HTTP2 Module in Node.js

The HTTP2 module in Node.js provides support for the HTTP/2 protocol, enabling faster and more efficient communication between clients and servers.

The HTTP2 module is a built-in module used to implement the HTTP/2 protocol in Node.js.
It improves performance through features like multiplexing, header compression, and server push.
It allows developers to create HTTP/2 servers and manage client–server communication efficiently.

JavaScript

// Node.js program to demonstrate the close event in HTTP2

const http2 = require('http2');

// Creating HTTP/2 server
const server = http2.createServer();

server.on('stream', (stream, headers) => {

    // Send response headers
    stream.respond({
        ':status': 200,
        'content-type': 'text/plain'
    });

    stream.write('Hello ');

    // Get Http2Session from stream
    const session = stream.session;

    // Get ALPN protocol used
    const protocol = session.alpnProtocol;

    stream.end("Session protocol: " + protocol);

    // Listen for session close event
    session.on('close', () => {
        console.log("Session is closed");
    });

    // Close the session
    session.close();
});

// Start server
server.listen(8000, () => {
    console.log("Server running at http://localhost:8000");
});


// Creating HTTP/2 client
const client = http2.connect('http://localhost:8000');

const req = client.request({
    ':method': 'GET',
    ':path': '/'
});

// Handle response headers
req.on('response', (headers) => {
    console.log("Status:", headers[':status']);
});

// Handle response data
req.on('data', (chunk) => {
    console.log("Received:", chunk.toString());
});

// Close client after response
req.on('end', () => {
    client.close(() => {
        console.log("Client destroyed");
    });
});

req.end();

Output:

status : 200
Received: hello
Received: local window size : 65535
client localSettings
server localSettings

Classes in the Node.js HTTP2 Module

1. Class: Http2Session

Represents an HTTP/2 session that manages communication between peers.

Events

timeout: The timeout event in Http2Session occurs when there is no activity for a specified time.
close: The close event in Http2Session is emitted when the session is destroyed.

Methods

state(): The state() method of Http2Session returns the current session state.
socket(): The socket() method of Http2Session returns the associated socket.
remoteSettings(): The remoteSettings() method of Http2Session returns remote session settings.
destroyed(): The destroyed() method of Http2Session checks if the session is destroyed.
type(): The type() method of Http2Session returns the session type.
encrypted(): The encrypted() method of Http2Session checks if the session uses TLS.
localSettings(): The localSettings() method of Http2Session returns local settings.
pendingSettingsAck(): The pendingSettingsAck() method of Http2Session checks for SETTINGS acknowledgment.
close(): The close() method of Http2Session closes the session.
closed(): The closed() method of Http2Session checks if the session is closed.
alpnProtocol(): The alpnProtocol() method of Http2Session returns the ALPN protocol used.
unref(): The unref() method of Http2Session returns the associated socket instance.
destroy(): The destroy() method of Http2Session destroys the session.
connecting(): The connecting() method of Http2Session checks if the session is connecting.
ping(): The ping() method of Http2Session sends a PING frame.
setTimeout(): The setTimeout() method of Http2Session sets a session timeout.

2. Class: ClientHttp2Session

ClientHttp2Session represents an HTTP/2 client session.

Methods

request(): The request() method of ClientHttp2Session returns a ClientHttp2Stream object.

3. Class: Http2Stream

Http2Stream represents an HTTP/2 stream for request–response communication.

Events

timeout: The timeout event in Http2Stream occurs when the stream is inactive.
close: The close event in Http2Stream is emitted when the stream is destroyed.

Methods

state(): The state() method of Http2Stream returns the stream state.
priority(): The priority() method of Http2Stream updates the stream priority.
setTimeout(): The setTimeout() method of Http2Stream sets a stream timeout.
id(): The id() method of Http2Stream returns the stream identifier.
closed(): The closed() method of Http2Stream checks if the stream is closed.
endAfterHeaders(): The endAfterHeaders() method of Http2Stream checks if the END_STREAM flag is set.
pending(): The pending() method of Http2Stream checks if the stream identifier is assigned.
destroyed(): The destroyed() method of Http2Stream checks if the stream is destroyed.
session(): The session() method of Http2Stream returns the associated Http2Session.
close(): The close() method of Http2Stream closes the stream.
rstCode(): The rstCode() method of Http2Stream returns the RST_STREAM error code.
sentHeaders(): The sentHeaders() method of Http2Stream returns sent headers.
sentInfoHeaders(): The sentInfoHeaders() method of Http2Stream returns informational headers.

