snapshot: consider all snapshots in the parents' chains
There are no reasons to only consider full snapshot as a possible base for an
intermediate snapshot. Now that the basic principles have been set, we can
start adding more levels of snapshots.
We now consider all snapshots in the parent's chains (full or intermediate).
This creates a chain of intermediate snapshots, each smaller than the previous
one.
# Effect On The Test Repository
In the test repository, we can see a decrease in the revlog size and slightly
shorter delta chain.
However, that approach creates snapshots more frequently, increasing the risk
of ending into problematic cases in very branchy repositories (not triggered
by the test repository). The next changesets will remove that risk by adding
logic that increases deltas reuse.
#!/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 ''