AU: Delta Diff Generator

src/platform/update_engine/graph_utils.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "update_engine/graph_utils.h"
 #include "base/basictypes.h"
 
 using std::vector;
 
 namespace chromeos_update_engine {
 
 namespace graph_utils {
 
 uint64 EdgeWeight(const Graph& graph, const Edge& edge) {
   uint64 weight = 0;
   const vector<Extent>& extents =
       graph[edge.first].out_edges.find(edge.second)->second.extents;
   for (vector<Extent>::const_iterator it = extents.begin();
        it != extents.end(); ++it) {
-    weight += it->num_blocks();
+    if (it->start_block() != kSparseHole)
+      weight += it->num_blocks();
   }
   return weight;
 }
 
 void AppendBlockToExtents(vector<Extent>* extents, uint64 block) {
   if (!extents->empty()) {
     Extent& extent = extents->back();
-    if (extent.start_block() + extent.num_blocks() == block) {
+    if (block == kSparseHole) {
+      if (extent.start_block() == kSparseHole) {
+        // Extend sparse hole extent
+        extent.set_num_blocks(extent.num_blocks() + 1);
+        return;
+      } else {
+        // Create new extent below outer 'if'
+      }
+    } else if (extent.start_block() + extent.num_blocks() == block) {
       extent.set_num_blocks(extent.num_blocks() + 1);
       return;
     }
   }
   Extent new_extent;
   new_extent.set_start_block(block);
   new_extent.set_num_blocks(1);
   extents->push_back(new_extent);
 }
 
 }  // namespace graph_utils
 
 }  // namespace chromeos_update_engine