- Assertion testing
- Asynchronous context tracking
- Async hooks
- Buffer
- C++ addons
- C/C++ addons with Node-API
- C++ embedder API
- Child processes
- Cluster
- Command-line options
- Console
- Corepack
- Crypto
- Debugger
- Deprecated APIs
- Diagnostics Channel
- DNS
- Domain
- Errors
- Events
- File system
- Globals
- HTTP
- HTTP/2
- HTTPS
- Inspector
- Internationalization
- Modules: CommonJS modules
- Modules: ECMAScript modules
- Modules:
node:module
API - Modules: Packages
- Net
- OS
- Path
- Performance hooks
- Permissions
- Process
- Punycode
- Query strings
- Readline
- REPL
- Report
- Single executable applications
- Stream
- String decoder
- Test runner
- Timers
- TLS/SSL
- Trace events
- TTY
- UDP/datagram
- URL
- Utilities
- V8
- VM
- WASI
- Web Crypto API
- Web Streams API
- Worker threads
- Zlib
Node.js v21.0.0-nightly202306061b4ce6981d documentation
- Node.js v21.0.0-nightly202306061b4ce6981d
-
►
Table of contents
- HTTP/2
- Determining if crypto support is unavailable
- Core API
- Server-side example
- Client-side example
- Class:
Http2Session
Http2Session
and sockets- Event:
'close'
- Event:
'connect'
- Event:
'error'
- Event:
'frameError'
- Event:
'goaway'
- Event:
'localSettings'
- Event:
'ping'
- Event:
'remoteSettings'
- Event:
'stream'
- Event:
'timeout'
http2session.alpnProtocol
http2session.close([callback])
http2session.closed
http2session.connecting
http2session.destroy([error][, code])
http2session.destroyed
http2session.encrypted
http2session.goaway([code[, lastStreamID[, opaqueData]]])
http2session.localSettings
http2session.originSet
http2session.pendingSettingsAck
http2session.ping([payload, ]callback)
http2session.ref()
http2session.remoteSettings
http2session.setLocalWindowSize(windowSize)
http2session.setTimeout(msecs, callback)
http2session.socket
http2session.state
http2session.settings([settings][, callback])
http2session.type
http2session.unref()
- Class:
ServerHttp2Session
- Class:
ClientHttp2Session
- Class:
Http2Stream
Http2Stream
Lifecycle- Event:
'aborted'
- Event:
'close'
- Event:
'error'
- Event:
'frameError'
- Event:
'ready'
- Event:
'timeout'
- Event:
'trailers'
- Event:
'wantTrailers'
http2stream.aborted
http2stream.bufferSize
http2stream.close(code[, callback])
http2stream.closed
http2stream.destroyed
http2stream.endAfterHeaders
http2stream.id
http2stream.pending
http2stream.priority(options)
http2stream.rstCode
http2stream.sentHeaders
http2stream.sentInfoHeaders
http2stream.sentTrailers
http2stream.session
http2stream.setTimeout(msecs, callback)
http2stream.state
http2stream.sendTrailers(headers)
- Class:
ClientHttp2Stream
- Class:
ServerHttp2Stream
- Class:
Http2Server
- Class:
Http2SecureServer
http2.createServer([options][, onRequestHandler])
http2.createSecureServer(options[, onRequestHandler])
http2.connect(authority[, options][, listener])
http2.constants
http2.getDefaultSettings()
http2.getPackedSettings([settings])
http2.getUnpackedSettings(buf)
http2.sensitiveHeaders
- Headers object
- Settings object
- Error handling
- Invalid character handling in header names and values
- Push streams on the client
- Supporting the
CONNECT
method - The extended
CONNECT
protocol
- Compatibility API
- ALPN negotiation
- Class:
http2.Http2ServerRequest
- Event:
'aborted'
- Event:
'close'
request.aborted
request.authority
request.complete
request.connection
request.destroy([error])
request.headers
request.httpVersion
request.method
request.rawHeaders
request.rawTrailers
request.scheme
request.setTimeout(msecs, callback)
request.socket
request.stream
request.trailers
request.url
- Event:
- Class:
http2.Http2ServerResponse
- Event:
'close'
- Event:
'finish'
response.addTrailers(headers)
response.connection
response.createPushResponse(headers, callback)
response.end([data[, encoding]][, callback])
response.finished
response.getHeader(name)
response.getHeaderNames()
response.getHeaders()
response.hasHeader(name)
response.headersSent
response.removeHeader(name)
response.req
response.sendDate
response.setHeader(name, value)
response.setTimeout(msecs[, callback])
response.socket
response.statusCode
response.statusMessage
response.stream
response.writableEnded
response.write(chunk[, encoding][, callback])
response.writeContinue()
response.writeEarlyHints(hints)
response.writeHead(statusCode[, statusMessage][, headers])
- Event:
- Collecting HTTP/2 performance metrics
- Note on
:authority
andhost
- HTTP/2
-
►
Index
- Assertion testing
- Asynchronous context tracking
- Async hooks
- Buffer
- C++ addons
- C/C++ addons with Node-API
- C++ embedder API
- Child processes
- Cluster
- Command-line options
- Console
- Corepack
- Crypto
- Debugger
- Deprecated APIs
- Diagnostics Channel
- DNS
- Domain
- Errors
- Events
- File system
- Globals
- HTTP
- HTTP/2
- HTTPS
- Inspector
- Internationalization
- Modules: CommonJS modules
- Modules: ECMAScript modules
- Modules:
node:module
API - Modules: Packages
- Net
- OS
- Path
- Performance hooks
- Permissions
- Process
- Punycode
- Query strings
- Readline
- REPL
- Report
- Single executable applications
- Stream
- String decoder
- Test runner
- Timers
- TLS/SSL
- Trace events
- TTY
- UDP/datagram
- URL
- Utilities
- V8
- VM
- WASI
- Web Crypto API
- Web Streams API
- Worker threads
- Zlib
- ► Other versions
- ► Options
Table of contents
- HTTP/2
- Determining if crypto support is unavailable
- Core API
- Server-side example
- Client-side example
- Class:
Http2Session
Http2Session
and sockets- Event:
'close'
- Event:
'connect'
- Event:
'error'
- Event:
'frameError'
- Event:
'goaway'
- Event:
'localSettings'
- Event:
'ping'
- Event:
'remoteSettings'
- Event:
'stream'
- Event:
'timeout'
http2session.alpnProtocol
http2session.close([callback])
http2session.closed
http2session.connecting
http2session.destroy([error][, code])
http2session.destroyed
http2session.encrypted
http2session.goaway([code[, lastStreamID[, opaqueData]]])
http2session.localSettings
http2session.originSet
http2session.pendingSettingsAck
http2session.ping([payload, ]callback)
http2session.ref()
http2session.remoteSettings
http2session.setLocalWindowSize(windowSize)
http2session.setTimeout(msecs, callback)
http2session.socket
http2session.state
http2session.settings([settings][, callback])
http2session.type
http2session.unref()
- Class:
ServerHttp2Session
- Class:
ClientHttp2Session
- Class:
Http2Stream
Http2Stream
Lifecycle- Event:
'aborted'
- Event:
'close'
- Event:
'error'
- Event:
'frameError'
- Event:
'ready'
- Event:
'timeout'
- Event:
'trailers'
- Event:
'wantTrailers'
http2stream.aborted
http2stream.bufferSize
http2stream.close(code[, callback])
http2stream.closed
http2stream.destroyed
http2stream.endAfterHeaders
http2stream.id
http2stream.pending
http2stream.priority(options)
http2stream.rstCode
http2stream.sentHeaders
http2stream.sentInfoHeaders
http2stream.sentTrailers
http2stream.session
http2stream.setTimeout(msecs, callback)
http2stream.state
http2stream.sendTrailers(headers)
- Class:
ClientHttp2Stream
- Class:
ServerHttp2Stream
- Class:
Http2Server
- Class:
Http2SecureServer
http2.createServer([options][, onRequestHandler])
http2.createSecureServer(options[, onRequestHandler])
http2.connect(authority[, options][, listener])
http2.constants
http2.getDefaultSettings()
http2.getPackedSettings([settings])
http2.getUnpackedSettings(buf)
http2.sensitiveHeaders
- Headers object
- Settings object
- Error handling
- Invalid character handling in header names and values
- Push streams on the client
- Supporting the
CONNECT
method - The extended
CONNECT
protocol
- Compatibility API
- ALPN negotiation
- Class:
http2.Http2ServerRequest
- Event:
'aborted'
- Event:
'close'
request.aborted
request.authority
request.complete
request.connection
request.destroy([error])
request.headers
request.httpVersion
request.method
request.rawHeaders
request.rawTrailers
request.scheme
request.setTimeout(msecs, callback)
request.socket
request.stream
request.trailers
request.url
- Event:
- Class:
http2.Http2ServerResponse
- Event:
'close'
- Event:
'finish'
response.addTrailers(headers)
response.connection
response.createPushResponse(headers, callback)
response.end([data[, encoding]][, callback])
response.finished
response.getHeader(name)
response.getHeaderNames()
response.getHeaders()
response.hasHeader(name)
response.headersSent
response.removeHeader(name)
response.req
response.sendDate
response.setHeader(name, value)
response.setTimeout(msecs[, callback])
response.socket
response.statusCode
response.statusMessage
response.stream
response.writableEnded
response.write(chunk[, encoding][, callback])
response.writeContinue()
response.writeEarlyHints(hints)
response.writeHead(statusCode[, statusMessage][, headers])
- Event:
- Collecting HTTP/2 performance metrics
- Note on
:authority
andhost
HTTP/2#
Source Code: lib/http2.js
The node:http2
module provides an implementation of the HTTP/2 protocol.
