i18n-pt_BR: synchronized with
149433e68974
changegroup: increase write buffer size to 128k
By default, Python defers to the operating system for choosing the
default buffer size on opened files. On my Linux machine, the default
is 4k, which is really small for 2016.
This patch bumps the write buffer size when writing
changegroups/bundles to 128k. This matches the 128k read buffer
we already use on revlogs.
It's worth noting that this only impacts when writing to an explicit
file (such as during `hg bundle`). Buffers when writing to bundle
files via the repo vfs or to a temporary file are not impacted.
When producing a none-v2 bundle file of the mozilla-unified repository,
this change caused the number of write() system calls to drop from
952,449 to 29,788. After this change, the most frequent system
calls are fstat(), read(), lseek(), and open(). There were
2,523,672 system calls after this patch (so a net decrease of
~950k is statistically significant).
This change shows no performance change on my system. But I have a
high-end system with a fast SSD. It is quite possible this change
will have a significant impact on network file systems, where
extra network round trips due to excessive I/O system calls could
introduce significant latency.
changegroup: skip delta when the underlying revlog do not use them
Revlog can now be configured to store full snapshot only. This is used on the
changelog. However, the changegroup packing was still recomputing deltas to be
sent over the wire.
We now just reuse the full snapshot directly in this case, skipping delta
computation. This provides use with a large speed up(-30%):
# perfchangegroupchangelog on mercurial
! wall 2.010326 comb 2.020000 user 2.000000 sys 0.020000 (best of 5)
! wall 1.382039 comb 1.380000 user 1.370000 sys 0.010000 (best of 8)
# perfchangegroupchangelog on pypy
! wall 5.792589 comb 5.780000 user 5.780000 sys 0.000000 (best of 3)
! wall 3.911158 comb 3.920000 user 3.900000 sys 0.020000 (best of 3)
# perfchangegroupchangelog on mozilla central
! wall 20.683727 comb 20.680000 user 20.630000 sys 0.050000 (best of 3)
! wall 14.190204 comb 14.190000 user 14.150000 sys 0.040000 (best of 3)
Many tests have to be updated because of the change in bundle content. All
theses update have been verified. Because diffing changelog was not very
valuable, the resulting bundle have similar size (often a bit smaller):
# full bundle of mozilla central
with delta:
1142740533B
without delta:
1142173300B
So this is a win all over the board.
revlog: make 'storedeltachains' a "public" attribute
The next changeset will make that attribute read by the changegroup packer. We
make it "public" beforehand.
manifest: don't store None in fulltextcache
When we read a value from fulltextcache, we expect it to be an array,
so we should not store None in it. Found while working on narrowhg.