outgoing: rework the handling of the `missingroots` case to be faster
The previous implementation was slow, to the point it was taking a significant
amount of `hg bundle --type none-streamv2` call. We rework the code to compute
the same value much faster, making the operation disappear from the `hg bundle
--type none-streamv2` profile. Someone would remark that producing a streamclone
does not requires an `outgoing` object. However that is a matter for another
day. There is other user of `missingroots` (non stream `hg bundle` call for
example), and they will also benefit from this rework.
We implement an old TODO in the process, directly computing the missing and
common attribute as we have most element at hand already.
### benchmark.name = hg.command.bundle
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.revs = all
# benchmark.variants.type = none-streamv2
## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog
before: 7.750458
after: 6.665565 (-14.00%, -1.08)
## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog
before: 0.700229
after: 0.496050 (-29.16%, -0.20)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
before: 346.508952
after: 316.749699 (-8.59%, -29.76)
## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog
before: 3.401700
after: 2.915810 (-14.28%, -0.49)
## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog
before: 1.870798
after: 1.461583 (-21.87%, -0.41)
note: this whole `missingroots` of outgoing has a limited number of callers and
could likely be replace by something simpler (like taking an explicit
"missing_revs" set for example). However this is a wider change and we focus on
a small impact, quick rework that does not change the API for now.
# Read the output of a "svn log --xml" command on stdin, parse it and
# print a subset of attributes common to all svn versions tested by
# hg.
import sys
import xml.dom.minidom
def xmltext(e):
return ''.join(c.data for c in e.childNodes if c.nodeType == c.TEXT_NODE)
def parseentry(entry):
e = {}
e['revision'] = entry.getAttribute('revision')
e['author'] = xmltext(entry.getElementsByTagName('author')[0])
e['msg'] = xmltext(entry.getElementsByTagName('msg')[0])
e['date'] = xmltext(entry.getElementsByTagName('date')[0])
e['paths'] = []
paths = entry.getElementsByTagName('paths')
if paths:
paths = paths[0]
for p in paths.getElementsByTagName('path'):
action = p.getAttribute('action').encode('utf-8')
path = xmltext(p).encode('utf-8')
frompath = p.getAttribute('copyfrom-path').encode('utf-8')
fromrev = p.getAttribute('copyfrom-rev').encode('utf-8')
e['paths'].append((path, action, frompath, fromrev))
return e
def parselog(data):
entries = []
doc = xml.dom.minidom.parseString(data)
for e in doc.getElementsByTagName('logentry'):
entries.append(parseentry(e))
return entries
def printentries(entries):
try:
fp = sys.stdout.buffer
except AttributeError:
fp = sys.stdout
for e in entries:
for k in ('revision', 'author', 'date', 'msg'):
fp.write(('%s: %s\n' % (k, e[k])).encode('utf-8'))
for path, action, fpath, frev in sorted(e['paths']):
frominfo = b''
if frev:
frominfo = b' (from %s@%s)' % (fpath, frev)
p = b' %s %s%s\n' % (action, path, frominfo)
fp.write(p)
if __name__ == '__main__':
data = sys.stdin.read()
entries = parselog(data)
printentries(entries)