pdf.js/src/worker.js
Artur Adib bbdec90c0d Lint
2012-01-20 18:44:51 -05:00

250 lines
6.8 KiB
JavaScript

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
'use strict';
function MessageHandler(name, comObj) {
this.name = name;
this.comObj = comObj;
this.callbackIndex = 1;
var callbacks = this.callbacks = {};
var ah = this.actionHandler = {};
ah['console_log'] = [function ahConsoleLog(data) {
console.log.apply(console, data);
}];
ah['console_error'] = [function ahConsoleError(data) {
console.error.apply(console, data);
}];
comObj.onmessage = function messageHandlerComObjOnMessage(event) {
var data = event.data;
if (data.isReply) {
var callbackId = data.callbackId;
if (data.callbackId in callbacks) {
var callback = callbacks[callbackId];
delete callbacks[callbackId];
callback(data.data);
} else {
throw 'Cannot resolve callback ' + callbackId;
}
} else if (data.action in ah) {
var action = ah[data.action];
if (data.callbackId) {
var promise = new Promise();
promise.then(function(resolvedData) {
comObj.postMessage({
isReply: true,
callbackId: data.callbackId,
data: resolvedData
});
});
action[0].call(action[1], data.data, promise);
} else {
action[0].call(action[1], data.data);
}
} else {
throw 'Unkown action from worker: ' + data.action;
}
};
}
MessageHandler.prototype = {
on: function messageHandlerOn(actionName, handler, scope) {
var ah = this.actionHandler;
if (ah[actionName]) {
throw 'There is already an actionName called "' + actionName + '"';
}
ah[actionName] = [handler, scope];
},
/**
* Sends a message to the comObj to invoke the action with the supplied data.
* @param {String} actionName Action to call.
* @param {JSON} data JSON data to send.
* @param {function} [callback] Optional callback that will handle a reply.
*/
send: function messageHandlerSend(actionName, data, callback) {
var message = {
action: actionName,
data: data
};
if (callback) {
var callbackId = this.callbackIndex++;
this.callbacks[callbackId] = callback;
message.callbackId = callbackId;
}
this.comObj.postMessage(message);
}
};
var WorkerMessageHandler = {
setup: function wphSetup(handler) {
var pdfDoc = null;
handler.on('test', function wphSetupTest(data) {
handler.send('test', data instanceof Uint8Array);
});
handler.on('doc', function wphSetupDoc(data) {
// Create only the model of the PDFDoc, which is enough for
// processing the content of the pdf.
pdfDoc = new PDFDocModel(new Stream(data));
});
handler.on('page_request', function wphSetupPageRequest(pageNum) {
pageNum = parseInt(pageNum);
// The following code does quite the same as
// Page.prototype.startRendering, but stops at one point and sends the
// result back to the main thread.
var gfx = new CanvasGraphics(null);
var start = Date.now();
var dependency = [];
var IRQueue = null;
try {
var page = pdfDoc.getPage(pageNum);
// Pre compile the pdf page and fetch the fonts/images.
IRQueue = page.getIRQueue(handler, dependency);
} catch (e) {
var minimumStackMessage =
'worker.js: while trying to getPage() and getIRQueue()';
// Turn the error into an obj that can be serialized
if (typeof e === 'string') {
e = {
message: e,
stack: minimumStackMessage
};
} else if (typeof e === 'object') {
e = {
message: e.message || e.toString(),
stack: e.stack || minimumStackMessage
};
} else {
e = {
message: 'Unknown exception type: ' + (typeof e),
stack: minimumStackMessage
};
}
handler.send('page_error', {
pageNum: pageNum,
error: e
});
return;
}
console.log('page=%d - getIRQueue: time=%dms, len=%d', pageNum,
Date.now() - start, IRQueue.fnArray.length);
// Filter the dependecies for fonts.
var fonts = {};
for (var i = 0, ii = dependency.length; i < ii; i++) {
var dep = dependency[i];
if (dep.indexOf('font_') == 0) {
fonts[dep] = true;
}
}
handler.send('page', {
pageNum: pageNum,
IRQueue: IRQueue,
depFonts: Object.keys(fonts)
});
}, this);
handler.on('font', function wphSetupFont(data) {
var objId = data[0];
var name = data[1];
var file = data[2];
var properties = data[3];
var font = {
name: name,
file: file,
properties: properties
};
// Some fonts don't have a file, e.g. the build in ones like Arial.
if (file) {
var fontFileDict = new Dict();
fontFileDict.map = file.dict.map;
var fontFile = new Stream(file.bytes, file.start,
file.end - file.start, fontFileDict);
// Check if this is a FlateStream. Otherwise just use the created
// Stream one. This makes complex_ttf_font.pdf work.
var cmf = file.bytes[0];
if ((cmf & 0x0f) == 0x08) {
font.file = new FlateStream(fontFile);
} else {
font.file = fontFile;
}
}
var obj = new Font(font.name, font.file, font.properties);
var str = '';
var objData = obj.data;
if (objData) {
var length = objData.length;
for (var j = 0; j < length; ++j)
str += String.fromCharCode(objData[j]);
}
obj.str = str;
// Remove the data array form the font object, as it's not needed
// anymore as we sent over the ready str.
delete obj.data;
handler.send('font_ready', [objId, obj]);
});
}
};
var consoleTimer = {};
var workerConsole = {
log: function log() {
var args = Array.prototype.slice.call(arguments);
postMessage({
action: 'console_log',
data: args
});
},
error: function error() {
var args = Array.prototype.slice.call(arguments);
postMessage({
action: 'console_error',
data: args
});
},
time: function time(name) {
consoleTimer[name] = Date.now();
},
timeEnd: function timeEnd(name) {
var time = consoleTimer[name];
if (time == null) {
throw 'Unkown timer name ' + name;
}
this.log('Timer:', name, Date.now() - time);
}
};
// Worker thread?
if (typeof window === 'undefined') {
globalScope.console = workerConsole;
var handler = new MessageHandler('worker_processor', this);
WorkerMessageHandler.setup(handler);
}