Commit Graph

113 Commits

Author SHA1 Message Date
Nguyễn Thái Ngọc Duy
9ac3f0e5b3 pack-objects: fix performance issues on packing large deltas
Let's start with some background about oe_delta_size() and
oe_set_delta_size(). If you already know, skip the next paragraph.

These two are added in 0aca34e826 (pack-objects: shrink delta_size
field in struct object_entry - 2018-04-14) to help reduce 'struct
object_entry' size. The delta size field in this struct is reduced to
only contain max 1MB. So if any new delta is produced and larger than
1MB, it's dropped because we can't really save such a large size
anywhere. Fallback is provided in case existing packfiles already have
large deltas, then we can retrieve it from the pack.

While this should help small machines repacking large repos without
large deltas (i.e. less memory pressure), dropping large deltas during
the delta selection process could end up with worse pack files. And if
existing packfiles already have >1MB delta and pack-objects is
instructed to not reuse deltas, all of them will be dropped on the
floor, and the resulting pack would be definitely bigger.

There is also a regression in terms of CPU/IO if we have large on-disk
deltas because fallback code needs to parse the pack every time the
delta size is needed and just access to the mmap'd pack data is enough
for extra page faults when memory is under pressure.

Both of these issues were reported on the mailing list. Here's some
numbers for comparison.

    Version  Pack (MB)  MaxRSS(kB)  Time (s)
    -------  ---------  ----------  --------
     2.17.0     5498     43513628    2494.85
     2.18.0    10531     40449596    4168.94

This patch provides a better fallback that is

- cheaper in terms of cpu and io because we won't have to read
  existing pack files as much

- better in terms of pack size because the pack heuristics is back to
  2.17.0 time, we do not drop large deltas at all

If we encounter any delta (on-disk or created during try_delta phase)
that is larger than the 1MB limit, we stop using delta_size_ field for
this because it can't contain such size anyway. A new array of delta
size is dynamically allocated and can hold all the deltas that 2.17.0
can. This array only contains delta sizes that delta_size_ can't
contain.

With this, we do not have to drop deltas in try_delta() anymore. Of
course the downside is we use slightly more memory, even compared to
2.17.0. But since this is considered an uncommon case, a bit more
memory consumption should not be a problem.

Delta size limit is also raised from 1MB to 16MB to better cover
common case and avoid that extra memory consumption (99.999% deltas in
this reported repo are under 12MB; Jeff noted binary artifacts topped
out at about 3MB in some other private repos). Other fields are
shuffled around to keep this struct packed tight. We don't use more
memory in common case even with this limit update.

A note about thread synchronization. Since this code can be run in
parallel during delta searching phase, we need a mutex. The realloc
part in packlist_alloc() is not protected because it only happens
during the object counting phase, which is always single-threaded.

Access to e->delta_size_ (and by extension
pack->delta_size[e - pack->objects]) is unprotected as before, the
thread scheduler in pack-objects must make sure "e" is never updated
by two different threads.

The area under the new lock is as small as possible, avoiding locking
at all in common case, since lock contention with high thread count
could be expensive (most blobs are small enough that delta compute
time is short and we end up taking the lock very often). The previous
attempt to always hold a lock in oe_delta_size() and
oe_set_delta_size() increases execution time by 33% when repacking
linux.git with with 40 threads.

Reported-by: Elijah Newren <newren@gmail.com>
Helped-by: Elijah Newren <newren@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-23 10:21:29 -07:00
Nguyễn Thái Ngọc Duy
ac77d0c370 pack-objects: shrink size field in struct object_entry
It's very very rare that an uncompressed object is larger than 4GB
(partly because Git does not handle those large files very well to
begin with). Let's optimize it for the common case where object size
is smaller than this limit.

Shrink size field down to 31 bits and one overflow bit. If the size is
too large, we read it back from disk. As noted in the previous patch,
we need to return the delta size instead of canonical size when the
to-be-reused object entry type is a delta instead of a canonical one.

Add two compare helpers that can take advantage of the overflow
bit (e.g. if the file is 4GB+, chances are it's already larger than
core.bigFileThreshold and there's no point in comparing the actual
value).

Another note about oe_get_size_slow(). This function MUST be thread
safe because SIZE() macro is used inside try_delta() which may run in
parallel. Outside parallel code, no-contention locking should be dirt
cheap (or insignificant compared to i/o access anyway). To exercise
this code, it's best to run the test suite with something like

    make test GIT_TEST_OE_SIZE=4

which forces this code on all objects larger than 3 bytes.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-16 12:38:59 +09:00
Nguyễn Thái Ngọc Duy
43fa44fa3b pack-objects: move in_pack out of struct object_entry
Instead of using 8 bytes (on 64 bit arch) to store a pointer to a
pack. Use an index instead since the number of packs should be
relatively small.

