HTTP2 headers are sent in (potentially) many frames, but all must be
sent sequentially with no traffic intervening.
This was not clear when I wrote the HPACK parser, and still indeed quite
contentious on the HTTP2 mailing lists.
Now that matter is well settled (years ago!) take advantage of the fact
by delaying parsing until all bytes are available.
A future change will leverage this to avoid having to store and verify
partial parse state, completely eliminating indirect calls within the
parser.
This is a fairly low effort migration of the current codebase into a C++ class, instead of free standing C code.
It builds upon #26657 as a necessary first step.
I've tried to minimize any changes to semantics or logic in this change, except where required to get a minimal amount of encapsulation - which is the major aim of this change.
A future change in this series will buffer slices until all HPACK headers are in memory for a stream prior to decoding -- it's important to have an encapsulated API to the parser before doing so however (hence this CL).
The next change after that will be an almost complete rewrite of the parsing functionality -- since we'll have the total set of header bytes, we'll no longer need to support suspending decoding at arbitrary points. This will allow us to move to a simple recursive descent parser, eliminate a bunch of indirection in this code, and end up in a much more malleable place for when we start doing metadata API changes.
(we likely also end up with some good performance wins!)
* De-experimentalize callback API
* Make FromServerContext based on ServerContextBase
* Fix lambda
* Fix headers
* De-experimentalize tests
* clang-format
* Fix consistency checks
* wip
* Fix const-ness of callback client read RPC requests
* Fix golden file
* Give full route_guide callback client example with Hold etc
* Complete example route-guide server
* De-experimentalize test services
* Omit unneeded using
* Remove some uses of non-experimental macro from test
* clang-format examples
* De-experimentalize async stub calls
* Remove experimental namespace use in qps, ubms
* De-experimentalize alarms, generic stubs, and context allocator
* De-experimentalize SetContextAllocator
* clang-format
* Fix conflicts
* Leave obsolete API in place until users can be migrated
* Resolve and test race between OnReadDone(ok=false) and IsCancelled
* Fix retry case
* Fix health check case
* Address reviewer comments.
* ADD TODO requested by markdroth
* rename ChannelData to ClientChannel
* make ClientChannel class definition public
* move retry code to its own filter
* move LB call factory method to ClientChannel class
* move dynamic termination filter out of ClientChannel class
* update comments
* remove retry parsing from client channel service config parser
* fix clang-tidy
* fix service_config_test
* clang-format
* Revert "Revert "xDS status notifier (#25321)" (#25702)"
This reverts commit 3c9f3972e3.
* Remove connection from map when OnClose is not registered
* Reviewer comments
The urgent argument is a platform-specific flag that leaked into the (ideally) platform-independent HTTP/2 transport layer. In an effort to clean up the cross-platform API surface, it would be helpful if we can remove this argument from the TCP Read api without losing the performance optimization that was introduced along with it (see #18240).
This replaces gflags. Added TODOs where use of `absl::Duration` or `absl::FlagSaver` might be preferred in follow-up cleanup. Fixes#24493.
This reverts commit da66b7d14e.
NEW:
* Adds references to `absl/flags/declare.h`, new to LTS 2020923.2 imported in commit 5b43440.
* Works around MSVC 2017 compiler error with large help text on flags by reducing the help text.
Craig Tiller