encoding: add fast path of from/toutf8b() for ASCII strings See the previous patch for why. The added test seems not making much sense because ASCII strings should never contain "\xed" and be valid UTF-8. (with mercurial repo) $ export HGRCPATH=/dev/null HGPLAIN= $ hg log --time --config experimental.stabilization=all -Tjson > /dev/null (original) time: real 6.830 secs (user 6.740+0.000 sys 0.080+0.000) time: real 6.690 secs (user 6.650+0.000 sys 0.040+0.000) time: real 6.700 secs (user 6.640+0.000 sys 0.060+0.000) (fast jsonescape) time: real 5.630 secs (user 5.550+0.000 sys 0.070+0.000) time: real 5.700 secs (user 5.650+0.000 sys 0.050+0.000) time: real 5.690 secs (user 5.640+0.000 sys 0.050+0.000) (this patch) time: real 5.190 secs (user 5.120+0.000 sys 0.070+0.000) time: real 5.230 secs (user 5.170+0.000 sys 0.050+0.000) time: real 5.220 secs (user 5.150+0.000 sys 0.070+0.000)

encoding: add fast path of from/tolocal() for ASCII strings This is micro optimization, but seems not bad since to/fromlocal() is called lots of times and isasciistr() is cheap and simple. We boldly assume that any non-ASCII characters have at least one 8-bit byte. This isn't true for some email character sets (e.g. ISO-2022-JP and UTF-7), but I believe no such encodings are used as a platform default. Shift_JIS, a major crap, is okay as it should have a leading byte in 0x80-0xff range. (with mercurial repo) $ export HGRCPATH=/dev/null HGPLAIN= $ hg log --time --config experimental.stabilization=all > /dev/null (original) time: real 7.460 secs (user 7.420+0.000 sys 0.030+0.000) time: real 7.670 secs (user 7.590+0.000 sys 0.080+0.000) time: real 7.560 secs (user 7.510+0.000 sys 0.040+0.000) (this patch) time: real 7.340 secs (user 7.260+0.000 sys 0.060+0.000) time: real 7.260 secs (user 7.210+0.000 sys 0.030+0.000) time: real 7.310 secs (user 7.260+0.000 sys 0.060+0.000)

encoding: add function to test if a str consists of ASCII characters Most strings are ASCII. Let's optimize for it. Using uint64_t is slightly faster than uint32_t on 64bit system, but there isn't huge difference.

encoding: add fast path of jsonescape() (issue5533) This isn't highly optimized as it copies characters one by one, but seems reasonably simple and not slow. (with mercurial repo) $ export HGRCPATH=/dev/null HGPLAIN= $ hg log --time --config experimental.stabilization=all -Tjson > /dev/null (original) time: real 6.830 secs (user 6.740+0.000 sys 0.080+0.000) time: real 6.690 secs (user 6.650+0.000 sys 0.040+0.000) time: real 6.700 secs (user 6.640+0.000 sys 0.060+0.000) (this patch) time: real 5.630 secs (user 5.550+0.000 sys 0.070+0.000) time: real 5.700 secs (user 5.650+0.000 sys 0.050+0.000) time: real 5.690 secs (user 5.640+0.000 sys 0.050+0.000)

encoding: extract stub for fast JSON escape This moves JSON character maps to pure/charencode.py because they will be used only when the fast-path fails.

journal: do not use atomictemp (issue5338) Writing journal files using `atomictemp` leads to quadratic performance that could be problematic if automation runs many commands. Other logs like blackbox does not use atomictemp, and journal logs are not critical for repo correctness. So let's make them non-atomictemp. Differential Revision: https://phab.mercurial-scm.org/D517

tests: update test-commandserver to pass our import checker

tests: add blank output lines to test-commandserver This helps the import checker notice when a Python heredoc has ended. It's not perfect, but it gets nasty quick and I think the better fix would be to add a real parser for .t-tests, which will have to wait.