81 KiB
HTTP2
Stability: 1 - Experimental
The http2
module provides an implementation of the HTTP/2 protocol. It
can be accessed using:
const http2 = require('http2');
Core API
The Core API provides a low-level interface designed specifically around support for HTTP/2 protocol features. It is specifically not designed for compatibility with the existing HTTP/1 module API. However, the Compatibility API is.
The following illustrates a simple, plain-text HTTP/2 server using the Core API:
const http2 = require('http2');
// Create a plain-text HTTP/2 server
const server = http2.createServer();
server.on('stream', (stream, headers) => {
// stream is a Duplex
stream.respond({
'content-type': 'text/html',
':status': 200
});
stream.end('<h1>Hello World</h1>');
});
server.listen(80);
Note that the above example is an HTTP/2 server that does not support SSL.
This is significant as most browsers support HTTP/2 only with SSL.
To make the above server be able to serve content to browsers,
replace http2.createServer()
with
http2.createSecureServer({key: /* your SSL key */, cert: /* your SSL cert */})
.
The following illustrates an HTTP/2 client:
const http2 = require('http2');
const client = http2.connect('http://localhost:80');
// req is a Duplex
const req = client.request({ ':path': '/' });
req.on('response', (headers) => {
console.log(headers[':status']);
console.log(headers['date']);
});
let data = '';
req.setEncoding('utf8');
req.on('data', (d) => data += d);
req.on('end', () => client.destroy());
req.end();
Class: Http2Session
- Extends: {EventEmitter}
Instances of the http2.Http2Session
class represent an active communications
session between an HTTP/2 client and server. Instances of this class are not
intended to be constructed directly by user code.
Each Http2Session
instance will exhibit slightly different behaviors
depending on whether it is operating as a server or a client. The
http2session.type
property can be used to determine the mode in which an
Http2Session
is operating. On the server side, user code should rarely
have occasion to work with the Http2Session
object directly, with most
actions typically taken through interactions with either the Http2Server
or
Http2Stream
objects.
Http2Session and Sockets
Every Http2Session
instance is associated with exactly one net.Socket
or
tls.TLSSocket
when it is created. When either the Socket
or the
Http2Session
are destroyed, both will be destroyed.
Because the of the specific serialization and processing requirements imposed
by the HTTP/2 protocol, it is not recommended for user code to read data from
or write data to a Socket
instance bound to a Http2Session
. Doing so can
put the HTTP/2 session into an indeterminate state causing the session and
the socket to become unusable.
Once a Socket
has been bound to an Http2Session
, user code should rely
solely on the API of the Http2Session
.
Event: 'close'
The 'close'
event is emitted once the Http2Session
has been terminated.
Event: 'connect'
The 'connect'
event is emitted once the Http2Session
has been successfully
connected to the remote peer and communication may begin.
Note: User code will typically not listen for this event directly.
Event: 'error'
The 'error'
event is emitted when an error occurs during the processing of
an Http2Session
.
Event: 'frameError'
The 'frameError'
event is emitted when an error occurs while attempting to
send a frame on the session. If the frame that could not be sent is associated
with a specific Http2Stream
, an attempt to emit 'frameError'
event on the
Http2Stream
is made.
When invoked, the handler function will receive three arguments:
- An integer identifying the frame type.
- An integer identifying the error code.
- An integer identifying the stream (or 0 if the frame is not associated with a stream).
If the 'frameError'
event is associated with a stream, the stream will be
closed and destroyed immediately following the 'frameError'
event. If the
event is not associated with a stream, the Http2Session
will be shutdown
immediately following the 'frameError'
event.
Event: 'goaway'
The 'goaway'
event is emitted when a GOAWAY frame is received. When invoked,
the handler function will receive three arguments:
errorCode
{number} The HTTP/2 error code specified in the GOAWAY frame.lastStreamID
{number} The ID of the last stream the remote peer successfully processed (or0
if no ID is specified).opaqueData
{Buffer} If additional opaque data was included in the GOAWAY frame, aBuffer
instance will be passed containing that data.
Note: The Http2Session
instance will be shutdown automatically when the
'goaway'
event is emitted.
Event: 'localSettings'
The 'localSettings'
event is emitted when an acknowledgement SETTINGS frame
has been received. When invoked, the handler function will receive a copy of
the local settings.
Note: When using http2session.settings()
to submit new settings, the
modified settings do not take effect until the 'localSettings'
event is
emitted.
session.settings({ enablePush: false });
session.on('localSettings', (settings) => {
/** use the new settings **/
});
Event: 'remoteSettings'
The 'remoteSettings'
event is emitted when a new SETTINGS frame is received
from the connected peer. When invoked, the handler function will receive a copy
of the remote settings.
session.on('remoteSettings', (settings) => {
/** use the new settings **/
});
Event: 'stream'
The 'stream'
event is emitted when a new Http2Stream
is created. When
invoked, the handler function will receive a reference to the Http2Stream
object, a Headers Object, and numeric flags associated with the creation
of the stream.
const http2 = require('http2');
const {
HTTP2_HEADER_METHOD,
HTTP2_HEADER_PATH,
HTTP2_HEADER_STATUS,
HTTP2_HEADER_CONTENT_TYPE
} = http2.constants;
session.on('stream', (stream, headers, flags) => {
const method = headers[HTTP2_HEADER_METHOD];
const path = headers[HTTP2_HEADER_PATH];
// ...
stream.respond({
[HTTP2_HEADER_STATUS]: 200,
[HTTP2_HEADER_CONTENT_TYPE]: 'text/plain'
});
stream.write('hello ');
stream.end('world');
});
On the server side, user code will typically not listen for this event directly,
and would instead register a handler for the 'stream'
event emitted by the
net.Server
or tls.Server
instances returned by http2.createServer()
and
http2.createSecureServer()
, respectively, as in the example below:
const http2 = require('http2');
// Create a plain-text HTTP/2 server
const server = http2.createServer();
server.on('stream', (stream, headers) => {
stream.respond({
'content-type': 'text/html',
':status': 200
});
stream.end('<h1>Hello World</h1>');
});
server.listen(80);
Event: 'socketError'
The 'socketError'
event is emitted when an 'error'
is emitted on the
Socket
instance bound to the Http2Session
. If this event is not handled,
the 'error'
event will be re-emitted on the Socket
.
For ServerHttp2Session
instances, a 'socketError'
event listener is always
registered that will, by default, forward the event on to the owning
Http2Server
instance if no additional handlers are registered.
Event: 'timeout'
After the http2session.setTimeout()
method is used to set the timeout period
for this Http2Session
, the 'timeout'
event is emitted if there is no
activity on the Http2Session
after the configured number of milliseconds.
session.setTimeout(2000);
session.on('timeout', () => { /** .. **/ });
http2session.destroy()
- Returns: {undefined}
Immediately terminates the Http2Session
and the associated net.Socket
or
tls.TLSSocket
.
http2session.destroyed
- Value: {boolean}
Will be true
if this Http2Session
instance has been destroyed and must no
longer be used, otherwise false
.
http2session.localSettings
- Value: {Settings Object}
A prototype-less object describing the current local settings of this
Http2Session
. The local settings are local to this Http2Session
instance.
http2session.pendingSettingsAck
- Value: {boolean}
Indicates whether or not the Http2Session
is currently waiting for an
acknowledgement for a sent SETTINGS frame. Will be true
after calling the
http2session.settings()
method. Will be false
once all sent SETTINGS
frames have been acknowledged.
http2session.remoteSettings
- Value: {Settings Object}
A prototype-less object describing the current remote settings of this
Http2Session
. The remote settings are set by the connected HTTP/2 peer.
http2session.request(headers[, options])
-
headers
{Headers Object} -
options
{Object}endStream
{boolean}true
if theHttp2Stream
writable side should be closed initially, such as when sending aGET
request that should not expect a payload body.exclusive
{boolean} Whentrue
andparent
identifies a parent Stream, the created stream is made the sole direct dependency of the parent, with all other existing dependents made a dependent of the newly created stream. Defaults tofalse
.parent
{number} Specifies the numeric identifier of a stream the newly created stream is dependent on.weight
{number} Specifies the relative dependency of a stream in relation to other streams with the sameparent
. The value is a number between1
and256
(inclusive).getTrailers
{Function} Callback function invoked to collect trailer headers.
