Don't traverse all pages to get a single page.

src/core/core.js

@@ -494,10 +494,6 @@ var PDFDocument = (function PDFDocumentClosure() {
       return shadow(this, 'fingerprint', fileID);
     },
 
-    traversePages: function PDFDocument_traversePages() {
-      this.catalog.traversePages();
-    },
-
     getPage: function PDFDocument_getPage(pageIndex) {
       return this.catalog.getPage(pageIndex);
     }

src/core/obj.js

@@ -217,14 +217,7 @@ var Catalog = (function CatalogClosure() {
     assertWellFormed(isDict(this.catDict),
       'catalog object is not a dictionary');
 
-    // Stores state as we traverse the pages catalog so that we can resume
-    // parsing if an exception is thrown
-    this.traversePagesQueue = [{
-      pagesDict: this.toplevelPagesDict,
-      posInKids: 0
-    }];
     this.pagePromises = [];
-    this.currPageIndex = 0;
   }
 
   Catalog.prototype = {
@@ -408,58 +401,146 @@ var Catalog = (function CatalogClosure() {
     },
 
     getPage: function Catalog_getPage(pageIndex) {
-      if (pageIndex < 0 || pageIndex >= this.numPages ||
-          (pageIndex|0) !== pageIndex) {
-        var pagePromise = new Promise();
-        pagePromise.reject(new Error('Invalid page index'));
-        return pagePromise;
-      }
       if (!(pageIndex in this.pagePromises)) {
-        this.pagePromises[pageIndex] = new Promise();
+        this.pagePromises[pageIndex] = this.getPageDict(pageIndex).then(
+          function (a) {
+            var dict = a[0];
+            var ref = a[1];
+            return new Page(this.pdfManager, this.xref, pageIndex, dict, ref);
+          }.bind(this)
+        );
       }
       return this.pagePromises[pageIndex];
     },
 
-    // Traverses pages in DFS order so that pages are processed in increasing
-    // order
-    traversePages: function Catalog_traversePages() {
-      var queue = this.traversePagesQueue;
-      while (queue.length) {
-        var queueItem = queue[queue.length - 1];
-        var pagesDict = queueItem.pagesDict;
-
-        var kids = pagesDict.get('Kids');
-        assert(isArray(kids), 'page dictionary kids object is not an array');
-        if (queueItem.posInKids >= kids.length) {
-          queue.pop();
-          continue;
-        }
-        var kidRef = kids[queueItem.posInKids];
-        assert(isRef(kidRef), 'page dictionary kid is not a reference');
-
-        var kid = this.xref.fetch(kidRef);
-        if (isDict(kid, 'Page') || (isDict(kid) && !kid.has('Kids'))) {
-          var pageIndex = this.currPageIndex++;
-          var page = new Page(this.pdfManager, this.xref, pageIndex, kid,
-                              kidRef);
-          if (!(pageIndex in this.pagePromises)) {
-            this.pagePromises[pageIndex] = new Promise();
+    getPageDict: function Catalog_getPageDict(pageIndex) {
+      var promise = new Promise();
+      var nodesToVisit = [this.catDict.getRaw('Pages')];
+      var currentPageIndex = 0;
+      var xref = this.xref;
+
+      function next() {
+        while (nodesToVisit.length) {
+          var currentNode = nodesToVisit.pop();
+
+          if (isRef(currentNode)) {
+            xref.fetchAsync(currentNode).then(function (obj) {
+              if ((isDict(obj, 'Page') || (isDict(obj) && !obj.has('Kids')))) {
+                if (pageIndex === currentPageIndex) {
+                  promise.resolve([obj, currentNode]);
+                } else {
+                  currentPageIndex++;
+                  next();
+                }
+                return;
+              }
+              nodesToVisit.push(obj);
+              next();
+            }.bind(this), promise.reject.bind(promise));
+            return;
           }
-          this.pagePromises[pageIndex].resolve(page);
 
-        } else { // must be a child page dictionary
+          // must be a child page dictionary
           assert(
-            isDict(kid),
+            isDict(currentNode),
             'page dictionary kid reference points to wrong type of object'
           );
+          var count = currentNode.get('Count');
+          // Skip nodes where the page can't be.
+          if (currentPageIndex + count <= pageIndex) {
+            currentPageIndex += count;
+            continue;
+          }
 
