AU: When generating delta, use scratch off end of filesystem

delta_diff_generator_unittest.cc

 // Copyright (c) 2010 The Chromium OS 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 <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <set>
 #include <sstream>
@@ skipping 507 matching lines @@
                                   NULL,
                                   &fd));
   ScopedFdCloser fd_closer(&fd);
   off_t data_file_size = 0;
 
 
   EXPECT_TRUE(DeltaDiffGenerator::ConvertGraphToDag(&graph,
                                                     temp_dir,
                                                     fd,
                                                     &data_file_size,
-                                                    &final_order));
+                                                    &final_order,
+                                                    Vertex::kInvalidIndex));
 
 
   Graph expected_graph(12);
   GenVertex(&expected_graph[0], empt, VectOfExt(200, 1), "", OP_REPLACE);
   GenVertex(&expected_graph[1], empt, VectOfExt(210, 10), "", OP_REPLACE);
   GenVertex(&expected_graph[2], empt, VectOfExt(220, 1), "", OP_REPLACE);
   GenVertex(&expected_graph[3],
             VectOfExt(10, 11),
             VectOfExt(0, 9),
             "",
@@ skipping 182 matching lines @@
                                                    &reverse_op_indexes,
                                                    cuts));
   EXPECT_FALSE(graph[6].valid);
   EXPECT_FALSE(graph[7].valid);
   EXPECT_EQ(1, graph[1].op.src_extents_size());
   EXPECT_EQ(2, graph[1].op.src_extents(0).start_block());
   EXPECT_EQ(1, graph[1].op.src_extents(0).num_blocks());
   EXPECT_EQ(OP_REPLACE_BZ, graph[5].op.type());
 }
 
+TEST_F(DeltaDiffGeneratorTest, CreateScratchNodeTest) {
+  Vertex vertex;
+  DeltaDiffGenerator::CreateScratchNode(12, 34, &vertex);
+  EXPECT_EQ(DeltaArchiveManifest_InstallOperation_Type_REPLACE_BZ,
+            vertex.op.type());
+  EXPECT_EQ(0, vertex.op.data_offset());
+  EXPECT_EQ(0, vertex.op.data_length());
+  EXPECT_EQ(1, vertex.op.dst_extents_size());
+  EXPECT_EQ(12, vertex.op.dst_extents(0).start_block());
+  EXPECT_EQ(34, vertex.op.dst_extents(0).num_blocks());
+}
+
 }  // namespace chromeos_update_engine