-
Returns: {ClientHttp2Stream}
For HTTP/2 Client Http2Session
instances only, the http2session.request()
creates and returns an Http2Stream
instance that can be used to send an
HTTP/2 request to the connected server.
This method is only available if http2session.type
is equal to
http2.constants.NGHTTP2_SESSION_CLIENT
.
const http2 = require('http2');
const clientSession = http2.connect('https://localhost:1234');
const {
HTTP2_HEADER_PATH,
HTTP2_HEADER_STATUS
} = http2.constants;
const req = clientSession.request({ [HTTP2_HEADER_PATH]: '/' });
req.on('response', (headers) => {
console.log(headers[HTTP2_HEADER_STATUS]);
req.on('data', (chunk) => { /** .. **/ });
req.on('end', () => { /** .. **/ });
});
When set, the options.getTrailers()
function is called immediately after
queuing the last chunk of payload data to be sent. The callback is passed a
single object (with a null
prototype) that the listener may used to specify
the trailing header fields to send to the peer.
Note: The HTTP/1 specification forbids trailers from containing HTTP/2
"pseudo-header" fields (e.g. ':method'
, ':path'
, etc). An 'error'
event
will be emitted if the getTrailers
callback attempts to set such header
fields.
http2session.rstStream(stream, code)
- stream {Http2Stream}
- code {number} Unsigned 32-bit integer identifying the error code. Defaults to
http2.constant.NGHTTP2_NO_ERROR
(0x00
) - Returns: {undefined}
Sends an RST_STREAM
frame to the connected HTTP/2 peer, causing the given
Http2Stream
to be closed on both sides using error code code
.
http2session.setTimeout(msecs, callback)
msecs
{number}callback
{Function}- Returns: {undefined}
Used to set a callback function that is called when there is no activity on
the Http2Session
after msecs
milliseconds. The given callback
is
registered as a listener on the 'timeout'
event.
http2session.shutdown(options[, callback])
options
{Object}graceful
{boolean}true
to attempt a polite shutdown of theHttp2Session
.errorCode
{number} The HTTP/2 error code to return. Note that this is not the same thing as an HTTP Response Status Code. Defaults to0x00
(No Error).lastStreamID
{number} The Stream ID of the last successfully processedHttp2Stream
on thisHttp2Session
.opaqueData
{Buffer|Uint8Array} ABuffer
orUint8Array
instance containing arbitrary additional data to send to the peer upon disconnection. This is used, typically, to provide additional data for debugging failures, if necessary.
callback
{Function} A callback that is invoked after the session shutdown has been completed.- Returns: {undefined}
Attempts to shutdown this Http2Session
using HTTP/2 defined procedures.
If specified, the given callback
function will be invoked once the shutdown
process has completed.
Note that calling http2session.shutdown()
does not destroy the session or
tear down the Socket
connection. It merely prompts both sessions to begin
preparing to cease activity.
During a "graceful" shutdown, the session will first send a GOAWAY
frame to
the connected peer identifying the last processed stream as 232-1.
Then, on the next tick of the event loop, a second GOAWAY
frame identifying
the most recently processed stream identifier is sent. This process allows the
remote peer to begin preparing for the connection to be terminated.
session.shutdown({
graceful: true,
opaqueData: Buffer.from('add some debugging data here')
}, () => session.destroy());
http2session.socket
- Value: {net.Socket|tls.TLSSocket}
A reference to the net.Socket
or tls.TLSSocket
to which this
Http2Session
instance is bound.
Note: It is not recommended for user code to interact directly with a
Socket
bound to an Http2Session
. See Http2Session and Sockets for
details.
http2session.state
- Value: {Object}
effectiveLocalWindowSize
{number}effectiveRecvDataLength
{number}nextStreamID
{number}localWindowSize
{number}lastProcStreamID
{number}remoteWindowSize
{number}outboundQueueSize
{number}deflateDynamicTableSize
{number}inflateDynamicTableSize
{number}
An object describing the current status of this Http2Session
.
http2session.priority(stream, options)
stream
{Http2Stream}options
{Object}exclusive
{boolean} Whentrue
andparent
identifies a parent Stream, the given stream is made the sole direct dependency of the parent, with all other existing dependents made a dependent of the given stream. Defaults tofalse
.parent
{number} Specifies the numeric identifier of a stream the given stream is dependent on.weight
{number} Specifies the relative dependency of a stream in relation to other streams with the sameparent
. The value is a number between1
and256
(inclusive).silent
{boolean} Whentrue
, changes the priority locally without sending aPRIORITY
frame to the connected peer.
- Returns: {undefined}
Updates the priority for the given Http2Stream
instance.
http2session.settings(settings)
settings
{Settings Object}- Returns {undefined}
Updates the current local settings for this Http2Session
and sends a new
SETTINGS
frame to the connected HTTP/2 peer.
Once called, the http2session.pendingSettingsAck
property will be true
while the session is waiting for the remote peer to acknowledge the new
settings.
Note: The new settings will not become effective until the SETTINGS
acknowledgement is received and the 'localSettings'
event is emitted. It
is possible to send multiple SETTINGS frames while acknowledgement is still
pending.
http2session.type
- Value: {number}
The http2session.type
will be equal to
http2.constants.NGHTTP2_SESSION_SERVER
if this Http2Session
instance is a
server, and http2.constants.NGHTTP2_SESSION_CLIENT
if the instance is a
client.
Class: Http2Stream
- Extends: {Duplex}
Each instance of the Http2Stream
class represents a bidirectional HTTP/2
communications stream over an Http2Session
instance. Any single Http2Session
may have up to 231-1 Http2Stream
instances over its lifetime.
User code will not construct Http2Stream
instances directly. Rather, these
are created, managed, and provided to user code through the Http2Session
instance. On the server, Http2Stream
instances are created either in response
to an incoming HTTP request (and handed off to user code via the 'stream'
event), or in response to a call to the http2stream.pushStream()
method.
On the client, Http2Stream
instances are created and returned when either the
http2session.request()
method is called, or in response to an incoming
'push'
event.
Note: The Http2Stream
class is a base for the ServerHttp2Stream
and
ClientHttp2Stream
classes, each of which are used specifically by either
the Server or Client side, respectively.
All Http2Stream
instances are Duplex
streams. The Writable
side of the
Duplex
is used to send data to the connected peer, while the Readable
side
is used to receive data sent by the connected peer.
Http2Stream Lifecycle
Creation
On the server side, instances of ServerHttp2Stream
are created either
when:
- A new HTTP/2
HEADERS
frame with a previously unused stream ID is received; - The
http2stream.pushStream()
method is called.
On the client side, instances of ClientHttp2Stream
are created when the
http2session.request()
method is called.
Note: On the client, the Http2Stream
instance returned by
http2session.request()
may not be immediately ready for use if the parent
Http2Session
has not yet been fully established. In such cases, operations
called on the Http2Stream
will be buffered until the 'ready'
event is
emitted. User code should rarely, if ever, have need to handle the 'ready'
event directly. The ready status of an Http2Stream
can be determined by
checking the value of http2stream.id
. If the value is undefined
, the stream
is not yet ready for use.
Destruction
All Http2Stream
instances are destroyed either when:
- An
RST_STREAM
frame for the stream is received by the connected peer. - The
http2stream.rstStream()
orhttp2session.rstStream()
methods are called. - The
http2stream.destroy()
orhttp2session.destroy()
methods are called.
When an Http2Stream
instance is destroyed, an attempt will be made to send an
RST_STREAM
frame will be sent to the connected peer.
Once the Http2Stream
instance is destroyed, the 'streamClosed'
event will
be emitted. Because Http2Stream
is an instance of stream.Duplex
, the
'end'
event will also be emitted if the stream data is currently flowing.
The 'error'
event may also be emitted if http2stream.destroy()
was called
with an Error
passed as the first argument.
After the Http2Stream
has been destroyed, the http2stream.destroyed
property will be true
and the http2stream.rstCode
property will specify the
RST_STREAM
error code. The Http2Stream
instance is no longer usable once
destroyed.
Event: 'aborted'
The 'aborted'
event is emitted whenever a Http2Stream
instance is
abnormally aborted in mid-communication.
Note: The 'aborted'
event will only be emitted if the Http2Stream
writable side has not been ended.
