z-worker.js

(function main(global){"use strict";if(global.zWorkerInitialized)throw new Error("z-worker.js should be run only once");global.zWorkerInitialized=true;addEventListener("message",function(event){var message=event.data,type=message.type,sn=message.sn;var handler=handlers[type];if(handler){try{handler(message)}catch(e){onError(type,sn,e)}}});var handlers={importScripts:doImportScripts,newTask:newTask,append:processData,flush:processData};var tasks={};function doImportScripts(msg){if(msg.scripts&&msg.scripts.length>0)importScripts.apply(undefined,msg.scripts);postMessage({type:"importScripts"})}function newTask(msg){var CodecClass=global[msg.codecClass];var sn=msg.sn;if(tasks[sn])throw Error("duplicated sn");tasks[sn]={codec:new CodecClass(msg.options),crcInput:msg.crcType==="input",crcOutput:msg.crcType==="output",crc:new Crc32};postMessage({type:"newTask",sn:sn})}var now=global.performance?global.performance.now.bind(global.performance):Date.now;function processData(msg){var sn=msg.sn,type=msg.type,input=msg.data;var task=tasks[sn];if(!task&&msg.codecClass){newTask(msg);task=tasks[sn]}var isAppend=type==="append";var start=now();var output;if(isAppend){try{output=task.codec.append(input,function onprogress(loaded){postMessage({type:"progress",sn:sn,loaded:loaded})})}catch(e){delete tasks[sn];throw e}}else{delete tasks[sn];output=task.codec.flush()}var codecTime=now()-start;start=now();if(input&&task.crcInput)task.crc.append(input);if(output&&task.crcOutput)task.crc.append(output);var crcTime=now()-start;var rmsg={type:type,sn:sn,codecTime:codecTime,crcTime:crcTime};var transferables=[];if(output){rmsg.data=output;transferables.push(output.buffer)}if(!isAppend&&(task.crcInput||task.crcOutput))rmsg.crc=task.crc.get();try{postMessage(rmsg,transferables)}catch(ex){postMessage(rmsg)}}function onError(type,sn,e){var msg={type:type,sn:sn,error:formatError(e)};postMessage(msg)}function formatError(e){return{message:e.message,stack:e.stack}}function Crc32(){this.crc=-1}Crc32.prototype.append=function append(data){var crc=this.crc|0,table=this.table;for(var offset=0,len=data.length|0;offset<len;offset++)crc=crc>>>8^table[(crc^data[offset])&255];this.crc=crc};Crc32.prototype.get=function get(){return~this.crc};Crc32.prototype.table=function(){var i,j,t,table=[];for(i=0;i<256;i++){t=i;for(j=0;j<8;j++)if(t&1)t=t>>>1^3988292384;else t=t>>>1;table[i]=t}return table}();function NOOP(){}global.NOOP=NOOP;NOOP.prototype.append=function append(bytes,onprogress){return bytes};NOOP.prototype.flush=function flush(){}})(this);