Introduced ChunkedByteBuffer class which will be needed by next speech recognition CLs.

content/browser/speech/chunked_byte_buffer_unittest.cc

+// Copyright (c) 2012 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.
+
+#include <string>
+
+#include "content/browser/speech/chunked_byte_buffer.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace speech {
+
+TEST(ChunkedByteBufferTest, BasicTest) {
+  ChunkedByteBuffer buffer;
+  const uint8 kChunks[] = {
+      0x00, 0x00, 0x00, 0x04, 0x01, 0x02, 0x03, 0x04,  // Chunk 1: 4 bytes
+      0x00, 0x00, 0x00, 0x02, 0x05, 0x06,  // Chunk 2: 2 bytes
+      0x00, 0x00, 0x00, 0x00, // Chunk 3: 0 bytes (still legit)
+  };
+
+  EXPECT_EQ(0U, buffer.Size());
+  EXPECT_EQ(false, buffer.CanReadChunk());
+
+  // Append partially chunk 1.
+  buffer.Append(kChunks, 2);
+  EXPECT_EQ(2U, buffer.Size());
+  EXPECT_EQ(false, buffer.CanReadChunk());
+
+  // Complete chunk 1.
+  size_t first_chunk_length = 0;
+  buffer.Append(kChunks + 2, 6);
+  EXPECT_EQ(8U, buffer.Size());
+  EXPECT_EQ(true, buffer.CanReadChunk(&first_chunk_length));
+  EXPECT_EQ(4U, first_chunk_length);
+
+  // Append fully chunk 2.
+  first_chunk_length = 0;
+  buffer.Append(kChunks + 8, 6);
+  EXPECT_EQ(14U, buffer.Size());
+  EXPECT_EQ(true, buffer.CanReadChunk(&first_chunk_length));
+  EXPECT_EQ(4U, first_chunk_length);
+
+
+  // Read and check chunk 1.
+  const uint8* first_chunk_start = NULL;
+  bool retval = buffer.ReadChunk(&first_chunk_start, &first_chunk_length);
+  EXPECT_EQ(true, retval);
+  EXPECT_EQ(4U, first_chunk_length);
+  EXPECT_EQ(0, std::char_traits<uint8>::compare(kChunks + 4,
+                                                first_chunk_start,
+                                                first_chunk_length));
+
+  // Remove chunk 1. Only chunk 2 should remain in the buffer.
+  buffer.RemoveChunk();
+  EXPECT_EQ(6U, buffer.Size());
+  EXPECT_EQ(true, buffer.CanReadChunk(&first_chunk_length));
+  EXPECT_EQ(2U, first_chunk_length);
+
+  // Read and check chunk 2.
+  retval = buffer.ReadChunk(&first_chunk_start, &first_chunk_length);
+  EXPECT_EQ(true, retval);
+  EXPECT_EQ(2U, first_chunk_length);
+  EXPECT_EQ(0, std::char_traits<uint8>::compare(kChunks + 12,
+                                                first_chunk_start,
+                                                first_chunk_length));
+
+  // Remove chunk 2. Buffer should be empty.
+  buffer.RemoveChunk();
+  EXPECT_EQ(0U, buffer.Size());
+  EXPECT_EQ(false, buffer.CanReadChunk());
+
+  // Append fully chunk 3.
+  first_chunk_length = 42; // Anything, but not 0.
+  buffer.Append(kChunks + 14, 4);
+  EXPECT_EQ(4U, buffer.Size());
+  EXPECT_EQ(true, buffer.CanReadChunk(&first_chunk_length));
+  EXPECT_EQ(0U, first_chunk_length);
+
+  // Remove chunk 3. Buffer should be empty.
+  buffer.RemoveChunk();
+  EXPECT_EQ(0U, buffer.Size());
+  EXPECT_EQ(false, buffer.CanReadChunk());
+}
+
+}  // namespace speech