This patch adds an alternative implementation of show_dirstat(), called
show_dirstat_by_line(), which uses the more expensive diffstat analysis
(as opposed to show_dirstat()'s own (relatively inexpensive) analysis)
to derive the numbers from which the --dirstat output is computed.
The alternative implementation is controlled by the new "lines" parameter
to the --dirstat option (or the diff.dirstat config variable).
For binary files, the diffstat analysis counts bytes instead of lines,
so to prevent binary files from dominating the dirstat results, the
byte counts for binary files are divided by 64 before being compared to
their textual/line-based counterparts. This is a stupid and ugly - but
very cheap - heuristic.
In linux-2.6.git, running the three different --dirstat modes:
time git diff v2.6.20..v2.6.30 --dirstat=changes > /dev/null
vs.
time git diff v2.6.20..v2.6.30 --dirstat=lines > /dev/null
vs.
time git diff v2.6.20..v2.6.30 --dirstat=files > /dev/null
yields the following average runtimes on my machine:
- "changes" (default): ~6.0 s
- "lines": ~9.6 s
- "files": ~0.1 s
So, as expected, there's a considerable performance hit (~60%) by going
through the full diffstat analysis as compared to the default "changes"
analysis (obviously, "files" is much faster than both). As such, the
"lines" mode is probably only useful if you really need the --dirstat
numbers to be consistent with the numbers returned from the other
--*stat options.
The patch also includes documentation and tests for the new dirstat mode.
Improved-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The new diff.dirstat config variable takes the same arguments as
'--dirstat=<args>', and specifies the default arguments for --dirstat.
The config is obviously overridden by --dirstat arguments passed on the
command line.
When not specified, the --dirstat defaults are 'changes,noncumulative,3'.
The patch also adds several tests verifying the interaction between the
diff.dirstat config variable, and the --dirstat command line option.
Improved-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Apart from the list of "valid values", 'diff.tool' can take any value,
provided there is a corresponding 'difftool.<tool>.cmd' option. Also,
describe this option just before the 'difftool.*' options.
Helped-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Although the gitattributes page contains comprehensive information
about these configuration options, they should be included in the
config documentation for completeness.
It may be better to rename the "driver" in "diff.<driver>.*" to
something like "content type" or "file type", but for now, let's keep
it consistent across this part of the documentation and the original
description in the gitattributes documentation.
Helped-by: Jakub Narebski <jnareb@gmail.com>
Helped-by: Michael J Gruber <git@drmicha.warpmail.net>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