This limits the number of packs we can handle to 1k. Since we can't be
sure people can never run into the situation where they have more than
1k pack files. Provide a fall back route for it.

If we find out they have too many packs, the new in_pack_by_idx[]
array (which has at most 1k elements) will not be used. Instead we
allocate in_pack[] array that holds nr_objects elements. This is
similar to how the optional in_pack_pos field is handled.

The new simple test is just to make sure the too-many-packs code path
is at least executed. The true test is running

    make test GIT_TEST_FULL_IN_PACK_ARRAY=1

to take advantage of other special case tests.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-16 12:38:58 +09:00
Nguyễn Thái Ngọc Duy
4c2db93807 read-cache.c: make $GIT_TEST_SPLIT_INDEX boolean
While at there, document about this special mode when running the test
suite.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-16 12:38:58 +09:00
Junio C Hamano
571e472dc4 Merge branch 'sg/test-x'
Running test scripts under -x option of the shell is often not a
useful way to debug them, because the error messages from the
commands tests try to capture and inspect are contaminated by the
tracing output by the shell.  An earlier work done to make it more
pleasant to run tests under -x with recent versions of bash is
extended to cover posix shells that do not support BASH_XTRACEFD.

* sg/test-x:
  travis-ci: run tests with '-x' tracing
  t/README: add a note about don't saving stderr of compound commands
  t1510-repo-setup: mark as untraceable with '-x'
  t9903-bash-prompt: don't check the stderr of __git_ps1()
  t5570-git-daemon: don't check the stderr of a subshell
  t5526: use $TRASH_DIRECTORY to specify the path of GIT_TRACE log file
  t5500-fetch-pack: don't check the stderr of a subshell
  t3030-merge-recursive: don't check the stderr of a subshell
  t1507-rev-parse-upstream: don't check the stderr of a shell function
  t: add means to disable '-x' tracing for individual test scripts
  t: prevent '-x' tracing from interfering with test helpers' stderr
2018-03-14 12:01:03 -07:00
SZEDER Gábor
94201a2b00 t/README: add a note about don't saving stderr of compound commands
Explain in 't/README' why it is a bad idea to redirect and verify the
stderr of compound commands, in the hope that future contributions
will follow this advice and the test suite will keep working with '-x'
tracing and /bin/sh.

While at it, since we can now run the test suite with '-x' without
needing a Bash version supporting BASH_XTRACEFD, remove the now
outdated caution note about non-Bash shells from the description of
the '-x' option.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-28 12:57:51 -08:00
SZEDER Gábor
5fc98e79fc t: add means to disable '-x' tracing for individual test scripts
The previous patch resolved most of the test failures caused by
running our test suite with '-x' tracing and /bin/sh, and the
following patches in this series will resolve almost all of the
remaining failures.  Unfortunately, not yet all.

Add means to disable '-x' tracing for individual test scripts by
setting the $test_untraceable variable to a non-empty value in the
test script before sourcing 'test-lib.sh'.  However, since '-x'
tracing is not an issue with recent Bash versions supporting
BASH_XTRACEFD, i.e. v4.1 and later, don't disable tracing when the
test script is run with such a Bash version even when
$test_untraceable is set.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-27 12:43:13 -08:00
Junio C Hamano
e3eb405027 Merge branch 'sg/doc-test-must-fail-args'
Devdoc update.

* sg/doc-test-must-fail-args:
  t: document 'test_must_fail ok=<signal-name>'
2018-02-27 10:33:58 -08:00
SZEDER Gábor
12e31a6b12 t: document 'test_must_fail ok=<signal-name>'
Since 'test_might_fail' is implemented as a thin wrapper around
'test_must_fail', it also accepts the same options.  Mention this in
the docs as well.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-12 11:00:38 -08:00
Junio C Hamano
d22512e019 Merge branch 'tg/t-readme-updates'
Developer doc updates.

