hg-ssh: refactor to have main() method
Refactor hg-ssh to have a main() function instead of a bunch of
top-level statements.
graphlog: turn getlogrevs() into a generator
This improves the poor "time to first changeset" compared to the
original log command. When running:
$ hg log -u user
log will enumerate the changelog and display matching revisions when
they are found. But:
$ hg log -G -u user
will first find all revisions matching the user then start to display
them.
Initially, I considered turning revset.match() into a generator. This is
doable but requires a fair amount of work. Instead,
cmdutil.increasingwindows() is reused to call the revset matcher
repeatedly. This has the nice properties of:
- Let us reorder the windows after filtering, which is necessary as the
matcher can reorder inputs but is an internal detail not a feature.
- Let us feed the matcher with windows in changelog order, which is good
for performances.
- Have a generator designed for log-like commands, returning small
windows at first then batching larger ones.
I feel that calling the matcher multiple times is correct, at least with
the revsets involved in getlogrevs() because they are:
- stateless (no limit())
- respecting f(a|b) = f(a) | f(b), though I have no valid argument about
that.
Known issues compared to log code:
- Calling the revset matcher multiple times can be slow when revset
functions have to create expensive data structure for filtering. This
will be addressed in a followup.
- Predicate combinations like "--user foo --user bar" or "--user foo and
--branch bar" are inherently slower because all input revision are
checked against the first condition, then against the second, and so
forth. log would enumerate the input revisions once and check each of
them once against all conditions, which is faster. There are solutions
but nothing cheap to implement.
Some numbers against mozilla repository:
first line total
* hg log -u rnewman
/Users/pmezard/bin/hg-2.2 0.148s 7.293s
/Users/pmezard/bin/hgdev 0.132s 5.747s
* hg log -u rnewman -u girard
/Users/pmezard/bin/hg-2.2 0.146s 7.323s
/Users/pmezard/bin/hgdev 0.136s 11.096s
* hg log -l 10
/Users/pmezard/bin/hg-2.2 0.137s 0.153s
/Users/pmezard/bin/hgdev 0.128s 0.144s
* hg log -l 10 -u rnewman
/Users/pmezard/bin/hg-2.2 0.146s 0.265s
/Users/pmezard/bin/hgdev 0.133s 0.236s
* hg log -b GECKO193a2_
20100228_RELBRANCH
/Users/pmezard/bin/hg-2.2 2.332s 6.618s
/Users/pmezard/bin/hgdev 1.972s 5.543s
* hg log xulrunner
/Users/pmezard/bin/hg-2.2 5.829s 5.958s
/Users/pmezard/bin/hgdev 0.194s 6.017s
* hg log --follow xulrunner/build.mk
/Users/pmezard/bin/hg-2.2 0.353s 0.438s
/Users/pmezard/bin/hgdev 0.394s 0.580s
* hg log -u girard tools
/Users/pmezard/bin/hg-2.2 5.853s 6.012s
/Users/pmezard/bin/hgdev 0.195s 6.030s
* hg log -b COMM2000_
20110314_RELBRANCH --copies
/Users/pmezard/bin/hg-2.2 2.231s 6.653s
/Users/pmezard/bin/hgdev 1.897s 5.585s
* hg log --follow
/Users/pmezard/bin/hg-2.2 0.137s 14.140s
/Users/pmezard/bin/hgdev 0.381s 44.246s
* hg log --follow -r 80000:90000
/Users/pmezard/bin/hg-2.2 0.127s 1.611s
/Users/pmezard/bin/hgdev 0.147s 1.847s
* hg log --follow -r 90000:80000
/Users/pmezard/bin/hg-2.2 0.130s 1.702s
/Users/pmezard/bin/hgdev 0.368s 6.106s
* hg log --follow -r 80000:90000 js/src/jsproxy.cpp
/Users/pmezard/bin/hg-2.2 0.343s 0.388s
/Users/pmezard/bin/hgdev 0.437s 0.631s
* hg log --follow -r 90000:80000 js/src/jsproxy.cpp
/Users/pmezard/bin/hg-2.2 0.342s 0.389s
/Users/pmezard/bin/hgdev 0.442s 0.628s
cmdutil: extract increasing_windows() from walkchangerevs()
It will be reused in the revset-based version.