svnwrap: use custom StringIO class in get_file() The wrappers were calling ra.get_file() with a cStringIO object. Empirically, svn 1.7.5 is writing 16kB blocks to the stream object, and cStringIO reallocates its internal buffer and doubles its size whenever it is filled. With large committed files this requires two large memory blocks at the same time. SimpleStringIO implements the mimimum StringIO interface used by ra.get_file() but instead stores all the blocks and "join" them at the end. It means more fragmentation but requires only one large block, without overallocation. Also, 16kB blocks should be friendly to most allocators. In practice, this simple change let me convert a revision containing multiple moderately large files, the largest being around 450MB, with a 32-bits Windows setup, python 2.7, swig svn 1.7.5, in stupid mode, while it was previously aborting with "not enough memory". The same revision still fails in replay mode.

function verify_current_revision()
{
    /bin/rm -rf *
    exportcmd="svn export `hg svn info 2> /dev/null | grep '^URL: ' | sed 's/URL: //'`@`hg svn info | grep ^Revision | sed 's/.*: //;s/ .*//'` . --force"
    `echo $exportcmd` > /dev/null
    x=$?
    if [[ "$x" != "0" ]] ; then
        echo $exportcmd
        echo 'export failed!'
        return 255
    fi
    if [[ "`hg st | wc -l | python -c 'import sys; print sys.stdin.read().strip()'`" == "0" ]] ; then
        return 0
    else
        if [[ $1 != "keep" ]] ; then
            revert_all_files
        fi
        return 1
    fi
}

function revert_all_files()
{
    hg revert --all
    hg purge
}