From 8eff962cab608341a6f2fedc640a0e32d96f26e2 Mon Sep 17 00:00:00 2001 From: altaf-creator Date: Sun, 9 Nov 2025 11:15:19 +0800 Subject: pain --- .../websocket-driver/lib/websocket/streams.js | 146 +++++++++++++++++++++ 1 file changed, 146 insertions(+) create mode 100644 frontend-old/node_modules/websocket-driver/lib/websocket/streams.js (limited to 'frontend-old/node_modules/websocket-driver/lib/websocket/streams.js') diff --git a/frontend-old/node_modules/websocket-driver/lib/websocket/streams.js b/frontend-old/node_modules/websocket-driver/lib/websocket/streams.js new file mode 100644 index 0000000..96ab31f --- /dev/null +++ b/frontend-old/node_modules/websocket-driver/lib/websocket/streams.js @@ -0,0 +1,146 @@ +'use strict'; + +/** + +Streams in a WebSocket connection +--------------------------------- + +We model a WebSocket as two duplex streams: one stream is for the wire protocol +over an I/O socket, and the other is for incoming/outgoing messages. + + + +----------+ +---------+ +----------+ + [1] write(chunk) -->| ~~~~~~~~ +----->| parse() +----->| ~~~~~~~~ +--> emit('data') [2] + | | +----+----+ | | + | | | | | + | IO | | [5] | Messages | + | | V | | + | | +---------+ | | + [4] emit('data') <--+ ~~~~~~~~ |<-----+ frame() |<-----+ ~~~~~~~~ |<-- write(chunk) [3] + +----------+ +---------+ +----------+ + + +Message transfer in each direction is simple: IO receives a byte stream [1] and +sends this stream for parsing. The parser will periodically emit a complete +message text on the Messages stream [2]. Similarly, when messages are written +to the Messages stream [3], they are framed using the WebSocket wire format and +emitted via IO [4]. + +There is a feedback loop via [5] since some input from [1] will be things like +ping, pong and close frames. In these cases the protocol responds by emitting +responses directly back to [4] rather than emitting messages via [2]. + +For the purposes of flow control, we consider the sources of each Readable +stream to be as follows: + +* [2] receives input from [1] +* [4] receives input from [1] and [3] + +The classes below express the relationships described above without prescribing +anything about how parse() and frame() work, other than assuming they emit +'data' events to the IO and Messages streams. They will work with any protocol +driver having these two methods. +**/ + + +var Stream = require('stream').Stream, + util = require('util'); + + +var IO = function(driver) { + this.readable = this.writable = true; + this._paused = false; + this._driver = driver; +}; +util.inherits(IO, Stream); + +// The IO pause() and resume() methods will be called when the socket we are +// piping to gets backed up and drains. Since IO output [4] comes from IO input +// [1] and Messages input [3], we need to tell both of those to return false +// from write() when this stream is paused. + +IO.prototype.pause = function() { + this._paused = true; + this._driver.messages._paused = true; +}; + +IO.prototype.resume = function() { + this._paused = false; + this.emit('drain'); + + var messages = this._driver.messages; + messages._paused = false; + messages.emit('drain'); +}; + +// When we receive input from a socket, send it to the parser and tell the +// source whether to back off. +IO.prototype.write = function(chunk) { + if (!this.writable) return false; + this._driver.parse(chunk); + return !this._paused; +}; + +// The IO end() method will be called when the socket piping into it emits +// 'close' or 'end', i.e. the socket is closed. In this situation the Messages +// stream will not emit any more data so we emit 'end'. +IO.prototype.end = function(chunk) { + if (!this.writable) return; + if (chunk !== undefined) this.write(chunk); + this.writable = false; + + var messages = this._driver.messages; + if (messages.readable) { + messages.readable = messages.writable = false; + messages.emit('end'); + } +}; + +IO.prototype.destroy = function() { + this.end(); +}; + + +var Messages = function(driver) { + this.readable = this.writable = true; + this._paused = false; + this._driver = driver; +}; +util.inherits(Messages, Stream); + +// The Messages pause() and resume() methods will be called when the app that's +// processing the messages gets backed up and drains. If we're emitting +// messages too fast we should tell the source to slow down. Message output [2] +// comes from IO input [1]. + +Messages.prototype.pause = function() { + this._driver.io._paused = true; +}; + +Messages.prototype.resume = function() { + this._driver.io._paused = false; + this._driver.io.emit('drain'); +}; + +// When we receive messages from the user, send them to the formatter and tell +// the source whether to back off. +Messages.prototype.write = function(message) { + if (!this.writable) return false; + if (typeof message === 'string') this._driver.text(message); + else this._driver.binary(message); + return !this._paused; +}; + +// The Messages end() method will be called when a stream piping into it emits +// 'end'. Many streams may be piped into the WebSocket and one of them ending +// does not mean the whole socket is done, so just process the input and move +// on leaving the socket open. +Messages.prototype.end = function(message) { + if (message !== undefined) this.write(message); +}; + +Messages.prototype.destroy = function() {}; + + +exports.IO = IO; +exports.Messages = Messages; -- cgit v1.2.3