www.aleph1.co.uk Git - yaffs-website/blob - node_modules/orchestrator/lib/runTask.js

   1 /*jshint node:true */\r
   2 \r
   3 "use strict";\r
   4 \r
   5 var eos = require('end-of-stream');\r
   6 var consume = require('stream-consume');\r
   7 \r
   8 module.exports = function (task, done) {\r
   9         var that = this, finish, cb, isDone = false, start, r;\r
  10 \r
  11         finish = function (err, runMethod) {\r
  12                 var hrDuration = process.hrtime(start);\r
  13 \r
  14                 if (isDone && !err) {\r
  15                         err = new Error('task completion callback called too many times');\r
  16                 }\r
  17                 isDone = true;\r
  18 \r
  19                 var duration = hrDuration[0] + (hrDuration[1] / 1e9); // seconds\r
  20 \r
  21                 done.call(that, err, {\r
  22                         duration: duration, // seconds\r
  23                         hrDuration: hrDuration, // [seconds,nanoseconds]\r
  24                         runMethod: runMethod\r
  25                 });\r
  26         };\r
  27 \r
  28         cb = function (err) {\r
  29                 finish(err, 'callback');\r
  30         };\r
  31 \r
  32         try {\r
  33                 start = process.hrtime();\r
  34                 r = task(cb);\r
  35         } catch (err) {\r
  36                 return finish(err, 'catch');\r
  37         }\r
  38 \r
  39         if (r && typeof r.then === 'function') {\r
  40                 // wait for promise to resolve\r
  41                 // FRAGILE: ASSUME: Promises/A+, see http://promises-aplus.github.io/promises-spec/\r
  42                 r.then(function () {\r
  43                         finish(null, 'promise');\r
  44                 }, function(err) {\r
  45                         finish(err, 'promise');\r
  46                 });\r
  47 \r
  48         } else if (r && typeof r.pipe === 'function') {\r
  49                 // wait for stream to end\r
  50 \r
  51                 eos(r, { error: true, readable: r.readable, writable: r.writable && !r.readable }, function(err){\r
  52                         finish(err, 'stream');\r
  53                 });\r
  54 \r
  55                 // Ensure that the stream completes\r
  56         consume(r);\r
  57 \r
  58         } else if (task.length === 0) {\r
  59                 // synchronous, function took in args.length parameters, and the callback was extra\r
  60                 finish(null, 'sync');\r
  61 \r
  62         //} else {\r
  63                 // FRAGILE: ASSUME: callback\r
  64 \r
  65         }\r
  66 };\r