+++ /dev/null
-'use strict';
-
-const Limiter = require('async-limiter');
-const zlib = require('zlib');
-
-const bufferUtil = require('./buffer-util');
-const constants = require('./constants');
-
-const TRAILER = Buffer.from([0x00, 0x00, 0xff, 0xff]);
-const EMPTY_BLOCK = Buffer.from([0x00]);
-
-const kPerMessageDeflate = Symbol('permessage-deflate');
-const kWriteInProgress = Symbol('write-in-progress');
-const kPendingClose = Symbol('pending-close');
-const kTotalLength = Symbol('total-length');
-const kCallback = Symbol('callback');
-const kBuffers = Symbol('buffers');
-const kError = Symbol('error');
-
-//
-// We limit zlib concurrency, which prevents severe memory fragmentation
-// as documented in https://github.com/nodejs/node/issues/8871#issuecomment-250915913
-// and https://github.com/websockets/ws/issues/1202
-//
-// Intentionally global; it's the global thread pool that's an issue.
-//
-let zlibLimiter;
-
-/**
- * permessage-deflate implementation.
- */
-class PerMessageDeflate {
- /**
- * Creates a PerMessageDeflate instance.
- *
- * @param {Object} options Configuration options
- * @param {Boolean} options.serverNoContextTakeover Request/accept disabling
- * of server context takeover
- * @param {Boolean} options.clientNoContextTakeover Advertise/acknowledge
- * disabling of client context takeover
- * @param {(Boolean|Number)} options.serverMaxWindowBits Request/confirm the
- * use of a custom server window size
- * @param {(Boolean|Number)} options.clientMaxWindowBits Advertise support
- * for, or request, a custom client window size
- * @param {Object} options.zlibDeflateOptions Options to pass to zlib on deflate
- * @param {Object} options.zlibInflateOptions Options to pass to zlib on inflate
- * @param {Number} options.threshold Size (in bytes) below which messages
- * should not be compressed
- * @param {Number} options.concurrencyLimit The number of concurrent calls to
- * zlib
- * @param {Boolean} isServer Create the instance in either server or client
- * mode
- * @param {Number} maxPayload The maximum allowed message length
- */
- constructor (options, isServer, maxPayload) {
- this._maxPayload = maxPayload | 0;
- this._options = options || {};
- this._threshold = this._options.threshold !== undefined
- ? this._options.threshold
- : 1024;
- this._isServer = !!isServer;
- this._deflate = null;
- this._inflate = null;
-
- this.params = null;
-
- if (!zlibLimiter) {
- const concurrency = this._options.concurrencyLimit !== undefined
- ? this._options.concurrencyLimit
- : 10;
- zlibLimiter = new Limiter({ concurrency });
- }
- }
-
- /**
- * @type {String}
- */
- static get extensionName () {
- return 'permessage-deflate';
- }
-
- /**
- * Create an extension negotiation offer.
- *
- * @return {Object} Extension parameters
- * @public
- */
- offer () {
- const params = {};
-
- if (this._options.serverNoContextTakeover) {
- params.server_no_context_takeover = true;
- }
- if (this._options.clientNoContextTakeover) {
- params.client_no_context_takeover = true;
- }
- if (this._options.serverMaxWindowBits) {
- params.server_max_window_bits = this._options.serverMaxWindowBits;
- }
- if (this._options.clientMaxWindowBits) {
- params.client_max_window_bits = this._options.clientMaxWindowBits;
- } else if (this._options.clientMaxWindowBits == null) {
- params.client_max_window_bits = true;
- }
-
- return params;
- }
-
- /**
- * Accept an extension negotiation offer/response.
- *
- * @param {Array} configurations The extension negotiation offers/reponse
- * @return {Object} Accepted configuration
- * @public
- */
- accept (configurations) {
- configurations = this.normalizeParams(configurations);
-
- this.params = this._isServer
- ? this.acceptAsServer(configurations)
- : this.acceptAsClient(configurations);
-
- return this.params;
- }
-
- /**
- * Releases all resources used by the extension.
- *
- * @public
- */
- cleanup () {
- if (this._inflate) {
- if (this._inflate[kWriteInProgress]) {
- this._inflate[kPendingClose] = true;
- } else {
- this._inflate.close();
- this._inflate = null;
- }
- }
- if (this._deflate) {
- if (this._deflate[kWriteInProgress]) {
- this._deflate[kPendingClose] = true;
- } else {
- this._deflate.close();
- this._deflate = null;
- }
- }
- }
-
- /**
- * Accept an extension negotiation offer.
