blob: abb73701db01a9da9b716071f0aa1d9497f2d7c0 [file] [log] [blame]
* Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
#include <stdint.h>
#include <algorithm>
#include <memory>
#include <utility>
#include <vector>
#include "api/function_view.h"
#include "rtc_base/checks.h"
namespace webrtc {
// This file contains helper class used to process the elements of two or more
// sorted lists in timestamp order. The effect is the same as doing a merge step
// in the merge-sort algorithm but without copying the elements or modifying the
// lists.
namespace event_processor_impl {
// Interface to allow "merging" lists of different types. ProcessNext()
// processes the next unprocesses element in the list. IsEmpty() checks if all
// elements have been processed. GetNextTime returns the timestamp of the next
// unprocessed element.
class ProcessableEventListInterface {
virtual ~ProcessableEventListInterface() = default;
virtual void ProcessNext() = 0;
virtual bool IsEmpty() const = 0;
virtual int64_t GetNextTime() const = 0;
virtual int GetTieBreaker() const = 0;
// ProcessableEventList encapsulates a list of events and a function that will
// be applied to each element of the list.
template <typename Iterator, typename T>
class ProcessableEventList : public ProcessableEventListInterface {
ProcessableEventList(Iterator begin,
Iterator end,
std::function<void(const T&)> f,
int tie_breaker)
: begin_(begin), end_(end), f_(f), tie_breaker_(tie_breaker) {}
void ProcessNext() override {
bool IsEmpty() const override { return begin_ == end_; }
int64_t GetNextTime() const override {
return begin_->log_time_us();
int GetTieBreaker() const override { return tie_breaker_; }
Iterator begin_;
Iterator end_;
std::function<void(const T&)> f_;
int tie_breaker_;
} // namespace event_processor_impl
// Helper class used to "merge" two or more lists of ordered RtcEventLog events
// so that they can be treated as a single ordered list. Since the individual
// lists may have different types, we need to access the lists via pointers to
// the common base class.
// Usage example:
// ParsedRtcEventLogNew log;
// auto incoming_handler = [] (LoggedRtcpPacketIncoming elem) { ... };
// auto outgoing_handler = [] (LoggedRtcpPacketOutgoing elem) { ... };
// RtcEventProcessor processor;
// processor.AddEvents(log.incoming_rtcp_packets(),
// incoming_handler);
// processor.AddEvents(log.outgoing_rtcp_packets(),
// outgoing_handler);
// processor.ProcessEventsInOrder();
class RtcEventProcessor {
// The elements of each list is processed in the index order. To process all
// elements in all lists in timestamp order, each list needs to be sorted in
// timestamp order prior to insertion.
// N.B. |iterable| is not owned by RtcEventProcessor. The caller must ensure
// that the iterable outlives RtcEventProcessor and it must not be modified
// until processing has finished.
template <typename Iterable>
void AddEvents(
const Iterable& iterable,
std::function<void(const typename Iterable::value_type&)> handler) {
if (iterable.begin() == iterable.end())
typename Iterable::const_iterator, typename Iterable::value_type>>(
iterable.begin(), iterable.end(), handler,
std::push_heap(event_lists_.begin(), event_lists_.end(), Cmp);
void ProcessEventsInOrder();
using ListPtrType =
int insertion_order_index_ = 0;
std::vector<ListPtrType> event_lists_;
// Comparison function to make |event_lists_| into a min heap.
static bool Cmp(const ListPtrType& a, const ListPtrType& b);
} // namespace webrtc