Event: 'error'
The 'error'
event is emitted when an error occurs during the processing of
an Http2Stream
.
Event: 'frameError'
The 'frameError'
event is emitted when an error occurs while attempting to
send a frame. When invoked, the handler function will receive an integer
argument identifying the frame type, and an integer argument identifying the
error code. The Http2Stream
instance will be destroyed immediately after the
'frameError'
event is emitted.
Event: 'streamClosed'
The 'streamClosed'
event is emitted when the Http2Stream
is destroyed. Once
this event is emitted, the Http2Stream
instance is no longer usable.
The listener callback is passed a single argument specifying the HTTP/2 error
code specified when closing the stream. If the code is any value other than
NGHTTP2_NO_ERROR
(0
), an 'error'
event will also be emitted.
Event: 'timeout'
The 'timeout'
event is emitted after no activity is received for this
'Http2Stream'
within the number of millseconds set using
http2stream.setTimeout()
.
Event: 'trailers'
The 'trailers'
event is emitted when a block of headers associated with
trailing header fields is received. The listener callback is passed the
Headers Object and flags associated with the headers.
stream.on('trailers', (headers, flags) => {
console.log(headers);
});
http2stream.aborted
- Value: {boolean}
Set to true
if the Http2Stream
instance was aborted abnormally. When set,
the 'aborted'
event will have been emitted.
http2stream.destroyed
- Value: {boolean}
Set to true
if the Http2Stream
instance has been destroyed and is no longer
usable.
http2stream.priority(options)
options
{Object}exclusive
{boolean} Whentrue
andparent
identifies a parent Stream, this stream is made the sole direct dependency of the parent, with all other existing dependents made a dependent of this stream. Defaults tofalse
.parent
{number} Specifies the numeric identifier of a stream this stream is dependent on.weight
{number} Specifies the relative dependency of a stream in relation to other streams with the sameparent
. The value is a number between1
and256
(inclusive).silent
{boolean} Whentrue
, changes the priority locally without sending aPRIORITY
frame to the connected peer.
- Returns: {undefined}
Updates the priority for this Http2Stream
instance.
http2stream.rstCode
- Value: {number}
Set to the RST_STREAM
error code reported when the Http2Stream
is
destroyed after either receiving an RST_STREAM
frame from the connected peer,
calling http2stream.rstStream()
, or http2stream.destroy()
. Will be
undefined
if the Http2Stream
has not been closed.
http2stream.rstStream(code)
- code {number} Unsigned 32-bit integer identifying the error code. Defaults to
http2.constant.NGHTTP2_NO_ERROR
(0x00
) - Returns: {undefined}
Sends an RST_STREAM
frame to the connected HTTP/2 peer, causing this
Http2Stream
to be closed on both sides using error code code
.
http2stream.rstWithNoError()
- Returns: {undefined}
Shortcut for http2stream.rstStream()
using error code 0x00
(No Error).
http2stream.rstWithProtocolError()
- Returns: {undefined}
Shortcut for http2stream.rstStream()
using error code 0x01
(Protocol Error).
http2stream.rstWithCancel()
- Returns: {undefined}
Shortcut for http2stream.rstStream()
using error code 0x08
(Cancel).
http2stream.rstWithRefuse()
- Returns: {undefined}
Shortcut for http2stream.rstStream()
using error code 0x07
(Refused Stream).
http2stream.rstWithInternalError()
- Returns: {undefined}
Shortcut for http2stream.rstStream()
using error code 0x02
(Internal Error).
http2stream.session
- Value: {Http2Sesssion}
A reference to the Http2Session
instance that owns this Http2Stream
. The
value will be undefined
after the Http2Stream
instance is destroyed.
http2stream.setTimeout(msecs, callback)
msecs
{number}callback
{Function}- Returns: {undefined}
const http2 = require('http2');
const client = http2.connect('http://example.org:8000');
const req = client.request({ ':path': '/' });
// Cancel the stream if there's no activity after 5 seconds
req.setTimeout(5000, () => req.rstStreamWithCancel());
http2stream.state
- Value: {Object}
localWindowSize
{number}state
{number}localClose
{number}remoteClose
{number}sumDependencyWeight
{number}weight
{number}
A current state of this Http2Stream
.
Class: ClientHttp2Stream
- Extends {Http2Stream}
The ClientHttp2Stream
class is an extension of Http2Stream
that is
used exclusively on HTTP/2 Clients. Http2Stream
instances on the client
provide events such as 'response'
and 'push'
that are only relevant on
the client.
Event: 'continue'
Emitted when the server sends a 100 Continue
status, usually because
the request contained Expect: 100-continue
. This is an instruction that
the client should send the request body.
Event: 'headers'
The 'headers'
event is emitted when an additional block of headers is received
for a stream, such as when a block of 1xx
informational headers are received.
The listener callback is passed the Headers Object and flags associated with
the headers.
stream.on('headers', (headers, flags) => {
console.log(headers);
});
Event: 'push'
The 'push'
event is emitted when response headers for a Server Push stream
are received. The listener callback is passed the Headers Object and flags
associated with the headers.
stream.on('push', (headers, flags) => {
console.log(headers);
});
Event: 'response'
The 'response'
event is emitted when a response HEADERS
frame has been
received for this stream from the connected HTTP/2 server. The listener is
invoked with two arguments: an Object containing the received
Headers Object, and flags associated with the headers.
For example:
const http2 = require('http2');
const client = http2.connect('https://localhost');
const req = client.request({ ':path': '/' });
req.on('response', (headers, flags) => {
console.log(headers[':status']);
});
Class: ServerHttp2Stream
- Extends: {Http2Stream}
The ServerHttp2Stream
class is an extension of Http2Stream
that is
used exclusively on HTTP/2 Servers. Http2Stream
instances on the server
provide additional methods such as http2stream.pushStream()
and
http2stream.respond()
that are only relevant on the server.
http2stream.additionalHeaders(headers)
headers
{Headers Object}- Returns: {undefined}
Sends an additional informational HEADERS
frame to the connected HTTP/2 peer.
http2stream.headersSent
- Value: {boolean}
Boolean (read-only). True if headers were sent, false otherwise.
http2stream.pushAllowed
- Value: {boolean}
Read-only property mapped to the SETTINGS_ENABLE_PUSH
flag of the remote
client's most recent SETTINGS
frame. Will be true
if the remote peer
accepts push streams, false
otherwise. Settings are the same for every
Http2Stream
in the same Http2Session
.
http2stream.pushStream(headers[, options], callback)
headers
{Headers Object}options
{Object}exclusive
{boolean} Whentrue
andparent
identifies a parent Stream, the created stream is made the sole direct dependency of the parent, with all other existing dependents made a dependent of the newly created stream. Defaults tofalse
.parent
{number} Specifies the numeric identifier of a stream the newly created stream is dependent on.weight
{number} Specifies the relative dependency of a stream in relation to other streams with the sameparent
. The value is a number between1
and256
(inclusive).
callback
{Function} Callback that is called once the push stream has been initiated.- Returns: {undefined}
Initiates a push stream. The callback is invoked with the new Http2Stream
instance created for the push stream.
const http2 = require('http2');
const server = http2.createServer();
server.on('stream', (stream) => {
stream.respond({ ':status': 200 });
stream.pushStream({ ':path': '/' }, (pushStream) => {
pushStream.respond({ ':status': 200 });
pushStream.end('some pushed data');
});
stream.end('some data');
});
http2stream.respond([headers[, options]])
headers
{Headers Object}options
{Object}endStream
{boolean} Set totrue
to indicate that the response will not include payload data.getTrailers
{function} Callback function invoked to collect trailer headers.
