1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
'use strict';
import arrayEach from 'lodash/_arrayEach';
import arrayEvery from 'lodash/_arrayEvery';
import baseHas from 'lodash/_baseHas';
import forOwn from 'lodash/forOwn';
import indexOf from 'lodash/indexOf';
import isArray from 'lodash/isArray';
import okeys from 'lodash/keys';
import noop from 'lodash/noop';
import once from 'lodash/once';
import rest from 'lodash/rest';
import onlyOnce from './internal/onlyOnce';
import setImmediate from './internal/setImmediate';
export default function (tasks, concurrency, callback) {
if (typeof arguments[1] === 'function') {
// concurrency is optional, shift the args.
callback = concurrency;
concurrency = null;
}
callback = once(callback || noop);
var keys = okeys(tasks);
var remainingTasks = keys.length;
if (!remainingTasks) {
return callback(null);
}
if (!concurrency) {
concurrency = remainingTasks;
}
var results = {};
var runningTasks = 0;
var hasError = false;
var listeners = [];
function addListener(fn) {
listeners.unshift(fn);
}
function removeListener(fn) {
var idx = indexOf(listeners, fn);
if (idx >= 0) listeners.splice(idx, 1);
}
function taskComplete() {
remainingTasks--;
arrayEach(listeners.slice(), function (fn) {
fn();
});
}
addListener(function () {
if (!remainingTasks) {
callback(null, results);
}
});
arrayEach(keys, function (k) {
if (hasError) return;
var task = isArray(tasks[k]) ? tasks[k]: [tasks[k]];
var taskCallback = onlyOnce(rest(function(err, args) {
runningTasks--;
if (args.length <= 1) {
args = args[0];
}
if (err) {
var safeResults = {};
forOwn(results, function(val, rkey) {
safeResults[rkey] = val;
});
safeResults[k] = args;
hasError = true;
listeners = [];
callback(err, safeResults);
}
else {
results[k] = args;
setImmediate(taskComplete);
}
}));
var requires = task.slice(0, task.length - 1);
checkForDeadlocks();
if (ready()) {
startNext();
} else {
addListener(listener);
}
function checkForDeadlocks() {
var len = requires.length;
var dep;
while (len--) {
if (!(dep = tasks[requires[len]])) {
throw new Error('Has non-existent dependency in ' +
requires.join(', '));
}
if (isArray(dep) && indexOf(dep, k) >= 0) {
throw new Error('Has cyclic dependencies');
}
}
}
function ready() {
return runningTasks < concurrency &&
!baseHas(results, k) &&
!hasError &&
arrayEvery(requires, function (x) {
return baseHas(results, x);
});
}
function startNext() {
runningTasks++;
var taskFn = task[task.length - 1];
if (requires.length > 0) {
taskFn(results, taskCallback);
} else {
taskFn(taskCallback);
}
}
function listener() {
if (ready()) {
removeListener(listener);
startNext();
}
}
});
}
|
