Stability: 1 - Experimental
The http2 module provides an implementation of the HTTP/2 protocol. It
can be accessed using:
const http2 = require('http2');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 http2 Core API is much more symmetric between client and server than the
http API. For instance, most events, like error and socketError, can be
emitted either by client-side code or server-side code.
The following illustrates a simple, plain-text HTTP/2 server using the Core API:
const http2 = require('http2');
const fs = require('fs');
const server = http2.createSecureServer({
key: fs.readFileSync('localhost-privkey.pem'),
cert: fs.readFileSync('localhost-cert.pem')
});
server.on('error', (err) => console.error(err));
server.on('socketError', (err) => console.error(err));
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(8443);To generate the certificate and key for this example, run:
openssl req -x509 -newkey rsa:2048 -nodes -sha256 -subj '/CN=localhost' \
-keyout localhost-privkey.pem -out localhost-cert.pemThe following illustrates an HTTP/2 client:
const http2 = require('http2');
const fs = require('fs');
const client = http2.connect('https://localhost:8443', {
ca: fs.readFileSync('localhost-cert.pem')
});
client.on('error', (err) => console.error(err));
client.on('socketError', (err) => console.error(err));
const req = client.request({ ':path': '/' });
req.on('response', (headers, flags) => {
for (const name in headers) {
console.log(`${name}: ${headers[name]}`);
}
});
req.setEncoding('utf8');
let data = '';
req.on('data', (chunk) => { data += chunk; });
req.on('end', () => {
console.log(`\n${data}`);
client.close();
});
req.end();- 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.
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.
The 'close' event is emitted once the Http2Session has been destroyed.
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.
The 'error' event is emitted when an error occurs during the processing of
an Http2Session.
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 shut down
immediately following the 'frameError' event.
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 (or0if no ID is specified).opaqueData{Buffer} If additional opaque data was included in the GOAWAY frame, aBufferinstance will be passed containing that data.
Note: The Http2Session instance will be shut down automatically when the
'goaway' event is emitted.
The 'localSettings' event is emitted when an acknowledgment 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 **/
});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 **/
});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');
session.on('stream', (stream, headers, flags) => {
const method = headers[':method'];
const path = headers[':path'];
// ...
stream.respond({
':status': 200,
'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);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', () => { /** .. **/ });- Value: {string|undefined}
Value will be undefined if the Http2Session is not yet connected to a
socket, h2c if the Http2Session is not connected to a TLSSocket, or
will return the value of the connected TLSSocket's own alpnProtocol
property.
callback{Function}
Gracefully closes the Http2Session, allowing any existing streams to
complete on their own and preventing new Http2Stream instances from being
created. Once closed, http2session.destroy() might be called if there
are no open Http2Stream instances.
If specified, the callback function is registered as a handler for the
'close' event.
- Value: {boolean}
Will be true if this Http2Session instance has been closed, otherwise
false.
error{Error} AnErrorobject if theHttp2Sessionis being destroyed due to an error.code{number} The HTTP/2 error code to send in the finalGOAWAYframe. If unspecified, anderroris not undefined, the default isINTERNAL_ERROR, otherwise defaults toNO_ERROR.- Returns: {undefined}
Immediately terminates the Http2Session and the associated net.Socket or
tls.TLSSocket.
Once destroyed, the Http2Session will emit the 'close' event. If error
is not undefined, an 'error' event will be emitted immediately after the
'close' event.
If there are any remaining open Http2Streams associated with the
Http2Session, those will also be destroyed.
- Value: {boolean}
Will be true if this Http2Session instance has been destroyed and must no
longer be used, otherwise false.
- Value: {boolean|undefined}
Value is undefined if the Http2Session session socket has not yet been
connected, true if the Http2Session is connected with a TLSSocket,
and false if the Http2Session is connected to any other kind of socket
or stream.
code{number} An HTTP/2 error codelastStreamID{number} The numeric ID of the last processedHttp2StreamopaqueData{Buffer|TypedArray|DataView} ATypedArrayorDataViewinstance containing additional data to be carried within the GOAWAY frame.
