487a7ddc7d
Given that Node.js doesn't support Workers, general PDF.js performance will be worse when compared to browsers. In an attempt to improve at least memory usage a little bit, update the Node.js examples to release page resources once parsing is done for that page.
79 lines
2.6 KiB
JavaScript
79 lines
2.6 KiB
JavaScript
/* Any copyright is dedicated to the Public Domain.
|
|
* http://creativecommons.org/publicdomain/zero/1.0/ */
|
|
|
|
//
|
|
// Basic node example that prints document metadata and text content.
|
|
// Requires single file built version of PDF.js -- please run
|
|
// `gulp singlefile` before running the example.
|
|
//
|
|
|
|
// Run `gulp dist-install` to generate 'pdfjs-dist' npm package files.
|
|
const pdfjsLib = require("pdfjs-dist/legacy/build/pdf.js");
|
|
|
|
// Loading file from file system into typed array
|
|
const pdfPath =
|
|
process.argv[2] || "../../web/compressed.tracemonkey-pldi-09.pdf";
|
|
|
|
// Will be using promises to load document, pages and misc data instead of
|
|
// callback.
|
|
const loadingTask = pdfjsLib.getDocument(pdfPath);
|
|
loadingTask.promise
|
|
.then(function (doc) {
|
|
const numPages = doc.numPages;
|
|
console.log("# Document Loaded");
|
|
console.log("Number of Pages: " + numPages);
|
|
console.log();
|
|
|
|
let lastPromise; // will be used to chain promises
|
|
lastPromise = doc.getMetadata().then(function (data) {
|
|
console.log("# Metadata Is Loaded");
|
|
console.log("## Info");
|
|
console.log(JSON.stringify(data.info, null, 2));
|
|
console.log();
|
|
if (data.metadata) {
|
|
console.log("## Metadata");
|
|
console.log(JSON.stringify(data.metadata.getAll(), null, 2));
|
|
console.log();
|
|
}
|
|
});
|
|
|
|
const loadPage = function (pageNum) {
|
|
return doc.getPage(pageNum).then(function (page) {
|
|
console.log("# Page " + pageNum);
|
|
const viewport = page.getViewport({ scale: 1.0 });
|
|
console.log("Size: " + viewport.width + "x" + viewport.height);
|
|
console.log();
|
|
return page
|
|
.getTextContent()
|
|
.then(function (content) {
|
|
// Content contains lots of information about the text layout and
|
|
// styles, but we need only strings at the moment
|
|
const strings = content.items.map(function (item) {
|
|
return item.str;
|
|
});
|
|
console.log("## Text Content");
|
|
console.log(strings.join(" "));
|
|
// Release page resources.
|
|
page.cleanup();
|
|
})
|
|
.then(function () {
|
|
console.log();
|
|
});
|
|
});
|
|
};
|
|
// Loading of the first page will wait on metadata and subsequent loadings
|
|
// will wait on the previous pages.
|
|
for (let i = 1; i <= numPages; i++) {
|
|
lastPromise = lastPromise.then(loadPage.bind(null, i));
|
|
}
|
|
return lastPromise;
|
|
})
|
|
.then(
|
|
function () {
|
|
console.log("# End of Document");
|
|
},
|
|
function (err) {
|
|
console.error("Error: " + err);
|
|
}
|
|
);
|