It can be accessed using:
const http2 = require('node:http2');
Determining if crypto support is unavailable#
It is possible for Node.js to be built without including support for the
node:crypto
module. In such cases, attempting to import
from node:http2
or
calling require('node:http2')
will result in an error being thrown.
When using CommonJS, the error thrown can be caught using try/catch:
let http2;
try {
http2 = require('node:http2');
} catch (err) {
console.error('http2 support is disabled!');
}
When using the lexical ESM import
keyword, the error can only be
caught if a handler for process.on('uncaughtException')
is registered
before any attempt to load the module is made (using, for instance,
a preload module).
When using ESM, if there is a chance that the code may be run on a build
of Node.js where crypto support is not enabled, consider using the
import()
function instead of the lexical import
keyword:
let http2;
try {
http2 = await import('node:http2');
} catch (err) {
console.error('http2 support is disabled!');
}
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 http2
Core API is much more symmetric between client and server than the
http
API. For instance, most events, like 'error'
, 'connect'
and
'stream'
, can be emitted either by client-side code or server-side code.
Server-side example#
The following illustrates a simple HTTP/2 server using the Core API.
Since there are no browsers known that support
unencrypted HTTP/2, the use of
http2.createSecureServer()
is necessary when communicating
with browser clients.
const http2 = require('node:http2');
const fs = require('node: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('stream', (stream, headers) => {
// stream is a Duplex
stream.respond({
'content-type': 'text/html; charset=utf-8',
':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.pem
Client-side example#
The following illustrates an HTTP/2 client:
const http2 = require('node:http2');
const fs = require('node:fs');
const client = http2.connect('https://localhost:8443', {
ca: fs.readFileSync('localhost-cert.pem'),
});
client.on('error', (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();
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.
User code will not create Http2Session
instances directly. Server-side
Http2Session
instances are created by the Http2Server
instance when a
new HTTP/2 connection is received. Client-side Http2Session
instances are
created using the http2.connect()
method.
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 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 destroyed. Its
listener does not expect any arguments.
Event: 'connect'
#
session
<Http2Session>socket
<net.Socket>
The 'connect'
event is emitted once the Http2Session
has been successfully
connected to the remote peer and communication may begin.
User code will typically not listen for this event directly.
Event: 'error'
#
error
<Error>
The 'error'
event is emitted when an error occurs during the processing of
an Http2Session
.
Event: 'frameError'
#
type
<integer> The frame type.code
<integer> The error code.id
<integer> The stream id (or0
if the frame isn't associated with a stream).
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 a 'frameError'
event on the
Http2Stream
is made.
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.
Event: 'goaway'
#
errorCode
<number> The HTTP/2 error code specified in theGOAWAY
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 theGOAWAY
frame, aBuffer
instance will be passed containing that data.
The 'goaway'
event is emitted when a GOAWAY
frame is received.
The Http2Session
instance will be shut down automatically when the 'goaway'
event is emitted.
Event: 'localSettings'
#
settings
<HTTP/2 Settings Object> A copy of theSETTINGS
frame received.
The 'localSettings'
event is emitted when an acknowledgment SETTINGS
frame
has been received.
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: 'ping'
#
payload
<Buffer> ThePING
frame 8-byte payload
The 'ping'
event is emitted whenever a PING
frame is received from the
connected peer.
Event: 'remoteSettings'
#
settings
<HTTP/2 Settings Object> A copy of theSETTINGS
frame received.
The 'remoteSettings'
event is emitted when a new SETTINGS
frame is received
from the connected peer.
session.on('remoteSettings', (settings) => {
/* Use the new settings */
});
Event: 'stream'
#
stream
<Http2Stream> A reference to the streamheaders
<HTTP/2 Headers Object> An object describing the headersflags
<number> The associated numeric flagsrawHeaders
<Array> An array containing the raw header names followed by their respective values.
The 'stream'
event is emitted when a new Http2Stream
is created.
const http2 = require('node:http2');
session.on('stream', (stream, headers, flags) => {
const method = headers[':method'];
const path = headers[':path'];
// ...
stream.respond({
':status': 200,
'content-type': 'text/plain; charset=utf-8',
});
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('node:http2');
// Create an unencrypted HTTP/2 server
const server = http2.createServer();
server.on('stream', (stream, headers) => {
stream.respond({
'content-type': 'text/html; charset=utf-8',
':status': 200,
});
stream.on('error', (error) => console.error(error));
stream.end('<h1>Hello World</h1>');
});
server.listen(8000);
Even though HTTP/2 streams and network sockets are not in a 1:1 correspondence, a network error will destroy each individual stream and must be handled on the stream level, as shown above.
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.
Its listener does not expect any arguments.
session.setTimeout(2000);
session.on('timeout', () => { /* .. */ });
http2session.alpnProtocol
#
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.
http2session.close([callback])
#
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.
http2session.closed
#
Will be true
if this Http2Session
instance has been closed, otherwise
false
.
http2session.connecting
#
Will be true
if this Http2Session
instance is still connecting, will be set
to false
before emitting connect
event and/or calling the http2.connect
callback.
http2session.destroy([error][, code])
#
error
<Error> AnError
object if theHttp2Session
is being destroyed due to an error.code
<number> The HTTP/2 error code to send in the finalGOAWAY
frame. If unspecified, anderror
is not undefined, the default isINTERNAL_ERROR
, otherwise defaults toNO_ERROR
.
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 before the
'close'
event.
If there are any remaining open Http2Streams
associated with the
Http2Session
, those will also be destroyed.
http2session.destroyed
#
Will be true
if this Http2Session
instance has been destroyed and must no
longer be used, otherwise false
.
http2session.encrypted
#
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.
http2session.goaway([code[, lastStreamID[, opaqueData]]])
#
code
<number> An HTTP/2 error codelastStreamID
<number> The numeric ID of the last processedHttp2Stream
opaqueData
<Buffer> | <TypedArray> | <DataView> ATypedArray
orDataView
instance containing additional data to be carried within theGOAWAY
frame.
Transmits a GOAWAY
frame to the connected peer without shutting down the
Http2Session
.
http2session.localSettings
#
A prototype-less object describing the current local settings of this
Http2Session
. The local settings are local to this Http2Session
instance.
http2session.originSet
#
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.
