Documentation ¶
Overview ¶
Package http2 implements the HTTP/2 protocol.
This is a work in progress. This package is low-level and intended to be used directly by very few people. Most users will use it indirectly through integration with the net/http package. See ConfigureServer. That ConfigureServer call will likely be automatic or available via an empty import in the future.
Index ¶
- Constants
- Variables
- func ConfigureServer(s *http.Server, conf *Server) error
- func ConfigureTransport(t1 *http.Transport) error
- type ClientConn
- type ClientConnPool
- type ConnectionError
- type ContinuationFrame
- type DataFrame
- type ErrCode
- type Flags
- type Frame
- type FrameHeader
- type FrameType
- type Framer
- func (fr *Framer) ReadFrame() (Frame, error)
- func (fr *Framer) SetMaxReadFrameSize(v uint32)
- func (f *Framer) WriteContinuation(streamID uint32, endHeaders bool, headerBlockFragment []byte) error
- func (f *Framer) WriteData(streamID uint32, endStream bool, data []byte) error
- func (f *Framer) WriteGoAway(maxStreamID uint32, code ErrCode, debugData []byte) error
- func (f *Framer) WriteHeaders(p HeadersFrameParam) error
- func (f *Framer) WritePing(ack bool, data [8]byte) error
- func (f *Framer) WritePriority(streamID uint32, p PriorityParam) error
- func (f *Framer) WritePushPromise(p PushPromiseParam) error
- func (f *Framer) WriteRSTStream(streamID uint32, code ErrCode) error
- func (f *Framer) WriteRawFrame(t FrameType, flags Flags, streamID uint32, payload []byte) error
- func (f *Framer) WriteSettings(settings ...Setting) error
- func (f *Framer) WriteSettingsAck() error
- func (f *Framer) WriteWindowUpdate(streamID, incr uint32) error
- type GoAwayFrame
- type HeadersFrame
- type HeadersFrameParam
- type PingFrame
- type PriorityFrame
- type PriorityParam
- type PushPromiseFrame
- type PushPromiseParam
- type RSTStreamFrame
- type RoundTripOpt
- type Server
- type Setting
- type SettingID
- type SettingsFrame
- type StreamError
- type Transport
- type UnknownFrame
- type WindowUpdateFrame
Constants ¶
const ( // ClientPreface is the string that must be sent by new // connections from clients. ClientPreface = "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n" // NextProtoTLS is the NPN/ALPN protocol negotiated during // HTTP/2's TLS setup. NextProtoTLS = "h2" )
Variables ¶
var DebugGoroutines = os.Getenv("DEBUG_HTTP2_GOROUTINES") == "1"
var ErrFrameTooLarge = errors.New("http2: frame too large")
ErrFrameTooLarge is returned from Framer.ReadFrame when the peer sends a frame that is larger than declared with SetMaxReadFrameSize.
var ErrNoCachedConn = errors.New("http2: no cached connection was available")
var VerboseLogs = false
Functions ¶
func ConfigureServer ¶
ConfigureServer adds HTTP/2 support to a net/http Server.
The configuration conf may be nil.
ConfigureServer must be called before s begins serving.
func ConfigureTransport ¶
ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2. It requires Go 1.6 or later and returns an error if the net/http package is too old or if t1 has already been HTTP/2-enabled.
Types ¶
type ClientConn ¶
type ClientConn struct {
// contains filtered or unexported fields
}
ClientConn is the state of a single HTTP/2 client connection to an HTTP/2 server.
func (*ClientConn) CanTakeNewRequest ¶
func (cc *ClientConn) CanTakeNewRequest() bool
type ClientConnPool ¶
type ClientConnPool interface { GetClientConn(req *http.Request, addr string) (*ClientConn, error) MarkDead(*ClientConn) }
ClientConnPool manages a pool of HTTP/2 client connections.
type ConnectionError ¶
type ConnectionError ErrCode
ConnectionError is an error that results in the termination of the entire connection.
