similar: get rid of quadratic addedfiles.remove() Instead, build a set of files to be removed and recreate addedfiles only if necessary. Benchmark with 50k added/removed files, on tmpfs: $ hg addremove --dry-run --time -q original: real 16.550 secs (user 15.000+0.000 sys 1.540+0.000) previous: real 16.730 secs (user 15.280+0.000 sys 1.440+0.000) this patch: real 16.070 secs (user 14.470+0.000 sys 1.580+0.000)

similar: sort files not by object id but by path for stable result Perhaps the original implementation would want to sort added/removed files alphabetically, but actually it did sort fctx objects by memory location. This patch removes the use of set()s in order to preserve the order of added/removed files. addedfiles.remove() becomes quadratic, but its cost appears not dominant. Anyway, the quadratic behavior will be eliminated by the next patch. Benchmark with 50k added/removed files, on tmpfs: $ mkdir src $ for n in `seq 0 49`; do > mkdir `printf src/%02d $n` > done $ for n in `seq 0 49999`; do > f=`printf src/%02d/%05d $(($n/1000)) $n` > dd if=/dev/urandom of=$f bs=8k count=1 status=none > done $ hg ci -qAm 'add 50k files of random content' $ mv src dest $ hg addremove --dry-run --time -q original: real 16.550 secs (user 15.000+0.000 sys 1.540+0.000) this patch: real 16.730 secs (user 15.280+0.000 sys 1.440+0.000)

debugfsinfo: print fstype information Since we have osutil.getfstype, it'll be handy if "debugfsinfo" prints it.

util: enable hardlink for copyfile This patch removes the global variable "allowhardlinks" that disables hardlink in all cases, so hardlink gets enabled if the filesystem type is whitelisted. Third party extensions wanting to enable hardlink support unconditionally can replace "_hardlinkfswhitelist.__contains__".

hghave: add a check about whitelisted filesystem that supports hardlink This is needed for the test added by the next patch.

util: disable hardlink for copyfile if fstype is outside a whitelist Since osutil.getfstype is available, use it to detect filesystem types. The whitelist currently includes common local filesystems on Linux where they should have good hardlink support. We may add new filesystems for other platforms later.