dirstate-tree: Avoid BTreeMap double-lookup when inserting a dirstate entry
The child nodes of a given node in the tree-shaped dirstate are kept in a
`BTreeMap` where keys are file names as strings. Finding or inserting a value
in the map takes `O(log(n))` string comparisons, which adds up when constructing
the tree.
The `entry` API allows finding a "spot" in the map that may or may not be
occupied and then access that value or insert a new one without doing map
lookup again. However the current API is limited in that calling `entry`
requires an owned key (and so a memory allocation), even if it ends up not
being used in the case where the map already has a value with an equal key.
This is still a win, with 4% better end-to-end time for `hg status` measured
here with hyperfine:
```
Benchmark #1: ../hg2/hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1
Time (mean ± σ): 1.337 s ± 0.018 s [User: 892.9 ms, System: 437.5 ms]
Range (min … max): 1.316 s … 1.373 s 10 runs
Benchmark #2: ./hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1
Time (mean ± σ): 1.291 s ± 0.008 s [User: 853.4 ms, System: 431.1 ms]
Range (min … max): 1.283 s … 1.309 s 10 runs
Summary
'./hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1' ran
1.04 ± 0.02 times faster than '../hg2/hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1'
```
* ./hg is this revision
* ../hg2/hg is its parent
* $REPO is an old snapshot of mozilla-central
Differential Revision: https://phab.mercurial-scm.org/D10550
#require serve ssl
Set up SMTP server:
$ CERTSDIR="$TESTDIR/sslcerts"
$ cat "$CERTSDIR/priv.pem" "$CERTSDIR/pub.pem" >> server.pem
$ "$PYTHON" "$TESTDIR/dummysmtpd.py" -p $HGPORT --pid-file a.pid -d \
> --tls smtps --certificate `pwd`/server.pem
listening at localhost:$HGPORT (?)
$ cat a.pid >> $DAEMON_PIDS
Set up repository:
$ hg init t
$ cd t
$ cat <<EOF >> .hg/hgrc
> [extensions]
> patchbomb =
> [email]
> method = smtp
> [smtp]
> host = localhost
> port = $HGPORT
> tls = smtps
> EOF
$ echo a > a
$ hg commit -Ama -d '1 0'
adding a
Utility functions:
$ DISABLECACERTS=
$ try () {
> hg email $DISABLECACERTS -f quux -t foo -c bar -r tip "$@"
> }
Our test cert is not signed by a trusted CA. It should fail to verify if
we are able to load CA certs:
#if no-defaultcacertsloaded
$ try
this patch series consists of 1 patches.
(an attempt was made to load CA certificates but none were loaded; see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this error)
(?i)abort: .*?certificate.verify.failed.* (re)
[255]
#endif
#if defaultcacertsloaded
$ try
this patch series consists of 1 patches.
(the full certificate chain may not be available locally; see "hg help debugssl") (windows !)
(?i)abort: .*?certificate.verify.failed.* (re)
[255]
#endif
$ DISABLECACERTS="--config devel.disableloaddefaultcerts=true"
Without certificates:
$ try --debug
this patch series consists of 1 patches.
(using smtps)
sending mail: smtp host localhost, port * (glob)
(verifying remote certificate)
abort: unable to verify security of localhost (no loaded CA certificates); refusing to connect
(see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this error or set hostsecurity.localhost:fingerprints=sha256:20:de:b3:ad:b4:cd:a5:42:f0:74:41:1c:a2:70:1e:da:6e:c0:5c:16:9e:e7:22:0f:f1:b7:e5:6e:e4:92:af:7e to trust this server)
[150]
With global certificates:
$ try --debug --config web.cacerts="$CERTSDIR/pub.pem"
this patch series consists of 1 patches.
(using smtps)
sending mail: smtp host localhost, port * (glob)
(verifying remote certificate)
sending [PATCH] a ...
With invalid certificates:
$ try --config web.cacerts="$CERTSDIR/pub-other.pem"
this patch series consists of 1 patches.
(the full certificate chain may not be available locally; see "hg help debugssl") (windows !)
(?i)abort: .*?certificate.verify.failed.* (re)
[255]
$ cd ..