Transmits a GOAWAY frame to the connected peer without shutting down the
Http2Session.
- Value: {Settings Object}
A prototype-less object describing the current local settings of this
Http2Session. The local settings are local to this Http2Session instance.
- Value: {string[]|undefined}
If the Http2Session is connected to a TLSSocket, the originSet property
will return an Array of origins for which the Http2Session may be
considered authoritative.
- Value: {boolean}
Indicates whether or not the Http2Session is currently waiting for an
acknowledgment 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.
payload{Buffer|TypedArray|DataView} Optional ping payload.callback{Function}- Returns: {boolean}
Sends a PING frame to the connected HTTP/2 peer. A callback function must
be provided. The method will return true if the PING was sent, false
otherwise.
The maximum number of outstanding (unacknowledged) pings is determined by the
maxOutstandingPings configuration option. The default maximum is 10.
If provided, the payload must be a Buffer, TypedArray, or DataView
containing 8 bytes of data that will be transmitted with the PING and
returned with the ping acknowledgment.
The callback will be invoked with three arguments: an error argument that will
be null if the PING was successfully acknowledged, a duration argument
that reports the number of milliseconds elapsed since the ping was sent and the
acknowledgment was received, and a Buffer containing the 8-byte PING
payload.
session.ping(Buffer.from('abcdefgh'), (err, duration, payload) => {
if (!err) {
console.log(`Ping acknowledged in ${duration} milliseconds`);
console.log(`With payload '${payload.toString()}`);
}
});If the payload argument is not specified, the default payload will be the
64-bit timestamp (little endian) marking the start of the PING duration.
Calls ref() on this Http2Session
instance's underlying net.Socket.
- 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.
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.
options{Object}errorCode{number} The HTTP/2 error code to return. Note that this is not the same thing as an HTTP Response Status Code. Default:0x00(No Error).lastStreamID{number} The Stream ID of the last successfully processedHttp2Streamon thisHttp2Session. If unspecified, will default to the ID of the most recently received stream.opaqueData{Buffer|Uint8Array} ABufferorUint8Arrayinstance 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 shut down this Http2Session using HTTP/2 defined procedures.
If specified, the given callback function will be invoked once the shutdown
process has completed.
If the Http2Session instance is a server-side session and the errorCode
option is 0x00 (No Error), a "graceful" shutdown will be initiated. During a
"graceful" shutdown, the session will first send a GOAWAY frame to
the connected peer identifying the last processed stream as 231-1.
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.close({
opaqueData: Buffer.from('add some debugging data here')
}, () => session.destroy());- Value: {net.Socket|tls.TLSSocket}
Returns a Proxy object that acts as a net.Socket (or tls.TLSSocket) but
limits available methods to ones safe to use with HTTP/2.
destroy, emit, end, pause, read, resume, and write will throw
an error with code ERR_HTTP2_NO_SOCKET_MANIPULATION. See
Http2Session and Sockets for more information.
setTimeout method will be called on this Http2Session.
All other interactions will be routed directly to the socket.
Provides miscellaneous information about the current state of the
Http2Session.
- Value: {Object}
effectiveLocalWindowSize{number} The current local (receive) flow control window size for theHttp2Session.effectiveRecvDataLength{number} The current number of bytes that have been received since the last flow controlWINDOW_UPDATE.nextStreamID{number} The numeric identifier to be used the next time a newHttp2Streamis created by thisHttp2Session.localWindowSize{number} The number of bytes that the remote peer can send without receiving aWINDOW_UPDATE.lastProcStreamID{number} The numeric id of theHttp2Streamfor which aHEADERSorDATAframe was most recently received.remoteWindowSize{number} The number of bytes that thisHttp2Sessionmay send without receiving aWINDOW_UPDATE.outboundQueueSize{number} The number of frames currently within the outbound queue for thisHttp2Session.deflateDynamicTableSize{number} The current size in bytes of the outbound header compression state table.inflateDynamicTableSize{number} The current size in bytes of the inbound header compression state table.