func (ConnectionError) Error ¶
func (e ConnectionError) Error() string
type ContinuationFrame ¶
type ContinuationFrame struct { FrameHeader // contains filtered or unexported fields }
A ContinuationFrame is used to continue a sequence of header block fragments. See http://http2.github.io/http2-spec/#rfc.section.6.10
func (*ContinuationFrame) HeaderBlockFragment ¶
func (f *ContinuationFrame) HeaderBlockFragment() []byte
func (*ContinuationFrame) HeadersEnded ¶
func (f *ContinuationFrame) HeadersEnded() bool
func (*ContinuationFrame) StreamEnded ¶
func (f *ContinuationFrame) StreamEnded() bool
type DataFrame ¶
type DataFrame struct { FrameHeader // contains filtered or unexported fields }
A DataFrame conveys arbitrary, variable-length sequences of octets associated with a stream. See http://http2.github.io/http2-spec/#rfc.section.6.1
func (*DataFrame) Data ¶
Data returns the frame's data octets, not including any padding size byte or padding suffix bytes. The caller must not retain the returned memory past the next call to ReadFrame.
func (*DataFrame) StreamEnded ¶
type ErrCode ¶
type ErrCode uint32
An ErrCode is an unsigned 32-bit error code as defined in the HTTP/2 spec.
const ( ErrCodeNo ErrCode = 0x0 ErrCodeProtocol ErrCode = 0x1 ErrCodeInternal ErrCode = 0x2 ErrCodeFlowControl ErrCode = 0x3 ErrCodeSettingsTimeout ErrCode = 0x4 ErrCodeStreamClosed ErrCode = 0x5 ErrCodeFrameSize ErrCode = 0x6 ErrCodeRefusedStream ErrCode = 0x7 ErrCodeCancel ErrCode = 0x8 ErrCodeCompression ErrCode = 0x9 ErrCodeConnect ErrCode = 0xa ErrCodeEnhanceYourCalm ErrCode = 0xb ErrCodeInadequateSecurity ErrCode = 0xc ErrCodeHTTP11Required ErrCode = 0xd )
type Flags ¶
type Flags uint8
Flags is a bitmask of HTTP/2 flags. The meaning of flags varies depending on the frame type.
const ( // Data Frame FlagDataEndStream Flags = 0x1 FlagDataPadded Flags = 0x8 // Headers Frame FlagHeadersEndStream Flags = 0x1 FlagHeadersEndHeaders Flags = 0x4 FlagHeadersPadded Flags = 0x8 FlagHeadersPriority Flags = 0x20 // Settings Frame FlagSettingsAck Flags = 0x1 // Ping Frame FlagPingAck Flags = 0x1 // Continuation Frame FlagContinuationEndHeaders Flags = 0x4 FlagPushPromiseEndHeaders Flags = 0x4 FlagPushPromisePadded Flags = 0x8 )
Frame-specific FrameHeader flag bits.
type Frame ¶
type Frame interface { Header() FrameHeader // contains filtered or unexported methods }
A Frame is the base interface implemented by all frame types. Callers will generally type-assert the specific frame type: *HeadersFrame, *SettingsFrame, *WindowUpdateFrame, etc.
Frames are only valid until the next call to Framer.ReadFrame.
type FrameHeader ¶
type FrameHeader struct { // Type is the 1 byte frame type. There are ten standard frame // types, but extension frame types may be written by WriteRawFrame // and will be returned by ReadFrame (as UnknownFrame). Type FrameType // Flags are the 1 byte of 8 potential bit flags per frame. // They are specific to the frame type. Flags Flags // Length is the length of the frame, not including the 9 byte header. // The maximum size is one byte less than 16MB (uint24), but only // frames up to 16KB are allowed without peer agreement. Length uint32 // StreamID is which stream this frame is for. Certain frames // are not stream-specific, in which case this field is 0. StreamID uint32 // contains filtered or unexported fields }
A FrameHeader is the 9 byte header of all HTTP/2 frames.
See http://http2.github.io/http2-spec/#FrameHeader
func ReadFrameHeader ¶
func ReadFrameHeader(r io.Reader) (FrameHeader, error)
ReadFrameHeader reads 9 bytes from r and returns a FrameHeader. Most users should use Framer.ReadFrame instead.
func (FrameHeader) Header ¶
func (h FrameHeader) Header() FrameHeader
Header returns h. It exists so FrameHeaders can be embedded in other specific frame types and implement the Frame interface.
