blob: 970421d9ea8d869a67e86b9d99907cbb8e0d42fd [file] [log] [blame]
// Copyright 2017 The Cobalt Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "cobalt/websocket/buffered_amount_tracker.h"
#include <algorithm>
#include "base/logging.h"
namespace cobalt {
namespace websocket {
std::size_t BufferedAmountTracker::Pop(const std::size_t number_bytes_to_pop) {
std::size_t size_left_pop = number_bytes_to_pop;
std::size_t payload_amount = 0;
while (!entries_.empty() && (size_left_pop > 0)) {
Entry& entry(entries_[0]);
std::size_t potential_payload_delta = 0;
// Cache this variable in case we do a |pop_front|.
const bool is_user_payload = entry.is_user_payload_;
if (entry.message_size_ > size_left_pop) {
potential_payload_delta = size_left_pop;
entry.message_size_ -= size_left_pop;
} else { // entry.message_size <= size_left
potential_payload_delta += entry.message_size_;
entries_.pop_front();
}
if (is_user_payload) {
payload_amount += potential_payload_delta;
}
size_left_pop -= potential_payload_delta;
}
// std::min prevents an underflow due to a bug.
DCHECK_LE(payload_amount, total_payload_inflight_);
total_payload_inflight_ -= std::min(total_payload_inflight_, payload_amount);
// Sort of an overflow check...
DCHECK_LE(size_left_pop, number_bytes_to_pop);
return payload_amount;
}
} // namespace websocket
} // namespace cobalt