An object describing the current status of this Http2Session.
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
acknowledgment is received and the 'localSettings' event is emitted. It
is possible to send multiple SETTINGS frames while acknowledgment is still
pending.
- 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.
Calls unref() on this Http2Session
instance's underlying net.Socket.
alt{string} A description of the alternative service configuration as defined by RFC 7838.originOrStream{number|string|URL|Object} Either a URL string specifying the origin (or an Object with anoriginproperty) or the numeric identifier of an activeHttp2Streamas given by thehttp2stream.idproperty.
Submits an ALTSVC frame (as defined by RFC 7838) to the connected client.
const http2 = require('http2');
const server = http2.createServer();
server.on('session', (session) => {
// Set altsvc for origin https://example.org:80
session.altsvc('h2=":8000"', 'https://example.org:80');
});
server.on('stream', (stream) => {
// Set altsvc for a specific stream
stream.session.altsvc('h2=":8000"', stream.id);
});Sending an ALTSVC frame with a specific stream ID indicates that the alternate
service is associated with the origin of the given Http2Stream.
The alt and origin string must contain only ASCII bytes and are
strictly interpreted as a sequence of ASCII bytes. The special value 'clear'
may be passed to clear any previously set alternative service for a given
domain.
When a string is passed for the originOrStream argument, it will be parsed as
a URL and the origin will be derived. For instance, the origin for the
HTTP URL 'https://example.org/foo/bar' is the ASCII string
'https://example.org'. An error will be thrown if either the given string
cannot be parsed as a URL or if a valid origin cannot be derived.
A URL object, or any object with an origin property, may be passed as
originOrStream, in which case the value of the origin property will be
used. The value of the origin property must be a properly serialized
ASCII origin.
The format of the alt parameter is strictly defined by RFC 7838 as an
ASCII string containing a comma-delimited list of "alternative" protocols
associated with a specific host and port.
For example, the value 'h2="example.org:81"' indicates that the HTTP/2
protocol is available on the host 'example.org' on TCP/IP port 81. The
host and port must be contained within the quote (") characters.
Multiple alternatives may be specified, for instance: 'h2="example.org:81", h2=":82"'
The protocol identifier ('h2' in the examples) may be any valid
ALPN Protocol ID.
The syntax of these values is not validated by the Node.js implementation and are passed through as provided by the user or received from the peer.
The 'altsvc' event is emitted whenever an ALTSVC frame is received by
the client. The event is emitted with the ALTSVC value, origin, and stream
ID, if any. If no origin is provided in the ALTSVC frame, origin will
be an empty string.
const http2 = require('http2');
const client = http2.connect('https://example.org');
client.on('altsvc', (alt, origin, stream) => {
console.log(alt);
console.log(origin);
console.log(stream);
});-
headers{Headers Object} -
options{Object}endStream{boolean}trueif theHttp2Streamwritable side should be closed initially, such as when sending aGETrequest that should not expect a payload body.exclusive{boolean} Whentrueandparentidentifies 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. Default:falseparent{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 between1and256(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 use 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.
The :method and :path pseudo-headers are not specified within headers,
they respectively default to:
:method='GET':path=/
- 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 is 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.
On the server side, instances of ServerHttp2Stream are created either
when:
- A new HTTP/2
HEADERSframe 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, 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.
All Http2Stream instances are destroyed either when:
- An
RST_STREAMframe for the stream is received by the connected peer. - The
http2stream.close()method is 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.
When the Http2Stream instance is destroyed, the 'close' 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.
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.
The 'close' 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.
The 'error' event is emitted when an error occurs during the processing of
an Http2Stream.
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.
The 'timeout' event is emitted after no activity is received for this
'Http2Stream' within the number of milliseconds set using
http2stream.setTimeout().
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);
});- Value: {boolean}
Set to true if the Http2Stream instance was aborted abnormally. When set,
the 'aborted' event will have been emitted.