- Returns: {undefined}
const http2 = require('http2');
const server = http2.createServer();
server.on('stream', (stream) => {
stream.respond({ ':status': 200 });
stream.end('some data');
});
When set, the options.getTrailers()
function is called immediately after
queuing the last chunk of payload data to be sent. The callback is passed a
single object (with a null
prototype) that the listener may used to specify
the trailing header fields to send to the peer.
const http2 = require('http2');
const server = http2.createServer();
server.on('stream', (stream) => {
stream.respond({ ':status': 200 }, {
getTrailers(trailers) {
trailers['ABC'] = 'some value to send';
}
});
stream.end('some data');
});
Note: The HTTP/1 specification forbids trailers from containing HTTP/2
"pseudo-header" fields (e.g. ':status'
, ':path'
, etc). An 'error'
event
will be emitted if the getTrailers
callback attempts to set such header
fields.
http2stream.respondWithFD(fd[, headers[, options]])
fd
{number} A readable file descriptorheaders
{Headers Object}options
{Object}statCheck
{Function}getTrailers
{Function} Callback function invoked to collect trailer headers.offset
{number} The offset position at which to begin readinglength
{number} The amount of data from the fd to send
Initiates a response whose data is read from the given file descriptor. No
validation is performed on the given file descriptor. If an error occurs while
attempting to read data using the file descriptor, the Http2Stream
will be
closed using an RST_STREAM
frame using the standard INTERNAL_ERROR
code.
When used, the Http2Stream
object's Duplex interface will be closed
automatically.
const http2 = require('http2');
const fs = require('fs');
const fd = fs.openSync('/some/file', 'r');
const server = http2.createServer();
server.on('stream', (stream) => {
const stat = fs.fstatSync(fd);
const headers = {
'content-length': stat.size,
'last-modified': stat.mtime.toUTCString(),
'content-type': 'text/plain'
};
stream.respondWithFD(fd, headers);
});
server.on('close', () => fs.closeSync(fd));
The optional options.statCheck
function may be specified to give user code
an opportunity to set additional content headers based on the fs.Stat
details
of the given fd. If the statCheck
function is provided, the
http2stream.respondWithFD()
method will perform an fs.fstat()
call to
collect details on the provided file descriptor.
The offset
and length
options may be used to limit the response to a
specific range subset. This can be used, for instance, to support HTTP Range
requests.
When set, the options.getTrailers()
function is called immediately after
queuing the last chunk of payload data to be sent. The callback is passed a
single object (with a null
prototype) that the listener may used to specify
the trailing header fields to send to the peer.
const http2 = require('http2');
const fs = require('fs');
const fd = fs.openSync('/some/file', 'r');
const server = http2.createServer();
server.on('stream', (stream) => {
const stat = fs.fstatSync(fd);
const headers = {
'content-length': stat.size,
'last-modified': stat.mtime.toUTCString(),
'content-type': 'text/plain'
};
stream.respondWithFD(fd, headers, {
getTrailers(trailers) {
trailers['ABC'] = 'some value to send';
}
});
});
server.on('close', () => fs.closeSync(fd));
Note: The HTTP/1 specification forbids trailers from containing HTTP/2
"pseudo-header" fields (e.g. ':status'
, ':path'
, etc). An 'error'
event
will be emitted if the getTrailers
callback attempts to set such header
fields.
http2stream.respondWithFile(path[, headers[, options]])
path
{string|Buffer|URL}headers
{Headers Object}options
{Object}statCheck
{Function}onError
{Function} Callback function invoked in the case of an Error before sendgetTrailers
{Function} Callback function invoked to collect trailer headers.offset
{number} The offset position at which to begin readinglength
{number} The amount of data from the fd to send
Sends a regular file as the response. The path
must specify a regular file
or an 'error'
event will be emitted on the Http2Stream
object.
When used, the Http2Stream
object's Duplex interface will be closed
automatically.
The optional options.statCheck
function may be specified to give user code
an opportunity to set additional content headers based on the fs.Stat
details
of the given file:
If an error occurs while attempting to read the file data, the Http2Stream
will be closed using an RST_STREAM
frame using the standard INTERNAL_ERROR
code. If the onError
callback is defined it will be called, otherwise
the stream will be destroyed.
Example using a file path:
const http2 = require('http2');
const server = http2.createServer();
server.on('stream', (stream) => {
function statCheck(stat, headers) {
headers['last-modified'] = stat.mtime.toUTCString();
}
function onError(err) {
if (err.code === 'ENOENT') {
stream.respond({ ':status': 404 });
} else {
stream.respond({ ':status': 500 });
}
stream.end();
}
stream.respondWithFile('/some/file',
{ 'content-type': 'text/plain' },
{ statCheck, onError });
});
The options.statCheck
function may also be used to cancel the send operation
by returning false
. For instance, a conditional request may check the stat
results to determine if the file has been modified to return an appropriate
304
response:
const http2 = require('http2');
const server = http2.createServer();
server.on('stream', (stream) => {
function statCheck(stat, headers) {
// Check the stat here...
stream.respond({ ':status': 304 });
return false; // Cancel the send operation
}
stream.respondWithFile('/some/file',
{ 'content-type': 'text/plain' },
{ statCheck });
});
The content-length
header field will be automatically set.
The offset
and length
options may be used to limit the response to a
specific range subset. This can be used, for instance, to support HTTP Range
requests.
The options.onError
function may also be used to handle all the errors
that could happen before the delivery of the file is initiated. The
default behavior is to destroy the stream.
When set, the options.getTrailers()
function is called immediately after
queuing the last chunk of payload data to be sent. The callback is passed a
single object (with a null
prototype) that the listener may used to specify
the trailing header fields to send to the peer.
const http2 = require('http2');
const server = http2.createServer();
server.on('stream', (stream) => {
function getTrailers(trailers) {
trailers['ABC'] = 'some value to send';
}
stream.respondWithFile('/some/file',
{ 'content-type': 'text/plain' },
{ getTrailers });
});
Note: The HTTP/1 specification forbids trailers from containing HTTP/2
"pseudo-header" fields (e.g. ':status'
, ':path'
, etc). An 'error'
event
will be emitted if the getTrailers
callback attempts to set such header
fields.
Class: Http2Server
- Extends: {net.Server}
In Http2Server
, there is no 'clientError'
event as there is in
HTTP1. However, there are 'socketError'
, 'sessionError'
, and
'streamError'
, for error happened on the socket, session or stream
respectively.
Event: 'socketError'
The 'socketError'
event is emitted when a 'socketError'
event is emitted by
an Http2Session
associated with the server.
Event: 'sessionError'
The 'sessionError'
event is emitted when an 'error'
event is emitted by
an Http2Session
object. If no listener is registered for this event, an
'error'
event is emitted.
Event: 'streamError'
socket
{http2.ServerHttp2Stream}
If an ServerHttp2Stream
emits an 'error'
event, it will be forwarded here.
The stream will already be destroyed when this event is triggered.
Event: 'stream'
The 'stream'
event is emitted when a 'stream'
event has been emitted by
an Http2Session
associated with the server.
const http2 = require('http2');
const {
HTTP2_HEADER_METHOD,
HTTP2_HEADER_PATH,
HTTP2_HEADER_STATUS,
HTTP2_HEADER_CONTENT_TYPE
} = http2.constants;
const server = http2.createServer();
server.on('stream', (stream, headers, flags) => {
const method = headers[HTTP2_HEADER_METHOD];
const path = headers[HTTP2_HEADER_PATH];
// ...
stream.respond({
[HTTP2_HEADER_STATUS]: 200,
[HTTP2_HEADER_CONTENT_TYPE]: 'text/plain'
});
stream.write('hello ');
stream.end('world');
});
Event: 'request'
request
{http2.Http2ServerRequest}response
{http2.Http2ServerResponse}
Emitted each time there is a request. Note that there may be multiple requests per session. See the Compatibility API.
Event: 'timeout'
The 'timeout'
event is emitted when there is no activity on the Server for
a given number of milliseconds set using http2server.setTimeout()
.
Event: 'checkContinue'
request
{http2.Http2ServerRequest}response
{http2.Http2ServerResponse}
If a 'request'
listener is registered or ['http2.createServer()'
][] is
supplied a callback function, the 'checkContinue'
event is emitted each time
a request with an HTTP Expect: 100-continue
is received. If this event is
not listened for, the server will automatically respond with a status
100 Continue
as appropriate.
Handling this event involves calling response.writeContinue()
if the client
should continue to send the request body, or generating an appropriate HTTP
response (e.g. 400 Bad Request) if the client should not continue to send the
request body.
Note that when this event is emitted and handled, the 'request'
event will
not be emitted.
Class: Http2SecureServer
- Extends: {tls.Server}
Event: 'sessionError'
The 'sessionError'
event is emitted when an 'error'
event is emitted by
an Http2Session
object. If no listener is registered for this event, an
'error'
event is emitted on the Http2Session
instance instead.
