"path"
	"slices"
	"strings"
	"time"
)

// Writer provides sequential writing of a tar archive.
// [Writer.WriteHeader] begins a new file with the provided [Header],
// and then Writer can be treated as an io.Writer to supply that file's data.
type Writer struct {
	w    io.Writer
	pad  int64      // Amount of padding to write after current file entry
	curr fileWriter // Writer for current file entry

// size. If the argument io.Writer is already a [Writer] with large enough
// size, it returns the underlying [Writer].
func NewWriterSize(w io.Writer, size int) *Writer {
	// Is it already a Writer?
	b, ok := w.(*Writer)
	if ok && len(b.buf) >= size {
		return b
	}
	if size <= 0 {
		size = defaultBufSize
	}
	return &Writer{
		buf: make([]byte, size),
		wr:  w,
	}
}

type Options struct {
	Writer        Writer
	Flagset       FlagSet
	Fetch         Fetcher
	Sym           Symbolizer
	Obj           ObjTool
	UI            UI
	HTTPServer    func(*HTTPServerArgs) error
	HTTPTransport http.RoundTripper
}

// Writer provides a mechanism to write data under a certain name,
// typically a filename.
type Writer interface {
	Open(name string) (io.WriteCloser, error)
}

var flateWriterPool sync.Pool

func newFlateWriter(w io.Writer) io.WriteCloser {
	fw, ok := flateWriterPool.Get().(*flate.Writer)
	if ok {
		fw.Reset(w)
	} else {
		fw, _ = flate.NewWriter(w, 5)
	}
	return &pooledFlateWriter{fw: fw}
}

type pooledFlateWriter struct {
	mu sync.Mutex // guards Close and Write
	fw *flate.Writer
}

func (w *pooledFlateWriter) Write(p []byte) (n int, err error) {
	w.mu.Lock()

			c.wroteSlashes = true
		}
		n0, err := c.W.Write(p[i : i+1])
		n += n0
		if err != nil {
			return n, err
		}
		if b == '\n' {
			c.wroteSlashes = false
		}
	}
	return len(p), nil
}

// An errWriter wraps a writer, recording whether a write error occurred.
type errWriter struct {
	w   io.Writer
	err error
}

func (w *errWriter) Write(b []byte) (int, error) {
	n, err := w.w.Write(b)

		}
	}
}

// testNonEmptyWriter wraps an io.Writer and ensures that
// Write is never called with an empty buffer.
type testNonEmptyWriter struct{ io.Writer }

func (w testNonEmptyWriter) Write(b []byte) (int, error) {
	if len(b) == 0 {
		return 0, errors.New("unexpected empty Write call")
	}
	return w.Writer.Write(b)
}

func TestFileWriter(t *testing.T) {
	type (

}

func (w *Writer) StringRef(s string) {
	w.Uint32(uint32(len(s)))
	w.Uint32(w.stringOff(s))
}

func (w *Writer) RawString(s string) {
	w.wr.WriteString(s)
	w.off += uint32(len(s))
}

func (w *Writer) Bytes(s []byte) {
	w.wr.Write(s)
	w.off += uint32(len(s))
}

func (w *Writer) Uint64(x uint64) {
	binary.LittleEndian.PutUint64(w.b[:], x)
	w.wr.Write(w.b[:])
	w.off += 8
}

	"errors"
	"fmt"
	"io"
	"sync"
	"time"
)

// lockedWriter serializes Write calls to an underlying Writer.
type lockedWriter struct {
	lock sync.Mutex
	w    io.Writer
}

func (w *lockedWriter) Write(b []byte) (int, error) {
	w.lock.Lock()
	defer w.lock.Unlock()
	return w.w.Write(b)
}

// testJSONFilter is an io.Writer filter that replaces the Package field in
// test2json output.
type testJSONFilter struct {

		}

		w := next.Value.(waiter)
		if s.size-s.cur < w.n {
			// Not enough tokens for the next waiter.  We could keep going (to try to
			// find a waiter with a smaller request), but under load that could cause
			// starvation for large requests; instead, we leave all remaining waiters
			// blocked.
			//
			// Consider a semaphore used as a read-write lock, with N tokens, N

	"testing"

	"cmd/internal/bio"
	"cmd/internal/objabi"
)

func dummyWriter(buf *bytes.Buffer) *Writer {
	wr := &bio.Writer{Writer: bufio.NewWriter(buf)} // hacky: no file, so cannot seek
	return NewWriter(wr)
}

func TestReadWrite(t *testing.T) {
	// Test that we get the same data in a write-read roundtrip.

	// Write a symbol, a relocation, and an aux info.
	var buf bytes.Buffer
	w := dummyWriter(&buf)

	var s Sym