// TraceOutput will print debug information on non-200 calls if set.
	TraceOutput io.Writer // Debug trace output

	httpClient *http.Client
	url        *url.URL
	auth       func() string

	sync.RWMutex // mutex for lastErr
	lastErr      error
	lastErrTime  time.Time
}

type restError string

func (e restError) Error() string {
	return string(e)
}

func (e restError) Timeout() bool {

type RingBuffer struct {
	buf       []byte
	size      int
	r         int // next position to read
	w         int // next position to write
	isFull    bool
	err       error
	block     bool
	mu        sync.Mutex
	wg        sync.WaitGroup
	readCond  *sync.Cond // Signaled when data has been read.
	writeCond *sync.Cond // Signaled when data has been written.
}

// New returns a new RingBuffer whose buffer has the given size.

	lastRead readOp // last read operation, so that Unread* can work correctly.

	// Copying and modifying a non-zero Buffer is prone to error,
	// but we cannot employ the noCopy trick used by WaitGroup and Mutex,
	// which causes vet's copylocks checker to report misuse, as vet
	// cannot reliably distinguish the zero and non-zero cases.
	// See #26462, #25907, #47276, #48398 for history.
}

	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()
	defer w.mu.Unlock()
	if w.fw == nil {
		return 0, errors.New("Write after Close")
	}

	prefixAll  string
}

// disconnectReader will ensure that no reads can take place on
// the upstream reader after close has been called.
type disconnectReader struct {
	r  io.Reader
	mu sync.Mutex
}

func (d *disconnectReader) Read(p []byte) (n int, err error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	if d.r != nil {
		return d.r.Read(p)
	}
	return 0, errors.New("reader closed")
}

	// into an SSE-S3 request. If enabled a valid, non-empty KMS
	// configuration must be present.
	globalAutoEncryption bool

	// Is compression enabled?
	globalCompressConfigMu sync.Mutex
	globalCompressConfig   compress.Config

	// Some standard object extensions which we strictly dis-allow for compression.

</p>

<pre>
// A Mutex is a data type with two methods, Lock and Unlock.
type Mutex struct         { /* Mutex fields */ }
func (m *Mutex) Lock()    { /* Lock implementation */ }
func (m *Mutex) Unlock()  { /* Unlock implementation */ }

// NewMutex has the same composition as Mutex but its method set is empty.
type NewMutex Mutex

package dsync

import (
	"math/rand"
	"sync"
)

// lockedRandSource provides protected rand source, implements rand.Source interface.
type lockedRandSource struct {
	lk  sync.Mutex
	src rand.Source
}

// Int63 returns a non-negative pseudo-random 63-bit integer as an int64.
func (r *lockedRandSource) Int63() (n int64) {
	r.lk.Lock()
	n = r.src.Int63()
	r.lk.Unlock()
	return n
}

[GC guide](/doc/gc-guide#Linux_transparent_huge_pages), or switch to a Linux
distribution that disables transparent huge pages altogether.

Go 1.22 added contention on runtime-internal locks to the [`mutex`
profile](/pkg/runtime/pprof#Profile). Contention on these locks is always
reported at `runtime._LostContendedRuntimeLock`. Complete stack traces of
runtime locks can be enabled with the [`runtimecontentionstacks`

import (
	"sync"
	"sync/atomic"
)

// Inspired from Golang sync.Once but it is only marked
// initialized when the provided function returns nil.

type lazyInit struct {
	done uint32
	m    sync.Mutex
}

func (l *lazyInit) Do(f func() error) error {
	if atomic.LoadUint32(&l.done) == 0 {
		return l.doSlow(f)
	}
	return nil
}

func (l *lazyInit) doSlow(f func() error) error {
	l.m.Lock()