- *
- * @param {Array} offers The extension negotiation offers
- * @return {Object} Accepted configuration
- * @private
- */
- acceptAsServer (offers) {
- const opts = this._options;
- const accepted = offers.find((params) => {
- if (
- (opts.serverNoContextTakeover === false &&
- params.server_no_context_takeover) ||
- (params.server_max_window_bits &&
- (opts.serverMaxWindowBits === false ||
- (typeof opts.serverMaxWindowBits === 'number' &&
- opts.serverMaxWindowBits > params.server_max_window_bits))) ||
- (typeof opts.clientMaxWindowBits === 'number' &&
- !params.client_max_window_bits)
- ) {
- return false;
- }
-
- return true;
- });
-
- if (!accepted) {
- throw new Error('None of the extension offers can be accepted');
- }
-
- if (opts.serverNoContextTakeover) {
- accepted.server_no_context_takeover = true;
- }
- if (opts.clientNoContextTakeover) {
- accepted.client_no_context_takeover = true;
- }
- if (typeof opts.serverMaxWindowBits === 'number') {
- accepted.server_max_window_bits = opts.serverMaxWindowBits;
- }
- if (typeof opts.clientMaxWindowBits === 'number') {
- accepted.client_max_window_bits = opts.clientMaxWindowBits;
- } else if (
- accepted.client_max_window_bits === true ||
- opts.clientMaxWindowBits === false
- ) {
- delete accepted.client_max_window_bits;
- }
-
- return accepted;
- }
-
- /**
- * Accept the extension negotiation response.
- *
- * @param {Array} response The extension negotiation response
- * @return {Object} Accepted configuration
- * @private
- */
- acceptAsClient (response) {
- const params = response[0];
-
- if (
- this._options.clientNoContextTakeover === false &&
- params.client_no_context_takeover
- ) {
- throw new Error('Unexpected parameter "client_no_context_takeover"');
- }
-
- if (!params.client_max_window_bits) {
- if (typeof this._options.clientMaxWindowBits === 'number') {
- params.client_max_window_bits = this._options.clientMaxWindowBits;
- }
- } else if (
- this._options.clientMaxWindowBits === false ||
- (typeof this._options.clientMaxWindowBits === 'number' &&
- params.client_max_window_bits > this._options.clientMaxWindowBits)
- ) {
- throw new Error(
- 'Unexpected or invalid parameter "client_max_window_bits"'
- );
- }
-
- return params;
- }
-
- /**
- * Normalize parameters.
- *
- * @param {Array} configurations The extension negotiation offers/reponse
- * @return {Array} The offers/response with normalized parameters
- * @private
- */
- normalizeParams (configurations) {
- configurations.forEach((params) => {
- Object.keys(params).forEach((key) => {
- var value = params[key];
-
- if (value.length > 1) {
- throw new Error(`Parameter "${key}" must have only a single value`);
- }
-
- value = value[0];
-
- if (key === 'client_max_window_bits') {
- if (value !== true) {
- const num = +value;
- if (!Number.isInteger(num) || num < 8 || num > 15) {
- throw new TypeError(
- `Invalid value for parameter "${key}": ${value}`
- );
- }
- value = num;
- } else if (!this._isServer) {
- throw new TypeError(
- `Invalid value for parameter "${key}": ${value}`
- );
- }
- } else if (key === 'server_max_window_bits') {
- const num = +value;
- if (!Number.isInteger(num) || num < 8 || num > 15) {
- throw new TypeError(
- `Invalid value for parameter "${key}": ${value}`
- );
- }
- value = num;
- } else if (
- key === 'client_no_context_takeover' ||
- key === 'server_no_context_takeover'
- ) {
- if (value !== true) {
- throw new TypeError(
- `Invalid value for parameter "${key}": ${value}`
- );
- }
- } else {
- throw new Error(`Unknown parameter "${key}"`);
- }
-
- params[key] = value;
- });
- });
-
- return configurations;
- }
-
- /**
- * Decompress data. Concurrency limited by async-limiter.
- *
- * @param {Buffer} data Compressed data
- * @param {Boolean} fin Specifies whether or not this is the last fragment
- * @param {Function} callback Callback
- * @public
- */
- decompress (data, fin, callback) {
- zlibLimiter.push((done) => {
- this._decompress(data, fin, (err, result) => {
- done();
- callback(err, result);
- });
- });
- }
-
- /**
- * Compress data. Concurrency limited by async-limiter.
- *
- * @param {Buffer} data Data to compress
- * @param {Boolean} fin Specifies whether or not this is the last fragment
- * @param {Function} callback Callback
- * @public
- */
- compress (data, fin, callback) {
- zlibLimiter.push((done) => {
- this._compress(data, fin, (err, result) => {
- done();
- callback(err, result);
- });
- });
- }
-
- /**
- * Decompress data.
