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diff --git a/middleware/node_modules/asynckit/README.md b/middleware/node_modules/asynckit/README.md new file mode 100644 index 0000000..ddcc7e6 --- /dev/null +++ b/middleware/node_modules/asynckit/README.md @@ -0,0 +1,233 @@ +# asynckit [](https://www.npmjs.com/package/asynckit) + +Minimal async jobs utility library, with streams support. + +[](https://travis-ci.org/alexindigo/asynckit) +[](https://travis-ci.org/alexindigo/asynckit) +[](https://ci.appveyor.com/project/alexindigo/asynckit) + +[](https://coveralls.io/github/alexindigo/asynckit?branch=master) +[](https://david-dm.org/alexindigo/asynckit) +[](https://www.bithound.io/github/alexindigo/asynckit) + +<!-- [](https://www.npmjs.com/package/reamde) --> + +AsyncKit provides harness for `parallel` and `serial` iterators over list of items represented by arrays or objects. +Optionally it accepts abort function (should be synchronously return by iterator for each item), and terminates left over jobs upon an error event. For specific iteration order built-in (`ascending` and `descending`) and custom sort helpers also supported, via `asynckit.serialOrdered` method. + +It ensures async operations to keep behavior more stable and prevent `Maximum call stack size exceeded` errors, from sync iterators. + +| compression | size | +| :----------------- | -------: | +| asynckit.js | 12.34 kB | +| asynckit.min.js | 4.11 kB | +| asynckit.min.js.gz | 1.47 kB | + + +## Install + +```sh +$ npm install --save asynckit +``` + +## Examples + +### Parallel Jobs + +Runs iterator over provided array in parallel. Stores output in the `result` array, +on the matching positions. In unlikely event of an error from one of the jobs, +will terminate rest of the active jobs (if abort function is provided) +and return error along with salvaged data to the main callback function. + +#### Input Array + +```javascript +var parallel = require('asynckit').parallel + , assert = require('assert') + ; + +var source = [ 1, 1, 4, 16, 64, 32, 8, 2 ] + , expectedResult = [ 2, 2, 8, 32, 128, 64, 16, 4 ] + , expectedTarget = [ 1, 1, 2, 4, 8, 16, 32, 64 ] + , target = [] + ; + +parallel(source, asyncJob, function(err, result) +{ + assert.deepEqual(result, expectedResult); + assert.deepEqual(target, expectedTarget); +}); + +// async job accepts one element from the array +// and a callback function +function asyncJob(item, cb) +{ + // different delays (in ms) per item + var delay = item * 25; + + // pretend different jobs take different time to finish + // and not in consequential order + var timeoutId = setTimeout(function() { + target.push(item); + cb(null, item * 2); + }, delay); + + // allow to cancel "leftover" jobs upon error + // return function, invoking of which will abort this job + return clearTimeout.bind(null, timeoutId); +} +``` + +More examples could be found in [test/test-parallel-array.js](test/test-parallel-array.js). + +#### Input Object + +Also it supports named jobs, listed via object. + +```javascript +var parallel = require('asynckit/parallel') + , assert = require('assert') + ; + +var source = { first: 1, one: 1, four: 4, sixteen: 16, sixtyFour: 64, thirtyTwo: 32, eight: 8, two: 2 } + , expectedResult = { first: 2, one: 2, four: 8, sixteen: 32, sixtyFour: 128, thirtyTwo: 64, eight: 16, two: 4 } + , expectedTarget = [ 1, 1, 2, 4, 8, 16, 32, 64 ] + , expectedKeys = [ 'first', 'one', 'two', 'four', 'eight', 'sixteen', 'thirtyTwo', 'sixtyFour' ] + , target = [] + , keys = [] + ; + +parallel(source, asyncJob, function(err, result) +{ + assert.deepEqual(result, expectedResult); + assert.deepEqual(target, expectedTarget); + assert.deepEqual(keys, expectedKeys); +}); + +// supports full value, key, callback (shortcut) interface +function asyncJob(item, key, cb) +{ + // different delays (in ms) per item + var delay = item * 25; + + // pretend different jobs take different time to finish + // and not in consequential order + var timeoutId = setTimeout(function() { + keys.push(key); + target.push(item); + cb(null, item * 2); + }, delay); + + // allow to cancel "leftover" jobs upon error + // return function, invoking of which will abort this job + return clearTimeout.bind(null, timeoutId); +} +``` + +More examples could be found in [test/test-parallel-object.js](test/test-parallel-object.js). + +### Serial Jobs + +Runs iterator over provided array sequentially. Stores output in the `result` array, +on the matching positions. In unlikely event of an error from one of the jobs, +will not proceed to the rest of the items in the list +and return error along with salvaged data to the main callback function. + +#### Input Array + +```javascript +var serial = require('asynckit/serial') + , assert = require('assert') + ; + +var source = [ 1, 1, 4, 16, 64, 32, 8, 2 ] + , expectedResult = [ 2, 2, 8, 32, 128, 64, 16, 4 ] + , expectedTarget = [ 0, 1, 2, 3, 4, 5, 6, 7 ] + , target = [] + ; + +serial(source, asyncJob, function(err, result) +{ + assert.deepEqual(result, expectedResult); + assert.deepEqual(target, expectedTarget); +}); + +// extended interface (item, key, callback) +// also supported for arrays +function asyncJob(item, key, cb) +{ + target.push(key); + + // it will be automatically made async + // even it iterator "returns" in the same event loop + cb(null, item * 2); +} +``` + +More examples could be found in [test/test-serial-array.js](test/test-serial-array.js). + +#### Input Object + +Also it supports named jobs, listed via object. + +```javascript +var serial = require('asynckit').serial + , assert = require('assert') + ; + +var source = [ 1, 1, 4, 16, 64, 32, 8, 2 ] + , expectedResult = [ 2, 2, 8, 32, 128, 64, 16, 4 ] + , expectedTarget = [ 0, 1, 2, 3, 4, 5, 6, 7 ] + , target = [] + ; + +var source = { first: 1, one: 1, four: 4, sixteen: 16, sixtyFour: 64, thirtyTwo: 32, eight: 8, two: 2 } + , expectedResult = { first: 2, one: 2, four: 8, sixteen: 32, sixtyFour: 128, thirtyTwo: 64, eight: 16, two: 4 } + , expectedTarget = [ 1, 1, 4, 16, 64, 32, 8, 2 ] + , target = [] + ; + + +serial(source, asyncJob, function(err, result) +{ + assert.deepEqual(result, expectedResult); + assert.deepEqual(target, expectedTarget); +}); + +// shortcut interface (item, callback) +// works for object as well as for the arrays +function asyncJob(item, cb) +{ + target.push(item); + + // it will be automatically made async + // even it iterator "returns" in the same event loop + cb(null, item * 2); +} +``` + +More examples could be found in [test/test-serial-object.js](test/test-serial-object.js). + +_Note: Since _object_ is an _unordered_ collection of properties, +it may produce unexpected results with sequential iterations. +Whenever order of the jobs' execution is important please use `serialOrdered` method._ + +### Ordered Serial Iterations + +TBD + +For example [compare-property](compare-property) package. + +### Streaming interface + +TBD + +## Want to Know More? + +More examples can be found in [test folder](test/). + +Or open an [issue](https://github.com/alexindigo/asynckit/issues) with questions and/or suggestions. + +## License + +AsyncKit is licensed under the MIT license. |