1 |
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2 |
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3 |
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4 |
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5 |
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6 |
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7 | var nextHandle = 1;
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8 | var tasksByHandle = {};
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9 | var currentlyRunningATask = false;
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10 | var doc = global.document;
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11 | var registerImmediate;
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12 |
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13 | export function setImmediate(callback) {
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14 |
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15 | if (typeof callback !== "function") {
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16 | callback = new Function("" + callback);
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17 | }
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18 |
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19 | var args = new Array(arguments.length - 1);
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20 | for (var i = 0; i < args.length; i++) {
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21 | args[i] = arguments[i + 1];
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22 | }
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23 |
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24 | var task = { callback: callback, args: args };
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25 | tasksByHandle[nextHandle] = task;
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26 | registerImmediate(nextHandle);
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27 | return nextHandle++;
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28 | }
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29 |
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30 | export function clearImmediate(handle) {
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31 | delete tasksByHandle[handle];
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32 | }
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33 |
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34 | function run(task) {
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35 | var callback = task.callback;
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36 | var args = task.args;
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37 | switch (args.length) {
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38 | case 0:
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39 | callback();
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40 | break;
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41 | case 1:
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42 | callback(args[0]);
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43 | break;
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44 | case 2:
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45 | callback(args[0], args[1]);
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46 | break;
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47 | case 3:
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48 | callback(args[0], args[1], args[2]);
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49 | break;
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50 | default:
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51 | callback.apply(undefined, args);
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52 | break;
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53 | }
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54 | }
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55 |
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56 | function runIfPresent(handle) {
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57 |
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58 |
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59 | if (currentlyRunningATask) {
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60 |
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61 |
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62 | setTimeout(runIfPresent, 0, handle);
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63 | } else {
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64 | var task = tasksByHandle[handle];
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65 | if (task) {
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66 | currentlyRunningATask = true;
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67 | try {
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68 | run(task);
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69 | } finally {
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70 | clearImmediate(handle);
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71 | currentlyRunningATask = false;
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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 | function installNextTickImplementation() {
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78 | registerImmediate = function(handle) {
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79 | process.nextTick(function () { runIfPresent(handle); });
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80 | };
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81 | }
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82 |
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83 | function canUsePostMessage() {
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84 |
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85 |
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86 | if (global.postMessage && !global.importScripts) {
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87 | var postMessageIsAsynchronous = true;
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88 | var oldOnMessage = global.onmessage;
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89 | global.onmessage = function() {
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90 | postMessageIsAsynchronous = false;
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91 | };
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92 | global.postMessage("", "*");
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93 | global.onmessage = oldOnMessage;
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94 | return postMessageIsAsynchronous;
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95 | }
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96 | }
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97 |
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98 | function installPostMessageImplementation() {
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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 | var messagePrefix = "setImmediate$" + Math.random() + "$";
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104 | var onGlobalMessage = function(event) {
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105 | if (event.source === global &&
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106 | typeof event.data === "string" &&
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107 | event.data.indexOf(messagePrefix) === 0) {
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108 | runIfPresent(+event.data.slice(messagePrefix.length));
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109 | }
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110 | };
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111 |
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112 | if (global.addEventListener) {
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113 | global.addEventListener("message", onGlobalMessage, false);
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114 | } else {
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115 | global.attachEvent("onmessage", onGlobalMessage);
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116 | }
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117 |
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118 | registerImmediate = function(handle) {
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119 | global.postMessage(messagePrefix + handle, "*");
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120 | };
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121 | }
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122 |
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123 | function installMessageChannelImplementation() {
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124 | var channel = new MessageChannel();
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125 | channel.port1.onmessage = function(event) {
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126 | var handle = event.data;
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127 | runIfPresent(handle);
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128 | };
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129 |
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130 | registerImmediate = function(handle) {
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131 | channel.port2.postMessage(handle);
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132 | };
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133 | }
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134 |
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135 | function installReadyStateChangeImplementation() {
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136 | var html = doc.documentElement;
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137 | registerImmediate = function(handle) {
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138 |
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139 |
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140 | var script = doc.createElement("script");
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141 | script.onreadystatechange = function () {
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142 | runIfPresent(handle);
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143 | script.onreadystatechange = null;
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144 | html.removeChild(script);
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145 | script = null;
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146 | };
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147 | html.appendChild(script);
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148 | };
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149 | }
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150 |
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151 | function installSetTimeoutImplementation() {
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152 | registerImmediate = function(handle) {
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153 | setTimeout(runIfPresent, 0, handle);
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154 | };
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155 | }
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156 |
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157 |
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158 | var attachTo = Object.getPrototypeOf && Object.getPrototypeOf(global);
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159 | attachTo = attachTo && attachTo.setTimeout ? attachTo : global;
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160 |
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161 |
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162 | if ({}.toString.call(global.process) === "[object process]") {
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163 |
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164 | installNextTickImplementation();
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165 |
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166 | } else if (canUsePostMessage()) {
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167 |
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168 | installPostMessageImplementation();
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169 |
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170 | } else if (global.MessageChannel) {
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171 |
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172 | installMessageChannelImplementation();
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173 |
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174 | } else if (doc && "onreadystatechange" in doc.createElement("script")) {
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175 |
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176 | installReadyStateChangeImplementation();
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177 |
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178 | } else {
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179 |
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180 | installSetTimeoutImplementation();
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181 | }
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182 | export default {
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183 | setTimeout: setTimeout,
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184 | clearTimeout: clearTimeout
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185 | }
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