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package gojay
import (
"sync"
"time"
)
// UnmarshalerStream is the interface to implement for a slice, an array or a slice
// to decode a line delimited JSON to.
type UnmarshalerStream interface {
UnmarshalStream(*StreamDecoder) error
}
// Stream is a struct holding the Stream api
var Stream = stream{}
type stream struct{}
// A StreamDecoder reads and decodes JSON values from an input stream.
//
// It implements conext.Context and provide a channel to notify interruption.
type StreamDecoder struct {
mux sync.RWMutex
*Decoder
done chan struct{}
deadline *time.Time
}
// DecodeStream reads the next line delimited JSON-encoded value from the decoder's input (io.Reader) and stores it in the value pointed to by c.
//
// c must implement UnmarshalerStream. Ideally c is a channel. See example for implementation.
//
// See the documentation for Unmarshal for details about the conversion of JSON into a Go value.
func (dec *StreamDecoder) DecodeStream(c UnmarshalerStream) error {
if dec.isPooled == 1 {
panic(InvalidUsagePooledDecoderError("Invalid usage of pooled decoder"))
}
if dec.r == nil {
dec.err = NoReaderError("No reader given to decode stream")
close(dec.done)
return dec.err
}
for ; dec.cursor < dec.length || dec.read(); dec.cursor++ {
switch dec.data[dec.cursor] {
case ' ', '\n', '\t', '\r', ',':
continue
default:
// char is not space start reading
for dec.nextChar() != 0 {
// calling unmarshal stream
err := c.UnmarshalStream(dec)
if err != nil {
dec.err = err
close(dec.done)
return err
}
// garbage collects buffer
// we don't want the buffer to grow extensively
dec.data = dec.data[dec.cursor:]
dec.length = dec.length - dec.cursor
dec.cursor = 0
}
// close the done channel to signal the end of the job
close(dec.done)
return nil
}
}
close(dec.done)
dec.mux.Lock()
err := dec.raiseInvalidJSONErr(dec.cursor)
dec.mux.Unlock()
return err
}
// context.Context implementation
// Done returns a channel that's closed when work is done.
// It implements context.Context
func (dec *StreamDecoder) Done() <-chan struct{} {
return dec.done
}
// Deadline returns the time when work done on behalf of this context
// should be canceled. Deadline returns ok==false when no deadline is
// set. Successive calls to Deadline return the same results.
func (dec *StreamDecoder) Deadline() (time.Time, bool) {
if dec.deadline != nil {
return *dec.deadline, true
}
return time.Time{}, false
}
// SetDeadline sets the deadline
func (dec *StreamDecoder) SetDeadline(t time.Time) {
dec.deadline = &t
}
// Err returns nil if Done is not yet closed.
// If Done is closed, Err returns a non-nil error explaining why.
// It implements context.Context
func (dec *StreamDecoder) Err() error {
select {
case <-dec.done:
dec.mux.RLock()
defer dec.mux.RUnlock()
return dec.err
default:
return nil
}
}
// Value implements context.Context
func (dec *StreamDecoder) Value(key interface{}) interface{} {
return nil
}
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