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 branches trunk
svn add *
svn ci -m 'branches trunk'
svn up

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

svn cp trunk branches/dev_branch
svn ci -m 'make a branch'
svn up

cd branches/dev_branch
echo epsilon > epsilon
svn add epsilon
svn ci -m 'Add a file on the branch.'
svn up
cd ../..

cd branches/dev_branch
svn ps 'svn:ignore' 'delta' .
svn ci -m 'Commit bogus propchange.'
svn up
cd ../../..

pwd
svnadmin dump repo > ../branch_prop_edit.svndump
cd ..
echo 'Dump created in branch_prop_edit.svndump. You can probably delete temp.'
exit 0