When encountering errors or unknown tokens while parsing parameters to the
--dirstat option, it makes sense to die() with an error message informing
the user of which parameter did not make sense. However, when parsing the
diff.dirstat config variable, we cannot simply die(), but should instead
(after warning the user) ignore the erroneous or unrecognized parameter.
After all, future Git versions might add more dirstat parameters, and
using two different Git versions on the same repo should not cripple the
older Git version just because of a parameter that is only understood by
a more recent Git version.
This patch fixes the issue by refactoring the dirstat parameter parsing
so that parse_dirstat_params() keeps on parsing parameters, even if an
earlier parameter was not recognized. When parsing has finished, it returns
zero if all parameters were successfully parsed, and non-zero if one or
more parameters were not recognized (with appropriate error messages
appended to the 'errmsg' argument).
The parse_dirstat_params() callers then decide (based on the return value
from parse_dirstat_params()) whether to warn and ignore (in case of
diff.dirstat), or to warn and die (in case of --dirstat).
The patch also adds a couple of tests verifying the correct behavior of
--dirstat and diff.dirstat in the face of unknown (possibly future) dirstat
parameters.
Suggested-by: Junio C Hamano <gitster@pobox.com>
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>
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>
Only the first digit after the decimal point is kept, as the dirstat
calculations all happen in permille.
Selftests verifying floating-point percentage input has been added.
Improved-by: Junio C Hamano <gitster@pobox.com>
Improved-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Instead of having multiple interconnected dirstat-related options, teach
the --dirstat option itself to accept all behavior modifiers as parameters.
- Preserve the current --dirstat=<limit> (where <limit> is an integer
specifying a cut-off percentage)
- Add --dirstat=cumulative, replacing --cumulative
- Add --dirstat=files, replacing --dirstat-by-file
- Also add --dirstat=changes and --dirstat=noncumulative for specifying the
current default behavior. These allow the user to reset other --dirstat
parameters (e.g. 'cumulative' and 'files') occuring earlier on the
command line.
The deprecated options (--cumulative and --dirstat-by-file) are still
functional, although they have been removed from the documentation.
Allow multiple parameters to be separated by commas, e.g.:
--dirstat=files,10,cumulative
Update the documentation accordingly, and add testcases verifying the
behavior of the new syntax.
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 expected output from --dirstat=0, is to include any directory with
changes, even if those changes contribute a minuscule portion of the total
changes. However, currently, directories that contribute less than 0.1% are
not included, since their 'permille' value is 0, and there is an
'if (permille)' check in gather_dirstat() that causes them to be ignored.
This test is obviously intended to exclude directories that contribute no
changes whatsoever, but in this case, it hits too broadly. The correct
check is against 'this_dir' from which the permille is calculated. Only if
this value is 0 does the directory truly contribute no changes, and should
be skipped from the output.
This patches fixes this issue, and updates corresponding testcases to
expect the new behvaior.
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, t4013 is the only selftest that exercises the --dirstat machinery,
but it only does a superficial verification of --dirstat's output.
This patch adds a new selftest - t4047-diff-dirstat.sh - which prepares a
commit containing:
- unchanged files, changed files and files with rearranged lines
- copied files, moved files, and unmoved files
It then verifies the correct dirstat output for that commit in the following
dirstat modes:
- --dirstat
- -X
- --dirstat=0
- -X0
- --cumulative
- --dirstat-by-file
- (plus combinations of the above)
Each of the above tests are also run with:
- no rename detection
- rename detection (-M)
- expensive copy detection (-C -C)
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>