- code {number} Unsigned 32-bit integer identifying the error code. Default:
http2.constants.NGHTTP2_NO_ERROR(0x00) callback{Function} An optional function registered to listen for the'close'event.- Returns: {undefined}
Closes the Http2Stream instance by sending an RST_STREAM frame to the
connected HTTP/2 peer.
- Value: {boolean}
Set to true if the Http2Stream instance has been closed.
- Value: {boolean}
Set to true if the Http2Stream instance has been destroyed and is no longer
usable.
- Value: {boolean}
Set to true if the Http2Stream instance has not yet been assigned a
numeric stream identifier.
options{Object}exclusive{boolean} Whentrueandparentidentifies 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. Default:falseparent{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 between1and256(inclusive).silent{boolean} Whentrue, changes the priority locally without sending aPRIORITYframe to the connected peer.
- Returns: {undefined}
Updates the priority for this Http2Stream instance.
- 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.close(), or http2stream.destroy(). Will be
undefined if the Http2Stream has not been closed.
- Value: {Headers Object}
An object containing the outbound headers sent for this Http2Stream.
- Value: {Headers Object[]}
An array of objects containing the outbound informational (additional) headers
sent for this Http2Stream.
- Value: {Headers Object}
An object containing the outbound trailers sent for this this HttpStream.
- Value: {Http2Session}
A reference to the Http2Session instance that owns this Http2Stream. The
value will be undefined after the Http2Stream instance is destroyed.
msecs{number}callback{Function}- Returns: {undefined}
const http2 = require('http2');
const client = http2.connect('http://example.org:8000');
const { NGHTTP2_CANCEL } = http2.constants;
const req = client.request({ ':path': '/' });
// Cancel the stream if there's no activity after 5 seconds
req.setTimeout(5000, () => req.close(NGHTTP2_CANCEL));Provides miscellaneous information about the current state of the
Http2Stream.
- Value: {Object}
localWindowSize{number} The number of bytes the connected peer may send for thisHttp2Streamwithout receiving aWINDOW_UPDATE.state{number} A flag indicating the low-level current state of theHttp2Streamas determined by nghttp2.localClose{number}trueif thisHttp2Streamhas been closed locally.remoteClose{number}trueif thisHttp2Streamhas been closed remotely.sumDependencyWeight{number} The sum weight of allHttp2Streaminstances that depend on thisHttp2Streamas specified usingPRIORITYframes.weight{number} The priority weight of thisHttp2Stream.
A current state of this Http2Stream.
- 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.
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.
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 is received.
The listener callback is passed the Headers Object and flags associated with
the headers.
stream.on('headers', (headers, flags) => {
console.log(headers);
});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);
});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']);
});- 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.
headers{Headers Object}- Returns: {undefined}
Sends an additional informational HEADERS frame to the connected HTTP/2 peer.
- Value: {boolean}
Boolean (read-only). True if headers were sent, false otherwise.
- 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.
headers{Headers Object}options{Object}exclusive{boolean} Whentrueandparentidentifies 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. Default:falseparent{number} Specifies the numeric identifier of a stream the newly created stream is dependent on.
callback{Function} Callback that is called once the push stream has been
initiated.err{Error}pushStream{ServerHttp2Stream} The returned pushStream object.headers{Headers Object} Headers object the pushStream was initiated with.
- Returns: {undefined}
Initiates a push stream. The callback is invoked with the new Http2Stream
instance created for the push stream passed as the second argument, or an
Error passed as the first argument.
const http2 = require('http2');
const server = http2.createServer();
server.on('stream', (stream) => {
stream.respond({ ':status': 200 });
stream.pushStream({ ':path': '/' }, (err, pushStream, headers) => {
if (err) throw err;
pushStream.respond({ ':status': 200 });
pushStream.end('some pushed data');
});
stream.end('some data');
});Setting the weight of a push stream is not allowed in the HEADERS frame. Pass
a weight value to http2stream.priority with the silent option set to
true to enable server-side bandwidth balancing between concurrent streams.
headers{Headers Object}options{Object}endStream{boolean} Set totrueto 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 use 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.
fd{number} A readable file descriptor.headers{Headers Object}options{Object}statCheck{Function}getTrailers{Function} Callback function invoked to collect trailer headers.offset{number} The offset position at which to begin reading.length{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 use 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.
path{string|Buffer|URL}headers{Headers Object}options{Object}statCheck{Function}onError{Function} Callback function invoked in the case of an Error before send.getTrailers{Function} Callback function invoked to collect trailer headers.offset{number} The offset position at which to begin reading.length{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, then 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 use 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.
