paratask-promises
所属分类：超算/并行计算
开发工具：JavaScript
文件大小：0KB
下载次数：0
上传日期：2015-07-31 06:24:11
上 传 者：
sh-1993
说明： Paratask是一种工具，它将使用多进程编程的全部潜力并行执行Node.js代码。与...相反...，
(Paratask is a tool that will execute your Node.js code in parallel using the full potential of multi-process programming. In contrast to asynchronous task management, Paratask will create a child Node.js process in which your task function will live .)
文件列表:
.npmignore (12, 2015-07-30)
.travis.yml (120, 2015-07-30)
Gruntfile.js (304, 2015-07-30)
build_tests/ (0, 2015-07-30)
build_tests/execution_error_test.js (1520, 2015-07-30)
build_tests/input_validation_test.js (2701, 2015-07-30)
build_tests/legacy_test.js (722, 2015-07-30)
build_tests/use_promise_test.js (1798, 2015-07-30)
lib/ (0, 2015-07-30)
lib/index.js (12865, 2015-07-30)
lib/promise.js (4333, 2015-07-30)
lib/shared_data/ (0, 2015-07-30)
lib/task_executor.js (5712, 2015-07-30)
lib/utils.js (61066, 2015-07-30)
license (1076, 2015-07-30)
package.json (1128, 2015-07-30)
tests/ (0, 2015-07-30)
tests/async_heavy_test.js (4744, 2015-07-30)
tests/async_light_test.js (2092, 2015-07-30)
tests/async_timeout_test.js (1724, 2015-07-30)
tests/paratask_heavy_test.js (5664, 2015-07-30)
tests/paratask_light_test.js (2383, 2015-07-30)
tests/paratask_timeout_test.js (1757, 2015-07-30)
tests/process_nextTick_heavy_test.js (4915, 2015-07-30)
tests/process_nextTick_light_test.js (2246, 2015-07-30)
tests/process_nextTick_timeout_test.js (1871, 2015-07-30)
# Paratask - Node Parallel Process Manager
[](http://travis-ci.org/IvanDimanov/paratask-promises)
[](http://badge.fury.io/js/paratask-promises)
Paratask is a tool that will execute your code in __parallel__ using the full potential of multi-process programming.
In contrast to asynchronous task management, Paratask will create a child Node/io.js process in which your task function will 'live'.
__Note:__ Scope dependency injection is at your service. More into in the examples below.
__Note:__ This modules embraces the __Promises/A+__ standard. If you're more into ES5 "callback" style you can use [paratask](https://github.com/IvanDimanov/paratask)
## Install
You can install Paratask __Promises/A+__ with the Node Package Manager:
```shell
npm install paratask-promises
```
or by getting it from [this repo](https://github.com/IvanDimanov/paratask-promises).
## Dependencies
Paratask uses only native Node/io.js modules that do not need additional installation: `fs` and `child_process`.
## Custom Promise lib
You like to use your own Promise constructor or 3rd party alternative?
No problem, just type:
```javascript
var paratask = require('paratask-promises');
paratask.usePromise( require('bluebird').Promise );
// or
paratask.usePromise( require('q').Promise );
// or
paratask.usePromise( require('when').Promise );
// or
paratask.usePromise( require('rsvp').Promise );
```
Thanks to [machinewu](https://github.com/machinewu) for the great suggestion.
### Example: Parallel calculation
Both `task_1` and `task_2` will fork a new Node/io.js process and will run __concurrently__.
When both call `resolve()`, the final results will be printed in the console.
__Note:__ `scope` property is your dependency injector. Can only be a valid `JSON.parse()` value (i.e. no functions allowed).
```javascript
var paratask = require('paratask-promises');
var task_1 = {
fork: function (resolve) {
// Some calculation using the 'count' scope var
var result = count * 10;
resolve(result);
},
scope: {
count: 10
}
};
var task_2 = {
fork: function (resolve) {
// Some calculation using the 'count' scope var
var result = count * 10;
resolve(result);
},
scope: {
count: 20
}
};
paratask([ task_1, task_2 ])
.then(function (results) {
console.log( results ); // [100, 200], 1st task result will be always the 1st in the results array even if completed last
});
```
### Example: Error handling
Both `task_1` and `task_2` will fork a new process but
when `task_2` call `reject('Error message')`
both processes will be killed and the final `.then()` will be executed.
__Note:__ `scope` property is optional.
```javascript
var paratask = require('paratask-promises');
var task_1 = {
fork: function (resolve) {
var count = 100000;
var factorial = 1;
while (--count) factorial *= count;
resolve(factorial);
}
};
var task_2 = {
fork: function (resolve, reject) {
reject('Error message');
}
};
paratask([ task_1, task_2 ])
.catch(function (error) {
console.log( error ); // 'Error message'
});
```
## Comparison tests
A palette of comparison tests between `paratask()`, `async.parallel()`, and `process.nextTick()` are available in `./tests` folder.
### Heavy calculation test:
```shell
node tests/async_heavy_test.js
```
```shell
node tests/process_nextTick_heavy_test.js
```
```shell
node tests/paratask_heavy_test.js
```
## Conclusion
Paratask is great when you have several time consuming task functions with few external dependencies.
In such cases, __multi-processing__ is the best approach.
When you want to manage several relevantly quick functions with asynchronous logic, [async](https://github.com/caolan/async) will handle it with beauty.
近期下载者：
相关文件：
收藏者：