kilo/vendor/github.com/json-iterator/go/stream.go

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package jsoniter
import (
"io"
)
// stream is a io.Writer like object, with JSON specific write functions.
// Error is not returned as return value, but stored as Error member on this stream instance.
type Stream struct {
cfg *frozenConfig
out io.Writer
buf []byte
Error error
indention int
Attachment interface{} // open for customized encoder
}
// NewStream create new stream instance.
// cfg can be jsoniter.ConfigDefault.
// out can be nil if write to internal buffer.
// bufSize is the initial size for the internal buffer in bytes.
func NewStream(cfg API, out io.Writer, bufSize int) *Stream {
return &Stream{
cfg: cfg.(*frozenConfig),
out: out,
buf: make([]byte, 0, bufSize),
Error: nil,
indention: 0,
}
}
// Pool returns a pool can provide more stream with same configuration
func (stream *Stream) Pool() StreamPool {
return stream.cfg
}
// Reset reuse this stream instance by assign a new writer
func (stream *Stream) Reset(out io.Writer) {
stream.out = out
stream.buf = stream.buf[:0]
}
// Available returns how many bytes are unused in the buffer.
func (stream *Stream) Available() int {
return cap(stream.buf) - len(stream.buf)
}
// Buffered returns the number of bytes that have been written into the current buffer.
func (stream *Stream) Buffered() int {
return len(stream.buf)
}
// Buffer if writer is nil, use this method to take the result
func (stream *Stream) Buffer() []byte {
return stream.buf
}
// SetBuffer allows to append to the internal buffer directly
func (stream *Stream) SetBuffer(buf []byte) {
stream.buf = buf
}
// Write writes the contents of p into the buffer.
// It returns the number of bytes written.
// If nn < len(p), it also returns an error explaining
// why the write is short.
func (stream *Stream) Write(p []byte) (nn int, err error) {
stream.buf = append(stream.buf, p...)
if stream.out != nil {
nn, err = stream.out.Write(stream.buf)
stream.buf = stream.buf[nn:]
return
}
return len(p), nil
}
// WriteByte writes a single byte.
func (stream *Stream) writeByte(c byte) {
stream.buf = append(stream.buf, c)
}
func (stream *Stream) writeTwoBytes(c1 byte, c2 byte) {
stream.buf = append(stream.buf, c1, c2)
}
func (stream *Stream) writeThreeBytes(c1 byte, c2 byte, c3 byte) {
stream.buf = append(stream.buf, c1, c2, c3)
}
func (stream *Stream) writeFourBytes(c1 byte, c2 byte, c3 byte, c4 byte) {
stream.buf = append(stream.buf, c1, c2, c3, c4)
}
func (stream *Stream) writeFiveBytes(c1 byte, c2 byte, c3 byte, c4 byte, c5 byte) {
stream.buf = append(stream.buf, c1, c2, c3, c4, c5)
}
// Flush writes any buffered data to the underlying io.Writer.
func (stream *Stream) Flush() error {
if stream.out == nil {
return nil
}
if stream.Error != nil {
return stream.Error
}
_, err := stream.out.Write(stream.buf)
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if err != nil {
if stream.Error == nil {
stream.Error = err
}
return err
}
stream.buf = stream.buf[:0]
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return nil
}
// WriteRaw write string out without quotes, just like []byte
func (stream *Stream) WriteRaw(s string) {
stream.buf = append(stream.buf, s...)
}
// WriteNil write null to stream
func (stream *Stream) WriteNil() {
stream.writeFourBytes('n', 'u', 'l', 'l')
}
// WriteTrue write true to stream
func (stream *Stream) WriteTrue() {
stream.writeFourBytes('t', 'r', 'u', 'e')
}
// WriteFalse write false to stream
func (stream *Stream) WriteFalse() {
stream.writeFiveBytes('f', 'a', 'l', 's', 'e')
}
// WriteBool write true or false into stream
func (stream *Stream) WriteBool(val bool) {
if val {
stream.WriteTrue()
} else {
stream.WriteFalse()
}
}
// WriteObjectStart write { with possible indention
func (stream *Stream) WriteObjectStart() {
stream.indention += stream.cfg.indentionStep
stream.writeByte('{')
stream.writeIndention(0)
}
// WriteObjectField write "field": with possible indention
func (stream *Stream) WriteObjectField(field string) {
stream.WriteString(field)
if stream.indention > 0 {
stream.writeTwoBytes(':', ' ')
} else {
stream.writeByte(':')
}
}
// WriteObjectEnd write } with possible indention
func (stream *Stream) WriteObjectEnd() {
stream.writeIndention(stream.cfg.indentionStep)
stream.indention -= stream.cfg.indentionStep
stream.writeByte('}')
}
// WriteEmptyObject write {}
func (stream *Stream) WriteEmptyObject() {
stream.writeByte('{')
stream.writeByte('}')
}
// WriteMore write , with possible indention
func (stream *Stream) WriteMore() {
stream.writeByte(',')
stream.writeIndention(0)
}
// WriteArrayStart write [ with possible indention
func (stream *Stream) WriteArrayStart() {
stream.indention += stream.cfg.indentionStep
stream.writeByte('[')
stream.writeIndention(0)
}
// WriteEmptyArray write []
func (stream *Stream) WriteEmptyArray() {
stream.writeTwoBytes('[', ']')
}
// WriteArrayEnd write ] with possible indention
func (stream *Stream) WriteArrayEnd() {
stream.writeIndention(stream.cfg.indentionStep)
stream.indention -= stream.cfg.indentionStep
stream.writeByte(']')
}
func (stream *Stream) writeIndention(delta int) {
if stream.indention == 0 {
return
}
stream.writeByte('\n')
toWrite := stream.indention - delta
for i := 0; i < toWrite; i++ {
stream.buf = append(stream.buf, ' ')
}
}