-          queue.push({
-            pagesDict: kid,
-            posInKids: 0
-          });
+          var kids = currentNode.get('Kids');
+          assert(isArray(kids), 'page dictionary kids object is not an array');
+          if (count === kids.length) {
+            // Nodes that don't have the page have been skipped and this is the
+            // bottom of the tree which means the page requested must be a
+            // descendant of this pages node. Ideally we would just resolve the
+            // promise with the page ref here, but there is the case where more
+            // pages nodes could link to single a page (see issue 3666 pdf). To
+            // handle this push it back on the queue so if it is a pages node it
+            // will be descended into.
+            nodesToVisit = [kids[pageIndex - currentPageIndex]];
+            currentPageIndex = pageIndex;
+            continue;
+          } else {
+            for (var last = kids.length - 1; last >= 0; last--) {
+              nodesToVisit.push(kids[last]);
+            }
+          }
         }
-        ++queueItem.posInKids;
+        promise.reject('Page index ' + pageIndex + ' not found.');
       }
+      next();
+      return promise;
+    },
+
+    getPageIndex: function Catalog_getPageIndex(ref) {
+      // The page tree nodes have the count of all the leaves below them. To get
+      // how many pages are before we just have to walk up the tree and keep
+      // adding the count of siblings to the left of the node.
+      var xref = this.xref;
+      function pagesBeforeRef(kidRef) {
+        var total = 0;
+        var parentRef;
+        return xref.fetchAsync(kidRef).then(function (node) {
+          if (!node) {
+            return null;
+          }
+          parentRef = node.getRaw('Parent');
+          return node.getAsync('Parent');
+        }).then(function (parent) {
+          if (!parent) {
+            return null;
+          }
+          return parent.getAsync('Kids');
+        }).then(function (kids) {
+          if (!kids) {
+            return null;
+          }
+          var kidPromises = [];
+          var found = false;
+          for (var i = 0; i < kids.length; i++) {
+            var kid = kids[i];
+            assert(isRef(kid), 'kids must be an ref');
+            if (kid.num == kidRef.num) {
+              found = true;
+              break;
+            }
+            kidPromises.push(xref.fetchAsync(kid).then(function (kid) {
+              if (kid.has('Count')) {
+                var count = kid.get('Count');
+                total += count;
+              } else { // page leaf node
+                total++;
+              }
+            }));
+          }
+          if (!found) {
+            error('kid ref not found in parents kids');
+          }
+          return Promise.all(kidPromises).then(function () {
+            return [total, parentRef];
+          });
+        });
+      }
+
+      var total = 0;
+      function next(ref) {
+        return pagesBeforeRef(ref).then(function (args) {
+          if (!args) {
+            return total;
+          }
+          var count = args[0];
+          var parentRef = args[1];
+          total += count;
+          return next(parentRef);
+        });
+      }
+
+      return next(ref);
     }
   };
 

src/core/worker.js

@@ -18,7 +18,7 @@
            MissingPDFException, PasswordException, PDFJS, Promise,
            UnknownErrorException, NetworkManager, LocalPdfManager,
            NetworkPdfManager, XRefParseException,
-           isInt, PasswordResponses, MessageHandler */
+           isInt, PasswordResponses, MessageHandler, Ref */
 
 'use strict';
 
@@ -193,7 +193,6 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
 
       var onSuccess = function(doc) {
         handler.send('GetDoc', { pdfInfo: doc });
-        pdfManager.ensureModel('traversePages', []).then(null, onFailure);
       };
 
       var onFailure = function(e) {
@@ -270,6 +269,13 @@ var WorkerMessageHandler = PDFJS.WorkerMessageHandler = {
       });
     });
 
+    handler.on('GetPageIndex', function wphSetupGetPageIndex(data, promise) {
+      var ref = new Ref(data.ref.num, data.ref.gen);
+      pdfManager.pdfModel.catalog.getPageIndex(ref).then(function (pageIndex) {
+        promise.resolve(pageIndex);
+      }, promise.reject.bind(promise));
+    });
+
     handler.on('GetDestinations',
       function wphSetupGetDestinations(data, promise) {
         pdfManager.ensureCatalog('destinations').then(function(destinations) {

src/display/api.js

@@ -187,6 +187,14 @@ var PDFDocumentProxy = (function PDFDocumentProxyClosure() {
     getPage: function PDFDocumentProxy_getPage(number) {
       return this.transport.getPage(number);
     },
+    /**
+     * @param {object} Must have 'num' and 'gen' properties.
+     * @return {Promise} A promise that is resolved with the page index that is
+     * associated with the reference.
+     */
+    getPageIndex: function PDFDocumentProxy_getPageIndex(ref) {
+      return this.transport.getPageIndex(ref);
+    },
     /**
      * @return {Promise} A promise that is resolved with a lookup table for
      * mapping named destinations to reference numbers.
@@ -861,6 +869,16 @@ var WorkerTransport = (function WorkerTransportClosure() {
       return promise;
     },
 
+    getPageIndex: function WorkerTransport_getPageIndexByRef(ref) {
+      var promise = new PDFJS.Promise();
+      this.messageHandler.send('GetPageIndex', { ref: ref },
+        function (pageIndex) {
+          promise.resolve(pageIndex);
+        }
+      );
+      return promise;
+    },
+
     getAnnotations: function WorkerTransport_getAnnotations(pageIndex) {
       this.messageHandler.send('GetAnnotationsRequest',
         { pageIndex: pageIndex });

src/shared/util.js

@@ -355,7 +355,7 @@ var MissingDataException = (function MissingDataExceptionClosure() {
   function MissingDataException(begin, end) {
     this.begin = begin;
     this.end = end;
-    this.message = 'Missing data [begin, end)';
+    this.message = 'Missing data [' + begin + ', ' + end + ')';
   }
 