The originSet
property is only available when using a secure TLS connection.
http2session.pendingSettingsAck
#
Indicates whether the Http2Session
is currently waiting for acknowledgment of
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.ping([payload, ]callback)
#
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.
http2session.ref()
#
Calls ref()
on this Http2Session
instance's underlying net.Socket
.
http2session.remoteSettings
#
A prototype-less object describing the current remote settings of this
Http2Session
. The remote settings are set by the connected HTTP/2 peer.
http2session.setLocalWindowSize(windowSize)
#
windowSize
<number>
Sets the local endpoint's window size.
The windowSize
is the total window size to set, not
the delta.
const http2 = require('node:http2');
const server = http2.createServer();
const expectedWindowSize = 2 ** 20;
server.on('connect', (session) => {
// Set local window size to be 2 ** 20
session.setLocalWindowSize(expectedWindowSize);
});
http2session.setTimeout(msecs, callback)
#
msecs
<number>callback
<Function>
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.socket
#
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.
http2session.state
#
Provides miscellaneous information about the current state of the
Http2Session
.
- <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 newHttp2Stream
is 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 theHttp2Stream
for which aHEADERS
orDATA
frame was most recently received.remoteWindowSize
<number> The number of bytes that thisHttp2Session
may 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
.
http2session.settings([settings][, callback])
#
settings
<HTTP/2 Settings Object>callback
<Function> Callback that is called once the session is connected or right away if the session is already connected.err
<Error> | <null>settings
<HTTP/2 Settings Object> The updatedsettings
object.duration
<integer>
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.
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.
http2session.type
#
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.
http2session.unref()
#
Calls unref()
on this Http2Session
instance's underlying net.Socket
.
Class: ServerHttp2Session
#
- Extends: <Http2Session>
serverhttp2session.altsvc(alt, originOrStream)
#
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 anObject
with anorigin
property) or the numeric identifier of an activeHttp2Stream
as given by thehttp2stream.id
property.
Submits an ALTSVC
frame (as defined by RFC 7838) to the connected client.
const http2 = require('node: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.
Specifying alternative services#
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.
serverhttp2session.origin(...origins)
#
Submits an ORIGIN
frame (as defined by RFC 8336) to the connected client
to advertise the set of origins for which the server is capable of providing
authoritative responses.
const http2 = require('node:http2');
const options = getSecureOptionsSomehow();
const server = http2.createSecureServer(options);
server.on('stream', (stream) => {
stream.respond();
stream.end('ok');
});
server.on('session', (session) => {
session.origin('https://example.com', 'https://example.org');
});
When a string is passed as an origin
, 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
an origin
, 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.
Alternatively, the origins
option may be used when creating a new HTTP/2
server using the http2.createSecureServer()
method:
const http2 = require('node:http2');
const options = getSecureOptionsSomehow();
options.origins = ['https://example.com', 'https://example.org'];
const server = http2.createSecureServer(options);
server.on('stream', (stream) => {
stream.respond();
stream.end('ok');
});
Class: ClientHttp2Session
#
- Extends: <Http2Session>
Event: 'altsvc'
#
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 no origin
is provided in the ALTSVC
frame, origin
will
be an empty string.
const http2 = require('node:http2');
const client = http2.connect('https://example.org');
client.on('altsvc', (alt, origin, streamId) => {
console.log(alt);
console.log(origin);
console.log(streamId);
});
Event: 'origin'
#
origins
<string[]>
The 'origin'
event is emitted whenever an ORIGIN
frame is received by
the client. The event is emitted with an array of origin
strings. The
http2session.originSet
will be updated to include the received
origins.
const http2 = require('node:http2');
const client = http2.connect('https://example.org');
client.on('origin', (origins) => {
for (let n = 0; n < origins.length; n++)
console.log(origins[n]);
});
The 'origin'
event is only emitted when using a secure TLS connection.
clienthttp2session.request(headers[, options])
#
-
headers
<HTTP/2 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. Default:false
.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).waitForTrailers
<boolean> Whentrue
, theHttp2Stream
will emit the'wantTrailers'
event after the finalDATA
frame has been sent.signal
<AbortSignal> An AbortSignal that may be used to abort an ongoing request.
-
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.
When a ClientHttp2Session
is first created, the socket may not yet be
connected. if clienthttp2session.request()
is called during this time, the
actual request will be deferred until the socket is ready to go.
If the session
is closed before the actual request be executed, an
ERR_HTTP2_GOAWAY_SESSION
is thrown.
This method is only available if http2session.type
is equal to
http2.constants.NGHTTP2_SESSION_CLIENT
.
const http2 = require('node: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 the options.waitForTrailers
option is set, the 'wantTrailers'
event
is emitted immediately after queuing the last chunk of payload data to be sent.
The http2stream.sendTrailers()
method can then be called to send trailing
headers to the peer.
When options.waitForTrailers
is set, the Http2Stream
will not automatically
close when the final DATA
frame is transmitted. User code must call either
http2stream.sendTrailers()
or http2stream.close()
to close the
Http2Stream
.
When options.signal
is set with an AbortSignal
and then abort
on the
corresponding AbortController
is called, the request will emit an 'error'
event with an AbortError
error.
The :method
and :path
pseudo-headers are not specified within headers
,
they respectively default to:
:method
='GET'
:path
=/
Class: Http2Stream
#
- Extends: <stream.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.
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.
The default text character encoding for an Http2Stream
is UTF-8. When using an
Http2Stream
to send text, use the 'content-type'
header to set the character
encoding.
stream.respond({
'content-type': 'text/html; charset=utf-8',
':status': 200,
});
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.
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.
Destruction#
All Http2Stream
instances are destroyed either when:
- An
RST_STREAM
frame for the stream is received by the connected peer, and (for client streams only) pending data has been read. - The
http2stream.close()
method is called, and (for client streams only) pending data has been read. - 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 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.
Event: 'aborted'
#
The 'aborted'
event is emitted whenever a Http2Stream
instance is
abnormally aborted in mid-communication.
Its listener does not expect any arguments.
The 'aborted'
event will only be emitted if the Http2Stream
writable side
has not been ended.
Event: 'close'
#
The 'close'
event is emitted when the Http2Stream
is destroyed. Once
this event is emitted, the Http2Stream
instance is no longer usable.
The HTTP/2 error code used when closing the stream can be retrieved using
the http2stream.rstCode
property. If the code is any value other than
NGHTTP2_NO_ERROR
(0
), an 'error'
event will have also been emitted.
Event: 'error'
#
error
<Error>
The 'error'
event is emitted when an error occurs during the processing of
an Http2Stream
.
Event: 'frameError'
#
type
<integer> The frame type.code
<integer> The error code.id
<integer> The stream id (or0
if the frame isn't associated with a stream).
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: 'ready'
#
The 'ready'
event is emitted when the Http2Stream
has been opened, has
been assigned an id
, and can be used. The listener does not expect any
arguments.
Event: 'timeout'
#
The 'timeout'
event is emitted after no activity is received for this
Http2Stream
within the number of milliseconds set using
http2stream.setTimeout()
.
Its listener does not expect any arguments.
Event: 'trailers'
#
headers
<HTTP/2 Headers Object> An object describing the headersflags
<number> The associated numeric flags
The 'trailers'
event is emitted when a block of headers associated with
trailing header fields is received. The listener callback is passed the
HTTP/2 Headers Object and flags associated with the headers.
This event might not be emitted if http2stream.end()
is called
before trailers are received and the incoming data is not being read or
listened for.
stream.on('trailers', (headers, flags) => {
console.log(headers);
});
Event: 'wantTrailers'
#
The 'wantTrailers'
event is emitted when the Http2Stream
has queued the
final DATA
frame to be sent on a frame and the Http2Stream
is ready to send
trailing headers. When initiating a request or response, the waitForTrailers
option must be set for this event to be emitted.
http2stream.aborted
#
Set to true
if the Http2Stream
instance was aborted abnormally. When set,
the 'aborted'
event will have been emitted.
http2stream.bufferSize
#
This property shows the number of characters currently buffered to be written.
See net.Socket.bufferSize
for details.
http2stream.close(code[, callback])
#
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.