Event: 'socketError'
The 'socketError'
event is emitted when a 'socketError'
event is emitted by
an Http2Session
associated with the server.
Event: 'unknownProtocol'
The 'unknownProtocol'
event is emitted when a connecting client fails to
negotiate an allowed protocol (i.e. HTTP/2 or HTTP/1.1). The event handler
receives the socket for handling. If no listener is registered for this event,
the connection is terminated. See the Compatibility API.
Event: 'stream'
The 'stream'
event is emitted when a 'stream'
event has been emitted by
an Http2Session
associated with the server.
const http2 = require('http2');
const {
HTTP2_HEADER_METHOD,
HTTP2_HEADER_PATH,
HTTP2_HEADER_STATUS,
HTTP2_HEADER_CONTENT_TYPE
} = http2.constants;
const options = getOptionsSomehow();
const server = http2.createSecureServer(options);
server.on('stream', (stream, headers, flags) => {
const method = headers[HTTP2_HEADER_METHOD];
const path = headers[HTTP2_HEADER_PATH];
// ...
stream.respond({
[HTTP2_HEADER_STATUS]: 200,
[HTTP2_HEADER_CONTENT_TYPE]: 'text/plain'
});
stream.write('hello ');
stream.end('world');
});
Event: 'request'
request
{http2.Http2ServerRequest}response
{http2.Http2ServerResponse}
Emitted each time there is a request. Note that there may be multiple requests per session. See the Compatibility API.
Event: 'timeout'
Event: 'checkContinue'
request
{http2.Http2ServerRequest}response
{http2.Http2ServerResponse}
If a 'request'
listener is registered or ['http2.createSecureServer()'
][]
is supplied a callback function, the 'checkContinue'
event is emitted each
time a request with an HTTP Expect: 100-continue
is received. If this event
is not listened for, the server will automatically respond with a status
100 Continue
as appropriate.
Handling this event involves calling response.writeContinue()
if the client
should continue to send the request body, or generating an appropriate HTTP
response (e.g. 400 Bad Request) if the client should not continue to send the
request body.
Note that when this event is emitted and handled, the 'request'
event will
not be emitted.
http2.createServer(options[, onRequestHandler])
options
{Object}maxDeflateDynamicTableSize
{number} Sets the maximum dynamic table size for deflating header fields. Defaults to 4Kib.maxSendHeaderBlockLength
{number} Sets the maximum allowed size for a serialized, compressed block of headers. Attempts to send headers that exceed this limit will result in a'frameError'
event being emitted and the stream being closed and destroyed.paddingStrategy
{number} Identifies the strategy used for determining the amount of padding to use for HEADERS and DATA frames. Defaults tohttp2.constants.PADDING_STRATEGY_NONE
. Value may be one of:http2.constants.PADDING_STRATEGY_NONE
- Specifies that no padding is to be applied.http2.constants.PADDING_STRATEGY_MAX
- Specifies that the maximum amount of padding, as determined by the internal implementation, is to be applied.http2.constants.PADDING_STRATEGY_CALLBACK
- Specifies that the user providedoptions.selectPadding
callback is to be used to determine the amount of padding.
peerMaxConcurrentStreams
{number} Sets the maximum number of concurrent streams for the remote peer as if a SETTINGS frame had been received. Will be overridden if the remote peer sets its own value formaxConcurrentStreams
. Defaults to 100.selectPadding
{Function} Whenoptions.paddingStrategy
is equal tohttp2.constants.PADDING_STRATEGY_CALLBACK
, provides the callback function used to determine the padding. See Using options.selectPadding.settings
{Settings Object} The initial settings to send to the remote peer upon connection.
onRequestHandler
{Function} See Compatibility API- Returns: {Http2Server}
Returns a net.Server
instance that creates and manages Http2Session
instances.
const http2 = require('http2');
// Create a plain-text HTTP/2 server
const server = http2.createServer();
server.on('stream', (stream, headers) => {
stream.respond({
'content-type': 'text/html',
':status': 200
});
stream.end('<h1>Hello World</h1>');
});
server.listen(80);
http2.createSecureServer(options[, onRequestHandler])
options
{Object}allowHTTP1
{boolean} Incoming client connections that do not support HTTP/2 will be downgraded to HTTP/1.x when set totrue
. The default value isfalse
. See the'unknownProtocol'
event. See ALPN negotiation.maxDeflateDynamicTableSize
{number} Sets the maximum dynamic table size for deflating header fields. Defaults to 4Kib.maxSendHeaderBlockLength
{number} Sets the maximum allowed size for a serialized, compressed block of headers. Attempts to send headers that exceed this limit will result in a'frameError'
event being emitted and the stream being closed and destroyed.paddingStrategy
{number} Identifies the strategy used for determining the amount of padding to use for HEADERS and DATA frames. Defaults tohttp2.constants.PADDING_STRATEGY_NONE
. Value may be one of:http2.constants.PADDING_STRATEGY_NONE
- Specifies that no padding is to be applied.http2.constants.PADDING_STRATEGY_MAX
- Specifies that the maximum amount of padding, as determined by the internal implementation, is to be applied.http2.constants.PADDING_STRATEGY_CALLBACK
- Specifies that the user providedoptions.selectPadding
callback is to be used to determine the amount of padding.
peerMaxConcurrentStreams
{number} Sets the maximum number of concurrent streams for the remote peer as if a SETTINGS frame had been received. Will be overridden if the remote peer sets its own value formaxConcurrentStreams
. Defaults to 100.selectPadding
{Function} Whenoptions.paddingStrategy
is equal tohttp2.constants.PADDING_STRATEGY_CALLBACK
, provides the callback function used to determine the padding. See Using options.selectPadding.settings
{Settings Object} The initial settings to send to the remote peer upon connection.- ...: Any
tls.createServer()
options can be provided. For servers, the identity options (pfx
orkey
/cert
) are usually required.
onRequestHandler
{Function} See Compatibility API- Returns {Http2SecureServer}
Returns a tls.Server
instance that creates and manages Http2Session
instances.
const http2 = require('http2');
const options = {
key: fs.readFileSync('server-key.pem'),
cert: fs.readFileSync('server-cert.pem')
};
// Create a secure HTTP/2 server
const server = http2.createSecureServer(options);
server.on('stream', (stream, headers) => {
stream.respond({
'content-type': 'text/html',
':status': 200
});
stream.end('<h1>Hello World</h1>');
});
server.listen(80);
http2.connect(authority[, options][, listener])
authority
{string|URL}options
{Object}maxDeflateDynamicTableSize
{number} Sets the maximum dynamic table size for deflating header fields. Defaults to 4Kib.maxReservedRemoteStreams
{number} Sets the maximum number of reserved push streams the client will accept at any given time. Once the current number of currently reserved push streams exceeds reaches this limit, new push streams sent by the server will be automatically rejected.maxSendHeaderBlockLength
{number} Sets the maximum allowed size for a serialized, compressed block of headers. Attempts to send headers that exceed this limit will result in a'frameError'
event being emitted and the stream being closed and destroyed.paddingStrategy
{number} Identifies the strategy used for determining the amount of padding to use for HEADERS and DATA frames. Defaults tohttp2.constants.PADDING_STRATEGY_NONE
. Value may be one of:http2.constants.PADDING_STRATEGY_NONE
- Specifies that no padding is to be applied.http2.constants.PADDING_STRATEGY_MAX
- Specifies that the maximum amount of padding, as determined by the internal implementation, is to be applied.http2.constants.PADDING_STRATEGY_CALLBACK
- Specifies that the user providedoptions.selectPadding
callback is to be used to determine the amount of padding.
peerMaxConcurrentStreams
{number} Sets the maximum number of concurrent streams for the remote peer as if a SETTINGS frame had been received. Will be overridden if the remote peer sets its own value formaxConcurrentStreams
. Defaults to 100.selectPadding
{Function} Whenoptions.paddingStrategy
is equal tohttp2.constants.PADDING_STRATEGY_CALLBACK
, provides the callback function used to determine the padding. See Using options.selectPadding.settings
{Settings Object} The initial settings to send to the remote peer upon connection.
listener
{Function}- Returns {Http2Session}
Returns a HTTP/2 client Http2Session
instance.
