patch: use opt.showsimilarity to calculate and show the similarity Tests have been added.

patch: add similarity config knob in experimental section This config knob will control whether or not to show the similarity calculation in the diff output: diff --git a/README.md b/foo.md similarity index 88% rename from README.md rename to foo.md --- a/README.md +++ b/foo.md

similar: move score function to module level Future patches will use this to report the similarity of a rename / copy in the patch output.

revset: abuse x:y syntax to specify line range of followlines() This slightly complicates the parsing (see the previous patch), but the overall result seems not bad. I keep x:, :y and : for future extension.

revset: do not transform range* operators in parsed tree This allows us to handle x:y range as a general range object. A primary user of it is followlines().

revset: add default value to getinteger() helper This seems handy.

revset: factor out getinteger() helper We have 4 revset functions that take integer arguments, and they handle their arguments in slightly different ways. This patch unifies them: - getstring() in place of getsymbol(), which is more consistent with the handling of integer revisions (both 1 and '1' are valid) - say "expects" instead of "requires" for type errors We don't need to catch TypeError since getstring() must return a string.

revset: rename rev argument of followlines() to startrev The rev argument has the same meaning as startrev of follow(), and I think startrev is more informative. followlines() is new function, we can make BC now.

help: use :hg: role and canonical name to point to revset string patterns Follows up 5dd67f0993ce. Now revisions.txt and revsets.txt has been merged, so use revisions.* as a pointer.

util: compression APIs to support revlog decompression Previously, compression engines had APIs for performing revlog compression but no mechanism to perform revlog decompression. This patch changes that. Revlog decompression is slightly more complicated than compression because in the compression case there is (currently) only a single engine that can be used at a time. However for decompression, a revlog could contain chunks from multiple compression engines. This means decompression needs to map to multiple engines and decompressors. This functionality is outside the scope of this patch. But it drives the decision for engines to declare a byte header sequence that identifies revlog data as belonging to an engine and an API for obtaining an engine from a revlog header.

crecord: add an experimental option for space key to move cursor down I really want to have an option of toggling a selection on a line and also moving cursor down as a single keystroke. It also kinda makes sense for space key to do this, because some other curses UIs in the wild do this (e.g. various file managers, htop). So I got an idea to make a config option that defaults to False for compatibility, but allows making crecord UI a lot more useful for people with big hunks. We add this an experimental option to experiment with this behavior.

perf: support multiple compression engines in perfrevlogchunks Now that the revlog has a reference to a compressor, it is possible to swap in other compression engines. So, teach `hg perfrevlogchunks` to do that. The default behavior of `hg perfrevlogchunks` is now to measure the compression performance of all compression engines implementing the revlog compressor API. This effectively adds the no-op "none" compressor and zstd (when available) into the default set. While we can't yet plug alternate compressors into revlogs, this command gives us a preview of the performance. On the mozilla-unified repository: $ hg perfrevlogchunks -c ! compress w/ none ! wall 0.115159 comb 0.110000 user 0.110000 sys 0.000000 (best of 86) ! compress w/ zlib ! wall 5.681406 comb 5.680000 user 5.680000 sys 0.000000 (best of 3) ! compress w/ zstd ! wall 2.624781 comb 2.620000 user 2.620000 sys 0.000000 (best of 4) $ hg perfrevlogchunks -m ! compress w/ none ! wall 0.124486 comb 0.120000 user 0.120000 sys 0.000000 (best of 79) ! compress w/ zlib ! wall 10.144701 comb 10.150000 user 10.150000 sys 0.000000 (best of 3) ! compress w/ zstd ! wall 4.383118 comb 4.390000 user 4.390000 sys 0.000000 (best of 3) Those numbers for zstd look promising. But they aren't the full story. For that, we'll need to look at decompression times and storage sizes. Stay tuned...