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diff --git a/o3d/command_buffer/client/id_allocator.h b/o3d/command_buffer/client/id_allocator.h
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+/*
+ * Copyright 2009, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+// This file contains the definition of the IdAllocator class.
+
+#ifndef GPU_COMMAND_BUFFER_CLIENT_CROSS_ID_ALLOCATOR_H_
+#define GPU_COMMAND_BUFFER_CLIENT_CROSS_ID_ALLOCATOR_H_
+
+#include <vector>
+#include "base/basictypes.h"
+#include "command_buffer/common/types.h"
+#include "command_buffer/common/resource.h"
+
+namespace command_buffer {
+
+// A class to manage the allocation of resource IDs. It uses a bitfield stored
+// into a vector of unsigned ints.
+class IdAllocator {
+ public:
+  IdAllocator();
+
+  // Allocates a new resource ID.
+  command_buffer::ResourceId AllocateID() {
+    unsigned int bit = FindFirstFree();
+    SetBit(bit, true);
+    return bit;
+  }
+
+  // Frees a resource ID.
+  void FreeID(command_buffer::ResourceId id) {
+    SetBit(id, false);
+  }
+
+  // Checks whether or not a resource ID is in use.
+  bool InUse(command_buffer::ResourceId id) {
+    return GetBit(id);
+  }
+ private:
+  void SetBit(unsigned int bit, bool value);
+  bool GetBit(unsigned int bit) const;
+  unsigned int FindFirstFree() const;
+
+  std::vector<Uint32> bitmap_;
+  DISALLOW_COPY_AND_ASSIGN(IdAllocator);
+};
+
+}  // namespace command_buffer
+
+#endif  // GPU_COMMAND_BUFFER_CLIENT_CROSS_ID_ALLOCATOR_H_