Merge pull request #8540 from Rob--W/svg-oom

Reduce memory requirements of pdf2svg.js example to avoid OOM

examples/node/domstubs.js

@@ -95,24 +95,27 @@ DOMElement.prototype = {
   },
 
   toString: function DOMElement_toString() {
-    var attrList = [];
+    var buf = [];
-    for (i in this.attributes) {
+    buf.push('<' + this.nodeName);
-      attrList.push(i + '="' + xmlEncode(this.attributes[i]) + '"');
+    if (this.nodeName === 'svg:svg') {
+      buf.push(' xmlns:xlink="http://www.w3.org/1999/xlink"' +
+               ' xmlns:svg="http://www.w3.org/2000/svg"');
     }
+    for (var i in this.attributes) {
+      buf.push(' ' + i + '="' + xmlEncode(this.attributes[i]) + '"');
+    }
+
+    buf.push('>');
 
     if (this.nodeName === 'svg:tspan' || this.nodeName === 'svg:style') {
-      var encText = xmlEncode(this.textContent);
+      buf.push(xmlEncode(this.textContent));
-      return '<' + this.nodeName + ' ' + attrList.join(' ') + '>' +
-             encText + '</' + this.nodeName + '>';
-    } else if (this.nodeName === 'svg:svg') {
-      var ns = 'xmlns:xlink="http://www.w3.org/1999/xlink" ' +
-               'xmlns:svg="http://www.w3.org/2000/svg"'
-      return '<' + this.nodeName + ' ' + ns + ' ' + attrList.join(' ') + '>' +
-             this.childNodes.join('') + '</' + this.nodeName + '>';
     } else {
-      return '<' + this.nodeName + ' ' + attrList.join(' ') + '>' +
+      this.childNodes.forEach(function(childNode) {
-             this.childNodes.join('') + '</' + this.nodeName + '>';
+        buf.push(childNode.toString());
+      });
     }
+    buf.push('</' + this.nodeName + '>');
+    return buf.join('');
   },
 
   cloneNode: function DOMElement_cloneNode() {

examples/node/pdf2svg.js

@@ -18,7 +18,7 @@ var pdfPath = process.argv[2] || '../../web/compressed.tracemonkey-pldi-09.pdf';
 var data = new Uint8Array(fs.readFileSync(pdfPath));
 
 // Dumps svg outputs to a folder called svgdump
-function writeToFile(svgdump, pageNum) {
+function writeToFile(svgdump, pageNum, callback) {
   var name = getFileNameFromPath(pdfPath);
   fs.mkdir('./svgdump/', function(err) {
     if (!err || err.code === 'EEXIST') {
@@ -29,7 +29,10 @@ function writeToFile(svgdump, pageNum) {
           } else {
             console.log('Page: ' + pageNum);
           }
+          callback();
         });
+    } else {
+      callback();
     }
   });
 }
@@ -67,7 +70,9 @@ pdfjsLib.getDocument({
         svgGfx.embedFonts = true;
         return svgGfx.getSVG(opList, viewport).then(function (svg) {
           var svgDump = svg.toString();
-          writeToFile(svgDump, pageNum);
+          return new Promise(function(resolve) {
+            writeToFile(svgDump, pageNum, resolve);
+          });
         });
       });
     })