Partial metadata rebuilding For highly active subversion repositories, it can be excruciatingly slow to pull updates one at a time from subversion. One way around this is to setup another mercurial repo that pulls new commits from svn periodicly (say every 5 minutes). When you want to update your repository, you can pull commits from this mercurial repository via native mercurial protocols, which will be much faster than pulling directly from svn. Unfortunately, your metadata will be out of date after doing so. Highly active repositories also tend to be very large, which means that it takes a long time to rebuild your metadata from scratch. To address this, this adds support to do a partial rebuild on the metadata by processing only revisions that have been added to the repository after the last revision we processed. With the rev map 1k revisions (~2 days) behind tip updatemeta is dramatically faster than rebuild meta: $ hg --time svn updatemeta Time: real 0.570 secs (user 0.480+0.000 sys 0.060+0.000) $ hg --time svn rebuildmeta Time: real 129.160 secs (user 128.570+0.000 sys 0.320+0.000)

#!/bin/sh
#
# Generate truncatedhistory.svndump
#

mkdir temp
cd temp

mkdir project-orig
cd project-orig
mkdir project1
mkdir project2
cd ..

svnadmin create testrepo
svnurl=file://`pwd`/testrepo
svn import project-orig $svnurl -m "init project"

svn co $svnurl project
# Make a single revision in trunk
cd project/project1
echo a > a
svn add a
svn ci -m "add a"
cd ..
svn up
# Rename the project
svn mv project1 project2/trunk
svn ci -m "rename project1"
cd project2/trunk
echo b > b
svn add b
svn ci -m "add b"
cd ../../..

svnadmin dump testrepo > ../truncatedhistory.svndump