Make the fuchsia mojo/public repo the source of truth.

mojo/public/cpp/bindings/lib/fixed_buffer.h

-// 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_FIXED_BUFFER_H_
-#define MOJO_PUBLIC_CPP_BINDINGS_LIB_FIXED_BUFFER_H_
-
-#include "mojo/public/cpp/bindings/lib/buffer.h"
-#include "mojo/public/cpp/system/macros.h"
-
-namespace mojo {
-namespace internal {
-
-// FixedBuffer provides a simple way to allocate objects within a fixed chunk
-// of memory. Objects are allocated by calling the |Allocate| method, which
-// extends the buffer accordingly. Objects allocated in this way are not freed
-// explicitly. Instead, they remain valid so long as the FixedBuffer remains
-// valid.  The Leak method may be used to steal the underlying memory from the
-// FixedBuffer.
-//
-// Typical usage:
-//
-//   {
-//     FixedBuffer buf(8 + 8);
-//
-//     int* a = static_cast<int*>(buf->Allocate(sizeof(int)));
-//     *a = 2;
-//
-//     double* b = static_cast<double*>(buf->Allocate(sizeof(double)));
-//     *b = 3.14f;
-//
-//     void* data = buf.Leak();
-//     Process(data);
-//
-//     free(data);
-//   }
-
-class FixedBuffer : public Buffer {
- public:
-  FixedBuffer();
-
-  // |size| should be aligned using internal::Align.
-  void Initialize(void* memory, size_t size);
-
-  size_t size() const { return size_; }
-
-  // Returns the number of bytes used so far.
-  // TODO(vardhan): Introduce this method in |Buffer|? Doesn't seem necessary.
-  size_t BytesUsed() const { return cursor_; }
-
-  // Grows the buffer by |num_bytes| and returns a pointer to the start of the
-  // addition. The resulting address is 8-byte aligned, and the content of the
-  // memory is zero-filled.
-  // TODO(vardhan): Allocate() should safely fail if we run out of buffer space.
-  // This will allow us to, e.g, fail when trying to consume a buffer to
-  // serialize into, and return an insufficient space error. Currently, there
-  // are consumers of FixedBuffer that rely on it CHECK-failing.
-  void* Allocate(size_t num_bytes) override;
-
- protected:
-  char* ptr_;
-  size_t cursor_;
-  size_t size_;
-
-  MOJO_DISALLOW_COPY_AND_ASSIGN(FixedBuffer);
-};
-
-class FixedBufferForTesting : public FixedBuffer {
- public:
-  explicit FixedBufferForTesting(size_t size);
-  ~FixedBufferForTesting() override;
-
-  // Returns the internal memory owned by the Buffer to the caller. The Buffer
-  // relinquishes its pointer, effectively resetting the state of the Buffer
-  // and leaving the caller responsible for freeing the returned memory address
-  // when no longer needed.
-  void* Leak();
-
- private:
-  MOJO_DISALLOW_COPY_AND_ASSIGN(FixedBufferForTesting);
-};
-
-}  // namespace internal
-}  // namespace mojo
-
-#endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_FIXED_BUFFER_H_