package/package.json000644 001750 000012 0000001076 12263446255013022 0ustar00000000 000000 { "name": "map-stream", "version": "0.1.0", "description": "construct pipes of streams of events", "homepage": "http://github.com/dominictarr/map-stream", "repository": { "type": "git", "url": "git://github.com/dominictarr/map-stream.git" }, "dependencies": { }, "devDependencies": { "asynct": "*", "it-is": "1", "ubelt": "~2.9", "stream-spec": "~0.2", "event-stream": "~2.1", "from": "0.0.2" }, "scripts": { "test": "asynct test/" }, "author": "Dominic Tarr (http://dominictarr.com)" } package/.npmignore000644 001750 000012 0000000052 12250501124012503 0ustar00000000 000000 node_modules node_modules/* npm_debug.log package/LICENCE000644 001750 000012 0000002056 12250501124011477 0ustar00000000 000000 Copyright (c) 2011 Dominic Tarr Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.package/index.js000644 001750 000012 0000006727 12263446161012205 0ustar00000000 000000 //filter will reemit the data if cb(err,pass) pass is truthy // reduce is more tricky // maybe we want to group the reductions or emit progress updates occasionally // the most basic reduce just emits one 'data' event after it has recieved 'end' var Stream = require('stream').Stream //create an event stream and apply function to each .write //emitting each response as data //unless it's an empty callback module.exports = function (mapper, opts) { var stream = new Stream() , self = this , inputs = 0 , outputs = 0 , ended = false , paused = false , destroyed = false , lastWritten = 0 , inNext = false this.opts = opts || {}; var errorEventName = this.opts.failures ? 'failure' : 'error'; // Items that are not ready to be written yet (because they would come out of // order) get stuck in a queue for later. var writeQueue = {} stream.writable = true stream.readable = true function queueData (data, number) { var nextToWrite = lastWritten + 1 if (number === nextToWrite) { // If it's next, and its not undefined write it if (data !== undefined) { stream.emit.apply(stream, ['data', data]) } lastWritten ++ nextToWrite ++ } else { // Otherwise queue it for later. writeQueue[number] = data } // If the next value is in the queue, write it if (writeQueue.hasOwnProperty(nextToWrite)) { var dataToWrite = writeQueue[nextToWrite] delete writeQueue[nextToWrite] return queueData(dataToWrite, nextToWrite) } outputs ++ if(inputs === outputs) { if(paused) paused = false, stream.emit('drain') //written all the incoming events if(ended) end() } } function next (err, data, number) { if(destroyed) return inNext = true if (!err || self.opts.failures) { queueData(data, number) } if (err) { stream.emit.apply(stream, [ errorEventName, err ]); } inNext = false; } // Wrap the mapper function by calling its callback with the order number of // the item in the stream. function wrappedMapper (input, number, callback) { return mapper.call(null, input, function(err, data){ callback(err, data, number) }) } stream.write = function (data) { if(ended) throw new Error('map stream is not writable') inNext = false inputs ++ try { //catch sync errors and handle them like async errors var written = wrappedMapper(data, inputs, next) paused = (written === false) return !paused } catch (err) { //if the callback has been called syncronously, and the error //has occured in an listener, throw it again. if(inNext) throw err next(err) return !paused } } function end (data) { //if end was called with args, write it, ended = true //write will emit 'end' if ended is true stream.writable = false if(data !== undefined) { return queueData(data, inputs) } else if (inputs == outputs) { //wait for processing stream.readable = false, stream.emit('end'), stream.destroy() } } stream.end = function (data) { if(ended) return end() } stream.destroy = function () { ended = destroyed = true stream.writable = stream.readable = paused = false process.nextTick(function () { stream.emit('close') }) } stream.pause = function () { paused = true } stream.resume = function () { paused = false } return stream } package/.travis.yml000644 001750 000012 0000000053 12250501124012616 0ustar00000000 000000 language: node_js node_js: - 0.6 - 0.8 package/examples/pretty.js000644 001750 000012 0000001532 12250501124014213 0ustar00000000 000000 var inspect = require('util').inspect if(!module.parent) { var map = require('..') //load map-stream var es = require('event-stream') //load event-stream es.pipe( //pipe joins streams together process.openStdin(), //open stdin es.split(), //split stream to break on newlines map(function (data, callback) { //turn this async function into a stream var j try { j = JSON.parse(data) //try to parse input into json } catch (err) { return callback(null, data) //if it fails just pass it anyway } callback(null, inspect(j)) //render it nicely }), process.stdout // pipe it to stdout ! ) } // run this // // curl -sS registry.npmjs.org/event-stream | node pretty.js // package/readme.markdown000644 001750 000012 0000002063 12263446161013526 0ustar00000000 000000 # MapStream Refactored out of [event-stream](https://github.com/dominictarr/event-stream) ##map (asyncFunction[, options]) Create a through stream from an asyncronous function. ``` js var map = require('map-stream') map(function (data, callback) { //transform data // ... callback(null, data) }) ``` Each map MUST call the callback. It may callback with data, with an error or with no arguments, * `callback()` drop this data. this makes the map work like `filter`, note:`callback(null,null)` is not the same, and will emit `null` * `callback(null, newData)` turn data into newData * `callback(error)` emit an error for this item. >Note: if a callback is not called, `map` will think that it is still being processed, >every call must be answered or the stream will not know when to end. > >Also, if the callback is called more than once, every call but the first will