4. Class: ServerHttp2Stream

ServerHttp2Stream represents an HTTP/2 stream on the server side.

Methods

additionalHeaders(): The additionalHeaders() method of ServerHttp2Stream sends extra headers.
headersSent(): The headersSent() method of ServerHttp2Stream checks if headers are sent.
pushAllowed(): The pushAllowed() method of ServerHttp2Stream checks if server push is allowed.
respond(): The respond() method of ServerHttp2Stream sends response headers.

5. Class: http2.Http2ServerRequest

Http2ServerRequest represents the incoming HTTP/2 request.

Properties

aborted: The aborted property of Http2ServerRequest indicates if the request is aborted.

Events

close: The close event in Http2ServerRequest occurs when the underlying stream closes.

Methods

url(): The url() method of Http2ServerRequest returns the request URL.
httpVersion(): The httpVersion() method of Http2ServerRequest returns the HTTP version.
headers(): The headers() method of Http2ServerRequest returns request headers.
rawHeaders(): The rawHeaders() method of Http2ServerRequest returns raw headers.
destroy(): The destroy() method of Http2ServerRequest destroys the request.
authority(): The authority() method of Http2ServerRequest returns the request authority.
complete(): The complete() method of Http2ServerRequest checks request completion.
method(): The method() method of Http2ServerRequest returns the request method.
scheme(): The scheme() method of Http2ServerRequest returns the request scheme.
rawTrailers(): The .rawTrailers() method of Http2ServerRequest returns trailer headers.
socket(): The socket() method of Http2ServerRequest returns a proxy socket object.

6. Class: http2.Http2ServerResponse

Http2ServerResponse represents the outgoing HTTP/2 response.

Properties

headersSent: The headersSent property of Http2ServerResponse indicates if headers were sent.

Events

close: The close event in Http2ServerResponse occurs when the stream closes.
finish: The finish event in Http2ServerResponse occurs when the response is fully sent.

Methods

setHeader(): The setHeader() method of Http2ServerResponse sets a response header.
setTimeout(): The setTimeout() method of Http2ServerResponse sets a response timeout.
stream(): The stream() method of Http2ServerResponse returns the HTTP stream.
statusMessage(): The statusMessage() method of Http2ServerResponse returns an empty string in HTTP/2.
writableEnded(): The writableEnded() method of Http2ServerResponse checks if response.end() was called.
write(): The write() method of Http2ServerResponse sends response data.
writeHead(): The writeHead() method of Http2ServerResponse sends response headers.
sendDate(): The sendDate() method of Http2ServerResponse checks automatic Date header generation.
socket(): The socket() method of Http2ServerResponse returns a proxy socket.
statusCode(): The statusCode() method of Http2ServerResponse returns the response status code.
getHeaderNames(): The getHeaderNames() method of Http2ServerResponse returns header names.
removeHeader(): The removeHeader() method of Http2ServerResponse removes a header.
hasHeader(): The hasHeader() method of Http2ServerResponse checks if a header exists.
getHeaders(): The getHeaders() method of Http2ServerResponse returns outgoing headers.
end(): The end() method of Http2ServerResponse completes the response.
finished(): The finished() method of Http2ServerResponse checks response completion.
getHeader(): The getHeader() method of Http2ServerResponse returns a queued header.

http2.constants

The http2.constants object provides predefined constants used in HTTP/2 operations.

Properties

constants: The constants property of http2.constants provides HTTP/2 error codes.

HTTP2 Module Methods

The Node.js HTTP2 module provides several classes that manage HTTP/2 sessions, streams, requests, and responses for efficient client–server communication.

getPackedSettings(): The getPackedSettings() method of http2 module returns serialized HTTP/2 settings.
connect(): The connect() method of http2 module creates a ClientHttp2Session.
getUnpackedSettings(): The getUnpackedSettings() method of http2 module returns deserialized settings.
getDefaultSettings(): The getDefaultSettings() method of http2 module returns default session settings.
createServer(): The createServer() method of http2 module creates an HTTP/2 server.
prompt.get(): The prompt.get() method performs input/output operations.
aborted(): The aborted() method checks if an aborted event is emitted.
bufferSize(): The bufferSize() method returns the number of buffered characters.

Classes in the Node.js HTTP2 Module

1. Class: Http2Session

2. Class: ClientHttp2Session

3. Class: Http2Stream

4. Class: ServerHttp2Stream

5. Class: http2.Http2ServerRequest

6. Class: http2.Http2ServerResponse

http2.constants

HTTP2 Module Methods

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