Closes the Http2Stream
instance by sending an RST_STREAM
frame to the
connected HTTP/2 peer.
http2stream.closed
#
Set to true
if the Http2Stream
instance has been closed.
http2stream.destroyed
#
Set to true
if the Http2Stream
instance has been destroyed and is no longer
usable.
http2stream.endAfterHeaders
#
Set to true
if the END_STREAM
flag was set in the request or response
HEADERS frame received, indicating that no additional data should be received
and the readable side of the Http2Stream
will be closed.
http2stream.id
#
The numeric stream identifier of this Http2Stream
instance. Set to undefined
if the stream identifier has not yet been assigned.
http2stream.pending
#
Set to true
if the Http2Stream
instance has not yet been assigned a
numeric stream identifier.
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. Default:false
.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.
Updates the priority for this Http2Stream
instance.
http2stream.rstCode
#
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.
http2stream.sentHeaders
#
An object containing the outbound headers sent for this Http2Stream
.
http2stream.sentInfoHeaders
#
An array of objects containing the outbound informational (additional) headers
sent for this Http2Stream
.
http2stream.sentTrailers
#
An object containing the outbound trailers sent for this HttpStream
.
http2stream.session
#
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>
const http2 = require('node: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));
http2stream.state
#
Provides miscellaneous information about the current state of the
Http2Stream
.
- <Object>
localWindowSize
<number> The number of bytes the connected peer may send for thisHttp2Stream
without receiving aWINDOW_UPDATE
.state
<number> A flag indicating the low-level current state of theHttp2Stream
as determined bynghttp2
.localClose
<number>1
if thisHttp2Stream
has been closed locally.remoteClose
<number>1
if thisHttp2Stream
has been closed remotely.sumDependencyWeight
<number> The sum weight of allHttp2Stream
instances that depend on thisHttp2Stream
as specified usingPRIORITY
frames.weight
<number> The priority weight of thisHttp2Stream
.
A current state of this Http2Stream
.
http2stream.sendTrailers(headers)
#
headers
<HTTP/2 Headers Object>
Sends a trailing HEADERS
frame to the connected HTTP/2 peer. This method
will cause the Http2Stream
to be immediately closed and must only be
called after the 'wantTrailers'
event has been emitted. When sending a
request or sending a response, the options.waitForTrailers
option must be set
in order to keep the Http2Stream
open after the final DATA
frame so that
trailers can be sent.
const http2 = require('node:http2');
const server = http2.createServer();
server.on('stream', (stream) => {
stream.respond(undefined, { waitForTrailers: true });
stream.on('wantTrailers', () => {
stream.sendTrailers({ xyz: 'abc' });
});
stream.end('Hello World');
});
The HTTP/1 specification forbids trailers from containing HTTP/2 pseudo-header
fields (e.g. ':method'
, ':path'
, etc).
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'
#
headers
<HTTP/2 Headers Object>flags
<number>
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 HTTP/2 Headers Object and flags
associated with the headers.
stream.on('headers', (headers, flags) => {
console.log(headers);
});
Event: 'push'
#
headers
<HTTP/2 Headers Object>flags
<number>
The 'push'
event is emitted when response headers for a Server Push stream
are received. The listener callback is passed the HTTP/2 Headers Object and
flags associated with the headers.
stream.on('push', (headers, flags) => {
console.log(headers);
});
Event: 'response'
#
headers
<HTTP/2 Headers Object>flags
<number>
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
HTTP/2 Headers Object, and flags associated with the headers.
const http2 = require('node: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
<HTTP/2 Headers Object>
Sends an additional informational HEADERS
frame to the connected HTTP/2 peer.
http2stream.headersSent
#
True if headers were sent, false otherwise (read-only).
http2stream.pushAllowed
#
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
<HTTP/2 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. Default:false
.parent
<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 returnedpushStream
object.headers
<HTTP/2 Headers Object> Headers object thepushStream
was initiated with.
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('node: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.
Calling http2stream.pushStream()
from within a pushed stream is not permitted
and will throw an error.
http2stream.respond([headers[, options]])
#
headers
<HTTP/2 Headers Object>options
<Object>
const http2 = require('node:http2');
const server = http2.createServer();
server.on('stream', (stream) => {
stream.respond({ ':status': 200 });
stream.end('some data');
});
Initiates a response. When the options.waitForTrailers
option is set, the
'wantTrailers'
event will be emitted immediately after queuing the last chunk
of payload data to be sent. The http2stream.sendTrailers()
method can then be
used to sent trailing header fields to the peer.
When options.waitForTrailers
is set, the Http2Stream
will not automatically
close when the final DATA
frame is transmitted. User code must call either
http2stream.sendTrailers()
or http2stream.close()
to close the
Http2Stream
.
const http2 = require('node:http2');
const server = http2.createServer();
server.on('stream', (stream) => {
stream.respond({ ':status': 200 }, { waitForTrailers: true });
stream.on('wantTrailers', () => {
stream.sendTrailers({ ABC: 'some value to send' });
});
stream.end('some data');
});
http2stream.respondWithFD(fd[, headers[, options]])
#
fd
<number> | <FileHandle> A readable file descriptor.headers
<HTTP/2 Headers Object>options
<Object>statCheck
<Function>waitForTrailers
<boolean> Whentrue
, theHttp2Stream
will emit the'wantTrailers'
event after the finalDATA
frame has been sent.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('node:http2');
const fs = require('node:fs');
const server = http2.createServer();
server.on('stream', (stream) => {
const fd = fs.openSync('/some/file', 'r');
const stat = fs.fstatSync(fd);
const headers = {
'content-length': stat.size,
'last-modified': stat.mtime.toUTCString(),
'content-type': 'text/plain; charset=utf-8',
};
stream.respondWithFD(fd, headers);
stream.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.
The file descriptor or FileHandle
is not closed when the stream is closed,
so it will need to be closed manually once it is no longer needed.
Using the same file descriptor concurrently for multiple streams
is not supported and may result in data loss. Re-using a file descriptor
after a stream has finished is supported.
When the options.waitForTrailers
option is set, the 'wantTrailers'
event
will be emitted immediately after queuing the last chunk of payload data to be
sent. The http2stream.sendTrailers()
method can then be used to sent trailing
header fields to the peer.
When options.waitForTrailers
is set, the Http2Stream
will not automatically
close when the final DATA
frame is transmitted. User code must call either
http2stream.sendTrailers()
or http2stream.close()
to close the
Http2Stream
.
const http2 = require('node:http2');
const fs = require('node:fs');
const server = http2.createServer();
server.on('stream', (stream) => {
const fd = fs.openSync('/some/file', 'r');
const stat = fs.fstatSync(fd);
const headers = {
'content-length': stat.size,
'last-modified': stat.mtime.toUTCString(),
'content-type': 'text/plain; charset=utf-8',
};
stream.respondWithFD(fd, headers, { waitForTrailers: true });
stream.on('wantTrailers', () => {
stream.sendTrailers({ ABC: 'some value to send' });
});
stream.on('close', () => fs.closeSync(fd));
});
http2stream.respondWithFile(path[, headers[, options]])
#
path
<string> | <Buffer> | <URL>headers
<HTTP/2 Headers Object>options
<Object>statCheck
<Function>onError
<Function> Callback function invoked in the case of an error before send.waitForTrailers
<boolean> Whentrue
, theHttp2Stream
will emit the'wantTrailers'
event after the finalDATA
frame has been sent.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('node:http2');
const server = http2.createServer();
server.on('stream', (stream) => {
function statCheck(stat, headers) {
headers['last-modified'] = stat.mtime.toUTCString();
}
function onError(err) {
// stream.respond() can throw if the stream has been destroyed by
// the other side.
try {
if (err.code === 'ENOENT') {
stream.respond({ ':status': 404 });
} else {
stream.respond({ ':status': 500 });
}
} catch (err) {
// Perform actual error handling.
console.error(err);
}
stream.end();
}
stream.respondWithFile('/some/file',
{ 'content-type': 'text/plain; charset=utf-8' },
{ 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('node: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; charset=utf-8' },
{ 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 the options.waitForTrailers
option is set, the 'wantTrailers'
event
will be emitted immediately after queuing the last chunk of payload data to be
sent. The http2stream.sendTrailers()
method can then be used to sent trailing
header fields to the peer.