* tg/t-readme-updates:
  t/README: document test_cmp_rev
  t/README: remove mention of adding copyright notices
2017-12-13 13:28:56 -08:00
Thomas Gummerer
5a0526264b t/README: document test_cmp_rev
test_cmp_rev is a useful function that's used in quite a few test
scripts.  It is however not documented in t/README.  Document it.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-27 10:36:58 +09:00
Thomas Gummerer
51b7a52522 t/README: remove mention of adding copyright notices
We generally no longer include copyright notices in new test scripts.
However t/README still mentions it as something to include at the top of
every new script.

Remove that mention as it's outdated.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-27 10:36:57 +09:00
Ævar Arnfjörð Bjarmason
ce9a257031 test-lib: add LIBPCRE1 & LIBPCRE2 prerequisites
Add LIBPCRE1 and LIBPCRE2 prerequisites which are true when git is
compiled with USE_LIBPCRE1=YesPlease or USE_LIBPCRE2=YesPlease,
respectively.

The syntax of PCRE1 and PCRE2 isn't the same in all cases (see
pcresyntax(3) and pcre2syntax(3)). If test are added that test for
those they'll need to be guarded by these new prerequisites.

The subsequent patch will make use of LIBPCRE2, so LIBPCRE1 isn't
strictly needed for now, but let's add it for consistency and so that
checking for it doesn't have to be done with the less obvious "PCRE,
!LIBPCRE2", which while semantically the same is more confusing, and
would lead to bugs if PCRE v3 is ever released as the tests would mean
v1, not any non-v2 version.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-24 16:12:24 +09:00
Kaartic Sivaraam
01e4be6c3d t/README: fix typo and grammatically improve a sentence
Signed-off-by: Kaartic Sivaraam <kaarticsivaraam91196@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-19 12:02:51 +09:00
Ævar Arnfjörð Bjarmason
68c7d2761d test-lib: add a PTHREADS prerequisite
Add a PTHREADS prerequisite which is false when git is compiled with
NO_PTHREADS=YesPlease.

There's lots of custom code that runs when threading isn't available,
but before this prerequisite there was no way to test it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-26 12:52:37 +09:00
Ævar Arnfjörð Bjarmason
3eb585c112 test-lib: rename the LIBPCRE prerequisite to PCRE
Rename the LIBPCRE prerequisite to PCRE. This is for preparation for
libpcre2 support, where having just "LIBPCRE" would be confusing as it
implies v1 of the library.

None of these tests are incompatible between versions 1 & 2 of
libpcre, it's less confusing to give them a more general name to make
it clear that they work on both library versions.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-21 08:25:37 +09:00
Ævar Arnfjörð Bjarmason
4473060bc2 t/README: clarify the test_have_prereq documentation
Clarify the test_have_prereq documentation so that it's clear in the
reader's mind when the text says "most common use of this directly"
what the answer to "as opposed to what?" is.

Usually this function isn't used in lieu of using the prerequisite
support built into test_expect_*, mention that explicitly.

This changes documentation that I added in commit
9a897893a7 ("t/README: Document the prereq functions, and 3-arg
test_*", 2010-07-02).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-26 15:58:25 -07:00
Ævar Arnfjörð Bjarmason
57f82f4f60 t/README: change "Inside <X> part" to "Inside the <X> part"
Change the mention of "Inside the <script> part, the standard
output..." to use the definite article, which makes more sense in this
context.

This changes documentation I originally added back in commit
20873f45e7 ("t/README: Document the do's and don'ts of tests",
2010-07-02).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-22 15:34:53 -07:00
Ævar Arnfjörð Bjarmason
c1d44cee95 t/README: link to metacpan.org, not search.cpan.org
Change a link to the web version of the TAP::Parser::Grammar
documentation to link to metacpan.org instead of search.cpan.org.

This is something I added back in commit 20873f45e7 ("t/README:
Document the do's and don'ts of tests", 2010-07-02), at the time
search.cpan.org was the more actively maintained CPAN web-interface,
nowadays that's metacpan.org.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-22 15:34:39 -07:00
Junio C Hamano
f4db874d9a Merge branch 'jk/tap-verbose-fix'
The Travis CI configuration we ship ran the tests with --verbose
option but this risks non-TAP output that happens to be "ok" to be
misinterpreted as TAP signalling a test that passed.  This resulted
in unnecessary failure.  This has been corrected by introducing a
new mode to run our tests in the test harness to send the verbose
output separately to the log file.

