revsets: huge speedups for fromsvn and svnrev I have a hgsubversion repo that contains over 300,000 commits. In that repo, this patch improves performance as follows: hg --time log -r 'first(fromsvn())' Before: 40.3 sec After: 0.8 sec hg --time log -r 'svnrev(350000)' Before: 40.3 sec After: 0.1 sec Note: the performance of these revset implementations is very sensitive to doing as little work as possible per line of the rev_map file. I originally attempted to hide the file format details by hoisting the parsing of each line up into RevMap.readmapfile, but the current less abstract code is dramatically (10x or more) faster. If the revmap file is missing, we error out and print a message describing what to do.

#!/bin/sh
mkdir temp
cd temp
svnadmin create repo
svn co file://`pwd`/repo wc

cd wc
mkdir brances trunk tags
svn add *
svn ci -m 'btt'

cd trunk
for a in alpha beta gamma delta ; do
    echo $a > $a
    svn add $a
done
svn ci -m 'Add files.'

cd ..
svn up
svn cp trunk brances/dev_branch
svn ci -m 'branch'

cd brances/dev_branch
svn rm delta
echo narf > alpha
echo iota > iota
svn add iota
svn ci -m 'branch changes'

cd ../..
svn up
svn mv brances branches
svn ci -m 'move branches to branches'

cd ..
cd ..

svnadmin dump temp/repo > rename_branch_parent_dir.svndump
echo
echo 'Complete.'
echo 'You probably want to clean up temp now.'
echo 'Dump in rename_branch_parent_dir.svndump'
exit 0