Keep track of DTLS packet sizes to prevent partial reads.
The current use of rtc::FifoBuffer can lead to reading across DTLS packet
boundaries which could cause packets to not being processed correctly.
This CL introduces the new class rtc::BufferQueue and changes the
StreamInterfaceChannel to use it instead of the rtc::FifoBuffer.
BUG=chromium:447431
R=juberti@google.com
Review URL: https://webrtc-codereview.appspot.com/52509004
Cr-Commit-Position: refs/heads/master@{#9254}
diff --git a/webrtc/base/bufferqueue.cc b/webrtc/base/bufferqueue.cc
new file mode 100644
index 0000000..955af51
--- /dev/null
+++ b/webrtc/base/bufferqueue.cc
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/bufferqueue.h"
+
+namespace rtc {
+
+BufferQueue::BufferQueue(size_t capacity, size_t default_size)
+ : capacity_(capacity), default_size_(default_size) {
+}
+
+BufferQueue::~BufferQueue() {
+ CritScope cs(&crit_);
+
+ for (Buffer* buffer : queue_) {
+ delete buffer;
+ }
+ for (Buffer* buffer : free_list_) {
+ delete buffer;
+ }
+}
+
+size_t BufferQueue::size() const {
+ CritScope cs(&crit_);
+ return queue_.size();
+}
+
+bool BufferQueue::ReadFront(void* buffer, size_t bytes, size_t* bytes_read) {
+ CritScope cs(&crit_);
+ if (queue_.empty()) {
+ return false;
+ }
+
+ Buffer* packet = queue_.front();
+ queue_.pop_front();
+
+ size_t next_packet_size = packet->size();
+ if (bytes > next_packet_size) {
+ bytes = next_packet_size;
+ }
+
+ memcpy(buffer, packet->data(), bytes);
+ if (bytes_read) {
+ *bytes_read = bytes;
+ }
+ free_list_.push_back(packet);
+ return true;
+}
+
+bool BufferQueue::WriteBack(const void* buffer, size_t bytes,
+ size_t* bytes_written) {
+ CritScope cs(&crit_);
+ if (queue_.size() == capacity_) {
+ return false;
+ }
+
+ Buffer* packet;
+ if (!free_list_.empty()) {
+ packet = free_list_.back();
+ free_list_.pop_back();
+ } else {
+ packet = new Buffer(bytes, default_size_);
+ }
+
+ packet->SetData(static_cast<const uint8_t*>(buffer), bytes);
+ if (bytes_written) {
+ *bytes_written = bytes;
+ }
+ queue_.push_back(packet);
+ return true;
+}
+
+} // namespace rtc
