Revert 165858 - Add QuicStream and friends to QUIC code.

net/quic/quic_stream_sequencer.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 "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