const http2 = require('http2');
const client = http2.connect('https://localhost:1234');
/** use the client **/
client.destroy();
http2.constants
Error Codes for RST_STREAM and GOAWAY
Value | Name | Constant |
---|---|---|
0x00 | No Error | http2.constants.NGHTTP2_NO_ERROR |
0x01 | Protocol Error | http2.constants.NGHTTP2_PROTOCOL_ERROR |
0x02 | Internal Error | http2.constants.NGHTTP2_INTERNAL_ERROR |
0x03 | Flow Control Error | http2.constants.NGHTTP2_FLOW_CONTROL_ERROR |
0x04 | Settings Timeout | http2.constants.NGHTTP2_SETTINGS_TIMEOUT |
0x05 | Stream Closed | http2.constants.NGHTTP2_STREAM_CLOSED |
0x06 | Frame Size Error | http2.constants.NGHTTP2_FRAME_SIZE_ERROR |
0x07 | Refused Stream | http2.constants.NGHTTP2_REFUSED_STREAM |
0x08 | Cancel | http2.constants.NGHTTP2_CANCEL |
0x09 | Compression Error | http2.constants.NGHTTP2_COMPRESSION_ERROR |
0x0a | Connect Error | http2.constants.NGHTTP2_CONNECT_ERROR |
0x0b | Enhance Your Calm | http2.constants.NGHTTP2_ENHANCE_YOUR_CALM |
0x0c | Inadequate Security | http2.constants.NGHTTP2_INADEQUATE_SECURITY |
0x0d | HTTP/1.1 Required | http2.constants.NGHTTP2_HTTP_1_1_REQUIRED |
The 'timeout'
event is emitted when there is no activity on the Server for
a given number of milliseconds set using http2server.setTimeout()
.
http2.getDefaultSettings()
- Returns: {Settings Object}
Returns an object containing the default settings for an Http2Session
instance. This method returns a new object instance every time it is called
so instances returned may be safely modified for use.
http2.getPackedSettings(settings)
settings
{Settings Object}- Returns: {Buffer}
Returns a Buffer
instance containing serialized representation of the given
HTTP/2 settings as specified in the HTTP/2 specification. This is intended
for use with the HTTP2-Settings
header field.
const http2 = require('http2');
const packed = http2.getPackedSettings({ enablePush: false });
console.log(packed.toString('base64'));
// Prints: AAIAAAAA
http2.getUnpackedSettings(buf)
buf
{Buffer|Uint8Array} The packed settings- Returns: {Settings Object}
Returns a Settings Object containing the deserialized settings from the
given Buffer
as generated by http2.getPackedSettings()
.
Headers Object
Headers are represented as own-properties on JavaScript objects. The property keys will be serialized to lower-case. Property values should be strings (if they are not they will be coerced to strings) or an Array of strings (in order to send more than one value per header field).
For example:
const headers = {
':status': '200',
'content-type': 'text-plain',
'ABC': ['has', 'more', 'than', 'one', 'value']
};
stream.respond(headers);
Note: Header objects passed to callback functions will have a null
prototype. This means that normal JavaScript object methods such as
Object.prototype.toString()
and Object.prototype.hasOwnProperty()
will
not work.
const http2 = require('http2');
const server = http2.createServer();
server.on('stream', (stream, headers) => {
console.log(headers[':path']);
console.log(headers.ABC);
});
Settings Object
The http2.getDefaultSettings()
, http2.getPackedSettings()
,
http2.createServer()
, http2.createSecureServer()
,
http2session.settings()
, http2session.localSettings
, and
http2session.remoteSettings
APIs either return or receive as input an
object that defines configuration settings for an Http2Session
object.
These objects are ordinary JavaScript objects containing the following
properties.
headerTableSize
{number} Specifies the maximum number of bytes used for header compression. The default value is 4,096 octets. The minimum allowed value is 0. The maximum allowed value is 232-1.enablePush
{boolean} Specifiestrue
if HTTP/2 Push Streams are to be permitted on theHttp2Session
instances.initialWindowSize
{number} Specifies the senders initial window size for stream-level flow control. The default value is 65,535 bytes. The minimum allowed value is 0. The maximum allowed value is 232-1.maxFrameSize
{number} Specifies the size of the largest frame payload. The default and the minimum allowed value is 16,384 bytes. The maximum allowed value is 224-1.maxConcurrentStreams
{number} Specifies the maximum number of concurrent streams permitted on anHttp2Session
. There is no default value which implies, at least theoretically, 231-1 streams may be open concurrently at any given time in anHttp2Session
. The minimum value is 0. The maximum allowed value is 231-1.maxHeaderListSize
{number} Specifies the maximum size (uncompressed octets) of header list that will be accepted. There is no default value. The minimum allowed value is 0. The maximum allowed value is 232-1.
All additional properties on the settings object are ignored.
Using options.selectPadding
When options.paddingStrategy
is equal to
http2.constants.PADDING_STRATEGY_CALLBACK
, the the HTTP/2 implementation will
consult the options.selectPadding
callback function, if provided, to determine
the specific amount of padding to use per HEADERS and DATA frame.
The options.selectPadding
function receives two numeric arguments,
frameLen
and maxFrameLen
and must return a number N
such that
frameLen <= N <= maxFrameLen
.
const http2 = require('http2');
const server = http2.createServer({
paddingStrategy: http2.constants.PADDING_STRATEGY_CALLBACK,
selectPadding(frameLen, maxFrameLen) {
return maxFrameLen;
}
});
Note: The options.selectPadding
function is invoked once for every
HEADERS and DATA frame. This has a definite noticeable impact on
performance.
Error Handling
There are several types of error conditions that may arise when using the
http2
module:
Validation Errors occur when an incorrect argument, option or setting value is
passed in. These will always be reported by a synchronous throw
.
State Errors occur when an action is attempted at an incorrect time (for
instance, attempting to send data on a stream after it has closed). These will
be reported using either a synchronous throw
or via an 'error'
event on
the Http2Stream
, Http2Session
or HTTP/2 Server objects, depending on where
and when the error occurs.
Internal Errors occur when an HTTP/2 session fails unexpectedly. These will be
reported via an 'error'
event on the Http2Session
or HTTP/2 Server objects.
Protocol Errors occur when various HTTP/2 protocol constraints are violated.
These will be reported using either a synchronous throw
or via an 'error'
event on the Http2Stream
, Http2Session
or HTTP/2 Server objects, depending
on where and when the error occurs.
Invalid character handling in header names and values
The HTTP/2 implementation applies stricter handling of invalid characters in HTTP header names and values than the HTTP/1 implementation.
Header field names are case-insensitive and are transmitted over the wire
strictly as lower-case strings. The API provided by Node.js allows header
names to be set as mixed-case strings (e.g. Content-Type
) but will convert
those to lower-case (e.g. content-type
) upon transmission.
Header field-names must only contain one or more of the following ASCII
characters: a
-z
, A
-Z
, 0
-9
, !
, #
, $
, %
, &
, '
, *
, +
,
-
, .
, ^
, _
, `
(backtick), |
, and ~
.
Using invalid characters within an HTTP header field name will cause the stream to be closed with a protocol error being reported.
Header field values are handled with more leniency but should not contain new-line or carriage return characters and should be limited to US-ASCII characters, per the requirements of the HTTP specification.
Push streams on the client
To receive pushed streams on the client, set a listener for the 'stream'
event on the ClientHttp2Session
:
const http2 = require('http2');
const client = http2.connect('http://localhost');
client.on('stream', (pushedStream, requestHeaders) => {
pushedStream.on('push', (responseHeaders) => {
// process response headers
});
pushedStream.on('data', (chunk) => { /* handle pushed data */ });
});
const req = client.request({ ':path': '/' });
Supporting the CONNECT method
The CONNECT
method is used to allow an HTTP/2 server to be used as a proxy
for TCP/IP connections.
