8039cdbe48
(NOTE: This and dependent CLs will be reverted in a few days after data collection from the field is complete.) This change introduces a new task queue concept, Voucher. They are associated with a currently running task tree. Whenever tasks are posted, the current voucher is inherited and set as current in the new task. The voucher exists for as long as there are direct and indirect tasks running that descend from the task where the voucher was created. Vouchers aggregate application-specific attachments, which perform logic unrelated to Voucher progression. This particular change adds an attachment that measures time from capture to all encode operations complete, and places it into the WebRTC.Video.CaptureToSendTimeMs UMA. An accompanying Chrome change crrev.com/c/4992282 ensures survival of vouchers across certain Mojo IPC. Bug: chromium:1498378 Change-Id: I2a27800a4e5504f219d8b9d33c56a48904cf6dde Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/325400 Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Markus Handell <handellm@webrtc.org> Cr-Commit-Position: refs/heads/main@{#41061}
How to write code in the api/ directory
Mostly, just follow the regular style guide, but:
- Note that
api/code is not exempt from the “.hand.ccfiles come in pairs” rule, so if you declare something inapi/path/to/foo.h, it should be defined inapi/path/to/foo.cc. - Headers in
api/should, if possible, not#includeheaders outsideapi/. It’s not always possible to avoid this, but be aware that it adds to a small mountain of technical debt that we’re trying to shrink. .ccfiles inapi/, on the other hand, are free to#includeheaders outsideapi/.- Avoid structs in api, prefer classes.
The preferred way for api/ code to access non-api/ code is to call
it from a .cc file, so that users of our API headers won’t transitively
#include non-public headers.
For headers in api/ that need to refer to non-public types, forward
declarations are often a lesser evil than including non-public header files. The
usual rules still apply, though.
.cc files in api/ should preferably be kept reasonably small. If a
substantial implementation is needed, consider putting it with our non-public
code, and just call it from the api/ .cc file.
Avoid defining api with structs as it makes harder for the api to evolve. Your struct may gain invariant, or change how it represents data. Evolving struct from the api is particular challenging as it is designed to be used in other code bases and thus needs to be updated independetly from its usage. Class with accessors and setters makes such migration safer. See Google C++ style guide for more.
If you need to evolve existent struct in api, prefer first to convert it into a class.