When options.waitForTrailers
is set, the Http2Stream
will not automatically
close when the final DATA
frame is transmitted. User code must call either
http2stream.sendTrailers()
or http2stream.close()
to close the
Http2Stream
.
const http2 = require('node:http2');
const server = http2.createServer();
server.on('stream', (stream) => {
stream.respondWithFile('/some/file',
{ 'content-type': 'text/plain; charset=utf-8' },
{ waitForTrailers: true });
stream.on('wantTrailers', () => {
stream.sendTrailers({ ABC: 'some value to send' });
});
});
Class: Http2Server
#
- Extends: <net.Server>
Instances of Http2Server
are created using the http2.createServer()
function. The Http2Server
class is not exported directly by the
node:http2
module.
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.
When this event is emitted and handled, the 'request'
event will
not be emitted.
Event: 'connection'
#
socket
<stream.Duplex>
This event is emitted when a new TCP stream is established. socket
is
typically an object of type net.Socket
. Usually users will not want to
access this event.
This event can also be explicitly emitted by users to inject connections
into the HTTP server. In that case, any Duplex
stream can be passed.
Event: 'request'
#
request
<http2.Http2ServerRequest>response
<http2.Http2ServerResponse>
Emitted each time there is a request. There may be multiple requests per session. See the Compatibility API.
Event: 'session'
#
session
<ServerHttp2Session>
The 'session'
event is emitted when a new Http2Session
is created by the
Http2Server
.
Event: 'sessionError'
#
error
<Error>session
<ServerHttp2Session>
The 'sessionError'
event is emitted when an 'error'
event is emitted by
an Http2Session
object associated with the Http2Server
.
Event: 'stream'
#
stream
<Http2Stream> A reference to the streamheaders
<HTTP/2 Headers Object> An object describing the headersflags
<number> The associated numeric flagsrawHeaders
<Array> An array containing the raw header names followed by their respective values.
The 'stream'
event is emitted when a 'stream'
event has been emitted by
an Http2Session
associated with the server.
See also Http2Session
's 'stream'
event.
const http2 = require('node: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; charset=utf-8',
});
stream.write('hello ');
stream.end('world');
});
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()
.
Default: 0 (no timeout)
server.close([callback])
#
callback
<Function>
Stops the server from establishing new sessions. This does not prevent new
request streams from being created due to the persistent nature of HTTP/2
sessions. To gracefully shut down the server, call http2session.close()
on
all active sessions.
If callback
is provided, it is not invoked until all active sessions have been
closed, although the server has already stopped allowing new sessions. See
net.Server.close()
for more details.
server.setTimeout([msecs][, callback])
#
msecs
<number> Default: 0 (no timeout)callback
<Function>- Returns: <Http2Server>
Used to set the timeout value for http2 server requests,
and sets a callback function that is called when there is no activity
on the Http2Server
after msecs
milliseconds.
The given callback is registered as a listener on the 'timeout'
event.
In case if callback
is not a function, a new ERR_INVALID_ARG_TYPE
error will be thrown.
server.timeout
#
- <number> Timeout in milliseconds. Default: 0 (no timeout)
The number of milliseconds of inactivity before a socket is presumed to have timed out.
A value of 0
will disable the timeout behavior on incoming connections.
The socket timeout logic is set up on connection, so changing this value only affects new connections to the server, not any existing connections.
server.updateSettings([settings])
#
settings
<HTTP/2 Settings Object>
Used to update the server with the provided settings.
Throws ERR_HTTP2_INVALID_SETTING_VALUE
for invalid settings
values.
Throws ERR_INVALID_ARG_TYPE
for invalid settings
argument.
Class: Http2SecureServer
#
- Extends: <tls.Server>
Instances of Http2SecureServer
are created using the
http2.createSecureServer()
function. The Http2SecureServer
class is not
exported directly by the node:http2
module.
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.
When this event is emitted and handled, the 'request'
event will
not be emitted.
Event: 'connection'
#
socket
<stream.Duplex>
This event is emitted when a new TCP stream is established, before the TLS
handshake begins. socket
is typically an object of type net.Socket
.
Usually users will not want to access this event.
This event can also be explicitly emitted by users to inject connections
into the HTTP server. In that case, any Duplex
stream can be passed.
Event: 'request'
#
request
<http2.Http2ServerRequest>response
<http2.Http2ServerResponse>
Emitted each time there is a request. There may be multiple requests per session. See the Compatibility API.
Event: 'session'
#
session
<ServerHttp2Session>
The 'session'
event is emitted when a new Http2Session
is created by the
Http2SecureServer
.
Event: 'sessionError'
#
error
<Error>session
<ServerHttp2Session>
The 'sessionError'
event is emitted when an 'error'
event is emitted by
an Http2Session
object associated with the Http2SecureServer
.
Event: 'stream'
#
stream
<Http2Stream> A reference to the streamheaders
<HTTP/2 Headers Object> An object describing the headersflags
<number> The associated numeric flagsrawHeaders
<Array> An array containing the raw header names followed by their respective values.
The 'stream'
event is emitted when a 'stream'
event has been emitted by
an Http2Session
associated with the server.
See also Http2Session
's 'stream'
event.
const http2 = require('node: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; charset=utf-8',
});
stream.write('hello ');
stream.end('world');
});
Event: 'timeout'
#
The 'timeout'
event is emitted when there is no activity on the Server for
a given number of milliseconds set using http2secureServer.setTimeout()
.
Default: 2 minutes.
Event: 'unknownProtocol'
#
socket
<stream.Duplex>
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. A timeout may be specified using the
'unknownProtocolTimeout'
option passed to http2.createSecureServer()
.
In earlier versions of Node.js, this event would be emitted if allowHTTP1
is
false
and, during the TLS handshake, the client either does not send an ALPN
extension or sends an ALPN extension that does not include HTTP/2 (h2
). Newer
versions of Node.js only emit this event if allowHTTP1
is false
and the
client does not send an ALPN extension. If the client sends an ALPN extension
that does not include HTTP/2 (or HTTP/1.1 if allowHTTP1
is true
), the TLS
handshake will fail and no secure connection will be established.
See the Compatibility API.
server.close([callback])
#
callback
<Function>
Stops the server from establishing new sessions. This does not prevent new
request streams from being created due to the persistent nature of HTTP/2
sessions. To gracefully shut down the server, call http2session.close()
on
all active sessions.
If callback
is provided, it is not invoked until all active sessions have been
closed, although the server has already stopped allowing new sessions. See
tls.Server.close()
for more details.
server.setTimeout([msecs][, callback])
#
msecs
<number> Default:120000
(2 minutes)callback
<Function>- Returns: <Http2SecureServer>
Used to set the timeout value for http2 secure server requests,
and sets a callback function that is called when there is no activity
on the Http2SecureServer
after msecs
milliseconds.
The given callback is registered as a listener on the 'timeout'
event.
In case if callback
is not a function, a new ERR_INVALID_ARG_TYPE
error will be thrown.
server.timeout
#
- <number> Timeout in milliseconds. Default: 0 (no timeout)
The number of milliseconds of inactivity before a socket is presumed to have timed out.
A value of 0
will disable the timeout behavior on incoming connections.
The socket timeout logic is set up on connection, so changing this value only affects new connections to the server, not any existing connections.
server.updateSettings([settings])
#
settings
<HTTP/2 Settings Object>
Used to update the server with the provided settings.
Throws ERR_HTTP2_INVALID_SETTING_VALUE
for invalid settings
values.
