99 lines
3.2 KiB
JavaScript
99 lines
3.2 KiB
JavaScript
/* Copyright 2017 Mozilla Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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var Canvas = require("canvas");
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var assert = require("assert").strict;
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var fs = require("fs");
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function NodeCanvasFactory() {}
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NodeCanvasFactory.prototype = {
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create: function NodeCanvasFactory_create(width, height) {
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assert(width > 0 && height > 0, "Invalid canvas size");
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var canvas = Canvas.createCanvas(width, height);
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var context = canvas.getContext("2d");
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return {
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canvas: canvas,
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context: context,
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};
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},
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reset: function NodeCanvasFactory_reset(canvasAndContext, width, height) {
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assert(canvasAndContext.canvas, "Canvas is not specified");
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assert(width > 0 && height > 0, "Invalid canvas size");
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canvasAndContext.canvas.width = width;
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canvasAndContext.canvas.height = height;
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},
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destroy: function NodeCanvasFactory_destroy(canvasAndContext) {
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assert(canvasAndContext.canvas, "Canvas is not specified");
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// Zeroing the width and height cause Firefox to release graphics
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// resources immediately, which can greatly reduce memory consumption.
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canvasAndContext.canvas.width = 0;
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canvasAndContext.canvas.height = 0;
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canvasAndContext.canvas = null;
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canvasAndContext.context = null;
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},
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};
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var pdfjsLib = require("pdfjs-dist/es5/build/pdf.js");
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// Relative path of the PDF file.
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var pdfURL = "../../../web/compressed.tracemonkey-pldi-09.pdf";
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// Read the PDF file into a typed array so PDF.js can load it.
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var rawData = new Uint8Array(fs.readFileSync(pdfURL));
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// Load the PDF file.
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var loadingTask = pdfjsLib.getDocument(rawData);
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loadingTask.promise
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.then(function(pdfDocument) {
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console.log("# PDF document loaded.");
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// Get the first page.
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pdfDocument.getPage(1).then(function(page) {
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// Render the page on a Node canvas with 100% scale.
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var viewport = page.getViewport({ scale: 1.0 });
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var canvasFactory = new NodeCanvasFactory();
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var canvasAndContext = canvasFactory.create(
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viewport.width,
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viewport.height
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);
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var renderContext = {
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canvasContext: canvasAndContext.context,
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viewport: viewport,
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canvasFactory: canvasFactory,
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};
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var renderTask = page.render(renderContext);
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renderTask.promise.then(function() {
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// Convert the canvas to an image buffer.
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var image = canvasAndContext.canvas.toBuffer();
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fs.writeFile("output.png", image, function(error) {
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if (error) {
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console.error("Error: " + error);
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} else {
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console.log(
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"Finished converting first page of PDF file to a PNG image."
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);
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}
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});
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});
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});
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})
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.catch(function(reason) {
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console.log(reason);
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});
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