- *
- * @param {Buffer} data Compressed data
- * @param {Boolean} fin Specifies whether or not this is the last fragment
- * @param {Function} callback Callback
- * @private
- */
- _decompress (data, fin, callback) {
- const endpoint = this._isServer ? 'client' : 'server';
-
- if (!this._inflate) {
- const key = `${endpoint}_max_window_bits`;
- const windowBits = typeof this.params[key] !== 'number'
- ? zlib.Z_DEFAULT_WINDOWBITS
- : this.params[key];
-
- this._inflate = zlib.createInflateRaw(
- Object.assign({}, this._options.zlibInflateOptions, { windowBits })
- );
- this._inflate[kPerMessageDeflate] = this;
- this._inflate[kTotalLength] = 0;
- this._inflate[kBuffers] = [];
- this._inflate.on('error', inflateOnError);
- this._inflate.on('data', inflateOnData);
- }
-
- this._inflate[kCallback] = callback;
- this._inflate[kWriteInProgress] = true;
-
- this._inflate.write(data);
- if (fin) this._inflate.write(TRAILER);
-
- this._inflate.flush(() => {
- const err = this._inflate[kError];
-
- if (err) {
- this._inflate.close();
- this._inflate = null;
- callback(err);
- return;
- }
-
- const data = bufferUtil.concat(
- this._inflate[kBuffers],
- this._inflate[kTotalLength]
- );
-
- if (
- (fin && this.params[`${endpoint}_no_context_takeover`]) ||
- this._inflate[kPendingClose]
- ) {
- this._inflate.close();
- this._inflate = null;
- } else {
- this._inflate[kWriteInProgress] = false;
- this._inflate[kTotalLength] = 0;
- this._inflate[kBuffers] = [];
- }
-
- callback(null, data);
- });
- }
-
- /**
- * Compress data.
- *
- * @param {Buffer} data Data to compress
- * @param {Boolean} fin Specifies whether or not this is the last fragment
- * @param {Function} callback Callback
- * @private
- */
- _compress (data, fin, callback) {
- if (!data || data.length === 0) {
- process.nextTick(callback, null, EMPTY_BLOCK);
- return;
- }
-
- const endpoint = this._isServer ? 'server' : 'client';
-
- if (!this._deflate) {
- const key = `${endpoint}_max_window_bits`;
- const windowBits = typeof this.params[key] !== 'number'
- ? zlib.Z_DEFAULT_WINDOWBITS
- : this.params[key];
-
- this._deflate = zlib.createDeflateRaw(
- Object.assign(
- // TODO deprecate memLevel/level and recommend zlibDeflateOptions instead
- {
- memLevel: this._options.memLevel,
- level: this._options.level
- },
- this._options.zlibDeflateOptions,
- { windowBits }
- )
- );
-
- this._deflate[kTotalLength] = 0;
- this._deflate[kBuffers] = [];
-
- //
- // `zlib.DeflateRaw` emits an `'error'` event only when an attempt to use
- // it is made after it has already been closed. This cannot happen here,
- // so we only add a listener for the `'data'` event.
- //
- this._deflate.on('data', deflateOnData);
- }
-
- this._deflate[kWriteInProgress] = true;
-
- this._deflate.write(data);
- this._deflate.flush(zlib.Z_SYNC_FLUSH, () => {
- var data = bufferUtil.concat(
- this._deflate[kBuffers],
- this._deflate[kTotalLength]
- );
-
- if (fin) data = data.slice(0, data.length - 4);
-
- if (
- (fin && this.params[`${endpoint}_no_context_takeover`]) ||
- this._deflate[kPendingClose]
- ) {
- this._deflate.close();
- this._deflate = null;
- } else {
- this._deflate[kWriteInProgress] = false;
- this._deflate[kTotalLength] = 0;
- this._deflate[kBuffers] = [];
- }
-
- callback(null, data);
- });
- }
-}
-
-module.exports = PerMessageDeflate;
-
-/**
- * The listener of the `zlib.DeflateRaw` stream `'data'` event.
- *
- * @param {Buffer} chunk A chunk of data
- * @private
- */
-function deflateOnData (chunk) {
- this[kBuffers].push(chunk);
- this[kTotalLength] += chunk.length;
-}
-
-/**
- * The listener of the `zlib.InflateRaw` stream `'data'` event.
- *
- * @param {Buffer} chunk A chunk of data
- * @private
- */
-function inflateOnData (chunk) {
- this[kTotalLength] += chunk.length;
-
- if (
- this[kPerMessageDeflate]._maxPayload < 1 ||
- this[kTotalLength] <= this[kPerMessageDeflate]._maxPayload
- ) {
- this[kBuffers].push(chunk);
- return;
- }
-
- this[kError] = new RangeError('Max payload size exceeded');
- this[kError][constants.kStatusCode] = 1009;
- this.removeListener('data', inflateOnData);
- this.reset();
-}
-
-/**
- * The listener of the `zlib.InflateRaw` stream `'error'` event.
- *
- * @param {Error} err The emitted error
- * @private
- */
-function inflateOnError (err) {
- //
- // There is no need to call `Zlib#close()` as the handle is automatically
- // closed when an error is emitted.
- //
- this[kPerMessageDeflate]._inflate = null;
- err[constants.kStatusCode] = 1007;
- this[kCallback](err);
-}
projects / VSoRC / .git / blobdiff