Index: net/quic/quic_stream_sequencer.cc |
diff --git a/net/quic/quic_stream_sequencer.cc b/net/quic/quic_stream_sequencer.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..f730379cb80ea4ed78fba47f61766663e2f9cbd7 |
--- /dev/null |
+++ b/net/quic/quic_stream_sequencer.cc |
@@ -0,0 +1,203 @@ |
+// 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 "net/quic/quic_stream_sequencer.h" |
+ |
+#include <algorithm> |
+#include <limits> |
+ |
+#include "base/logging.h" |
+#include "net/quic/reliable_quic_stream.h" |
+ |
+using std::min; |
+using std::numeric_limits; |
+ |
+namespace net { |
+ |
+QuicStreamSequencer::QuicStreamSequencer(ReliableQuicStream* quic_stream) |
+ : stream_(quic_stream), |
+ num_bytes_consumed_(0), |
+ max_frame_memory_(numeric_limits<size_t>::max()), |
+ close_offset_(numeric_limits<QuicStreamOffset>::max()), |
+ half_close_(true) { |
+} |
+ |
+QuicStreamSequencer::QuicStreamSequencer(size_t max_frame_memory, |
+ ReliableQuicStream* quic_stream) |
+ : stream_(quic_stream), |
+ num_bytes_consumed_(0), |
+ max_frame_memory_(max_frame_memory), |
+ close_offset_(numeric_limits<QuicStreamOffset>::max()), |
+ half_close_(true) { |
+ if (max_frame_memory < kMaxPacketSize) { |
+ LOG(DFATAL) << "Setting max frame memory to " << max_frame_memory |
+ << ". Some frames will be impossible to handle."; |
+ } |
+} |
+ |
+QuicStreamSequencer::~QuicStreamSequencer() { |
+} |
+ |
+bool QuicStreamSequencer::WillAcceptStreamFrame( |
+ const QuicStreamFrame& frame) const { |
+ QuicStreamOffset byte_offset = frame.offset; |
+ size_t data_len = frame.data.size(); |
+ DCHECK_LE(data_len, max_frame_memory_); |
+ |
+ if (byte_offset < num_bytes_consumed_ || |
+ frames_.find(byte_offset) != frames_.end()) { |
+ return false; |
+ } |
+ if (data_len > max_frame_memory_) { |
+ // We're never going to buffer this frame and we can't pass it up the |
+ // stream might only consume part of it and we'd need a partial ack. |
+ // |
+ // Ideally this should never happen, as we check that |
+ // max_frame_memory_ > kMaxPacketSize and lower levels should reject |
+ // frames larger than that. |
+ return false; |
+ } |
+ if (byte_offset + data_len - num_bytes_consumed_ > max_frame_memory_) { |
+ // We can buffer this but not right now. Toss it. |
+ // It might be worth trying an experiment where we try best-effort buffering |
+ return false; |
+ } |
+ return true; |
+} |
+ |
+bool QuicStreamSequencer::OnStreamFrame(const QuicStreamFrame& frame) { |
+ QuicStreamOffset byte_offset = frame.offset; |
+ const char* data = frame.data.data(); |
+ size_t data_len = frame.data.size(); |
+ |
+ if (!WillAcceptStreamFrame(frame)) { |
+ // This should not happen, as WillAcceptFrame should be called before |
+ // OnStreamFrame. Error handling should be done by the caller. |
+ return false; |
+ } |
+ |
+ if (byte_offset == num_bytes_consumed_) { |
+ DVLOG(1) << "Processing byte offset " << byte_offset; |
+ size_t bytes_consumed = stream_->ProcessData(data, data_len); |
+ num_bytes_consumed_ += bytes_consumed; |
+ |
+ if (MaybeCloseStream()) { |
+ return true; |
+ } |
+ if (bytes_consumed > data_len) { |
+ stream_->Close(QUIC_SERVER_ERROR_PROCESSING_STREAM); |
+ return false; |
+ } else if (bytes_consumed == data_len) { |
+ FlushBufferedFrames(); |
+ return true; // it's safe to ack this frame. |