* jk/tap-verbose-fix:
  test-lib: bail out when "-v" used under "prove"
  travis: use --verbose-log test option
  test-lib: add --verbose-log option
  test-lib: handle TEST_OUTPUT_DIRECTORY with spaces
2016-10-26 13:14:54 -07:00
Jeff King
452320f1f5 test-lib: add --verbose-log option
The "--verbose" option redirects output from arbitrary
test commands to stdout. This is useful for examining the
output manually, like:

  ./t5547-push-quarantine.sh -v | less

But it also means that the output is intermingled with the
TAP directives, which can confuse a TAP parser like "prove".
This has always been a potential problem, but became an
issue recently when one test happened to output the word
"ok" on a line by itself, which prove interprets as a test
success:

  $ prove t5547-push-quarantine.sh :: -v
  t5547-push-quarantine.sh .. 1/? To dest.git
   * [new branch]      HEAD -> master
  To dest.git
   ! [remote rejected] reject -> reject (pre-receive hook declined)
  error: failed to push some refs to 'dest.git'
  fatal: git cat-file d08c8eba97f4e683ece08654c7c8d2ba0c03b129: bad file
  t5547-push-quarantine.sh .. Failed -1/4 subtests

  Test Summary Report
  -------------------
  t5547-push-quarantine.sh (Wstat: 0 Tests: 5 Failed: 0)
    Parse errors: Tests out of sequence.  Found (2) but expected (3)
                  Tests out of sequence.  Found (3) but expected (4)
                  Tests out of sequence.  Found (4) but expected (5)
                  Bad plan.  You planned 4 tests but ran 5.
  Files=1, Tests=5,  0 wallclock secs ( 0.01 usr +  0.01 sys =  0.02 CPU)
  Result: FAIL

One answer is "if it hurts, don't do it", but that's not
quite the whole story. The Travis tests use "--verbose
--tee" so that they can get the benefit of prove's parallel
options, along with a verbose log in case there is a
failure. We just need the verbose output to go to the log,
but keep stdout clean.

Getting this right turns out to be surprisingly difficult.
Here's the progression of alternatives I considered:

 1. Add an option to write verbose output to stderr. This is
    hard to capture, though, because we want each test to
    have its own log (because they're all run in parallel
    and the jumbled output would be useless).

 2. Add an option to write verbose output to a file in
    test-results. This works, but the log is missing all of
    the non-verbose output, which gives context.

 3. Like (2), but teach say_color() to additionally output
    to the log. This mostly works, but misses any output
    that happens outside of the say() functions (which isn't
    a lot, but is a potential maintenance headache).

 4. Like (2), but make the log file the same as the "--tee"
    file. That almost works, but now we have two processes
    opening the same file. That gives us two separate
    descriptors, each with their own idea of the current
    position. They'll each start writing at offset 0, and
    overwrite each other's data.

 5. Like (4), but in each case open the file for appending.
    That atomically positions each write at the end of the
    file.

    It's possible we may still get sheared writes between
    the two processes, but this is already the case when
    writing to stdout. It's not a problem in practice
    because the test harness generally waits for snippets to
    finish before writing the TAP output.

    We can ignore buffering issues with tee, because POSIX
    mandates that it does not buffer. Likewise, POSIX
    specifies "tee -a", so it should be available
    everywhere.

This patch implements option (5), which seems to work well
in practice.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-21 09:54:35 -07:00
Ville Skyttä
2e3a16b279 Spelling fixes
<BAD>                     <CORRECTED>
    accidently                accidentally
    commited                  committed
    dependancy                dependency
    emtpy                     empty
    existance                 existence
    explicitely               explicitly
    git-upload-achive         git-upload-archive
    hierachy                  hierarchy
    indegee                   indegree
    intial                    initial
    mulitple                  multiple
    non-existant              non-existent
    precendence.              precedence.
    priviledged               privileged
    programatically           programmatically
    psuedo-binary             pseudo-binary
    soemwhere                 somewhere
    successfull               successful
    transfering               transferring
    uncommited                uncommitted
    unkown                    unknown
    usefull                   useful
    writting                  writing

Signed-off-by: Ville Skyttä <ville.skytta@iki.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-11 14:35:42 -07:00
Junio C Hamano
68a6e976a8 Merge branch 'jk/test-send-sh-x-trace-elsewhere' into maint
Running tests with '-x' option to trace the individual command
executions is a useful way to debug test scripts, but some tests
that capture the standard error stream and check what the command
said can be broken with the trace output mixed in.  When running
our tests under "bash", however, we can redirect the trace output
to another file descriptor to keep the standard error of programs
being tested intact.