- Extends: {net.Server}
In Http2Server, there is no 'clientError' event as there is in
HTTP1. However, there are 'socketError', 'sessionError', and
'streamError', for errors emitted on the socket, Http2Session, or
Http2Stream.
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.
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.
The 'session' event is emitted when a new Http2Session is created by the
Http2Server.
The 'sessionError' event is emitted when an 'error' event is emitted by
an Http2Session object associated with the Http2Server.
If a ServerHttp2Stream emits an 'error' event, it will be forwarded here.
The stream will already be destroyed when this event is triggered.
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');
});The 'timeout' event is emitted when there is no activity on the Server for
a given number of milliseconds set using http2server.setTimeout().
- Extends: {tls.Server}
The 'sessionError' event is emitted when an 'error' event is emitted by
an Http2Session object associated with the Http2SecureServer.
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.
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');
});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.
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.
options{Object}maxDeflateDynamicTableSize{number} Sets the maximum dynamic table size for deflating header fields. Default:4KibmaxSessionMemory{number} Sets the maximum memory that theHttp2Sessionis permitted to use. The value is expressed in terms of number of megabytes, e.g.1equal 1 megabyte. The minimum value allowed is1. Default:10. This is a credit based limit, existingHttp2Streams may cause this limit to be exceeded, but newHttp2Streaminstances will be rejected while this limit is exceeded. The current number ofHttp2Streamsessions, the current memory use of the header compression tables, current data queued to be sent, and unacknowledged PING and SETTINGS frames are all counted towards the current limit.maxHeaderListPairs{number} Sets the maximum number of header entries. Default:128. The minimum value is4.maxOutstandingPings{number} Sets the maximum number of outstanding, unacknowledged pings. The default is10.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. Default:http2.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.selectPaddingcallback is to be used to determine the amount of padding.http2.constants.PADDING_STRATEGY_ALIGNED- Will attempt to apply enough padding to ensure that the total frame length, including the 9-byte header, is a multiple of 8. For each frame, however, there is a maximum allowed number of padding bytes that is determined by current flow control state and settings. If this maximum is less than the calculated amount needed to ensure alignment, the maximum will be used and the total frame length will not necessarily be aligned at 8 bytes.
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 for.maxConcurrentStreams. Default100selectPadding{Function} Whenoptions.paddingStrategyis 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);options{Object}allowHTTP1{boolean} Incoming client connections that do not support HTTP/2 will be downgraded to HTTP/1.x when set totrue. Default:false. See the'unknownProtocol'event. See ALPN negotiation.maxDeflateDynamicTableSize{number} Sets the maximum dynamic table size for deflating header fields. Default:4KibmaxSessionMemory{number} Sets the maximum memory that theHttp2Sessionis permitted to use. The value is expressed in terms of number of megabytes, e.g.1equal 1 megabyte. The minimum value allowed is1. Default:10. This is a credit based limit, existingHttp2Streams may cause this limit to be exceeded, but newHttp2Streaminstances will be rejected while this limit is exceeded. The current number ofHttp2Streamsessions, the current memory use of the header compression tables, current data queued to be sent, and unacknowledged PING and SETTINGS frames are all counted towards the current limit.maxHeaderListPairs{number} Sets the maximum number of header entries. Default:128. The minimum value is4.maxOutstandingPings{number} Sets the maximum number of outstanding, unacknowledged pings. The default is10.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. Default:http2.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.selectPaddingcallback is to be used to determine the amount of padding.http2.constants.PADDING_STRATEGY_ALIGNED- Will attempt to apply enough padding to ensure that the total frame length, including the 9-byte header, is a multiple of 8. For each frame, however, there is a maximum allowed number of padding bytes that is determined by current flow control state and settings. If this maximum is less than the calculated amount needed to ensure alignment, the maximum will be used and the total frame length will not necessarily be aligned at 8 bytes.
