scriby / asyncblock Goto Github PK

npm install asyncblock

asyncblock(function(flow){
    console.time('time');

    setTimeout(flow.add(), 1000);
    flow.wait(); //Wait for the first setTimeout to finish

    setTimeout(flow.add(), 2000);
    flow.wait(); //Wait for the second setTimeout to finish

    console.timeEnd('time'); //3 seconds
});

var ab = require('asyncblock');

ab(function(flow){
    console.time('time');

    setTimeout(flow.add(), 1000);
    setTimeout(flow.add(), 2000);
    flow.wait(); //Wait for both setTimeouts to finish

    console.timeEnd('time'); //2 seconds
});

var ab = require('asyncblock');

ab(function(flow) {
    //Start two parallel file reads
    fs.readFile(path1, 'utf8', flow.set('contents1'));
    fs.readFile(path2, 'utf8', flow.set('contents2'));
    
    //Print the concatenation of the results when both reads are finished
    console.log(flow.get('contents1') + flow.get('contents2'));
    
    //Wait for a large number of tasks
    for(var i = 0; i < 100; i++){
        //Add each task in parallel with i as the key
        fs.readFile(paths[i], 'utf8', flow.add(i));                                    
    }
    
    //Wait for all the tasks to finish. Results is an object of the form {key1: value1, key2: value2, ...}
    var results = flow.wait();
    
    //One-liner syntax for waiting on a single task
    var contents = flow.sync( fs.readFile(path, 'utf8', flow.callback()) );
    
    //See overview & API docs for more extensive description of techniques
});

//asyncblock.enableTransform() must be called before requiring modules using this syntax.
//See overview / API for more details

var ab = require('asyncblock');

if (ab.enableTransform(module)) { return; }

ab(function(flow) {
    //Start two parallel file reads
    var contents1 = fs.readFile(path1, 'utf8').defer();
    var contents2 = fs.readFile(path2, 'utf8').defer();
    
    //Print the concatenation of the results when both reads are finished
    console.log(contents1 + contents2);
    
    var files = [];
    //Wait for a large number of tasks
    for(var i = 0; i < 100; i++){
        //Add each task in parallel with i as the key
        files.push( fs.readFile(paths[i], 'utf8').future() );
    }
    
    //Get an array containing the file read results
    var results = files.map(function(future){
        return future.result;
    });
    
    //One-liner syntax for waiting on a single task
    var contents = fs.readFile(path, 'utf8').sync();
    
    //See overview & API docs for more extensive description of techniques
});

var ab = require('asyncblock');

if (ab.enableTransform(module)) { return; }

var asyncTask = function(callback) {
    ab(function(flow) {
        var contents = fs.readFile(path, 'utf8').sync(); //If readFile encountered an error, it would automatically get passed to the callback

        return contents; //Return the value you want to be passed to the callback
    }, callback); //The callback can be specified as the 2nd arg to asyncblock. It will be called with the value returned from the asyncblock as the 2nd arg.
                  //If an error occurs, the callback will be called with the error as the first argument.
});

function example(callback){
    var finishedCount = 0;
    var fileContents = [];

    var continuation = function(){
        if(finishedCount < 2){
            return;
        }

        fs.writeFile('path3', fileContents[0] + fileContents[1], function(err) {
            if(err) {
                throw new Error(err);
            }

            fs.readFile('path3', 'utf8', function(err, data){ 
                console.log(data);
                console.log('all done');
            });
        });
    };

    fs.readFile('path1', 'utf8', function(err, data) {
        if(err) {
            throw new Error(err);
        }

        fnishedCount++;
        fileContents[0] = data;

        continuation();
    });

    fs.readFile('path2', 'utf8', function(err, data) {
        if(err) {
            throw new Error(err);
        }

        fnishedCount++;
        fileContents[1] = data;

        continuation();
    });
}

var async = require('async');

var fileContents = [];

async.series([
    function(callback){
        async.parallel([
            function(callback) {
                fs.readFile('path1', 'utf8', callback);
            },

            function(callback) {
                fs.readFile('path2', 'utf8', callback);
            }
        ],
            function(err, results){
                fileContents = results;                                    
                callback(err);
            }
        );
    },

    function(callback) {
        fs.writeFile('path3', fileContents[0] + fileContents[1], callback);
    },

    function(callback) {
        fs.readFile('path3', 'utf8', function(err, data){
            console.log(data);
            callback(err);
        });
    }
],
    function(err) {
        if(err) {
            throw new Error(err);
        }
        
        console.log('all done');
    }
);

var ab = require('asyncblock');

ab(function(flow){
    fs.readFile('path1', 'utf8', flow.add('first'));
    fs.readFile('path2', 'utf8', flow.add('second'));
    
    //Wait until done reading the first and second files, then write them to another file
    fs.writeFile('path3', flow.wait('first') + flow.wait('second'), flow.add()); 
    flow.wait(); //Wait on all outstanding tasks

    fs.readFile('path3', 'utf8', flow.add('data'));

    console.log(flow.wait('data')); //Print the 3rd file's data
    console.log('all done');
});

//Requires asyncblock.enableTransform to be called before requiring this module
var ab = require('asyncblock');

if (ab.enableTransform(module)) { return; }

ab(function(flow){
    var first = fs.readFile('path1', 'utf8').defer();
    var second = fs.readFile('path2', 'utf8').defer();
    
    fs.writeFile('path3', first + second).sync();

    var third = fs.readFile('path3', 'utf8').defer();

    console.log(third);
    console.log('all done');
});