* jk/test-send-sh-x-trace-elsewhere:
  test-lib: set BASH_XTRACEFD automatically
2016-05-31 14:08:27 -07:00
Junio C Hamano
372731810e Merge branch 'jk/test-send-sh-x-trace-elsewhere'
Running tests with '-x' option to trace the individual command
executions is a useful way to debug test scripts, but some tests
that capture the standard error stream and check what the command
said can be broken with the trace output mixed in.  When running
our tests under "bash", however, we can redirect the trace output
to another file descriptor to keep the standard error of programs
being tested intact.

* jk/test-send-sh-x-trace-elsewhere:
  test-lib: set BASH_XTRACEFD automatically
2016-05-17 14:38:36 -07:00
Jeff King
d88785e424 test-lib: set BASH_XTRACEFD automatically
Passing "-x" to a test script enables the shell's "set -x"
tracing, which can help with tracking down the command that
is causing a failure. Unfortunately, it can also _cause_
failures in some tests that redirect the stderr of a shell
function.  Inside the function the shell continues to
respect "set -x", and the trace output is collected along
with whatever stderr is generated normally by the function.

You can see an example of this by running:

  ./t0040-parse-options.sh -x -i

which will fail immediately in the first test, as it
expects:

  test_must_fail some-cmd 2>output.err

to leave output.err empty (but with "-x" it has our trace
output).

Unfortunately there isn't a portable or scalable solution to
this. We could teach test_must_fail to disable "set -x", but
that doesn't help any of the other functions or subshells.

However, we can work around it by pointing the "set -x"
output to our descriptor 4, which always points to the
original stderr of the test script. Unfortunately this only
works for bash, but it's better than nothing (and other
shells will just ignore the BASH_XTRACEFD variable).

The patch itself is a simple one-liner, but note the caveats
in the accompanying comments.

Automatic tests for our "-x" option may be a bit too meta
(and a pain, because they are bash-specific), but I did
confirm that it works correctly both with regular "-x" and
with "--verbose-only=1". This works because the latter flips
"set -x" off and on for particular tests (if it didn't, we
would get tracing for all tests, as going to descriptor 4
effectively circumvents the verbose flag).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-05-11 14:03:14 -07:00
Johannes Schindelin
6a94088cc3 test: facilitate debugging Git executables in tests with gdb
When prefixing a Git call in the test suite with 'debug ', it will
now be run with GDB, allowing the developer to debug test failures
more conveniently.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-30 14:02:38 -07:00
Jeff King
bb79af9d09 t/test-lib: introduce --chain-lint option
It's easy to miss an "&&"-chain in a test script, like:

  test_expect_success 'check something important' '
	cmd1 &&
	cmd2
	cmd3
  '

The test harness will notice if cmd3 fails, but a failure of
cmd1 or cmd2 will go unnoticed, as their exit status is lost
after cmd3 runs.

The toy example above is easy to spot because the "cmds" are
all the same length, but real code is much more complicated.
It's also difficult to detect these situations by statically
analyzing the shell code with regexps (like the
check-non-portable-shell script does); there's too much
context required to know whether a &&-chain is appropriate
on a given line or not.

This patch instead lets the shell check each test by
sticking a command with a specific and unusual return code
at the top of each test, like:

  (exit 117) &&
  cmd1 &&
  cmd2
  cmd3

In a well-formed test, the non-zero exit from the first
command prevents any of the rest from being run, and the
test's exit code is 117. In a bad test (like the one above),
the 117 is lost, and cmd3 is run.

When we encounter a failure of this check, we abort the test
script entirely. For one thing, we have no clue which subset
of the commands in the test snippet were actually run.
Running further tests would be pointless, because we're now
in an unknown state. And two, this is not a "test failure"
in the traditional sense. The test script is buggy, not the
code it is testing. We should be able to fix these problems
in the script once, and not have them come back later as a
regression in git's code.

After checking a test snippet for --chain-lint, we do still
run the test itself.  We could actually have a pure-lint
mode which just checks each test, but there are a few
reasons not to. One, because the tests are executing
arbitrary code, which could impact the later environment
(e.g., that could impact which set of tests we run at all).
And two, because a pure-lint mode would still be expensive
to run, because a significant amount of code runs outside of
the test_expect_* blocks.  Instead, this option is designed
to be used as part of a normal test suite run, where it adds
very little overhead.

Turning on this option detects quite a few problems in
existing tests, which will be fixed in subsequent patches.
However, there are a number of places it cannot reach:

 - it cannot find a failure to break out of loops on error,
   like:

     cmd1 &&
     for i in a b c; do
	     cmd2 $i
     done &&
     cmd3

   which will not notice failures of "cmd2 a" or "cmd b"

 - it cannot find a missing &&-chain inside a block or
   subfunction, like:

     foo () {
	     cmd1
	     cmd2
     }

     foo &&
     bar

   which will not notice a failure of cmd1.

