AU: Some graph types and a couple utility functions

src/platform/update_engine/graph_utils.h

Index: src/platform/update_engine/graph_utils.h
diff --git a/src/platform/update_engine/graph_utils.h b/src/platform/update_engine/graph_utils.h
new file mode 100644
index 0000000000000000000000000000000000000000..c7f4aef38af22196f4f84e957d2b7c942caf4e7b
--- /dev/null
+++ b/src/platform/update_engine/graph_utils.h
@@ -0,0 +1,27 @@
+// 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.
+
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_UTILS_H__
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_UTILS_H__
+
+#include <vector>
+#include "base/basictypes.h"
+#include "update_engine/graph_types.h"
+#include "update_engine/update_metadata.pb.h"
+
+// A few utility functions for graphs
+
+namespace chromeos_update_engine {
+
+// Returns the number of blocks represented by all extents in the edge.
+uint64 EdgeWeight(const Graph& graph, const Edge& edge);

[Daniel Erat, 2010/02/05 17:55:19]

mind moving these into a graph_utils namespace?  it makes it easier to find
where functions like this are defined later

[adlr, 2010/02/22 23:27:31]

Done.

+
+// block must either be the next block in the last extent or a block
+// in the next extent. This function will not handle inserting block
+// into an arbitrary place in the extents

[Daniel Erat, 2010/02/05 17:55:19]

nit: add trailing period

[adlr, 2010/02/22 23:27:31]

Done.

+void AppendBlockToExtents(uint64 block, std::vector<Extent>* extents);
+
+}  // namespace chromeos_update_engine
+
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_UTILS_H__