// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:generate bundle -o=h2_bundle.go -prefix=http2 -tags=!nethttpomithttp2 golang.org/x/net/http2

package http

import (
	
	
	
	
	

	
)

// incomparable is a zero-width, non-comparable type. Adding it to a struct
// makes that struct also non-comparable, and generally doesn't add
// any size (as long as it's first).
type incomparable [0]func()

// maxInt64 is the effective "infinite" value for the Server and
// Transport's byte-limiting readers.
const maxInt64 = 1<<63 - 1

// aLongTimeAgo is a non-zero time, far in the past, used for
// immediate cancellation of network operations.
var aLongTimeAgo = time.Unix(1, 0)

// omitBundledHTTP2 is set by omithttp2.go when the nethttpomithttp2
// build tag is set. That means h2_bundle.go isn't compiled in and we
// shouldn't try to use it.
var omitBundledHTTP2 bool

// TODO(bradfitz): move common stuff here. The other files have accumulated
// generic http stuff in random places.

// contextKey is a value for use with context.WithValue. It's used as
// a pointer so it fits in an interface{} without allocation.
type contextKey struct {
	name string
}

func ( *contextKey) () string { return "net/http context value " + .name }

// Given a string of the form "host", "host:port", or "[ipv6::address]:port",
// return true if the string includes a port.
func hasPort( string) bool { return strings.LastIndex(, ":") > strings.LastIndex(, "]") }

// removeEmptyPort strips the empty port in ":port" to ""
// as mandated by RFC 3986 Section 6.2.3.
func removeEmptyPort( string) string {
	if hasPort() {
		return strings.TrimSuffix(, ":")
	}
	return 
}

func isNotToken( rune) bool {
	return !httpguts.IsTokenRune()
}

// stringContainsCTLByte reports whether s contains any ASCII control character.
func stringContainsCTLByte( string) bool {
	for  := 0;  < len(); ++ {
		 := []
		if  < ' ' ||  == 0x7f {
			return true
		}
	}
	return false
}

func hexEscapeNonASCII( string) string {
	 := 0
	for  := 0;  < len(); ++ {
		if [] >= utf8.RuneSelf {
			 += 3
		} else {
			++
		}
	}
	if  == len() {
		return 
	}
	 := make([]byte, 0, )
	var  int
	for  := 0;  < len(); ++ {
		if [] >= utf8.RuneSelf {
			if  <  {
				 = append(, [:]...)
			}
			 = append(, '%')
			 = strconv.AppendInt(, int64([]), 16)
			 =  + 1
		}
	}
	if  < len() {
		 = append(, [:]...)
	}
	return string()
}

// NoBody is an [io.ReadCloser] with no bytes. Read always returns EOF
// and Close always returns nil. It can be used in an outgoing client
// request to explicitly signal that a request has zero bytes.
// An alternative, however, is to simply set [Request.Body] to nil.
var NoBody = noBody{}

type noBody struct{}

func (noBody) ([]byte) (int, error)         { return 0, io.EOF }
func (noBody) () error                     { return nil }
func (noBody) (io.Writer) (int64, error) { return 0, nil }

var (
	// verify that an io.Copy from NoBody won't require a buffer:
	_ io.WriterTo   = NoBody
	_ io.ReadCloser = NoBody
)

// PushOptions describes options for [Pusher.Push].
type PushOptions struct {
	// Method specifies the HTTP method for the promised request.
	// If set, it must be "GET" or "HEAD". Empty means "GET".
	Method string

	// Header specifies additional promised request headers. This cannot
	// include HTTP/2 pseudo header fields like ":path" and ":scheme",
	// which will be added automatically.
	Header Header
}

// Pusher is the interface implemented by ResponseWriters that support
// HTTP/2 server push. For more background, see
// https://tools.ietf.org/html/rfc7540#section-8.2.
type Pusher interface {
	// Push initiates an HTTP/2 server push. This constructs a synthetic
	// request using the given target and options, serializes that request
	// into a PUSH_PROMISE frame, then dispatches that request using the
	// server's request handler. If opts is nil, default options are used.
	//
	// The target must either be an absolute path (like "/path") or an absolute
	// URL that contains a valid host and the same scheme as the parent request.
	// If the target is a path, it will inherit the scheme and host of the
	// parent request.
	//
	// The HTTP/2 spec disallows recursive pushes and cross-authority pushes.
	// Push may or may not detect these invalid pushes; however, invalid
	// pushes will be detected and canceled by conforming clients.
	//
	// Handlers that wish to push URL X should call Push before sending any
	// data that may trigger a request for URL X. This avoids a race where the
	// client issues requests for X before receiving the PUSH_PROMISE for X.
	//
	// Push will run in a separate goroutine making the order of arrival
	// non-deterministic. Any required synchronization needs to be implemented
	// by the caller.
	//
	// Push returns ErrNotSupported if the client has disabled push or if push
	// is not supported on the underlying connection.
	Push(target string, opts *PushOptions) error
}