Summary:
- Add flags to exit after an idle time or client count.
- Add flags to control daemonization.
- Add flags to control output.
- Add flags to skip the "hello" frame of the protocol.
- Make the client launch a server if one does not exist.
The one-time overhead to launch a server and run a command through it looks to be ~130% of the overhead to run the command directly with "hg", so even if we never run a second command we're not paying too much.
The incremental overhead to run subsequent command appears to be less than 3% of the overhead to run the command directly with "hg" (and maybe less than 1%, I'm not sure how long the computation part of a command like 'hg log' "actually" takes).
The overhead to launch a PHP client, connect to an existing server, run a command, and then print it and exit is roughly 50% of the overhead to run the command directly with "hg". So theoretically a user can achieve an amortized 2x performance increase for all 'hg' commands by aliasing 'hg' to the PHP client in their shell.
Test Plan:
- Ran servers with idle and client count limits, let them idle and/or hit their connection limits, saw them exit.
- Ran foreground and background servers.
- Ran a daemon server with redirected stdout/stderr. Verified logs appeared.
- Ran with --quiet.
- Ran clients and servers with and without --skip-hello, things work if they agree and break if they disagree. The throughput gain on this is fairly small (maybe 5%?) but it seems simple enough to keep for the moment.
- Ran serverless clients and verified that servers launched the first time, were available subsequently, and relaunched after 15 seconds idle.
Reviewers: csilvers, vrana, btrahan
Reviewed By: csilvers
CC: aran
Differential Revision: https://secure.phabricator.com/D2680
Summary:
This need a bunch of work, but is a sort of minimum viable product for the hgdaemon.
The two ProtocolChannels implement the client and server halves of the protocol.
The Server implements the server logic, the Client implements the client logic.
Test Plan: Launched a server and client on the same repo, got hg output in ~2-3ms instead of 100ms+.
Reviewers: csilvers, btrahan, vrana
Reviewed By: csilvers
CC: aran
Differential Revision: https://secure.phabricator.com/D2665
