manifestmerge: use dicthelpers.diff and join
This patch improves manifestmerge performance significantly.
In a repository with 170,000 files, the following results were observed on a
clean working directory. Revision '.' adds one file.
hg perfmergecalculate -r .
- before: 0.41 seconds
- after: 0.13 seconds
hg perfmergecalculate -r .^
- before: 0.53 seconds
- after: 0.24 seconds
Comparing against '.' is much faster than comparing against '.^' because with
'.', the wctx and p2 manifest strings have the same identity, so comparisons
are simply pointer equality. With '.^', the strings have different identities
so we need to perform memcmps.
Any operation that uses manifestmerge benefits.
- hg update . goes from 2.04 seconds to 1.75
- hg update .^ goes from 2.52 seconds to 2.25
- hg rebase -r . -d .~6 (involves 4 merges) goes from 11.8 seconds to 10.8
Environment setup for MQ
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ hg qinit
Should fail if no patches applied
$ hg qrefresh
no patches applied
[1]
$ hg qrefresh -e
no patches applied
[1]
$ hg qnew -m "First commit message" first-patch
$ echo aaaa > file
$ hg add file
$ hg qrefresh
Should display 'First commit message'
$ hg log -l1 --template "{desc}\n"
First commit message
Testing changing message with -m
$ echo bbbb > file
$ hg qrefresh -m "Second commit message"
Should display 'Second commit message'
$ hg log -l1 --template "{desc}\n"
Second commit message
Testing changing message with -l
$ echo "Third commit message" > logfile
$ echo " This is the 3rd log message" >> logfile
$ echo bbbb > file
$ hg qrefresh -l logfile
Should display 'Third commit message\\\n This is the 3rd log message'
$ hg log -l1 --template "{desc}\n"
Third commit message
This is the 3rd log message
Testing changing message with -l-
$ hg qnew -m "First commit message" second-patch
$ echo aaaa > file2
$ hg add file2
$ echo bbbb > file2
$ (echo "Fifth commit message"; echo " This is the 5th log message") | hg qrefresh -l-
Should display 'Fifth commit message\\\n This is the 5th log message'
$ hg log -l1 --template "{desc}\n"
Fifth commit message
This is the 5th log message