Use flat_map/flat_set in RtpDemuxer

Except for a use of std::multimap (for which there currently is no
drop-in replacement), use webrtc::flat_map and flat_set for increased
performance.

The number of ssrcs/mids/payload types/etc is likely to be small and is
generally updated very rarely, but looked up a lot.

RtpDemuxer::ResolveSink's use of std::map represents about 0.6% CPU in
heavily loaded media servers. It does quite a few map lookups, and by
taking advantage of the increased cache locality of the flat_map and
flat_set containers, performance should be increased.

A previous attempt to use std::unordered_map failed in change 216243,
which was reverted. This is the second attempt.

Bug: webrtc:12689
Change-Id: Ifdbec63b2fd8f2f52e45ebaf12834b11dd7a41c5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/224662
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34429}
3 files changed
tree: 00cc1438f5fa6e7ca991c7290b842d97a7c68ae4
  1. api/
  2. audio/
  3. build_overrides/
  4. call/
  5. common_audio/
  6. common_video/
  7. data/
  8. docs/
  9. examples/
  10. g3doc/
  11. logging/
  12. media/
  13. modules/
  14. net/
  15. p2p/
  16. pc/
  17. resources/
  18. rtc_base/
  19. rtc_tools/
  20. sdk/
  21. stats/
  22. system_wrappers/
  23. test/
  24. tools_webrtc/
  25. video/
  26. .clang-format
  27. .git-blame-ignore-revs
  28. .gitignore
  29. .gn
  30. .vpython
  31. AUTHORS
  32. BUILD.gn
  33. CODE_OF_CONDUCT.md
  34. codereview.settings
  35. DEPS
  36. DIR_METADATA
  37. ENG_REVIEW_OWNERS
  38. g3doc.lua
  39. LICENSE
  40. license_template.txt
  41. native-api.md
  42. OWNERS
  43. PATENTS
  44. PRESUBMIT.py
  45. presubmit_test.py
  46. presubmit_test_mocks.py
  47. pylintrc
  48. README.chromium
  49. README.md
  50. WATCHLISTS
  51. webrtc.gni
  52. webrtc_lib_link_test.cc
  53. whitespace.txt
README.md

WebRTC is a free, open software project that provides browsers and mobile applications with Real-Time Communications (RTC) capabilities via simple APIs. The WebRTC components have been optimized to best serve this purpose.

Our mission: To enable rich, high-quality RTC applications to be developed for the browser, mobile platforms, and IoT devices, and allow them all to communicate via a common set of protocols.

The WebRTC initiative is a project supported by Google, Mozilla and Opera, amongst others.

Development

See here for instructions on how to get started developing with the native code.

Authoritative list of directories that contain the native API header files.

More info