func (FrameHeader) String ¶
func (h FrameHeader) String() string
type FrameType ¶
type FrameType uint8
A FrameType is a registered frame type as defined in http://http2.github.io/http2-spec/#rfc.section.11.2
const ( FrameData FrameType = 0x0 FrameHeaders FrameType = 0x1 FramePriority FrameType = 0x2 FrameRSTStream FrameType = 0x3 FrameSettings FrameType = 0x4 FramePushPromise FrameType = 0x5 FramePing FrameType = 0x6 FrameGoAway FrameType = 0x7 FrameWindowUpdate FrameType = 0x8 FrameContinuation FrameType = 0x9 )
type Framer ¶
type Framer struct { // AllowIllegalWrites permits the Framer's Write methods to // write frames that do not conform to the HTTP/2 spec. This // permits using the Framer to test other HTTP/2 // implementations' conformance to the spec. // If false, the Write methods will prefer to return an error // rather than comply. AllowIllegalWrites bool // contains filtered or unexported fields }
A Framer reads and writes Frames.
func (*Framer) ReadFrame ¶
ReadFrame reads a single frame. The returned Frame is only valid until the next call to ReadFrame. If the frame is larger than previously set with SetMaxReadFrameSize, the returned error is ErrFrameTooLarge.
func (*Framer) SetMaxReadFrameSize ¶
SetMaxReadFrameSize sets the maximum size of a frame that will be read by a subsequent call to ReadFrame. It is the caller's responsibility to advertise this limit with a SETTINGS frame.
func (*Framer) WriteContinuation ¶
func (f *Framer) WriteContinuation(streamID uint32, endHeaders bool, headerBlockFragment []byte) error
WriteContinuation writes a CONTINUATION frame.
It will perform exactly one Write to the underlying Writer. It is the caller's responsibility to not call other Write methods concurrently.
func (*Framer) WriteData ¶
WriteData writes a DATA frame.
It will perform exactly one Write to the underlying Writer. It is the caller's responsibility to not call other Write methods concurrently.
func (*Framer) WriteGoAway ¶
func (*Framer) WriteHeaders ¶
func (f *Framer) WriteHeaders(p HeadersFrameParam) error
WriteHeaders writes a single HEADERS frame.
This is a low-level header writing method. Encoding headers and splitting them into any necessary CONTINUATION frames is handled elsewhere.
It will perform exactly one Write to the underlying Writer. It is the caller's responsibility to not call other Write methods concurrently.
func (*Framer) WritePriority ¶
func (f *Framer) WritePriority(streamID uint32, p PriorityParam) error
WritePriority writes a PRIORITY frame.
It will perform exactly one Write to the underlying Writer. It is the caller's responsibility to not call other Write methods concurrently.
func (*Framer) WritePushPromise ¶
func (f *Framer) WritePushPromise(p PushPromiseParam) error
WritePushPromise writes a single PushPromise Frame.
As with Header Frames, This is the low level call for writing individual frames. Continuation frames are handled elsewhere.
It will perform exactly one Write to the underlying Writer. It is the caller's responsibility to not call other Write methods concurrently.
func (*Framer) WriteRSTStream ¶
WriteRSTStream writes a RST_STREAM frame.
It will perform exactly one Write to the underlying Writer. It is the caller's responsibility to not call other Write methods concurrently.
func (*Framer) WriteRawFrame ¶
WriteRawFrame writes a raw frame. This can be used to write extension frames unknown to this package.
func (*Framer) WriteSettings ¶
WriteSettings writes a SETTINGS frame with zero or more settings specified and the ACK bit not set.
It will perform exactly one Write to the underlying Writer. It is the caller's responsibility to not call other Write methods concurrently.
func (*Framer) WriteSettingsAck ¶
WriteSettings writes an empty SETTINGS frame with the ACK bit set.
It will perform exactly one Write to the underlying Writer. It is the caller's responsibility to not call other Write methods concurrently.
func (*Framer) WriteWindowUpdate ¶
WriteWindowUpdate writes a WINDOW_UPDATE frame. The increment value must be between 1 and 2,147,483,647, inclusive. If the Stream ID is zero, the window update applies to the connection as a whole.
type GoAwayFrame ¶
type GoAwayFrame struct { FrameHeader LastStreamID uint32 ErrCode ErrCode // contains filtered or unexported fields }
A GoAwayFrame informs the remote peer to stop creating streams on this connection. See http://http2.github.io/http2-spec/#rfc.section.6.8
func (*GoAwayFrame) DebugData ¶
func (f *GoAwayFrame) DebugData() []byte
DebugData returns any debug data in the GOAWAY frame. Its contents are not defined. The caller must not retain the returned memory past the next call to ReadFrame.
