package ioutil

import (
	"io"
	"sync"
)

// PipeWriter is similar to io.PipeWriter with wait group
type PipeWriter struct {
	*io.PipeWriter
	once sync.Once
	done func()
}

// CloseWithError close with supplied error the writer end.
func (w *PipeWriter) CloseWithError(err error) error {
	err = w.PipeWriter.CloseWithError(err)
	w.once.Do(func() {
		w.done()
	})
	return err
}

// CloseWithError never overwrites the previous error if it exists
// and always returns nil.
func (r *PipeReader) CloseWithError(err error) error {
	return r.pipe.closeRead(err)
}

// A PipeWriter is the write half of a pipe.
type PipeWriter struct{ r PipeReader }

// Write implements the standard Write interface:
// it writes data to the pipe, blocking until one or more readers
// have consumed all the data or the read end is closed.

}

type pipe struct {
	*io.PipeReader
	*io.PipeWriter
}

type pipeAddr int

func (pipeAddr) Network() string {
	return "pipe"
}

func (pipeAddr) String() string {
	return "pipe"
}

func (p *pipe) Close() error {
	err := p.PipeReader.Close()
	err1 := p.PipeWriter.Close()
	if err == nil {
		err = err1
	}
	return err
}

// on ch.
type populateResponse struct {
	res          *Response
	ch           chan *Response
	wroteHeader  bool
	hasContent   bool
	sentResponse bool
	pw           *io.PipeWriter
}

func (pr *populateResponse) finish() {
	if !pr.wroteHeader {
		pr.WriteHeader(500)
	}
	if !pr.sentResponse {
		pr.sendResponse()
	}
	pr.pw.Close()
}

	// This will also flush the ring buffer if used.
	err := b.iow.Close()

	// Wait for all data to be written before returning else it causes race conditions.
	// Race condition is because of io.PipeWriter implementation. i.e consider the following
	// sequent of operations:
	// 1) pipe.Write()
	// 2) pipe.Close()
	// Now pipe.Close() can return before the data is read on the other end of the pipe and written to the disk

	opts Options

	// f is the currently open file used for appends.
	// Writes to f are only synchronized once Close() is called,
	// or when files are being rotated.
	f *os.File

	pw *xioutil.PipeWriter
	pr *xioutil.PipeReader
}

// Write writes p into the current file, rotating if necessary.
// Write is non-blocking, if the writer's queue is not full.
// Write is blocking otherwise.

	"net/http/cgi"
	"os"
	"strings"
	"time"
)

// request holds the state for an in-progress request. As soon as it's complete,
// it's converted to an http.Request.
type request struct {
	pw        *io.PipeWriter
	reqId     uint16
	params    map[string]string
	buf       [1024]byte
	rawParams []byte
	keepConn  bool
}

// envVarsContextKey uniquely identifies a mapping of CGI

		err = w.err
	default:
		err = w.w.Close()
	}
	for i := range w.buffer {
		delete(w.buffer, i)
	}
	w.wg.Wait()
	return err
}

type writerAt struct {
	w      *io.PipeWriter
	r      *io.PipeReader
	wg     *sync.WaitGroup
	buffer map[int64][]byte
	err    error

	nextOffset int64
	m          sync.Mutex
}

		{"(*OffsetWriter).WriteAt", Method, 20},
		{"(*PipeReader).Close", Method, 0},
		{"(*PipeReader).CloseWithError", Method, 0},
		{"(*PipeReader).Read", Method, 0},
		{"(*PipeWriter).Close", Method, 0},
		{"(*PipeWriter).CloseWithError", Method, 0},
		{"(*PipeWriter).Write", Method, 0},
		{"(*SectionReader).Outer", Method, 22},
		{"(*SectionReader).Read", Method, 0},
		{"(*SectionReader).ReadAt", Method, 0},

	const numReqs = 5
	reqBody := func(n int) string { return fmt.Sprintf("request body %d", n) }
	reqID := func(n int) string { return fmt.Sprintf("REQ-ID-%d", n) }

	send100Response := func(w *io.PipeWriter, r *io.PipeReader) {
		defer w.Close()
		defer r.Close()
		br := bufio.NewReader(r)
		n := 0
		for {
			n++
			req, err := ReadRequest(br)
			if err == io.EOF {
				return
			}