+ } else { |
+ // Set ourselves up to buffer what's left |
+ data_len -= bytes_consumed; |
+ data += bytes_consumed; |
+ byte_offset += bytes_consumed; |
+ } |
+ } |
+ |
+ DVLOG(1) << "Buffering packet at offset " << byte_offset; |
+ frames_.insert(make_pair(byte_offset, string(data, data_len))); |
+ return true; |
+} |
+ |
+void QuicStreamSequencer::CloseStreamAtOffset(QuicStreamOffset offset, |
+ bool half_close) { |
+ const QuicStreamOffset kMaxOffset = numeric_limits<QuicStreamOffset>::max(); |
+ |
+ // If we have a scheduled termination or close, any new offset should match |
+ // it. |
+ if (close_offset_ != kMaxOffset && offset != close_offset_) { |
+ stream_->Close(QUIC_MULTIPLE_TERMINATION_OFFSETS); |
+ return; |
+ } |
+ |
+ close_offset_ = offset; |
+ // Full close overrides half close. |
+ if (half_close == false) { |
+ half_close_ = false; |
+ } |
+ |
+ MaybeCloseStream(); |
+} |
+ |
+bool QuicStreamSequencer::MaybeCloseStream() { |
+ if (IsHalfClosed()) { |
+ DVLOG(1) << "Passing up termination, as we've processed " |
+ << num_bytes_consumed_ << " of " << close_offset_ |
+ << " bytes."; |
+ // Technically it's an error if num_bytes_consumed isn't exactly |
+ // equal, but error handling seems silly at this point. |
+ stream_->TerminateFromPeer(half_close_); |
+ return true; |
+ } |
+ return false; |
+} |
+ |
+void QuicStreamSequencer::AdvanceReadablePtr(size_t data_read) { |
+ FrameMap::iterator it = frames_.begin(); |
+ |
+ while (data_read) { |
+ if (it->first != num_bytes_consumed_ || it == frames_.end()) { |
+ stream_->Close(QUIC_SERVER_ERROR_PROCESSING_STREAM); // Programming error |
+ return; |
+ } |
+ |
+ if (data_read >= it->second.size()) { |
+ data_read -= it->second.size(); |
+ num_bytes_consumed_ += it->second.size(); |
+ frames_.erase(it); |
+ it = frames_.begin(); |
+ } else { |
+ frames_.insert(make_pair(it->first + data_read, |
+ it->second.substr(data_read))); |
+ frames_.erase(frames_.begin()); |
+ num_bytes_consumed_ += data_read; |
+ data_read = 0; |
+ } |
+ } |
+} |
+ |
+bool QuicStreamSequencer::HasBytesToRead() { |
+ FrameMap::iterator it = frames_.begin(); |
+ |
+ return it != frames_.end() && it->first == num_bytes_consumed_; |
+} |
+ |
+bool QuicStreamSequencer::IsHalfClosed() { |
+ return num_bytes_consumed_ >= close_offset_; |
+} |
+ |
+bool QuicStreamSequencer::IsClosed() { |
+ return num_bytes_consumed_ >= close_offset_ && half_close_ == false; |
+} |
+ |
+void QuicStreamSequencer::FlushBufferedFrames() { |
+ FrameMap::iterator it = frames_.find(num_bytes_consumed_); |
+ while (it != frames_.end()) { |
+ DVLOG(1) << "Flushing buffered packet at offset " << it->first; |
+ string* data = &it->second; |
+ size_t bytes_consumed = stream_->ProcessData(data->c_str(), data->size()); |
+ num_bytes_consumed_ += bytes_consumed; |
+ if (MaybeCloseStream()) { |
+ return; |
+ } |
+ if (bytes_consumed > data->size()) { |
+ stream_->Close(QUIC_SERVER_ERROR_PROCESSING_STREAM); // Programming error |
+ return; |
+ } else if (bytes_consumed == data->size()) { |
+ frames_.erase(it); |
+ it = frames_.find(num_bytes_consumed_); |
+ } else { |
+ string new_data = it->second.substr(bytes_consumed); |
+ frames_.erase(it); |
+ frames_.insert(make_pair(num_bytes_consumed_, new_data)); |
+ return; |
+ } |
+ } |
+} |
+ |
+} // namespace net |