
+const separator = "---"
+
+// splitYAMLDocument is a bufio.SplitFunc for splitting YAML streams into individual documents.
+func splitYAMLDocument(data []byte, atEOF bool) (advance int, token []byte, err error) {
+	if atEOF && len(data) == 0 {
+		return 0, nil, nil
+	}
+	sep := len([]byte(yamlSeparator))
+	if i := bytes.Index(data, []byte(yamlSeparator)); i >= 0 {
+		// We have a potential document terminator
+		i += sep
+		after := data[i:]
+		if len(after) == 0 {
+			// we can't read any more characters
+			if atEOF {
+				return len(data), data[:len(data)-sep], nil
+			}
+			return 0, nil, nil
+		}
+		if j := bytes.IndexByte(after, '\n'); j >= 0 {
+			return i + j + 1, data[0 : i-sep], nil
+		}
+		return 0, nil, nil
+	}
+	// If we're at EOF, we have a final, non-terminated line. Return it.
+	if atEOF {
+		return len(data), data, nil
+	}
+	// Request more data.
+	return 0, nil, nil
+}
+
+// decoder is a convenience interface for Decode.
+type decoder interface {
+	Decode(into interface{}) error
+}
+
+// YAMLOrJSONDecoder attempts to decode a stream of JSON documents or
+// YAML documents by sniffing for a leading { character.
+type YAMLOrJSONDecoder struct {
+	r          io.Reader
+	bufferSize int
+
+	decoder decoder
+	rawData []byte
+}
+
+type JSONSyntaxError struct {
+	Line int
+	Err  error
+}
+
+func (e JSONSyntaxError) Error() string {
+	return fmt.Sprintf("json: line %d: %s", e.Line, e.Err.Error())
+}
+
+type YAMLSyntaxError struct {
+	err error
+}
+
+func (e YAMLSyntaxError) Error() string {
+	return e.err.Error()
+}
+
+// NewYAMLOrJSONDecoder returns a decoder that will process YAML documents
+// or JSON documents from the given reader as a stream. bufferSize determines
+// how far into the stream the decoder will look to figure out whether this
+// is a JSON stream (has whitespace followed by an open brace).
+func NewYAMLOrJSONDecoder(r io.Reader, bufferSize int) *YAMLOrJSONDecoder {
+	return &YAMLOrJSONDecoder{
+		r:          r,
+		bufferSize: bufferSize,
+	}
+}
+
+// Decode unmarshals the next object from the underlying stream into the
+// provide object, or returns an error.
+func (d *YAMLOrJSONDecoder) Decode(into interface{}) error {
+	if d.decoder == nil {
+		buffer, origData, isJSON := GuessJSONStream(d.r, d.bufferSize)
+		if isJSON {
+			glog.V(4).Infof("decoding stream as JSON")
+			d.decoder = json.NewDecoder(buffer)
+			d.rawData = origData
+		} else {
+			glog.V(4).Infof("decoding stream as YAML")
+			d.decoder = NewYAMLToJSONDecoder(buffer)
+		}
+	}
+	err := d.decoder.Decode(into)
+	if jsonDecoder, ok := d.decoder.(*json.Decoder); ok {
+		if syntax, ok := err.(*json.SyntaxError); ok {
+			data, readErr := ioutil.ReadAll(jsonDecoder.Buffered())
+			if readErr != nil {
+				glog.V(4).Infof("reading stream failed: %v", readErr)
+			}
+			js := string(data)
+
+			// if contents from io.Reader are not complete,
+			// use the original raw data to prevent panic
+			if int64(len(js)) <= syntax.Offset {
+				js = string(d.rawData)
+			}
+
+			start := strings.LastIndex(js[:syntax.Offset], "\n") + 1
+			line := strings.Count(js[:start], "\n")
+			return JSONSyntaxError{
+				Line: line,
+				Err:  fmt.Errorf(syntax.Error()),
+			}
+		}
+	}
+	return err
+}
+
+type Reader interface {
+	Read() ([]byte, error)
+}
+
+type YAMLReader struct {
+	reader Reader
+}
+
+func NewYAMLReader(r *bufio.Reader) *YAMLReader {
+	return &YAMLReader{
+		reader: &LineReader{reader: r},
+	}
+}
+
+// Read returns a full YAML document.
+func (r *YAMLReader) Read() ([]byte, error) {
+	var buffer bytes.Buffer
+	for {
+		line, err := r.reader.Read()
+		if err != nil && err != io.EOF {
+			return nil, err
+		}
+
+		sep := len([]byte(separator))
+		if i := bytes.Index(line, []byte(separator)); i == 0 {
+			// We have a potential document terminator
+			i += sep
+			after := line[i:]
+			if len(strings.TrimRightFunc(string(after), unicode.IsSpace)) == 0 {
+				if buffer.Len() != 0 {
+					return buffer.Bytes(), nil
+				}
+				if err == io.EOF {
+					return nil, err
+				}
+			}
+		}
+		if err == io.EOF {
+			if buffer.Len() != 0 {
+				// If we're at EOF, we have a final, non-terminated line. Return it.
+				return buffer.Bytes(), nil
+			}
+			return nil, err
+		}
+		buffer.Write(line)
+	}
+}
+
+type LineReader struct {
+	reader *bufio.Reader
+}
+
+// Read returns a single line (with '\n' ended) from the underlying reader.
+// An error is returned iff there is an error with the underlying reader.
+func (r *LineReader) Read() ([]byte, error) {
+	var (
+		isPrefix bool  = true
+		err      error = nil
+		line     []byte
+		buffer   bytes.Buffer
+	)
+
+	for isPrefix && err == nil {
+		line, isPrefix, err = r.reader.ReadLine()
+		buffer.Write(line)
+	}
+	buffer.WriteByte('\n')
+	return buffer.Bytes(), err
+}
+
+// GuessJSONStream scans the provided reader up to size, looking
+// for an open brace indicating this is JSON. It will return the
+// bufio.Reader it creates for the consumer.
+func GuessJSONStream(r io.Reader, size int) (io.Reader, []byte, bool) {
+	buffer := bufio.NewReaderSize(r, size)
+	b, _ := buffer.Peek(size)
+	return buffer, b, hasJSONPrefix(b)
+}
+
+var jsonPrefix = []byte("{")
+
+// hasJSONPrefix returns true if the provided buffer appears to start with
+// a JSON open brace.
+func hasJSONPrefix(buf []byte) bool {
+	return hasPrefix(buf, jsonPrefix)
+}
+
+// Return true if the first non-whitespace bytes in buf is
+// prefix.
+func hasPrefix(buf []byte, prefix []byte) bool {
+	trim := bytes.TrimLeftFunc(buf, unicode.IsSpace)
+	return bytes.HasPrefix(trim, prefix)
+}