blob: 826f7ff3da5bd01165668e0c8267aac79281c25f [file] [log] [blame]
// 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.
package http
import (
"io"
"strconv"
"strings"
"time"
"unicode/utf8"
"golang_org/x/net/lex/httplex"
)
// 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 cancelation of network operations.
var aLongTimeAgo = time.Unix(233431200, 0)
// 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 (k *contextKey) String() string { return "net/http context value " + k.name }
// Given a string of the form "host", "host:port", or "[ipv6::address]:port",
// return true if the string includes a port.
func hasPort(s string) bool { return strings.LastIndex(s, ":") > strings.LastIndex(s, "]") }
// removeEmptyPort strips the empty port in ":port" to ""
// as mandated by RFC 3986 Section 6.2.3.
func removeEmptyPort(host string) string {
if hasPort(host) {
return strings.TrimSuffix(host, ":")
}
return host
}
func isNotToken(r rune) bool {
return !httplex.IsTokenRune(r)
}
func isASCII(s string) bool {
for i := 0; i < len(s); i++ {
if s[i] >= utf8.RuneSelf {
return false
}
}
return true
}
func hexEscapeNonASCII(s string) string {
newLen := 0
for i := 0; i < len(s); i++ {
if s[i] >= utf8.RuneSelf {
newLen += 3
} else {
newLen++
}
}
if newLen == len(s) {
return s
}
b := make([]byte, 0, newLen)
for i := 0; i < len(s); i++ {
if s[i] >= utf8.RuneSelf {
b = append(b, '%')
b = strconv.AppendInt(b, int64(s[i]), 16)
} else {
b = append(b, s[i])
}
}
return string(b)
}
// 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) Read([]byte) (int, error) { return 0, io.EOF }
func (noBody) Close() error { return nil }
func (noBody) WriteTo(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 returns ErrNotSupported if the client has disabled push or if push
// is not supported on the underlying connection.
Push(target string, opts *PushOptions) error
}