be ignored. ##Options * `failures` - `boolean` continue mapping even if error occured. On error `map-stream` will emit `failure` event. (default: `false`) package/test/simple-map.asynct.js000644 001750 000012 0000014375 12263446161015417 0ustar00000000 000000 'use strict'; var map = require('../') , it = require('it-is') , u = require('ubelt') , spec = require('stream-spec') , from = require('from') , Stream = require('stream') , es = require('event-stream') //REFACTOR THIS TEST TO USE es.readArray and es.writeArray function writeArray(array, stream) { array.forEach( function (j) { stream.write(j) }) stream.end() } function readStream(stream, done) { var array = [] stream.on('data', function (data) { array.push(data) }) stream.on('error', done) stream.on('end', function (data) { done(null, array) }) } //call sink on each write, //and complete when finished. function pauseStream (prob, delay) { var pauseIf = ( 'number' == typeof prob ? function () { return Math.random() < prob } : 'function' == typeof prob ? prob : 0.1 ) var delayer = ( !delay ? process.nextTick : 'number' == typeof delay ? function (next) { setTimeout(next, delay) } : delay ) return es.through(function (data) { if(!this.paused && pauseIf()) { console.log('PAUSE STREAM PAUSING') this.pause() var self = this delayer(function () { console.log('PAUSE STREAM RESUMING') self.resume() }) } console.log("emit ('data', " + data + ')') this.emit('data', data) }) } exports ['simple map applied to a stream'] = function (test) { var input = [1,2,3,7,5,3,1,9,0,2,4,6] //create event stream from var doubler = map(function (data, cb) { cb(null, data * 2) }) spec(doubler).through().validateOnExit() //a map is only a middle man, so it is both readable and writable it(doubler).has({ readable: true, writable: true, }) readStream(doubler, function (err, output) { it(output).deepEqual(input.map(function (j) { return j * 2 })) // process.nextTick(x.validate) test.done() }) writeArray(input, doubler) } exports ['stream comes back in the correct order'] = function (test) { var input = [3, 2, 1] var delayer = map(function(data, cb){ setTimeout(function () { cb(null, data) }, 100 * data) }) readStream(delayer, function (err, output) { it(output).deepEqual(input) test.done() }) writeArray(input, delayer) } exports ['continues on error event with failures `true`'] = function (test) { var input = [1, 2, 3] var delayer = map(function(data, cb){ cb(new Error('Something gone wrong'), data) }, { failures: true }) readStream(delayer, function (err, output) { it(output).deepEqual(input) test.done() }) writeArray(input, delayer) } exports['pipe two maps together'] = function (test) { var input = [1,2,3,7,5,3,1,9,0,2,4,6] //create event stream from function dd (data, cb) { cb(null, data * 2) } var doubler1 = map(dd), doubler2 = map(dd) doubler1.pipe(doubler2) spec(doubler1).through().validateOnExit() spec(doubler2).through().validateOnExit() readStream(doubler2, function (err, output) { it(output).deepEqual(input.map(function (j) { return j * 4 })) test.done() }) writeArray(input, doubler1) } //next: // // test pause, resume and drian. // // then make a pipe joiner: // // plumber (evStr1, evStr2, evStr3, evStr4, evStr5) // // will return a single stream that write goes to the first exports ['map will not call end until the callback'] = function (test) { var ticker = map(function (data, cb) { process.nextTick(function () { cb(null, data * 2) }) }) spec(ticker).through().validateOnExit() ticker.write('x') ticker.end() ticker.on('end', function () { test.done() }) } exports ['emit failures with opts.failures === `ture`'] = function (test) { var err = new Error('INTENSIONAL ERROR') , mapper = map(function () { throw err }, { failures: true }) mapper.on('failure', function (_err) { it(_err).equal(err) test.done() }) mapper.write('hello') } exports ['emit error thrown'] = function (test) { var err = new Error('INTENSIONAL ERROR') , mapper = map(function () { throw err }) mapper.on('error', function (_err) { it(_err).equal(err) test.done() }) mapper.write('hello') } exports ['emit error calledback'] = function (test) { var err = new Error('INTENSIONAL ERROR') , mapper = map(function (data, callback) { callback(err) }) mapper.on('error', function (_err) { it(_err).equal(err) test.done() }) mapper.write('hello') } exports ['do not emit drain if not paused'] = function (test) { var maps = map(function (data, callback) { u.delay(callback)(null, 1) return true }) spec(maps).through().pausable().validateOnExit() maps.on('drain', function () { it(false).ok('should not emit drain unless the stream is paused') }) it(maps.write('hello')).equal(true) it(maps.write('hello')).equal(true) it(maps.write('hello')).equal(true) setTimeout(function () {maps.end()},10) maps.on('end', test.done) } exports ['emits drain if paused, when all '] = function (test) { var active = 0 var drained = false var maps = map(function (data, callback) { active ++ u.delay(function () { active -- callback(null, 1) })() console.log('WRITE', false) return false }) spec(maps).through().validateOnExit() maps.on('drain', function () { drained = true it(active).equal(0, 'should emit drain when all maps are done') }) it(maps.write('hello')).equal(false) it(maps.write('hello')).equal(false) it(maps.write('hello')).equal(false) process.nextTick(function () {maps.end()},10) maps.on('end', function () { console.log('end') it(drained).ok('shoud have emitted drain before end') test.done() }) } exports ['map applied to a stream with filtering'] = function (test) { var input = [1,2,3,7,5,3,1,9,0,2,4,6] var doubler = map(function (data, callback) { if (data % 2) callback(null, data * 2) else callback() }) readStream(doubler, function (err, output) { it(output).deepEqual(input.filter(function (j) { return j % 2 }).map(function (j) { return j * 2 })) test.done() }) spec(doubler).through().validateOnExit() writeArray(input, doubler) }