1 files changed, 54 insertions, 0 deletions
diff --git a/mojo/public/cpp/bindings/lib/scratch_buffer.h b/mojo/public/cpp/bindings/lib/scratch_buffer.h
new file mode 100644
index 0000000..462c6fe
--- /dev/null
+++ b/mojo/public/cpp/bindings/lib/scratch_buffer.h
@@ -0,0 +1,54 @@
+// Copyright 2014 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 MOJO_PUBLIC_CPP_BINDINGS_LIB_SCRATCH_BUFFER_H_
+#define MOJO_PUBLIC_CPP_BINDINGS_LIB_SCRATCH_BUFFER_H_
+
+#include <deque>
+
+#include "mojo/public/cpp/bindings/buffer.h"
+#include "mojo/public/cpp/system/macros.h"
+
+namespace mojo {
+namespace internal {
+
+// The following class is designed to be allocated on the stack.  If necessary,
+// it will failover to allocating objects on the heap.
+class ScratchBuffer : public Buffer {
+ public:
+  ScratchBuffer();
+  virtual ~ScratchBuffer();
+
+  virtual void* Allocate(size_t num_bytes, Destructor func = NULL)
+      MOJO_OVERRIDE;
+
+ private:
+  enum { kMinSegmentSize = 512 };
+
+  struct Segment {
+    Segment* next;
+    char* cursor;
+    char* end;
+  };
+
+  void* AllocateInSegment(Segment* segment, size_t num_bytes);
+  void AddOverflowSegment(size_t delta);
+
+  char fixed_data_[kMinSegmentSize];
+  Segment fixed_;
+  Segment* overflow_;
+
+  struct PendingDestructor {
+    Destructor func;
+    void* address;
+  };
+  std::deque<PendingDestructor> pending_dtors_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(ScratchBuffer);
+};
+
+}  // namespace internal
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_SCRATCH_BUFFER_H_