A simple TCP Server:
const net = require('net');
const server = net.createServer((socket) => {
let name = '';
socket.setEncoding('utf8');
socket.on('data', (chunk) => name += chunk);
socket.on('end', () => socket.end(`hello ${name}`));
});
server.listen(8000);
An HTTP/2 CONNECT proxy:
const http2 = require('http2');
const net = require('net');
const { URL } = require('url');
const proxy = http2.createServer();
proxy.on('stream', (stream, headers) => {
if (headers[':method'] !== 'CONNECT') {
// Only accept CONNECT requests
stream.rstWithRefused();
return;
}
const auth = new URL(`tcp://${headers[':authority']}`);
// It's a very good idea to verify that hostname and port are
// things this proxy should be connecting to.
const socket = net.connect(auth.port, auth.hostname, () => {
stream.respond();
socket.pipe(stream);
stream.pipe(socket);
});
socket.on('error', (error) => {
stream.rstStream(http2.constants.NGHTTP2_CONNECT_ERROR);
});
});
proxy.listen(8001);
An HTTP/2 CONNECT client:
const http2 = require('http2');
const client = http2.connect('http://localhost:8001');
// Must not specify the ':path' and ':scheme' headers
// for CONNECT requests or an error will be thrown.
const req = client.request({
':method': 'CONNECT',
':authority': `localhost:${port}`
});
req.on('response', (headers) => {
console.log(headers[http2.constants.HTTP2_HEADER_STATUS]);
});
let data = '';
req.setEncoding('utf8');
req.on('data', (chunk) => data += chunk);
req.on('end', () => {
console.log(`The server says: ${data}`);
client.destroy();
});
req.end('Jane');
Compatibility API
The Compatibility API has the goal of providing a similar developer experience of HTTP/1 when using HTTP/2, making it possible to develop applications that supports both HTTP/1 and HTTP/2. This API targets only the public API of the HTTP/1, however many modules uses internal methods or state, and those are not supported as it is a completely different implementation.
The following example creates an HTTP/2 server using the compatibility API:
const http2 = require('http2');
const server = http2.createServer((req, res) => {
res.setHeader('Content-Type', 'text/html');
res.setHeader('X-Foo', 'bar');
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('ok');
});
In order to create a mixed HTTPS and HTTP/2 server, refer to the ALPN negotiation section. Upgrading from non-tls HTTP/1 servers is not supported.
The HTTP2 compatibility API is composed of Http2ServerRequest
and
Http2ServerResponse
. They aim at API compatibility with HTTP/1, but
they do not hide the differences between the protocols. As an example,
the status message for HTTP codes is ignored.
ALPN negotiation
ALPN negotiation allows to support both HTTPS and HTTP/2 over
the same socket. The req
and res
objects can be either HTTP/1 or
HTTP/2, and an application must restrict itself to the public API of
HTTP/1, and detect if it is possible to use the more advanced
features of HTTP/2.
The following example creates a server that supports both protocols:
const { createSecureServer } = require('http2');
const { readFileSync } = require('fs');
const cert = readFileSync('./cert.pem');
const key = readFileSync('./key.pem');
const server = createSecureServer(
{ cert, key, allowHTTP1: true },
onRequest
).listen(4443);
function onRequest(req, res) {
// detects if it is a HTTPS request or HTTP/2
const { socket: { alpnProtocol } } = req.httpVersion === '2.0' ?
req.stream.session : req;
res.writeHead(200, { 'content-type': 'application/json' });
res.end(JSON.stringify({
alpnProtocol,
httpVersion: req.httpVersion
}));
}
The 'request'
event works identically on both HTTPS and
HTTP/2.
Class: http2.Http2ServerRequest
A Http2ServerRequest
object is created by http2.Server
or
http2.SecureServer
and passed as the first argument to the
'request'
event. It may be used to access a request status, headers and
data.
It implements the Readable Stream interface, as well as the following additional events, methods, and properties.
Event: 'aborted'
The 'aborted'
event is emitted whenever a Http2ServerRequest
instance is
abnormally aborted in mid-communication.
Note: The 'aborted'
event will only be emitted if the
Http2ServerRequest
writable side has not been ended.
Event: 'close'
Indicates that the underlying Http2Stream
was closed.
Just like 'end'
, this event occurs only once per response.
request.destroy([error])
error
{Error}
Calls destroy()
on the Http2Stream
that received
the Http2ServerRequest
. If error
is provided, an 'error'
event
is emitted and error
is passed as an argument to any listeners on the event.
It does nothing if the stream was already destroyed.
request.headers
- {Object}
The request/response headers object.
Key-value pairs of header names and values. Header names are lower-cased. Example:
// Prints something like:
//
// { 'user-agent': 'curl/7.22.0',
// host: '127.0.0.1:8000',
// accept: '*/*' }
console.log(request.headers);
See Headers Object.
request.httpVersion
- {string}
In case of server request, the HTTP version sent by the client. In the case of
client response, the HTTP version of the connected-to server. Returns
'2.0'
.
Also message.httpVersionMajor
is the first integer and
message.httpVersionMinor
is the second.
request.method
- {string}
The request method as a string. Read only. Example:
'GET'
, 'DELETE'
.
request.rawHeaders
- {Array}
The raw request/response headers list exactly as they were received.
Note that the keys and values are in the same list. It is not a list of tuples. So, the even-numbered offsets are key values, and the odd-numbered offsets are the associated values.
Header names are not lowercased, and duplicates are not merged.
// Prints something like:
//
// [ 'user-agent',
// 'this is invalid because there can be only one',
// 'User-Agent',
// 'curl/7.22.0',
// 'Host',
// '127.0.0.1:8000',
// 'ACCEPT',
// '*/*' ]
console.log(request.rawHeaders);
request.rawTrailers
- {Array}
The raw request/response trailer keys and values exactly as they were
received. Only populated at the 'end'
event.
request.setTimeout(msecs, callback)
msecs
{number}callback
{Function}
Sets the Http2Stream
's timeout value to msecs
. If a callback is
provided, then it is added as a listener on the 'timeout'
event on
the response object.
If no 'timeout'
listener is added to the request, the response, or
the server, then Http2Stream
s are destroyed when they time out. If a
handler is assigned to the request, the response, or the server's 'timeout'
events, timed out sockets must be handled explicitly.
Returns request
.
request.socket
- {net.Socket}
Returns a Proxy object that acts as a net.Socket
but applies getters,
setters and methods based on HTTP/2 logic.
destroyed
, readable
, and writable
properties will be retrieved from and
set on request.stream
.
destroy
, emit
, end
, on
and once
methods will be called on
request.stream
.
setTimeout
method will be called on request.stream.session
.
pause
, read
, resume
, and write
will throw an error with code
ERR_HTTP2_NO_SOCKET_MANIPULATION
. See [Http2Session and Sockets
][] for
more information.
All other interactions will be routed directly to the socket. With TLS support,
use request.socket.getPeerCertificate()
to obtain the client's
authentication details.
request.stream
- {http2.Http2Stream}
The Http2Stream
object backing the request.
request.trailers
- {Object}
The request/response trailers object. Only populated at the 'end'
event.
request.url
- {string}
Request URL string. This contains only the URL that is present in the actual HTTP request. If the request is:
GET /status?name=ryan HTTP/1.1\r\n
Accept: text/plain\r\n
\r\n
Then request.url
will be:
'/status?name=ryan'
To parse the url into its parts require('url').parse(request.url)
can be used. Example:
$ node
> require('url').parse('/status?name=ryan')
Url {
protocol: null,
slashes: null,
auth: null,
host: null,
port: null,
hostname: null,
hash: null,
search: '?name=ryan',
query: 'name=ryan',
pathname: '/status',
path: '/status?name=ryan',
href: '/status?name=ryan' }
To extract the parameters from the query string, the
require('querystring').parse
function can be used, or
true
can be passed as the second argument to require('url').parse
.
Example:
$ node
> require('url').parse('/status?name=ryan', true)
Url {
protocol: null,
slashes: null,
auth: null,
host: null,
port: null,
hostname: null,
hash: null,
search: '?name=ryan',
query: { name: 'ryan' },
pathname: '/status',
path: '/status?name=ryan',
href: '/status?name=ryan' }
Class: http2.Http2ServerResponse
This object is created internally by an HTTP server--not by the user. It is
passed as the second parameter to the 'request'
event.
The response implements, but does not inherit from, the Writable Stream
interface. This is an EventEmitter
with the following events:
Event: 'close'
Indicates that the underlying Http2Stream
was terminated before
response.end()
was called or able to flush.
Event: 'finish'
Emitted when the response has been sent. More specifically, this event is emitted when the last segment of the response headers and body have been handed off to the HTTP/2 multiplexing for transmission over the network. It does not imply that the client has received anything yet.
After this event, no more events will be emitted on the response object.
response.addTrailers(headers)
headers
{Object}
This method adds HTTP trailing headers (a header but at the end of the message) to the response.
