documentation: add some internals documentation about bid merge
This is an important algorithm that was only documented on the wiki so far.
Some update to the algorithm (and associated doc) is to expected in the future
since the bid merge algorithm is bug-ridden when it comes to file deletion comes
to play.
Differential Revision: https://phab.mercurial-scm.org/D8711
# 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').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', '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)