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. Default:100selectPadding{Function} Whenoptions.paddingStrategyis 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 (pfxorkey/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);authority{string|URL}options{Object}maxDeflateDynamicTableSize{number} Sets the maximum dynamic table size for deflating header fields. Default:4KibmaxSessionMemory{number} Sets the maximum memory that theHttp2Sessionis permitted to use. The value is expressed in terms of number of megabytes, e.g.1equal 1 megabyte. The minimum value allowed is1. Default:10. This is a credit based limit, existingHttp2Streams may cause this limit to be exceeded, but newHttp2Streaminstances will be rejected while this limit is exceeded. The current number ofHttp2Streamsessions, the current memory use of the header compression tables, current data queued to be sent, and unacknowledged PING and SETTINGS frames are all counted towards the current limit.maxHeaderListPairs{number} Sets the maximum number of header entries. Default:128. The minimum value is1.maxOutstandingPings{number} Sets the maximum number of outstanding, unacknowledged pings. The default is10.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. Default:http2.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.selectPaddingcallback is to be used to determine the amount of padding.http2.constants.PADDING_STRATEGY_ALIGNED- Will attempt to apply enough padding to ensure that the total frame length, including the 9-byte header, is a multiple of 8. For each frame, however, there is a maximum allowed number of padding bytes that is determined by current flow control state and settings. If this maximum is less than the calculated amount needed to ensure alignment, the maximum will be used and the total frame length will not necessarily be aligned at 8 bytes.
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. Default:100selectPadding{Function} Whenoptions.paddingStrategyis 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.createConnection{Function} An optional callback that receives theURLinstance passed toconnectand theoptionsobject, and returns anyDuplexstream that is to be used as the connection for this session.- ...: Any
net.connect()ortls.connect()options can be provided.
listener{Function}- Returns {ClientHttp2Session}
Returns a ClientHttp2Session instance.
const http2 = require('http2');
const client = http2.connect('https://localhost:1234');
/** use the client **/
client.close();| 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().
- 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.
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: AAIAAAAAbuf{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 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);
});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. Default:4,096 octets. The minimum allowed value is 0. The maximum allowed value is 232-1.enablePush{boolean} Specifiestrueif HTTP/2 Push Streams are to be permitted on theHttp2Sessioninstances.initialWindowSize{number} Specifies the senders initial window size for stream-level flow control. Default: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. Default:16,384 bytes. The minimum allowed value is 16,384. 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. The minimum allowed value is 0. The maximum allowed value is 232-1. Default: 65535.
All additional properties on the settings object are ignored.
When options.paddingStrategy is equal to
http2.constants.PADDING_STRATEGY_CALLBACK, 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.
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.
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.
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': '/' });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 ${name}`));
});
server.listen(8000);An HTTP/2 CONNECT proxy:
const http2 = require('http2');
const { NGHTTP2_REFUSED_STREAM } = http2.constants;
const net = require('net');
const { URL } = require('url');
const proxy = http2.createServer();
proxy.on('stream', (stream, headers) => {
if (headers[':method'] !== 'CONNECT') {
// Only accept CONNECT requests
stream.close(NGHTTP2_REFUSED_STREAM);
return;
}
const auth = new URL(`tcp://${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.close(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.close();
});
req.end('Jane');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 support both HTTP/1 and HTTP/2. This API targets only the public API of the HTTP/1. However many modules use 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 allows supporting 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.
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.
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.
Indicates that the underlying Http2Stream was closed.
Just like 'end', this event occurs only once per response.
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.
- {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.
Note: In HTTP/2, the request path, hostname, protocol, and method are
represented as special headers prefixed with the : character (e.g. ':path').