Attempting to set a header field name or value that contains invalid characters
will result in a TypeError
being thrown.
response.connection
- {net.Socket}
See response.socket
.
response.end([data][, encoding][, callback])
data
{string|Buffer}encoding
{string}callback
{Function}
This method signals to the server that all of the response headers and body
have been sent; that server should consider this message complete.
The method, response.end()
, MUST be called on each response.
If data
is specified, it is equivalent to calling
response.write(data, encoding)
followed by response.end(callback)
.
If callback
is specified, it will be called when the response stream
is finished.
response.finished
- {boolean}
Boolean value that indicates whether the response has completed. Starts
as false
. After response.end()
executes, the value will be true
.
response.getHeader(name)
name
{string}- Returns: {string}
Reads out a header that has already been queued but not sent to the client. Note that the name is case insensitive.
Example:
const contentType = response.getHeader('content-type');
response.getHeaderNames()
- Returns: {Array}
Returns an array containing the unique names of the current outgoing headers. All header names are lowercase.
Example:
response.setHeader('Foo', 'bar');
response.setHeader('Set-Cookie', ['foo=bar', 'bar=baz']);
const headerNames = response.getHeaderNames();
// headerNames === ['foo', 'set-cookie']
response.getHeaders()
- Returns: {Object}
Returns a shallow copy of the current outgoing headers. Since a shallow copy is used, array values may be mutated without additional calls to various header-related http module methods. The keys of the returned object are the header names and the values are the respective header values. All header names are lowercase.
Note: The object returned by the response.getHeaders()
method does not
prototypically inherit from the JavaScript Object
. This means that typical
Object
methods such as obj.toString()
, obj.hasOwnProperty()
, and others
are not defined and will not work.
Example:
response.setHeader('Foo', 'bar');
response.setHeader('Set-Cookie', ['foo=bar', 'bar=baz']);
const headers = response.getHeaders();
// headers === { foo: 'bar', 'set-cookie': ['foo=bar', 'bar=baz'] }
response.hasHeader(name)
name
{string}- Returns: {boolean}
Returns true
if the header identified by name
is currently set in the
outgoing headers. Note that the header name matching is case-insensitive.
Example:
const hasContentType = response.hasHeader('content-type');
response.headersSent
- {boolean}
Boolean (read-only). True if headers were sent, false otherwise.
response.removeHeader(name)
name
{string}
Removes a header that has been queued for implicit sending.
Example:
response.removeHeader('Content-Encoding');
response.sendDate
- {boolean}
When true, the Date header will be automatically generated and sent in the response if it is not already present in the headers. Defaults to true.
This should only be disabled for testing; HTTP requires the Date header in responses.
response.setHeader(name, value)
name
{string}value
{string | string[]}
Sets a single header value for implicit headers. If this header already exists in the to-be-sent headers, its value will be replaced. Use an array of strings here to send multiple headers with the same name.
Example:
response.setHeader('Content-Type', 'text/html');
or
response.setHeader('Set-Cookie', ['type=ninja', 'language=javascript']);
Attempting to set a header field name or value that contains invalid characters
will result in a TypeError
being thrown.
When headers have been set with response.setHeader()
, they will be merged
with any headers passed to response.writeHead()
, with the headers passed
to response.writeHead()
given precedence.
// returns content-type = text/plain
const server = http2.createServer((req, res) => {
res.setHeader('Content-Type', 'text/html');
res.setHeader('X-Foo', 'bar');
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('ok');
});
response.setTimeout(msecs[, callback])
msecs
{number}callback
{Function}
Sets the Http2Stream
's timeout value to msecs
. If a callback is
provided, then it is added as a listener on the 'timeout'
event on
the response object.
If no 'timeout'
listener is added to the request, the response, or
the server, then Http2Stream
s are destroyed when they time out. If a
handler is assigned to the request, the response, or the server's 'timeout'
events, timed out sockets must be handled explicitly.
Returns response
.
response.socket
- {net.Socket}
Returns a Proxy object that acts as a net.Socket
but applies getters,
setters and methods based on HTTP/2 logic.
destroyed
, readable
, and writable
properties will be retrieved from and
set on response.stream
.
destroy
, emit
, end
, on
and once
methods will be called on
response.stream
.
setTimeout
method will be called on response.stream.session
.
pause
, read
, resume
, and write
will throw an error with code
ERR_HTTP2_NO_SOCKET_MANIPULATION
. See [Http2Session and Sockets
][] for
more information.
All other interactions will be routed directly to the socket.
Example:
const http2 = require('http2');
const server = http2.createServer((req, res) => {
const ip = req.socket.remoteAddress;
const port = req.socket.remotePort;
res.end(`Your IP address is ${ip} and your source port is ${port}.`);
}).listen(3000);
response.statusCode
- {number}
When using implicit headers (not calling response.writeHead()
explicitly),
this property controls the status code that will be sent to the client when
the headers get flushed.
Example:
response.statusCode = 404;
After response header was sent to the client, this property indicates the status code which was sent out.
response.statusMessage
- {string}
Status message is not supported by HTTP/2 (RFC7540 8.1.2.4). It returns an empty string.
response.stream
- {http2.Http2Stream}
The Http2Stream
object backing the response.
response.write(chunk[, encoding][, callback])
chunk
{string|Buffer}encoding
{string}callback
{Function}- Returns: {boolean}
If this method is called and response.writeHead()
has not been called,
it will switch to implicit header mode and flush the implicit headers.
This sends a chunk of the response body. This method may be called multiple times to provide successive parts of the body.
Note that in the http
module, the response body is omitted when the
request is a HEAD request. Similarly, the 204
and 304
responses
must not include a message body.
chunk
can be a string or a buffer. If chunk
is a string,
the second parameter specifies how to encode it into a byte stream.
By default the encoding
is 'utf8'
. callback
will be called when this chunk
of data is flushed.
Note: This is the raw HTTP body and has nothing to do with higher-level multi-part body encodings that may be used.
The first time response.write()
is called, it will send the buffered
header information and the first chunk of the body to the client. The second
time response.write()
is called, Node.js assumes data will be streamed,
and sends the new data separately. That is, the response is buffered up to the
first chunk of the body.
Returns true
if the entire data was flushed successfully to the kernel
buffer. Returns false
if all or part of the data was queued in user memory.
'drain'
will be emitted when the buffer is free again.
response.writeContinue()
Sends a status 100 Continue
to the client, indicating that the request body
should be sent. See the 'checkContinue'
event on Http2Server
and
Http2SecureServer
.
response.writeHead(statusCode[, statusMessage][, headers])
statusCode
{number}statusMessage
{string}headers
{Object}
Sends a response header to the request. The status code is a 3-digit HTTP
status code, like 404
. The last argument, headers
, are the response headers.
For compatibility with HTTP/1, a human-readable statusMessage
may be
passed as the second argument. However, because the statusMessage
has no
meaning within HTTP/2, the argument will have no effect and a process warning
will be emitted.
Example:
const body = 'hello world';
response.writeHead(200, {
'Content-Length': Buffer.byteLength(body),
'Content-Type': 'text/plain' });
Note that Content-Length is given in bytes not characters. The
Buffer.byteLength()
API may be used to determine the number of bytes in a
given encoding. On outbound messages, Node.js does not check if Content-Length
and the length of the body being transmitted are equal or not. However, when
receiving messages, Node.js will automatically reject messages when the
Content-Length does not match the actual payload size.
This method may be called at most one time on a message before
response.end()
is called.
If response.write()
or response.end()
are called before calling
this, the implicit/mutable headers will be calculated and call this function.
When headers have been set with response.setHeader()
, they will be merged
with any headers passed to response.writeHead()
, with the headers passed
to response.writeHead()
given precedence.
// returns content-type = text/plain
const server = http2.createServer((req, res) => {
res.setHeader('Content-Type', 'text/html');
res.setHeader('X-Foo', 'bar');
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('ok');
});
Attempting to set a header field name or value that contains invalid characters
will result in a TypeError
being thrown.
response.createPushResponse(headers, callback)
Call http2stream.pushStream()
with the given headers, and wraps the
given newly created Http2Stream
on Http2ServerRespose
.
The callback will be called with an error with code ERR_HTTP2_STREAM_CLOSED
if the stream is closed.