Throws ERR_INVALID_ARG_TYPE
for invalid settings
argument.
http2.createServer([options][, onRequestHandler])
#
options
<Object>maxDeflateDynamicTableSize
<number> Sets the maximum dynamic table size for deflating header fields. Default:4Kib
.maxSettings
<number> Sets the maximum number of settings entries perSETTINGS
frame. The minimum value allowed is1
. Default:32
.maxSessionMemory
<number> Sets the maximum memory that theHttp2Session
is permitted to use. The value is expressed in terms of number of megabytes, e.g.1
equal 1 megabyte. The minimum value allowed is1
. This is a credit based limit, existingHttp2Stream
s may cause this limit to be exceeded, but newHttp2Stream
instances will be rejected while this limit is exceeded. The current number ofHttp2Stream
sessions, the current memory use of the header compression tables, current data queued to be sent, and unacknowledgedPING
andSETTINGS
frames are all counted towards the current limit. Default:10
.maxHeaderListPairs
<number> Sets the maximum number of header entries. This is similar toserver.maxHeadersCount
orrequest.maxHeadersCount
in thenode:http
module. The minimum value is4
. Default:128
.maxOutstandingPings
<number> Sets the maximum number of outstanding, unacknowledged pings. Default:10
.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. While this sets the maximum allowed size to the entire block of headers,nghttp2
(the internal http2 library) has a limit of65536
for each decompressed key/value pair.paddingStrategy
<number> The strategy used for determining the amount of padding to use forHEADERS
andDATA
frames. Default:http2.constants.PADDING_STRATEGY_NONE
. Value may be one of:http2.constants.PADDING_STRATEGY_NONE
: No padding is applied.http2.constants.PADDING_STRATEGY_MAX
: The maximum amount of padding, determined by the internal implementation, is applied.http2.constants.PADDING_STRATEGY_ALIGNED
: Attempts to apply enough padding to ensure that the total frame length, including the 9-byte header, is a multiple of 8. For each frame, 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 is used and the total frame length is not necessarily aligned at 8 bytes.
peerMaxConcurrentStreams
<number> Sets the maximum number of concurrent streams for the remote peer as if aSETTINGS
frame had been received. Will be overridden if the remote peer sets its own value formaxConcurrentStreams
. Default:100
.maxSessionInvalidFrames
<integer> Sets the maximum number of invalid frames that will be tolerated before the session is closed. Default:1000
.maxSessionRejectedStreams
<integer> Sets the maximum number of rejected upon creation streams that will be tolerated before the session is closed. Each rejection is associated with anNGHTTP2_ENHANCE_YOUR_CALM
error that should tell the peer to not open any more streams, continuing to open streams is therefore regarded as a sign of a misbehaving peer. Default:100
.settings
<HTTP/2 Settings Object> The initial settings to send to the remote peer upon connection.Http1IncomingMessage
<http.IncomingMessage> Specifies theIncomingMessage
class to used for HTTP/1 fallback. Useful for extending the originalhttp.IncomingMessage
. Default:http.IncomingMessage
.Http1ServerResponse
<http.ServerResponse> Specifies theServerResponse
class to used for HTTP/1 fallback. Useful for extending the originalhttp.ServerResponse
. Default:http.ServerResponse
.Http2ServerRequest
<http2.Http2ServerRequest> Specifies theHttp2ServerRequest
class to use. Useful for extending the originalHttp2ServerRequest
. Default:Http2ServerRequest
.Http2ServerResponse
<http2.Http2ServerResponse> Specifies theHttp2ServerResponse
class to use. Useful for extending the originalHttp2ServerResponse
. Default:Http2ServerResponse
.unknownProtocolTimeout
<number> Specifies a timeout in milliseconds that a server should wait when an'unknownProtocol'
is emitted. If the socket has not been destroyed by that time the server will destroy it. Default:10000
.- ...: Any
net.createServer()
option can be provided.
onRequestHandler
<Function> See Compatibility API- Returns: <Http2Server>
Returns a net.Server
instance that creates and manages Http2Session
instances.
Since there are no browsers known that support
unencrypted HTTP/2, the use of
http2.createSecureServer()
is necessary when communicating
with browser clients.
const http2 = require('node:http2');
// Create an unencrypted HTTP/2 server.
// Since there are no browsers known that support
// unencrypted HTTP/2, the use of `http2.createSecureServer()`
// is necessary when communicating with browser clients.
const server = http2.createServer();
server.on('stream', (stream, headers) => {
stream.respond({
'content-type': 'text/html; charset=utf-8',
':status': 200,
});
stream.end('<h1>Hello World</h1>');
});
server.listen(8000);
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
. See the'unknownProtocol'
event. See ALPN negotiation. Default:false
.maxDeflateDynamicTableSize
<number> Sets the maximum dynamic table size for deflating header fields. Default:4Kib
.maxSettings
<number> Sets the maximum number of settings entries perSETTINGS
frame. The minimum value allowed is1
. Default:32
.maxSessionMemory
<number> Sets the maximum memory that theHttp2Session
is permitted to use. The value is expressed in terms of number of megabytes, e.g.1
equal 1 megabyte. The minimum value allowed is1
. This is a credit based limit, existingHttp2Stream
s may cause this limit to be exceeded, but newHttp2Stream
instances will be rejected while this limit is exceeded. The current number ofHttp2Stream
sessions, the current memory use of the header compression tables, current data queued to be sent, and unacknowledgedPING
andSETTINGS
frames are all counted towards the current limit. Default:10
.maxHeaderListPairs
<number> Sets the maximum number of header entries. This is similar toserver.maxHeadersCount
orrequest.maxHeadersCount
in thenode:http
module. The minimum value is4
. Default:128
.maxOutstandingPings
<number> Sets the maximum number of outstanding, unacknowledged pings. Default:10
.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> Strategy used for determining the amount of padding to use forHEADERS
andDATA
frames. Default:http2.constants.PADDING_STRATEGY_NONE
. Value may be one of:http2.constants.PADDING_STRATEGY_NONE
: No padding is applied.http2.constants.PADDING_STRATEGY_MAX
: The maximum amount of padding, determined by the internal implementation, is applied.http2.constants.PADDING_STRATEGY_ALIGNED
: Attempts to apply enough padding to ensure that the total frame length, including the 9-byte header, is a multiple of 8. For each frame, 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 is used and the total frame length is not necessarily aligned at 8 bytes.
peerMaxConcurrentStreams
<number> Sets the maximum number of concurrent streams for the remote peer as if aSETTINGS
frame had been received. Will be overridden if the remote peer sets its own value formaxConcurrentStreams
. Default:100
.maxSessionInvalidFrames
<integer> Sets the maximum number of invalid frames that will be tolerated before the session is closed. Default:1000
.maxSessionRejectedStreams
<integer> Sets the maximum number of rejected upon creation streams that will be tolerated before the session is closed. Each rejection is associated with anNGHTTP2_ENHANCE_YOUR_CALM
error that should tell the peer to not open any more streams, continuing to open streams is therefore regarded as a sign of a misbehaving peer. Default:100
.settings
<HTTP/2 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. origins
<string[]> An array of origin strings to send within anORIGIN
frame immediately following creation of a new serverHttp2Session
.unknownProtocolTimeout
<number> Specifies a timeout in milliseconds that a server should wait when an'unknownProtocol'
event is emitted. If the socket has not been destroyed by that time the server will destroy it. Default:10000
.
onRequestHandler
<Function> See Compatibility API- Returns: <Http2SecureServer>
Returns a tls.Server
instance that creates and manages Http2Session
instances.
