opusdev/vector-similarity-api
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1# asynckit [](https://www.npmjs.com/package/asynckit)2 3Minimal async jobs utility library, with streams support.4 5[](https://travis-ci.org/alexindigo/asynckit)6[](https://travis-ci.org/alexindigo/asynckit)7[](https://ci.appveyor.com/project/alexindigo/asynckit)8 9[](https://coveralls.io/github/alexindigo/asynckit?branch=master)10[](https://david-dm.org/alexindigo/asynckit)11[](https://www.bithound.io/github/alexindigo/asynckit)12 13<!-- [](https://www.npmjs.com/package/reamde) -->14 15AsyncKit provides harness for `parallel` and `serial` iterators over list of items represented by arrays or objects.16Optionally 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.17 18It ensures async operations to keep behavior more stable and prevent `Maximum call stack size exceeded` errors, from sync iterators.19 20| compression | size |21| :----------------- | -------: |22| asynckit.js | 12.34 kB |23| asynckit.min.js | 4.11 kB |24| asynckit.min.js.gz | 1.47 kB |25 26 27## Install28 29```sh30$ npm install --save asynckit31```32 33## Examples34 35### Parallel Jobs36 37Runs iterator over provided array in parallel. Stores output in the `result` array,38on the matching positions. In unlikely event of an error from one of the jobs,39will terminate rest of the active jobs (if abort function is provided)40and return error along with salvaged data to the main callback function.41 42#### Input Array43 44```javascript45var parallel = require('asynckit').parallel46 , assert = require('assert')47 ;48 49var source = [ 1, 1, 4, 16, 64, 32, 8, 2 ]50 , expectedResult = [ 2, 2, 8, 32, 128, 64, 16, 4 ]51 , expectedTarget = [ 1, 1, 2, 4, 8, 16, 32, 64 ]52 , target = []53 ;54 55parallel(source, asyncJob, function(err, result)56{57 assert.deepEqual(result, expectedResult);58 assert.deepEqual(target, expectedTarget);59});60 61// async job accepts one element from the array62// and a callback function63function asyncJob(item, cb)64{65 // different delays (in ms) per item66 var delay = item * 25;67 68 // pretend different jobs take different time to finish69 // and not in consequential order70 var timeoutId = setTimeout(function() {71 target.push(item);72 cb(null, item * 2);73 }, delay);74 75 // allow to cancel "leftover" jobs upon error76 // return function, invoking of which will abort this job77 return clearTimeout.bind(null, timeoutId);78}79```80 81More examples could be found in [test/test-parallel-array.js](test/test-parallel-array.js).82 83#### Input Object84 85Also it supports named jobs, listed via object.86 87```javascript88var parallel = require('asynckit/parallel')89 , assert = require('assert')90 ;91 92var source = { first: 1, one: 1, four: 4, sixteen: 16, sixtyFour: 64, thirtyTwo: 32, eight: 8, two: 2 }93 , expectedResult = { first: 2, one: 2, four: 8, sixteen: 32, sixtyFour: 128, thirtyTwo: 64, eight: 16, two: 4 }94 , expectedTarget = [ 1, 1, 2, 4, 8, 16, 32, 64 ]95 , expectedKeys = [ 'first', 'one', 'two', 'four', 'eight', 'sixteen', 'thirtyTwo', 'sixtyFour' ]96 , target = []97 , keys = []98 ;99 100parallel(source, asyncJob, function(err, result)101{102 assert.deepEqual(result, expectedResult);103 assert.deepEqual(target, expectedTarget);104 assert.deepEqual(keys, expectedKeys);105});106 107// supports full value, key, callback (shortcut) interface108function asyncJob(item, key, cb)109{110 // different delays (in ms) per item111 var delay = item * 25;112 113 // pretend different jobs take different time to finish114 // and not in consequential order115 var timeoutId = setTimeout(function() {116 keys.push(key);117 target.push(item);118 cb(null, item * 2);119 }, delay);120 121 // allow to cancel "leftover" jobs upon error122 // return function, invoking of which will abort this job123 return clearTimeout.bind(null, timeoutId);124}125```126 127More examples could be found in [test/test-parallel-object.js](test/test-parallel-object.js).128 129### Serial Jobs130 131Runs iterator over provided array sequentially. Stores output in the `result` array,132on the matching positions. In unlikely event of an error from one of the jobs,133will not proceed to the rest of the items in the list134and return error along with salvaged data to the main callback function.135 136#### Input Array137 138```javascript139var serial = require('asynckit/serial')140 , assert = require('assert')141 ;142 143var source = [ 1, 1, 4, 16, 64, 32, 8, 2 ]144 , expectedResult = [ 2, 2, 8, 32, 128, 64, 16, 4 ]145 , expectedTarget = [ 0, 1, 2, 3, 4, 5, 6, 7 ]146 , target = []147 ;148 149serial(source, asyncJob, function(err, result)150{151 assert.deepEqual(result, expectedResult);152 assert.deepEqual(target, expectedTarget);153});154 155// extended interface (item, key, callback)156// also supported for arrays157function asyncJob(item, key, cb)158{159 target.push(key);160 161 // it will be automatically made async162 // even it iterator "returns" in the same event loop163 cb(null, item * 2);164}165```166 167More examples could be found in [test/test-serial-array.js](test/test-serial-array.js).168 169#### Input Object170 171Also it supports named jobs, listed via object.172 173```javascript174var serial = require('asynckit').serial175 , assert = require('assert')176 ;177 178var source = [ 1, 1, 4, 16, 64, 32, 8, 2 ]179 , expectedResult = [ 2, 2, 8, 32, 128, 64, 16, 4 ]180 , expectedTarget = [ 0, 1, 2, 3, 4, 5, 6, 7 ]181 , target = []182 ;183 184var source = { first: 1, one: 1, four: 4, sixteen: 16, sixtyFour: 64, thirtyTwo: 32, eight: 8, two: 2 }185 , expectedResult = { first: 2, one: 2, four: 8, sixteen: 32, sixtyFour: 128, thirtyTwo: 64, eight: 16, two: 4 }186 , expectedTarget = [ 1, 1, 4, 16, 64, 32, 8, 2 ]187 , target = []188 ;189 190 191serial(source, asyncJob, function(err, result)192{193 assert.deepEqual(result, expectedResult);194 assert.deepEqual(target, expectedTarget);195});196 197// shortcut interface (item, callback)198// works for object as well as for the arrays199function asyncJob(item, cb)200{201 target.push(item);202 203 // it will be automatically made async204 // even it iterator "returns" in the same event loop205 cb(null, item * 2);206}207```208 209More examples could be found in [test/test-serial-object.js](test/test-serial-object.js).210 211_Note: Since _object_ is an _unordered_ collection of properties,212it may produce unexpected results with sequential iterations.213Whenever order of the jobs' execution is important please use `serialOrdered` method._214 215### Ordered Serial Iterations216 217TBD218 219For example [compare-property](compare-property) package.220 221### Streaming interface222 223TBD224 225## Want to Know More?226 227More examples can be found in [test folder](test/).228 229Or open an [issue](https://github.com/alexindigo/asynckit/issues) with questions and/or suggestions.230 231## License232 233AsyncKit is licensed under the MIT license.234