   MissingDataException.prototype = new Error();
@@ -928,7 +928,7 @@ var Promise = PDFJS.Promise = (function PromiseClosure() {
   /**
    * Builds a promise that is resolved when all the passed in promises are
    * resolved.
-   * @param {Promise[]} promises Array of promises to wait for.
+   * @param {array} array of data and/or promises to wait for.
    * @return {Promise} New dependant promise.
    */
   Promise.all = function Promise_all(promises) {
@@ -948,7 +948,7 @@ var Promise = PDFJS.Promise = (function PromiseClosure() {
     }
     for (var i = 0, ii = promises.length; i < ii; ++i) {
       var promise = promises[i];
-      promise.then((function(i) {
+      var resolve = (function(i) {
         return function(value) {
           if (deferred._status === STATUS_REJECTED) {
             return;
@@ -958,11 +958,24 @@ var Promise = PDFJS.Promise = (function PromiseClosure() {
           if (unresolved === 0)
             deferred.resolve(results);
         };
-      })(i), reject);
+      })(i);
+      if (Promise.isPromise(promise)) {
+        promise.then(resolve, reject);
+      } else {
+        resolve(promise);
+      }
     }
     return deferred;
   };
 
+  /**
+   * Checks if the value is likely a promise (has a 'then' function).
+   * @return {boolean} true if x is thenable
+   */
+  Promise.isPromise = function Promise_isPromise(value) {
+    return value && typeof value.then === 'function';
+  };
+
   Promise.prototype = {
     _status: null,
     _value: null,
@@ -976,7 +989,7 @@ var Promise = PDFJS.Promise = (function PromiseClosure() {
       }
 
       if (status == STATUS_RESOLVED &&
-          value && typeof(value.then) === 'function') {
+          Promise.isPromise(value)) {
         value.then(this._updateStatus.bind(this, STATUS_RESOLVED),
                    this._updateStatus.bind(this, STATUS_REJECTED));
         return;

test/pdfs/issue3848.pdf.link

@@ -0,0 +1,2 @@
+http://www.unicode.org/L2/L2006/06334-reph-telugu-gurmukhi.pdf
+

test/test_manifest.json

@@ -611,6 +611,15 @@
       "link": true,
       "type": "eq"
     },
+    {  "id": "issue3848",
+      "file": "pdfs/issue3848.pdf",
+      "md5": "2498cf0650cc97ceca3e24dfa0425a73",
+      "rounds": 1,
+      "lastPage": 1,
+      "link": true,
+      "type": "load",
+      "about": "Document tree with pages and page nodes on the same level."
+    },
     {  "id": "issue1015",
       "file": "pdfs/issue1015.pdf",
       "md5": "b61503d1b445742b665212866afb60e2",

web/viewer.js

@@ -623,9 +623,9 @@ var PDFView = {
         // Update the browsing history.
         PDFHistory.push({ dest: dest, hash: destString, page: pageNumber });
       } else {
-        self.pendingRefStrLoaded = new PDFJS.Promise();
-        self.pendingRefStr = destRef.num + ' ' + destRef.gen + ' R';
-        self.pendingRefStrLoaded.then(function() {
+        self.pdfDocument.getPageIndex(destRef).then(function (pageIndex) {
+          var pageNum = pageIndex + 1;
+          self.pagesRefMap[destRef.num + ' ' + destRef.gen + ' R'] = pageNum;
           goToDestination(destRef);
         });
       }
@@ -849,32 +849,6 @@ var PDFView = {
 
       PDFView.loadingBar.setWidth(container);
 
-      for (var pageNum = 1; pageNum <= pagesCount; ++pageNum) {
-        var pagePromise = pdfDocument.getPage(pageNum);
-        pagePromise.then(function(pdfPage) {
-          var pageNum = pdfPage.pageNumber;
-          var pageView = pages[pageNum - 1];
-          if (!pageView.pdfPage) {
-            // The pdfPage might already be set if we've already entered
-            // pageView.draw()
-            pageView.setPdfPage(pdfPage);
-          }
-          var thumbnailView = thumbnails[pageNum - 1];
-          if (!thumbnailView.pdfPage) {
-            thumbnailView.setPdfPage(pdfPage);
-          }
-
-          var pageRef = pdfPage.ref;
-          var refStr = pageRef.num + ' ' + pageRef.gen + ' R';
-          pagesRefMap[refStr] = pdfPage.pageNumber;
-
-          if (self.pendingRefStr && self.pendingRefStr === refStr) {
-            self.pendingRefStrLoaded.resolve();
-          }
-        });
-        pagePromises.push(pagePromise);
-      }
-
       PDFFindController.firstPagePromise.resolve();
 
       PDFJS.Promise.all(pagePromises).then(function(pages) {