const http2 = require('node:http2');
const fs = require('node:fs');
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; charset=utf-8',
':status': 200,
});
stream.end('<h1>Hello World</h1>');
});
server.listen(8443);
http2.connect(authority[, options][, listener])
#
authority
<string> | <URL> The remote HTTP/2 server to connect to. This must be in the form of a minimal, valid URL with thehttp://
orhttps://
prefix, host name, and IP port (if a non-default port is used). Userinfo (user ID and password), path, querystring, and fragment details in the URL will be ignored.options
<Object>maxDeflateDynamicTableSize
<number> Sets the maximum dynamic table size for deflating header fields. Default:4Kib
.maxSettings
<number> Sets the maximum number of settings entries perSETTINGS
frame. The minimum value allowed is1
. Default:32
.maxSessionMemory
<number> Sets the maximum memory that theHttp2Session
is permitted to use. The value is expressed in terms of number of megabytes, e.g.1
equal 1 megabyte. The minimum value allowed is1
. This is a credit based limit, existingHttp2Stream
s may cause this limit to be exceeded, but newHttp2Stream
instances will be rejected while this limit is exceeded. The current number ofHttp2Stream
sessions, the current memory use of the header compression tables, current data queued to be sent, and unacknowledgedPING
andSETTINGS
frames are all counted towards the current limit. Default:10
.maxHeaderListPairs
<number> Sets the maximum number of header entries. This is similar toserver.maxHeadersCount
orrequest.maxHeadersCount
in thenode:http
module. The minimum value is1
. Default:128
.maxOutstandingPings
<number> Sets the maximum number of outstanding, unacknowledged pings. Default:10
.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. The minimum allowed value is 0. The maximum allowed value is 232-1. A negative value sets this option to the maximum allowed value. Default:200
.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> Strategy used for determining the amount of padding to use forHEADERS
andDATA
frames. Default:http2.constants.PADDING_STRATEGY_NONE
. Value may be one of:http2.constants.PADDING_STRATEGY_NONE
: No padding is applied.http2.constants.PADDING_STRATEGY_MAX
: The maximum amount of padding, determined by the internal implementation, is applied.http2.constants.PADDING_STRATEGY_ALIGNED
: Attempts to apply enough padding to ensure that the total frame length, including the 9-byte header, is a multiple of 8. For each frame, 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 is used and the total frame length is not necessarily aligned at 8 bytes.
peerMaxConcurrentStreams
<number> Sets the maximum number of concurrent streams for the remote peer as if aSETTINGS
frame had been received. Will be overridden if the remote peer sets its own value formaxConcurrentStreams
. Default:100
.protocol
<string> The protocol to connect with, if not set in theauthority
. Value may be either'http:'
or'https:'
. Default:'https:'
settings
<HTTP/2 Settings Object> The initial settings to send to the remote peer upon connection.createConnection
<Function> An optional callback that receives theURL
instance passed toconnect
and theoptions
object, and returns anyDuplex
stream that is to be used as the connection for this session.- ...: Any
net.connect()
ortls.connect()
options can be provided. unknownProtocolTimeout
<number> Specifies a timeout in milliseconds that a server should wait when an'unknownProtocol'
event is emitted. If the socket has not been destroyed by that time the server will destroy it. Default:10000
.
listener
<Function> Will be registered as a one-time listener of the'connect'
event.- Returns: <ClientHttp2Session>
Returns a ClientHttp2Session
instance.
const http2 = require('node:http2');
const client = http2.connect('https://localhost:1234');
/* Use the client */
client.close();
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: <HTTP/2 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
<HTTP/2 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('node:http2');
const packed = http2.getPackedSettings({ enablePush: false });
console.log(packed.toString('base64'));
// Prints: AAIAAAAA
http2.getUnpackedSettings(buf)
#
buf
<Buffer> | <TypedArray> The packed settings.- Returns: <HTTP/2 Settings Object>
Returns a HTTP/2 Settings Object containing the deserialized settings from
the given Buffer
as generated by http2.getPackedSettings()
.
http2.sensitiveHeaders
#
This symbol can be set as a property on the HTTP/2 headers object with an array value in order to provide a list of headers considered sensitive. See Sensitive headers for more details.
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).
const headers = {
':status': '200',
'content-type': 'text-plain',
'ABC': ['has', 'more', 'than', 'one', 'value'],
};
stream.respond(headers);
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.
For incoming headers:
- The
:status
header is converted tonumber
. - Duplicates of
:status
,:method
,:authority
,:scheme
,:path
,:protocol
,age
,authorization
,access-control-allow-credentials
,access-control-max-age
,access-control-request-method
,content-encoding
,content-language
,content-length
,content-location
,content-md5
,content-range
,content-type
,date
,dnt
,etag
,expires
,from
,host
,if-match
,if-modified-since
,if-none-match
,if-range
,if-unmodified-since
,last-modified
,location
,max-forwards
,proxy-authorization
,range
,referer
,retry-after
,tk
,upgrade-insecure-requests
,user-agent
orx-content-type-options
are discarded. set-cookie
is always an array. Duplicates are added to the array.- For duplicate
cookie
headers, the values are joined together with '; '. - For all other headers, the values are joined together with ', '.
const http2 = require('node:http2');
const server = http2.createServer();
server.on('stream', (stream, headers) => {
console.log(headers[':path']);
console.log(headers.ABC);
});
Sensitive headers#
HTTP2 headers can be marked as sensitive, which means that the HTTP/2
header compression algorithm will never index them. This can make sense for
header values with low entropy and that may be considered valuable to an
attacker, for example Cookie
or Authorization
. To achieve this, add
the header name to the [http2.sensitiveHeaders]
property as an array:
const headers = {
':status': '200',
'content-type': 'text-plain',
'cookie': 'some-cookie',
'other-sensitive-header': 'very secret data',
[http2.sensitiveHeaders]: ['cookie', 'other-sensitive-header'],
};
stream.respond(headers);
For some headers, such as Authorization
and short Cookie
headers,
this flag is set automatically.
This property is also set for received headers. It will contain the names of all headers marked as sensitive, including ones marked that way automatically.
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 minimum allowed value is 0. The maximum allowed value is 232-1. Default:4096
.enablePush
<boolean> Specifiestrue
if HTTP/2 Push Streams are to be permitted on theHttp2Session
instances. Default:true
.initialWindowSize
<number> Specifies the sender's initial window size in bytes for stream-level flow control. The minimum allowed value is 0. The maximum allowed value is 232-1. Default:65535
.maxFrameSize
<number> Specifies the size in bytes of the largest frame payload. The minimum allowed value is 16,384. The maximum allowed value is 224-1. Default:16384
.maxConcurrentStreams
<number> Specifies the maximum number of concurrent streams permitted on anHttp2Session
. There is no default value which implies, at least theoretically, 232-1 streams may be open concurrently at any given time in anHttp2Session
. The minimum value is 0. The maximum allowed value is 232-1. Default:4294967295
.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
.maxHeaderSize
<number> Alias formaxHeaderListSize
.enableConnectProtocol
<boolean> Specifiestrue
if the "Extended Connect Protocol" defined by RFC 8441 is to be enabled. This setting is only meaningful if sent by the server. Once theenableConnectProtocol
setting has been enabled for a givenHttp2Session
, it cannot be disabled. Default:false
.
All additional properties on the settings object are ignored.
Error handling#
There are several types of error conditions that may arise when using the
node: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('node: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('node:net');
const server = net.createServer((socket) => {
let name = '';
socket.setEncoding('utf8');
socket.on('data', (chunk) => name += chunk);
socket.on('end', () => socket.end(`hello ${name}`));
});
server.listen(8000);
An HTTP/2 CONNECT proxy:
const http2 = require('node:http2');
const { NGHTTP2_REFUSED_STREAM } = http2.constants;
const net = require('node:net');
const proxy = http2.createServer();
proxy.on('stream', (stream, headers) => {
if (headers[':method'] !== 'CONNECT') {
// Only accept CONNECT requests
stream.close(NGHTTP2_REFUSED_STREAM);
return;
}
const auth = new URL(`tcp://${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('node: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:8000',
});
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 extended CONNECT
protocol#
RFC 8441 defines an "Extended CONNECT Protocol" extension to HTTP/2 that
may be used to bootstrap the use of an Http2Stream
using the CONNECT
method as a tunnel for other communication protocols (such as WebSockets).
The use of the Extended CONNECT Protocol is enabled by HTTP/2 servers by using
the enableConnectProtocol
setting:
const http2 = require('node:http2');
const settings = { enableConnectProtocol: true };
const server = http2.createServer({ settings });
Once the client receives the SETTINGS
frame from the server indicating that
the extended CONNECT may be used, it may send CONNECT
requests that use the
':protocol'
HTTP/2 pseudo-header:
const http2 = require('node:http2');
const client = http2.connect('http://localhost:8080');
client.on('remoteSettings', (settings) => {
if (settings.enableConnectProtocol) {
const req = client.request({ ':method': 'CONNECT', ':protocol': 'foo' });
// ...
