| 1 | 'use strict'
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| 2 |
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| 3 | function id (e) { return e }
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| 4 | var prop = require('../util/prop')
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| 5 |
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| 6 | module.exports = function asyncMap (map) {
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| 7 | if(!map) return id
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| 8 | map = prop(map)
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| 9 | var busy = false, abortCb, aborted
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| 10 | return function (read) {
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| 11 | return function next (abort, cb) {
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| 12 | if(aborted) return cb(aborted)
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| 13 | if(abort) {
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| 14 | aborted = abort
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| 15 | if(!busy) read(abort, cb)
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| 16 | else read(abort, function () {
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| 17 |
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| 18 | if(busy) abortCb = cb
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| 19 | else cb(abort)
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| 20 | })
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| 21 | }
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| 22 | else
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| 23 | read(null, function (end, data) {
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| 24 | if(end) cb(end)
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| 25 | else if(aborted) cb(aborted)
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| 26 | else {
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| 27 | busy = true
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| 28 | map(data, function (err, data) {
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| 29 | busy = false
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| 30 | if(aborted) {
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| 31 | cb(aborted)
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| 32 | abortCb(aborted)
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| 33 | }
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| 34 | else if(err) next (err, cb)
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| 35 | else cb(null, data)
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| 36 | })
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| 37 | }
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| 38 | })
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| 39 | }
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| 40 | }
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| 41 | }
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| 42 |
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| 43 |
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