type HeadersFrame ¶
type HeadersFrame struct { FrameHeader // Priority is set if FlagHeadersPriority is set in the FrameHeader. Priority PriorityParam // contains filtered or unexported fields }
A HeadersFrame is used to open a stream and additionally carries a header block fragment.
func (*HeadersFrame) HasPriority ¶
func (f *HeadersFrame) HasPriority() bool
func (*HeadersFrame) HeaderBlockFragment ¶
func (f *HeadersFrame) HeaderBlockFragment() []byte
func (*HeadersFrame) HeadersEnded ¶
func (f *HeadersFrame) HeadersEnded() bool
func (*HeadersFrame) StreamEnded ¶
func (f *HeadersFrame) StreamEnded() bool
type HeadersFrameParam ¶
type HeadersFrameParam struct { // StreamID is the required Stream ID to initiate. StreamID uint32 // BlockFragment is part (or all) of a Header Block. BlockFragment []byte // EndStream indicates that the header block is the last that // the endpoint will send for the identified stream. Setting // this flag causes the stream to enter one of "half closed" // states. EndStream bool // EndHeaders indicates that this frame contains an entire // header block and is not followed by any // CONTINUATION frames. EndHeaders bool // PadLength is the optional number of bytes of zeros to add // to this frame. PadLength uint8 // Priority, if non-zero, includes stream priority information // in the HEADER frame. Priority PriorityParam }
HeadersFrameParam are the parameters for writing a HEADERS frame.
type PingFrame ¶
type PingFrame struct { FrameHeader Data [8]byte }
A PingFrame is a mechanism for measuring a minimal round trip time from the sender, as well as determining whether an idle connection is still functional. See http://http2.github.io/http2-spec/#rfc.section.6.7
type PriorityFrame ¶
type PriorityFrame struct { FrameHeader PriorityParam }
A PriorityFrame specifies the sender-advised priority of a stream. See http://http2.github.io/http2-spec/#rfc.section.6.3
type PriorityParam ¶
type PriorityParam struct { // StreamDep is a 31-bit stream identifier for the // stream that this stream depends on. Zero means no // dependency. StreamDep uint32 // Exclusive is whether the dependency is exclusive. Exclusive bool // Weight is the stream's zero-indexed weight. It should be // set together with StreamDep, or neither should be set. Per // the spec, "Add one to the value to obtain a weight between // 1 and 256." Weight uint8 }
PriorityParam are the stream prioritzation parameters.
func (PriorityParam) IsZero ¶
func (p PriorityParam) IsZero() bool
type PushPromiseFrame ¶
type PushPromiseFrame struct { FrameHeader PromiseID uint32 // contains filtered or unexported fields }
A PushPromiseFrame is used to initiate a server stream. See http://http2.github.io/http2-spec/#rfc.section.6.6
func (*PushPromiseFrame) HeaderBlockFragment ¶
func (f *PushPromiseFrame) HeaderBlockFragment() []byte
func (*PushPromiseFrame) HeadersEnded ¶
func (f *PushPromiseFrame) HeadersEnded() bool
type PushPromiseParam ¶
type PushPromiseParam struct { // StreamID is the required Stream ID to initiate. StreamID uint32 // PromiseID is the required Stream ID which this // Push Promises PromiseID uint32 // BlockFragment is part (or all) of a Header Block. BlockFragment []byte // EndHeaders indicates that this frame contains an entire // header block and is not followed by any // CONTINUATION frames. EndHeaders bool // PadLength is the optional number of bytes of zeros to add // to this frame. PadLength uint8 }
PushPromiseParam are the parameters for writing a PUSH_PROMISE frame.
type RSTStreamFrame ¶
type RSTStreamFrame struct { FrameHeader ErrCode ErrCode }
A RSTStreamFrame allows for abnormal termination of a stream. See http://http2.github.io/http2-spec/#rfc.section.6.4
type RoundTripOpt ¶
type RoundTripOpt struct { // OnlyCachedConn controls whether RoundTripOpt may // create a new TCP connection. If set true and // no cached connection is available, RoundTripOpt // will return ErrNoCachedConn. OnlyCachedConn bool }
RoundTripOpt are options for the Transport.RoundTripOpt method.