}
});
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 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('node: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; charset=utf-8' });
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 HTTP/2 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 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('node:http2');
const { readFileSync } = require('node: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
#
- Extends: <stream.Readable>
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.
Event: 'aborted'
#
The 'aborted'
event is emitted whenever a Http2ServerRequest
instance is
abnormally aborted in mid-communication.
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.aborted
#
The request.aborted
property will be true
if the request has
been aborted.
request.authority
#
The request authority pseudo header field. Because HTTP/2 allows requests
to set either :authority
or host
, this value is derived from
req.headers[':authority']
if present. Otherwise, it is derived from
req.headers['host']
.
request.complete
#
The request.complete
property will be true
if the request has
been completed, aborted, or destroyed.
request.connection
#
request.socket
.See request.socket
.
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
#
The request/response headers object.
Key-value pairs of header names and values. Header names are lower-cased.
// Prints something like:
//
// { 'user-agent': 'curl/7.22.0',
// host: '127.0.0.1:8000',
// accept: '*/*' }
console.log(request.headers);
In HTTP/2, the request path, host name, 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
request.httpVersion
#
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
#
The request method as a string. Read-only. Examples: 'GET'
, 'DELETE'
.
request.rawHeaders
#
The raw request/response headers list exactly as they were received.
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
#
The raw request/response trailer keys and values exactly as they were
received. Only populated at the 'end'
event.
request.scheme
#
The request scheme pseudo header field indicating the scheme portion of the target URL.
request.setTimeout(msecs, callback)
#
msecs
<number>callback
<Function>- Returns: <http2.Http2ServerRequest>
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.
request.socket
#
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.
request.stream
#
The Http2Stream
object backing the request.
request.trailers
#
The request/response trailers object. Only populated at the 'end'
event.
request.url
#
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
Accept: text/plain
Then request.url
will be:
'/status?name=ryan'
To parse the url into its parts, new URL()
can be used:
$ node
> new URL('/status?name=ryan', 'http://example.com')
URL {
href: 'http://example.com/status?name=ryan',
origin: 'http://example.com',
protocol: 'http:',
username: '',
password: '',
host: 'example.com',
hostname: 'example.com',
port: '',
pathname: '/status',
search: '?name=ryan',
searchParams: URLSearchParams { 'name' => 'ryan' },
hash: ''
}
Class: http2.Http2ServerResponse
#
- Extends: <Stream>
This object is created internally by an HTTP server, not by the user. It is
passed as the second parameter to the 'request'
event.
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
#
response.socket
.See response.socket
.
response.createPushResponse(headers, callback)
#
headers
<HTTP/2 Headers Object> An object describing the headerscallback
<Function> Called oncehttp2stream.pushStream()
is finished, or either when the attempt to create the pushedHttp2Stream
has failed or has been rejected, or the state ofHttp2ServerRequest
is closed prior to calling thehttp2stream.pushStream()
methoderr
<Error>res
<http2.Http2ServerResponse> The newly-createdHttp2ServerResponse
object
Call http2stream.pushStream()
with the given headers, and wrap the
given Http2Stream
on a newly created Http2ServerResponse
as the callback
parameter if successful. When Http2ServerRequest
is closed, the callback is
called with an error ERR_HTTP2_INVALID_STREAM
.
response.end([data[, encoding]][, callback])
#
data
<string> | <Buffer> | <Uint8Array>encoding
<string>callback
<Function>- Returns: <this>
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
#
response.writableEnded
.Boolean value that indicates whether the response has completed. Starts
as false
. After response.end()
executes, the value will be true
.
response.getHeader(name)
#
Reads out a header that has already been queued but not sent to the client. The name is case-insensitive.
const contentType = response.getHeader('content-type');
response.getHeaderNames()
#
- Returns: <string[]>
Returns an array containing the unique names of the current outgoing headers. All header names are lowercase.
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.
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.
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)
#
Returns true
if the header identified by name
is currently set in the
outgoing headers. The header name matching is case-insensitive.
const hasContentType = response.hasHeader('content-type');
response.headersSent
#
True if headers were sent, false otherwise (read-only).
response.removeHeader(name)
#
name
<string>
Removes a header that has been queued for implicit sending.
response.removeHeader('Content-Encoding');
response.req
#
A reference to the original HTTP2 request
object.
response.sendDate
#
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.
response.setHeader('Content-Type', 'text/html; charset=utf-8');
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; charset=utf-8');
res.setHeader('X-Foo', 'bar');
res.writeHead(200, { 'Content-Type': 'text/plain; charset=utf-8' });
res.end('ok');
});
response.setTimeout(msecs[, callback])
#
msecs
<number>callback
<Function>- Returns: <http2.Http2ServerResponse>
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.
response.socket
#
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.
const http2 = require('node: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
#
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.
response.statusCode = 404;
After response header was sent to the client, this property indicates the status code which was sent out.
response.statusMessage
#
Status message is not supported by HTTP/2 (RFC 7540 8.1.2.4). It returns an empty string.
response.stream
#
The Http2Stream
object backing the response.
response.writableEnded
#
Is true
after response.end()
has been called. This property
does not indicate whether the data has been flushed, for this use
writable.writableFinished
instead.
response.write(chunk[, encoding][, callback])
#
chunk
<string> | <Buffer> | <Uint8Array>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.
In the node: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.
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.writeEarlyHints(hints)
#
hints
<Object>
Sends a status 103 Early Hints
to the client with a Link header,
indicating that the user agent can preload/preconnect the linked resources.
The hints
is an object containing the values of headers to be sent with
early hints message.
Example
const earlyHintsLink = '</styles.css>; rel=preload; as=style';
response.writeEarlyHints({
'link': earlyHintsLink,
});
const earlyHintsLinks = [
'</styles.css>; rel=preload; as=style',
'</scripts.js>; rel=preload; as=script',
];
response.writeEarlyHints({
'link': earlyHintsLinks,
});
response.writeHead(statusCode[, statusMessage][, headers])
#
statusCode
<number>statusMessage
<string>headers
<Object> | <Array>- Returns: <http2.Http2ServerResponse>
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.
Returns a reference to the Http2ServerResponse
, so that calls can be chained.
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.
const body = 'hello world';
response.writeHead(200, {
'Content-Length': Buffer.byteLength(body),
'Content-Type': 'text/plain; charset=utf-8',
});
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; charset=utf-8');
res.setHeader('X-Foo', 'bar');
res.writeHead(200, { 'Content-Type': 'text/plain; charset=utf-8' });
res.end('ok');
});
Attempting to set a header field name or value that contains invalid characters
will result in a TypeError
being thrown.
Collecting HTTP/2 performance metrics#
The Performance Observer API can be used to collect basic performance
metrics for each Http2Session
and Http2Stream
instance.
const { PerformanceObserver } = require('node: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 ofDATA
frame bytes received for thisHttp2Stream
.bytesWritten
<number> The number ofDATA
frame bytes sent for thisHttp2Stream
.id
<number> The identifier of the associatedHttp2Stream
timeToFirstByte
<number> The number of milliseconds elapsed between thePerformanceEntry
startTime
and the reception of the firstDATA
frame.timeToFirstByteSent
<number> The number of milliseconds elapsed between thePerformanceEntry
startTime
and sending of the firstDATA
frame.timeToFirstHeader
<number> The number of milliseconds elapsed between thePerformanceEntry
startTime
and 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 aPING
frame and the reception of its acknowledgment. Only present if aPING
frame has been sent on theHttp2Session
.streamAverageDuration
<number> The average duration (in milliseconds) for allHttp2Stream
instances.streamCount
<number> The number ofHttp2Stream
instances processed by theHttp2Session
.type
<string> Either'server'
or'client'
to identify the type ofHttp2Session
.
Note on :authority
and host
#
HTTP/2 requires requests to have either the :authority
pseudo-header
or the host
header. Prefer :authority
when constructing an HTTP/2
request directly, and host
when converting from HTTP/1 (in proxies,
for instance).
The compatibility API falls back to host
if :authority
is not
present. See request.authority
for more information. However,
if you don't use the compatibility API (or use req.headers
directly),
you need to implement any fall-back behavior yourself.