}

func TestWriterReset(t *testing.T) {
	var buf1, buf2, buf3, buf4, buf5 strings.Builder
	w := NewWriter(&buf1)
	w.WriteString("foo")

	w.Reset(&buf2) // and not flushed
	w.WriteString("bar")
	w.Flush()
	if buf1.String() != "" {
		t.Errorf("buf1 = %q; want empty", buf1.String())
	}
	if buf2.String() != "bar" {
		t.Errorf("buf2 = %q; want bar", buf2.String())
	}

		for i := 0; i < b.N; i++ {
			j := IndexRune(buf, needle)
			if j != n {
				b.Fatal("bad index", j)
			}
		}
		for i := range buf {
			buf[i] = '\x00'
		}
	}
}

func BenchmarkEqual(b *testing.B) {
	b.Run("0", func(b *testing.B) {
		var buf [4]byte
		buf1 := buf[0:0]
		buf2 := buf[1:1]
		for i := 0; i < b.N; i++ {
			eq := Equal(buf1, buf2)
			if !eq {
				b.Fatal("bad equal")
			}

	var buf bytes.Buffer
	for i := 0; i < 4; i++ {
		b := buf.AvailableBuffer()
		b = strconv.AppendInt(b, int64(i), 10)
		b = append(b, ' ')
		buf.Write(b)
	}
	os.Stdout.Write(buf.Bytes())
	// Output: 0 1 2 3
}

func ExampleBuffer_Cap() {
	buf1 := bytes.NewBuffer(make([]byte, 10))
	buf2 := bytes.NewBuffer(make([]byte, 0, 10))
	fmt.Println(buf1.Cap())
	fmt.Println(buf2.Cap())
	// Output:
	// 10
	// 10
}

	startBlock := int64(0)
	endBlock := totalLength / e.blockSize
	if totalLength%e.blockSize != 0 {
		endBlock++
	}

	var bufs [][]byte
	for block := startBlock; block < endBlock; block++ {
		var err error
		bufs, err = reader.Read(bufs)
		if len(bufs) > 0 {
			if errors.Is(err, errFileNotFound) || errors.Is(err, errFileCorrupt) {
				if derr == nil {
					derr = err
				}
			}

		}
	}
	defer syscall.Close(fd)

	bufp := direntPool.Get()
	defer direntPool.Put(bufp)
	buf := *bufp

	boff := 0 // starting read position in buf
	nbuf := 0 // end valid data in buf

	for {
		if boff >= nbuf {
			boff = 0
			stop := globalOSMetrics.time(osMetricReadDirent)
			nbuf, err = syscall.ReadDirent(fd, buf)
			stop()
			if err != nil {
				if isSysErrNotDir(err) {

	pool bpool.Pool[*[]byte]
}

func (b *bufPool) Put(buf []byte) {
	if cap(buf) < b.sz || cap(buf) > b.sz*2 {
		// Buffer too small or will likely leak memory after being expanded.
		// Drop it.
		return
	}
	b.pool.Put(&buf)
}

func (b *bufPool) Get() []byte {
	bufp := b.pool.Get()
	if bufp == nil || cap(*bufp) < b.sz {
		return make([]byte, 0, b.sz)
	}
	return (*bufp)[:b.sz]
}

	}

	var written int64
	for {
		buf := alignedBuf
		if totalSize > 0 {
			remaining := totalSize - written
			if remaining < int64(len(buf)) {
				buf = buf[:remaining]
			}
		}

		nr, err := io.ReadFull(r, buf)
		eof := errors.Is(err, io.EOF) || errors.Is(err, io.ErrUnexpectedEOF)
		if err != nil && !eof {
			return written, err
		}

		buf = buf[:nr]
		var (
			n  int
			un int

	r, err := NewReader(bytes.NewReader(buf.Bytes()), int64(buf.Len()))
	if err != nil {
		t.Fatal(err)
	}
	for i, wt := range writeTests {
		testReadFile(t, r.File[i], &wt)
	}
}

func TestWriterFlush(t *testing.T) {
	var buf bytes.Buffer
	w := NewWriter(struct{ io.Writer }{&buf})
	_, err := w.Create("foo")
	if err != nil {
		t.Fatal(err)
	}
	if buf.Len() > 0 {

}

// Verify that contents of buf match the string s.
func check(t *testing.T, testname string, buf *Buffer, s string) {
	bytes := buf.Bytes()
	str := buf.String()
	if buf.Len() != len(bytes) {
		t.Errorf("%s: buf.Len() == %d, len(buf.Bytes()) == %d", testname, buf.Len(), len(bytes))
	}

	if buf.Len() != len(str) {
		t.Errorf("%s: buf.Len() == %d, len(buf.String()) == %d", testname, buf.Len(), len(str))
	}

	bufp := poolBuf8k.Get()
	buf := *bufp
	defer poolBuf8k.Put(bufp)

	for {
		_, err := io.ReadFull(respBody, tmp[:])
		if err != nil {
			return err
		}
		// Check if we have a response ready or a filler byte.
		switch tmp[0] {
		case 0:
			// 0 is unbuffered, copy the rest.
			_, err := io.CopyBuffer(w, respBody, buf)
			if err == io.EOF {
				return nil