Xray-core/transport/internet/splithttp/lazy_reader.go

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package splithttp
import (
"io"
"sync"
"github.com/xtls/xray-core/common/errors"
)
type LazyReader struct {
readerSync sync.Mutex
CreateReader func() (io.ReadCloser, error)
reader io.ReadCloser
readerError error
}
func (r *LazyReader) getReader() (io.ReadCloser, error) {
r.readerSync.Lock()
defer r.readerSync.Unlock()
if r.reader != nil {
return r.reader, nil
}
if r.readerError != nil {
return nil, r.readerError
}
reader, err := r.CreateReader()
if err != nil {
r.readerError = err
return nil, err
}
r.reader = reader
return reader, nil
}
func (r *LazyReader) Read(b []byte) (int, error) {
reader, err := r.getReader()
if err != nil {
return 0, err
}
n, err := reader.Read(b)
return n, err
}
func (r *LazyReader) Close() error {
r.readerSync.Lock()
defer r.readerSync.Unlock()
var err error
if r.reader != nil {
err = r.reader.Close()
r.reader = nil
r.readerError = errors.New("closed reader")
}
return err
}