Moving WebRTC logging related files from content to chrome.

content/common/partial_circular_buffer.cc

-// Copyright (c) 2013 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 "content/common/partial_circular_buffer.h"
-
-#include <algorithm>
-
-#include "base/logging.h"
-
-namespace content {
-
-namespace {
-
-inline uint32 Min3(uint32 a, uint32 b, uint32 c) {
-  return std::min(a, std::min(b, c));
-}
-
-}  // namespace
-
-PartialCircularBuffer::PartialCircularBuffer(void* buffer,
-                                             uint32 buffer_size)
-    : buffer_data_(reinterpret_cast<BufferData*>(buffer)),
-      memory_buffer_size_(buffer_size),
-      data_size_(0),
-      position_(0),
-      total_read_(0) {
-  uint32 header_size =
-      buffer_data_->data - reinterpret_cast<uint8*>(buffer_data_);
-  data_size_ = memory_buffer_size_ - header_size;
-
-  DCHECK(buffer_data_);
-  DCHECK_GE(memory_buffer_size_, header_size);
-  DCHECK_LE(buffer_data_->total_written, data_size_);
-  DCHECK_LT(buffer_data_->wrap_position, data_size_);
-  DCHECK_LT(buffer_data_->end_position, data_size_);
-}
-
-PartialCircularBuffer::PartialCircularBuffer(void* buffer,
-                                             uint32 buffer_size,
-                                             uint32 wrap_position)
-    : buffer_data_(reinterpret_cast<BufferData*>(buffer)),
-      memory_buffer_size_(buffer_size),
-      data_size_(0),
-      position_(0),
-      total_read_(0) {
-  uint32 header_size =
-      buffer_data_->data - reinterpret_cast<uint8*>(buffer_data_);
-  data_size_ = memory_buffer_size_ - header_size;
-
-  DCHECK(buffer_data_);
-  DCHECK_GE(memory_buffer_size_, header_size);
-  DCHECK_LT(wrap_position, data_size_);
-
-  buffer_data_->total_written = 0;
-  buffer_data_->wrap_position = wrap_position;
-  buffer_data_->end_position = 0;
-}
-
-uint32 PartialCircularBuffer::Read(void* buffer, uint32 buffer_size) {
-  DCHECK(buffer_data_);
-  if (total_read_ >= buffer_data_->total_written)
-    return 0;
-
-  uint8* buffer_uint8 = reinterpret_cast<uint8*>(buffer);
-  uint32 read = 0;
-
-  // Read from beginning part.
-  if (position_ < buffer_data_->wrap_position) {
-    uint32 to_wrap_pos = buffer_data_->wrap_position - position_;
-    uint32 to_eow = buffer_data_->total_written - total_read_;
-    uint32 to_read = Min3(buffer_size, to_wrap_pos, to_eow);
-    memcpy(buffer_uint8, buffer_data_->data + position_, to_read);
-    position_ += to_read;
-    total_read_ += to_read;
-    read += to_read;
-    if (position_ == buffer_data_->wrap_position &&
-        buffer_data_->total_written == data_size_) {
-      // We've read all the beginning part, set the position to the middle part.
-      // (The second condition above checks if the wrapping part is filled, i.e.
-      // writing has wrapped.)
-      position_ = buffer_data_->end_position;
-    }
-    if (read >= buffer_size) {
-      DCHECK_EQ(read, buffer_size);
-      return read;
-    }
-    if (read >= to_eow) {
-      DCHECK_EQ(read, to_eow);
-      DCHECK_EQ(total_read_, buffer_data_->total_written);
-      return read;
-    }
-  }
-
-  // Read from middle part.
-  DCHECK_GE(position_, buffer_data_->wrap_position);
-  if (position_ >= buffer_data_->end_position) {
-    uint32 remaining_buffer_size = buffer_size - read;
-    uint32 to_eof = data_size_ - position_;
-    uint32 to_eow = buffer_data_->total_written - total_read_;
-    uint32 to_read = Min3(remaining_buffer_size, to_eof, to_eow);
-    memcpy(buffer_uint8 + read, buffer_data_->data + position_, to_read);
-    position_ += to_read;
-    total_read_ += to_read;
-    read += to_read;
-    if (position_ == data_size_) {
-      // We've read all the middle part, set position to the end part.
-      position_ = buffer_data_->wrap_position;
-    }
-    if (read >= buffer_size) {
-      DCHECK_EQ(read, buffer_size);
-      return read;
-    }
-    if (total_read_ >= buffer_data_->total_written) {
-      DCHECK_EQ(total_read_, buffer_data_->total_written);
-      return read;
-    }
-  }
-
-  // Read from end part.
-  DCHECK_GE(position_, buffer_data_->wrap_position);
-  DCHECK_LT(position_, buffer_data_->end_position);
-  uint32 remaining_buffer_size = buffer_size - read;
-  uint32 to_eob = buffer_data_->end_position - position_;
-  uint32 to_eow = buffer_data_->total_written - total_read_;
-  uint32 to_read = Min3(remaining_buffer_size, to_eob, to_eow);
-  memcpy(buffer_uint8 + read, buffer_data_->data + position_, to_read);
-  position_ += to_read;
-  total_read_ += to_read;
-  read += to_read;
-  DCHECK_LE(read, buffer_size);
-  DCHECK_LE(total_read_, buffer_data_->total_written);
-  return read;
-}
-
-void PartialCircularBuffer::Write(const void* buffer, uint32 buffer_size) {
-  DCHECK(buffer_data_);
-  uint32 position_before_write = position_;
-
-  uint32 to_eof = data_size_ - position_;
-  uint32 to_write = std::min(buffer_size, to_eof);
-  DoWrite(buffer_data_->data + position_, buffer, to_write);
-  if (position_ >= data_size_) {
-    DCHECK_EQ(position_, data_size_);
-    position_ = buffer_data_->wrap_position;
-  }
-
-  if (to_write < buffer_size) {
-    uint32 remainder_to_write = buffer_size - to_write;
-    DCHECK_LT(position_, position_before_write);
-    DCHECK_LE(position_ + remainder_to_write, position_before_write);
-    DoWrite(buffer_data_->data + position_,
-            reinterpret_cast<const uint8*>(buffer) + to_write,
-            remainder_to_write);
-  }
-}
-
-void PartialCircularBuffer::DoWrite(void* dest, const void* src, uint32 num) {
-  memcpy(dest, src, num);
-  position_ += num;
-  buffer_data_->total_written =
-      std::min(buffer_data_->total_written + num, data_size_);
-  buffer_data_->end_position = position_;
-}
-
-}  // namespace content