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// 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_packet_generator.h"
#include "base/logging.h"
#include "net/quic/quic_fec_group.h"
#include "net/quic/quic_utils.h"
using base::StringPiece;
namespace net {
class QuicAckNotifier;
QuicPacketGenerator::QuicPacketGenerator(DelegateInterface* delegate,
DebugDelegateInterface* debug_delegate,
QuicPacketCreator* creator)
: delegate_(delegate),
debug_delegate_(debug_delegate),
packet_creator_(creator),
batch_mode_(false),
should_send_ack_(false),
should_send_feedback_(false) {
}
QuicPacketGenerator::~QuicPacketGenerator() {
for (QuicFrames::iterator it = queued_control_frames_.begin();
it != queued_control_frames_.end(); ++it) {
switch (it->type) {
case PADDING_FRAME:
delete it->padding_frame;
break;
case STREAM_FRAME:
delete it->stream_frame;
break;
case ACK_FRAME:
delete it->ack_frame;
break;
case CONGESTION_FEEDBACK_FRAME:
delete it->congestion_feedback_frame;
break;
case RST_STREAM_FRAME:
delete it->rst_stream_frame;
break;
case CONNECTION_CLOSE_FRAME:
delete it->connection_close_frame;
break;
case GOAWAY_FRAME:
delete it->goaway_frame;
break;
case NUM_FRAME_TYPES:
DCHECK(false) << "Cannot delete type: " << it->type;
}
}
}
void QuicPacketGenerator::SetShouldSendAck(bool also_send_feedback) {
should_send_ack_ = true;
should_send_feedback_ = also_send_feedback;
SendQueuedFrames();
}
void QuicPacketGenerator::AddControlFrame(const QuicFrame& frame) {
queued_control_frames_.push_back(frame);
SendQueuedFrames();
}
QuicConsumedData QuicPacketGenerator::ConsumeData(QuicStreamId id,
StringPiece data,
QuicStreamOffset offset,
bool fin,
QuicAckNotifier* notifier) {
IsHandshake handshake = id == kCryptoStreamId ? IS_HANDSHAKE : NOT_HANDSHAKE;
// The caller should have flushed pending frames before sending handshake
// messages.
DCHECK(handshake == NOT_HANDSHAKE || !HasPendingFrames());
SendQueuedFrames();
size_t total_bytes_consumed = 0;
bool fin_consumed = false;
if (!packet_creator_->HasRoomForStreamFrame(id, offset)) {
SerializeAndSendPacket();
}
while (delegate_->CanWrite(NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA,
handshake)) {
QuicFrame frame;
size_t bytes_consumed;
if (notifier != NULL) {
// We want to track which packet this stream frame ends up in.
bytes_consumed = packet_creator_->CreateStreamFrameWithNotifier(
id, data, offset + total_bytes_consumed, fin, notifier, &frame);
} else {
bytes_consumed = packet_creator_->CreateStreamFrame(
id, data, offset + total_bytes_consumed, fin, &frame);
}
if (!AddFrame(frame)) {
LOG(DFATAL) << "Failed to add stream frame.";
// Inability to add a STREAM frame creates an unrecoverable hole in a
// the stream, so it's best to close the connection.
delegate_->CloseConnection(QUIC_INTERNAL_ERROR, false);
return QuicConsumedData(0, false);
}
total_bytes_consumed += bytes_consumed;
fin_consumed = fin && bytes_consumed == data.size();
data.remove_prefix(bytes_consumed);
DCHECK(data.empty() || packet_creator_->BytesFree() == 0u);
// TODO(ianswett): Restore packet reordering.
if (!InBatchMode() || !packet_creator_->HasRoomForStreamFrame(id, offset)) {
SerializeAndSendPacket();
}
if (data.empty()) {
// We're done writing the data. Exit the loop.
