Mercurial > hg
view tests/svnxml.py @ 39178:274acf379dbb
setdiscovery: precompute children revisions to avoid quadratic lookup
Moving away from dagutil a few commits ago introduced quadratic
behavior when resolving children revisions during discovery.
This commit introduces a precompute step of the children revisions
to avoid the bad behavior.
I believe the new code should have near identical performance to
what dagutil was doing before. Behavior is still slightly different
because we take into account filtered revisions. But this change was
made when we moved off dagutil.
I added a comment about multiple invocations of this function
redundantly calculating the children revisions. I believe this
potentially undesirable behavior was present when we used dagutil,
as the call to inverse() previously in this function created a new
object and required computing children on every invocation. I thought
we should document the potential for a performance issue rather than
let it go undocumented.
Differential Revision: https://phab.mercurial-scm.org/D4326
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 17 Aug 2018 19:35:24 +0000 |
parents | 812eb3b7dc43 |
children | c17d73bf6a4d |
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# 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. from __future__ import absolute_import 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['paths'] = [] paths = entry.getElementsByTagName('paths') if paths: paths = paths[0] for p in paths.getElementsByTagName('path'): action = p.getAttribute('action') path = xmltext(p) frompath = p.getAttribute('copyfrom-path') fromrev = p.getAttribute('copyfrom-rev') 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): fp = sys.stdout for e in entries: for k in ('revision', 'author', 'msg'): fp.write(('%s: %s\n' % (k, e[k])).encode('utf-8')) for path, action, fpath, frev in sorted(e['paths']): frominfo = '' if frev: frominfo = ' (from %s@%s)' % (fpath, frev) p = ' %s %s%s\n' % (action, path, frominfo) fp.write(p.encode('utf-8')) if __name__ == '__main__': data = sys.stdin.read() entries = parselog(data) printentries(entries)