revlog: add clone method
Upcoming patches will introduce functionality for in-place
repository/store "upgrades." Copying the contents of a revlog
feels sufficiently low-level to warrant being in the revlog
class. So this commit implements that functionality.
Because full delta recomputation can be *very* expensive (we're
talking several hours on the Firefox repository), we support
multiple modes of execution with regards to delta (re)use. This
will allow repository upgrades to choose the "level" of
processing/optimization they wish to perform when converting
revlogs.
It's not obvious from this commit, but "addrevisioncb" will be
used for progress reporting.
#!/bin/rc
# 9diff - Mercurial extdiff wrapper for diff(1)
rfork e
fn getfiles {
cd $1 &&
for(f in `{du -as | awk '{print $2}'})
test -f $f && echo `{cleanname $f}
}
fn usage {
echo >[1=2] usage: 9diff [diff options] parent child root
exit usage
}
opts=()
while(~ $1 -*){
opts=($opts $1)
shift
}
if(! ~ $#* 3)
usage
# extdiff will set the parent and child to a single file if there is
# only one change. If there are multiple changes, directories will be
# set. diff(1) does not cope particularly with directories; instead we
# do the recursion ourselves and diff each file individually.
if(test -f $1)
diff $opts $1 $2
if not{
# extdiff will create a snapshot of the working copy to prevent
# conflicts during the diff. We circumvent this behavior by
# diffing against the repository root to produce plumbable
# output. This is antisocial.
for(f in `{sort -u <{getfiles $1} <{getfiles $2}}){
file1=$1/$f; test -f $file1 || file1=/dev/null
file2=$3/$f; test -f $file2 || file2=/dev/null
diff $opts $file1 $file2
}
}
exit ''