// We don't make this a precondition because we could have 0 bytes of data
// if we're simply writing a fin.
break;
}
}
// Ensure the FEC group is closed at the end of this method if not in batch
// mode.
if (!InBatchMode() && packet_creator_->ShouldSendFec(true)) {
SerializedPacket serialized_fec = packet_creator_->SerializeFec();
DCHECK(serialized_fec.packet);
delegate_->OnSerializedPacket(serialized_fec);
}
DCHECK(InBatchMode() || !packet_creator_->HasPendingFrames());
return QuicConsumedData(total_bytes_consumed, fin_consumed);
}
bool QuicPacketGenerator::CanSendWithNextPendingFrameAddition() const {
DCHECK(HasPendingFrames());
HasRetransmittableData retransmittable =
(should_send_ack_ || should_send_feedback_) ? NO_RETRANSMITTABLE_DATA
: HAS_RETRANSMITTABLE_DATA;
if (retransmittable == HAS_RETRANSMITTABLE_DATA) {
DCHECK(!queued_control_frames_.empty()); // These are retransmittable.
}
return delegate_->CanWrite(NOT_RETRANSMISSION, retransmittable,
NOT_HANDSHAKE);
}
void QuicPacketGenerator::SendQueuedFrames() {
packet_creator_->MaybeStartFEC();
// Only add pending frames if we are SURE we can then send the whole packet.
while (HasPendingFrames() && CanSendWithNextPendingFrameAddition()) {
if (!AddNextPendingFrame()) {
// Packet was full, so serialize and send it.
SerializeAndSendPacket();
}
}
if (!InBatchMode()) {
if (packet_creator_->HasPendingFrames()) {
SerializeAndSendPacket();
}
// Ensure the FEC group is closed at the end of this method unless other
// writes are pending.
if (packet_creator_->ShouldSendFec(true)) {
SerializedPacket serialized_fec = packet_creator_->SerializeFec();
DCHECK(serialized_fec.packet);
delegate_->OnSerializedPacket(serialized_fec);
packet_creator_->MaybeStartFEC();
}
}
}
bool QuicPacketGenerator::InBatchMode() {
return batch_mode_;
}
void QuicPacketGenerator::StartBatchOperations() {
batch_mode_ = true;
}
void QuicPacketGenerator::FinishBatchOperations() {
batch_mode_ = false;
SendQueuedFrames();
}
bool QuicPacketGenerator::HasQueuedFrames() const {
return packet_creator_->HasPendingFrames() || HasPendingFrames();
}
bool QuicPacketGenerator::HasPendingFrames() const {
return should_send_ack_ || should_send_feedback_ ||
!queued_control_frames_.empty();
}
bool QuicPacketGenerator::AddNextPendingFrame() {
if (should_send_ack_) {
pending_ack_frame_.reset(delegate_->CreateAckFrame());
// If we can't this add the frame now, then we still need to do so later.
should_send_ack_ = !AddFrame(QuicFrame(pending_ack_frame_.get()));
// Return success if we have cleared out this flag (i.e., added the frame).
// If we still need to send, then the frame is full, and we have failed.
return !should_send_ack_;
}
if (should_send_feedback_) {
pending_feedback_frame_.reset(delegate_->CreateFeedbackFrame());
// If we can't this add the frame now, then we still need to do so later.
should_send_feedback_ = !AddFrame(QuicFrame(pending_feedback_frame_.get()));
// Return success if we have cleared out this flag (i.e., added the frame).
// If we still need to send, then the frame is full, and we have failed.
return !should_send_feedback_;
}
DCHECK(!queued_control_frames_.empty());
if (!AddFrame(queued_control_frames_.back())) {
// Packet was full.
return false;
}
queued_control_frames_.pop_back();
return true;
}
bool QuicPacketGenerator::AddFrame(const QuicFrame& frame) {
bool success = packet_creator_->AddSavedFrame(frame);
if (success && debug_delegate_) {
debug_delegate_->OnFrameAddedToPacket(frame);
}
return success;
}
void QuicPacketGenerator::SerializeAndSendPacket() {
SerializedPacket serialized_packet = packet_creator_->SerializePacket();
DCHECK(serialized_packet.packet);
delegate_->OnSerializedPacket(serialized_packet);
if (packet_creator_->ShouldSendFec(false)) {
SerializedPacket serialized_fec = packet_creator_->SerializeFec();
DCHECK(serialized_fec.packet);
delegate_->OnSerializedPacket(serialized_fec);
packet_creator_->MaybeStartFEC();
}
}
} // namespace net
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