Implemented NameTree.get() using binary search

mozilla · Oct 6, 2014 · 695b3c1 · 695b3c1
1 parent f814117
commit 695b3c1
Showing 1 changed file with 41 additions and 9 deletions.
diff --git a/src/core/obj.js b/src/core/obj.js
@@ -485,15 +485,7 @@ var Catalog = (function CatalogClosure() {
       }
       if (nameTreeRef) {
         var nameTree = new NameTree(nameTreeRef, xref);
-        var names = nameTree.getAll();
-        for (var name in names) {
-          if (!names.hasOwnProperty(name)) {
-            continue;
-          }
-          if (name === destinationId) {
-            dest = fetchDestination(names[name]);
-          }
-        }
+        dest = fetchDestination(nameTree.get(destinationId));
       }
       return dest;
     },
@@ -1398,6 +1390,46 @@ var NameTree = (function NameTreeClosure() {
         }
       }
       return dict;
+    },
+
+    get: function NameTree_get(destinationId, root) {
+      if (!root) {
+        root = this.root;
+      }
+      var xref = this.xref;
+      root = xref.fetchIfRef(root);
+      var kids = root.get('Kids');
+      var names = root.get('Names');
+
+      if (isArray(kids)) {
+        var l = 0;
+        var r = kids.length - 1;
+
+        while (l < r) {
+          var m = (l + r) >> 1;
+          var kid = xref.fetchIfRef(kids[m]);
+          var limits = kid.get('Limits');
+
+          if (destinationId < limits[0]) {
+            r = m - 1;
+          } else if (destinationId > limits[1]) {
+            l = m + 1;
+          } else {
+            return this.get(destinationId, kids[m]);
+          }
+        }
+        return this.get(destinationId, kids[l]);
+      }
+
+      if (isArray(names)) {
+        for (var i = 0, n = names.length; i < n; i += 2) {
+          if (names[i] === destinationId) {
+            return xref.fetchIfRef(names[i + 1]);
+          }
+        }
+      }
+
+      return null;
     }
   };
   return NameTree;