Gregory Szorc <gregory.szorc@gmail.com> [Thu, 21 May 2015 10:27:45 -0700] rev 25236
exchange: move code for consuming streaming clone into exchange
For reasons outlined in the previous commit, we want to make the code
for consuming "stream bundles" reusable. This patch extracts the code
into a standalone function.
Gregory Szorc <gregory.szorc@gmail.com> [Thu, 21 May 2015 10:27:22 -0700] rev 25235
exchange: move code for generating a streaming clone into exchange
Streaming clones are fast because they are essentially tar files.
On mozilla-central, a streaming clone only consumes ~55s CPU time
on clients as opposed to ~340s CPU time for a regular clone or gzip
bundle unbundle.
Mozilla is deploying static file "lookaside" support to our Mercurial
server. Static bundles are pre-generated and uploaded to S3. When a
clone is performed, the static file is fetched, applied, and then an
incremental pull is performed. Unfortunately, on an ideal network
connection this still takes as much wall and CPU time as a regular
clone (although it does save significant server resources).
We like the client-side wall time wins of streaming clones. But we want
to leverage S3-based pre-generated files for serving the bulk of clone
data.
This patch moves the code for producing a "stream bundle" into its
own standalone function, away from the wire protocol. This will enable
stream bundle files to be produced outside the context of the wire
protocol.
A bikeshed on whether exchange is the best module for this function
might be warranted. I selected exchange instead of changegroup because
"stream bundles" aren't changegroups (yet).
Martin von Zweigbergk <martinvonz@google.com> [Tue, 19 May 2015 10:13:43 -0700] rev 25234
dirstate: avoid match.files() in walk()