These special headers will be included in the request.headers object. Care
must be taken not to inadvertently modify these special headers or errors may
occur. For instance, removing all headers from the request will cause errors
to occur:
removeAllHeaders(request.headers);
assert(request.url); // Fails because the :path header has been removed- {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.
- {string}
The request method as a string. Read-only. Example:
'GET', 'DELETE'.
- {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);- {Array}
The raw request/response trailer keys and values exactly as they were
received. Only populated at the 'end' event.
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 Http2Streams 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.
- {net.Socket|tls.TLSSocket}
Returns a Proxy object that acts as a net.Socket (or tls.TLSSocket) 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.
- {http2.Http2Stream}
The Http2Stream object backing the request.
- {Object}
The request/response trailers object. Only populated at the 'end' event.
- {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\nThen 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' }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:
Indicates that the underlying Http2Stream was terminated before
response.end() was called or able to flush.
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.
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.
- {net.Socket|tls.TLSSocket}
See response.socket.
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.
- {boolean}
Boolean value that indicates whether the response has completed. Starts
as false. After response.end() executes, the value will be true.
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');- 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']- 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'] }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');- {boolean}
Boolean (read-only). True if headers were sent, false otherwise.
name{string}
Removes a header that has been queued for implicit sending.
Example:
response.removeHeader('Content-Encoding');- {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.
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');
});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 Http2Streams 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.
- {net.Socket|tls.TLSSocket}
Returns a Proxy object that acts as a net.Socket (or tls.TLSSocket) 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);- {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.
- {string}
Status message is not supported by HTTP/2 (RFC7540 8.1.2.4). It returns an empty string.
- {http2.Http2Stream}
The Http2Stream object backing the response.
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.
Sends a status 100 Continue to the client, indicating that the request body
should be sent. See the 'checkContinue' event on Http2Server and
Http2SecureServer.
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.
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.
The Performance Observer API can be used to collect basic performance
metrics for each Http2Session and Http2Stream instance.
const { PerformanceObserver } = require('perf_hooks');
const obs = new PerformanceObserver((items) => {
const entry = items.getEntries()[0];
console.log(entry.entryType); // prints 'http2'
if (entry.name === 'Http2Session') {
// entry contains statistics about the Http2Session
} else if (entry.name === 'Http2Stream') {
// entry contains statistics about the Http2Stream
}
});
obs.observe({ entryTypes: ['http2'] });The entryType property of the PerformanceEntry will be equal to 'http2'.
The name property of the PerformanceEntry will be equal to either
'Http2Stream' or 'Http2Session'.
If name is equal to Http2Stream, the PerformanceEntry will contain the
following additional properties:
bytesRead{number} The number of DATA frame bytes received for thisHttp2Stream.bytesWritten{number} The number of DATA frame bytes sent for thisHttp2Stream.id{number} The identifier of the associatedHttp2StreamtimeToFirstByte{number} The number of milliseconds elapsed between thePerformanceEntrystartTimeand the reception of the firstDATAframe.timeToFirstByteSent{number} The number of milliseconds elapsed between thePerformanceEntrystartTimeand sending of the firstDATAframe.timeToFirstHeader{number} The number of milliseconds elapsed between thePerformanceEntrystartTimeand the reception of the first header.
If name is equal to Http2Session, the PerformanceEntry will contain the
following additional properties:
bytesRead{number} The number of bytes received for thisHttp2Session.bytesWritten{number} The number of bytes sent for thisHttp2Session.framesReceived{number} The number of HTTP/2 frames received by theHttp2Session.framesSent{number} The number of HTTP/2 frames sent by theHttp2Session.maxConcurrentStreams{number} The maximum number of streams concurrently open during the lifetime of theHttp2Session.pingRTT{number} The number of milliseconds elapsed since the transmission of aPINGframe and the reception of its acknowledgment. Only present if aPINGframe has been sent on theHttp2Session.streamAverageDuration{number} The average duration (in milliseconds) for allHttp2Streaminstances.streamCount{number} The number ofHttp2Streaminstances processed by theHttp2Session.type{string} Either'server'or'client'to identify the type ofHttp2Session.