Commit Graph

5 Commits

Author SHA1 Message Date
Thomas Rast
209618860c log -L: fix overlapping input ranges
The existing code was too defensive, and would trigger the assert in
range_set_append() if the user gave overlapping ranges.

The intent was always to define overlapping ranges as just the union
of all of them, as evidenced by the call to sort_and_merge_range_set().
(Which was already used, unlike what the comment said.)

Fix by splitting out the meat of range_set_append() to a new _unsafe()
function that lacks the paranoia.  sort_and_merge_range_set will fix
up the ranges, so we don't need the checks there.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-05 10:39:09 -07:00
Thomas Rast
4596f190d3 log -L: check range set invariants when we look it up
lookup_line_range() is a good place to check that the range sets
satisfy the invariants: they have been computed and set in earlier
iterations, and we now start working with them.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-05 10:39:08 -07:00
Thomas Rast
39410bf0bf Speed up log -L... -M
So far log -L only used the implicit diff filtering by pathspec.  If
the user specifies -M, we cannot do that, and so we simply handed the
whole diff queue (which is approximately 'git show --raw') to
diffcore_std().

Unfortunately this is very slow.  We can optimize a lot if we throw
out files that we know cannot possibly be interesting, in the same
spirit that the pathspec filtering reduces the number of files.

However, in this case, we have to be more careful.  Because we want to
look out for renames, we need to keep all filepairs where something
was deleted.

This is a bit hacky and should really be replaced by equivalent
support in --follow, and just using that.  However, in the meantime it
speeds up 'log -M -L' by an order of magnitude.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-28 10:30:28 -07:00
Thomas Rast
13b8f68c1f log -L: :pattern:file syntax to find by funcname
This new syntax finds a funcname matching /pattern/, and then takes from there
up to (but not including) the next funcname.  So you can say

  git log -L:main:main.c

and it will dig up the main() function and show its line-log, provided
there are no other funcnames matching 'main'.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-28 10:30:04 -07:00
Thomas Rast
12da1d1f6f Implement line-history search (git log -L)
This is a rewrite of much of Bo's work, mainly in an effort to split
it into smaller, easier to understand routines.

The algorithm is built around the struct range_set, which encodes a
series of line ranges as intervals [a,b).  This is used in two
contexts:

* A set of lines we are tracking (which will change as we dig through
  history).
* To encode diffs, as pairs of ranges.

The main routine is range_set_map_across_diff().  It processes the
diff between a commit C and some parent P.  It determines which diff
hunks are relevant to the ranges tracked in C, and computes the new
ranges for P.

The algorithm is then simply to process history in topological order
from newest to oldest, computing ranges and (partial) diffs.  At
branch points, we need to merge the ranges we are watching.  We will
find that many commits do not affect the chosen ranges, and mark them
TREESAME (in addition to those already filtered by pathspec limiting).
Another pass of history simplification then gets rid of such commits.

This is wired as an extra filtering pass in the log machinery.  This
currently only reduces code duplication, but should allow for other
simplifications and options to be used.

Finally, we hook a diff printer into the output chain.  Ideally we
would wire directly into the diff logic, to optionally use features
like word diff.  However, that will require some major reworking of
the diff chain, so we completely replace the output with our own diff
for now.

As this was a GSoC project, and has quite some history by now, many
people have helped.  In no particular order, thanks go to

  Jakub Narebski <jnareb@gmail.com>
  Jens Lehmann <Jens.Lehmann@web.de>
  Jonathan Nieder <jrnieder@gmail.com>
  Junio C Hamano <gitster@pobox.com>
  Ramsay Jones <ramsay@ramsay1.demon.co.uk>
  Will Palmer <wmpalmer@gmail.com>

Apologies to everyone I forgot.

Signed-off-by: Bo Yang <struggleyb.nku@gmail.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-28 10:29:22 -07:00