type Server ¶
type Server struct { // MaxHandlers limits the number of http.Handler ServeHTTP goroutines // which may run at a time over all connections. // Negative or zero no limit. // TODO: implement MaxHandlers int // MaxConcurrentStreams optionally specifies the number of // concurrent streams that each client may have open at a // time. This is unrelated to the number of http.Handler goroutines // which may be active globally, which is MaxHandlers. // If zero, MaxConcurrentStreams defaults to at least 100, per // the HTTP/2 spec's recommendations. MaxConcurrentStreams uint32 // MaxReadFrameSize optionally specifies the largest frame // this server is willing to read. A valid value is between // 16k and 16M, inclusive. If zero or otherwise invalid, a // default value is used. MaxReadFrameSize uint32 // PermitProhibitedCipherSuites, if true, permits the use of // cipher suites prohibited by the HTTP/2 spec. PermitProhibitedCipherSuites bool }
Server is an HTTP/2 server.
type Setting ¶
type Setting struct { // ID is which setting is being set. // See http://http2.github.io/http2-spec/#SettingValues ID SettingID // Val is the value. Val uint32 }
Setting is a setting parameter: which setting it is, and its value.
type SettingID ¶
type SettingID uint16
A SettingID is an HTTP/2 setting as defined in http://http2.github.io/http2-spec/#iana-settings
type SettingsFrame ¶
type SettingsFrame struct { FrameHeader // contains filtered or unexported fields }
A SettingsFrame conveys configuration parameters that affect how endpoints communicate, such as preferences and constraints on peer behavior.
See http://http2.github.io/http2-spec/#SETTINGS
func (*SettingsFrame) ForeachSetting ¶
func (f *SettingsFrame) ForeachSetting(fn func(Setting) error) error
ForeachSetting runs fn for each setting. It stops and returns the first error.
func (*SettingsFrame) IsAck ¶
func (f *SettingsFrame) IsAck() bool
type StreamError ¶
StreamError is an error that only affects one stream within an HTTP/2 connection.
func (StreamError) Error ¶
func (e StreamError) Error() string
type Transport ¶
type Transport struct { // DialTLS specifies an optional dial function for creating // TLS connections for requests. // // If DialTLS is nil, tls.Dial is used. // // If the returned net.Conn has a ConnectionState method like tls.Conn, // it will be used to set http.Response.TLS. DialTLS func(network, addr string, cfg *tls.Config) (net.Conn, error) // TLSClientConfig specifies the TLS configuration to use with // tls.Client. If nil, the default configuration is used. TLSClientConfig *tls.Config // ConnPool optionally specifies an alternate connection pool to use. // If nil, the default is used. ConnPool ClientConnPool // contains filtered or unexported fields }
Transport is an HTTP/2 Transport.
A Transport internally caches connections to servers. It is safe for concurrent use by multiple goroutines.
func (*Transport) CloseIdleConnections ¶
func (t *Transport) CloseIdleConnections()
CloseIdleConnections closes any connections which were previously connected from previous requests but are now sitting idle. It does not interrupt any connections currently in use.
func (*Transport) NewClientConn ¶
func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error)
func (*Transport) RoundTripOpt ¶
RoundTripOpt is like RoundTrip, but takes options.
type UnknownFrame ¶
type UnknownFrame struct { FrameHeader // contains filtered or unexported fields }
An UnknownFrame is the frame type returned when the frame type is unknown or no specific frame type parser exists.
func (*UnknownFrame) Payload ¶
func (f *UnknownFrame) Payload() []byte
Payload returns the frame's payload (after the header). It is not valid to call this method after a subsequent call to Framer.ReadFrame, nor is it valid to retain the returned slice. The memory is owned by the Framer and is invalidated when the next frame is read.
type WindowUpdateFrame ¶
type WindowUpdateFrame struct { FrameHeader Increment uint32 // never read with high bit set }
A WindowUpdateFrame is used to implement flow control. See http://http2.github.io/http2-spec/#rfc.section.6.9
Source Files ¶
Directories ¶
Path | Synopsis |
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The h2i command is an interactive HTTP/2 console.
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The h2i command is an interactive HTTP/2 console. |
Package hpack implements HPACK, a compression format for efficiently representing HTTP header fields in the context of HTTP/2.
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Package hpack implements HPACK, a compression format for efficiently representing HTTP header fields in the context of HTTP/2. |