1 |
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2 |
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3 |
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4 |
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5 | try {
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6 | var EventEmitter = require('events').EventEmitter;
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7 | if (!EventEmitter) throw new Error();
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8 | } catch (err) {
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9 | var Emitter = require('emitter');
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10 | }
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11 |
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12 |
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13 |
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14 |
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15 |
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16 | var defer = typeof process !== 'undefined' && process && typeof process.nextTick === 'function'
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17 | ? process.nextTick
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18 | : function(fn){ setTimeout(fn); };
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19 |
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20 |
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21 |
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22 |
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23 |
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24 | function noop(){}
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25 |
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26 |
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27 |
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28 |
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29 |
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30 | module.exports = Batch;
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31 |
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32 |
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33 |
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34 |
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35 |
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36 | function Batch() {
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37 | if (!(this instanceof Batch)) return new Batch;
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38 | this.fns = [];
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39 | this.concurrency(Infinity);
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40 | this.throws(true);
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41 | for (var i = 0, len = arguments.length; i < len; ++i) {
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42 | this.push(arguments[i]);
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43 | }
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44 | }
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45 |
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46 |
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47 |
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48 |
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49 |
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50 | if (EventEmitter) {
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51 | Batch.prototype.__proto__ = EventEmitter.prototype;
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52 | } else {
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53 | Emitter(Batch.prototype);
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54 | }
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55 |
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56 |
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57 |
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58 |
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59 |
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60 |
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61 |
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62 |
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63 |
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64 | Batch.prototype.concurrency = function(n){
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65 | this.n = n;
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66 | return this;
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67 | };
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68 |
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69 |
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70 |
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71 |
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72 |
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73 |
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74 |
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75 |
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76 |
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77 | Batch.prototype.push = function(fn){
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78 | this.fns.push(fn);
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79 | return this;
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80 | };
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81 |
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82 |
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83 |
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84 |
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85 |
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86 |
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87 |
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88 |
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89 | Batch.prototype.throws = function(throws) {
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90 | this.e = !!throws;
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91 | return this;
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92 | };
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93 |
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94 |
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95 |
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96 |
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97 |
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98 |
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99 |
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100 |
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101 |
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102 |
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103 | Batch.prototype.end = function(cb){
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104 | var self = this
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105 | , total = this.fns.length
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106 | , pending = total
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107 | , results = []
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108 | , errors = []
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109 | , cb = cb || noop
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110 | , fns = this.fns
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111 | , max = this.n
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112 | , throws = this.e
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113 | , index = 0
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114 | , done;
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115 |
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116 |
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117 | if (!fns.length) return defer(function(){
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118 | cb(null, results);
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119 | });
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120 |
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121 |
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122 | function next() {
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123 | var i = index++;
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124 | var fn = fns[i];
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125 | if (!fn) return;
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126 | var start = new Date;
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127 |
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128 | try {
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129 | fn(callback);
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130 | } catch (err) {
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131 | callback(err);
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132 | }
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133 |
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134 | function callback(err, res){
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135 | if (done) return;
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136 | if (err && throws) return done = true, defer(function(){
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137 | cb(err);
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138 | });
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139 | var complete = total - pending + 1;
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140 | var end = new Date;
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141 |
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142 | results[i] = res;
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143 | errors[i] = err;
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144 |
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145 | self.emit('progress', {
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146 | index: i,
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147 | value: res,
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148 | error: err,
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149 | pending: pending,
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150 | total: total,
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151 | complete: complete,
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152 | percent: complete / total * 100 | 0,
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153 | start: start,
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154 | end: end,
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155 | duration: end - start
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156 | });
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157 |
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158 | if (--pending) next();
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159 | else defer(function(){
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160 | if(!throws) cb(errors, results);
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161 | else cb(null, results);
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162 | });
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163 | }
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164 | }
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165 |
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166 |
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167 | for (var i = 0; i < fns.length; i++) {
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168 | if (i == max) break;
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169 | next();
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170 | }
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171 |
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172 | return this;
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173 | };
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