// Copyright (c) 2016 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/core/quic_header_list.h"

#include "net/quic/core/quic_packets.h"
#include "net/quic/platform/api/quic_flags.h"
#include "net/spdy/core/spdy_protocol.h"

using std::string;

namespace net {

QuicHeaderList::QuicHeaderList()
    : max_header_list_size_(kDefaultMaxUncompressedHeaderSize),
      current_header_list_size_(0),
      uncompressed_header_bytes_(0),
      compressed_header_bytes_(0) {}

QuicHeaderList::QuicHeaderList(QuicHeaderList&& other) = default;

QuicHeaderList::QuicHeaderList(const QuicHeaderList& other) = default;

QuicHeaderList& QuicHeaderList::operator=(const QuicHeaderList& other) =
    default;

QuicHeaderList& QuicHeaderList::operator=(QuicHeaderList&& other) = default;

QuicHeaderList::~QuicHeaderList() {}

void QuicHeaderList::OnHeaderBlockStart() {
  if (FLAGS_quic_restart_flag_quic_header_list_size) {
    QUIC_BUG_IF(current_header_list_size_ != 0)
        << "OnHeaderBlockStart called more than once!";
  } else {
    QUIC_BUG_IF(uncompressed_header_bytes_ != 0)
        << "OnHeaderBlockStart called more than once!";
  }
}

void QuicHeaderList::OnHeader(QuicStringPiece name, QuicStringPiece value) {
  // Avoid infinite buffering of headers. No longer store headers
  // once the current headers are over the limit.
  if (FLAGS_quic_restart_flag_quic_header_list_size) {
    if (current_header_list_size_ < max_header_list_size_) {
      current_header_list_size_ += name.size();
      current_header_list_size_ += value.size();
      current_header_list_size_ += kPerHeaderOverhead;
      header_list_.emplace_back(string(name), string(value));
    }
  } else {
    if (uncompressed_header_bytes_ == 0 || !header_list_.empty()) {
      header_list_.emplace_back(string(name), string(value));
    }
  }
}

void QuicHeaderList::OnHeaderBlockEnd(size_t uncompressed_header_bytes,
                                      size_t compressed_header_bytes) {
  uncompressed_header_bytes_ = uncompressed_header_bytes;
  compressed_header_bytes_ = compressed_header_bytes;
  if (FLAGS_quic_restart_flag_quic_header_list_size) {
    if (current_header_list_size_ > max_header_list_size_) {
      Clear();
    }
  } else {
    if (uncompressed_header_bytes_ > max_header_list_size_) {
      Clear();
    }
  }
}

void QuicHeaderList::Clear() {
  header_list_.clear();
  current_header_list_size_ = 0;
  uncompressed_header_bytes_ = 0;
  compressed_header_bytes_ = 0;
}

string QuicHeaderList::DebugString() const {
  string s = "{ ";
  for (const auto& p : *this) {
    s.append(p.first + "=" + p.second + ", ");
  }
  s.append("}");
  return s;
}

}  // namespace net