 - it only checks tests that you run; every platform will
   have some tests skipped due to missing prequisites,
   so it's impossible to say from one run that the test
   suite is free of broken &&-chains. However, all tests get
   run by _somebody_, so eventually we will notice problems.

 - it does not operate on test_when_finished or prerequisite
   blocks. It could, but these tends to be much shorter and
   less of a problem, so I punted on them in this patch.

This patch was inspired by an earlier patch by Jonathan
Nieder:

  http://article.gmane.org/gmane.comp.version-control.git/235913

This implementation and all bugs are mine.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-20 10:20:12 -07:00
Junio C Hamano
63296d583c Merge branch 'jc/refer-to-t-readme-from-submitting-patches'
* jc/refer-to-t-readme-from-submitting-patches:
  t/README: justify why "! grep foo" is sufficient
  SubmittingPatches: refer to t/README for tests
2014-12-22 12:26:38 -08:00
Junio C Hamano
53de742470 t/README: justify why "! grep foo" is sufficient
We require use of test_must_fail to check expected non-zero exit by
Git itself, but discourage test_must_fail to be used for checking
exit status of non Git commands that are supplied by the system.
The current text explains the reason for the former but not the
latter.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-11-24 09:47:07 -08:00
Jeff King
a136f6d8ff test-lib.sh: support -x option for shell-tracing
Usually running a test under "-v" makes it clear which
command is failing. However, sometimes it can be useful to
also see a complete trace of the shell commands being run in
the test. You can do so without any support from the test
suite by running "sh -x tXXXX-foo.sh". However, this
produces quite a large bit of output, as we see a trace of
the entire test suite.

This patch instead introduces a "-x" option to the test
scripts (i.e., "./tXXXX-foo.sh -x"). When enabled, this
turns on "set -x" only for the tests themselves. This can
still be a bit verbose, but should keep things to a more
manageable level. You can even use "--verbose-only" to see
the trace only for a specific test.

The implementation is a little invasive. We turn on the "set
-x" inside the "eval" of the test code. This lets the eval
itself avoid being reported in the trace (which would be
long, and redundant with the verbose listing we already
showed). And then after the eval runs, we do some trickery
with stderr to avoid showing the "set +x" to the user.

We also show traces for test_cleanup functions (since they
can impact the test outcome, too). However, we do avoid
running the noop ":" cleanup (the default if the test does
not use test_cleanup at all), as it creates unnecessary
noise in the "set -x" output.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-13 15:39:57 -07:00
Junio C Hamano
7e1a5381b0 Merge branch 'ib/test-selectively-run'
Allow specifying only certain individual test pieces to be run
using a range notation (e.g. "t1234-test.sh --run='1-4 6 8 9-'").

* ib/test-selectively-run:
  t0000-*.sh: fix the GIT_SKIP_TESTS sub-tests
  test-lib: '--run' to run only specific tests
  test-lib: tests skipped by GIT_SKIP_TESTS say so
  test-lib: document short options in t/README
2014-06-16 12:18:56 -07:00
Jonathan Nieder
bb98b01ee8 test doc: test_write_lines does not split its arguments
test_write_lines carefully quotes its arguments as "$@", so

	test_write_lines "a b" c

writes two lines as requested, not three.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 13:09:05 -07:00
Michael S. Tsirkin
ac9afcc31c test: add test_write_lines helper
API and implementation as suggested by Junio.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 13:09:00 -07:00
Ilya Bobyr
0445e6f0a1 test-lib: '--run' to run only specific tests
Allow better control of the set of tests that will be executed for a
single test suite.  Mostly useful while debugging or developing as it
allows to focus on a specific test.

Signed-off-by: Ilya Bobyr <ilya.bobyr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-06 13:48:00 -07:00
Ilya Bobyr
5e3b4fce42 test-lib: document short options in t/README
Most arguments that could be provided to a test have short forms.
Unless documented, the only way to learn them is to read the code.

Signed-off-by: Ilya Bobyr <ilya.bobyr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-06 13:47:54 -07:00
Junio C Hamano
a3a9cff037 Merge branch 'jk/wrap-perl-used-in-tests'
* jk/wrap-perl-used-in-tests:
  t: use perl instead of "$PERL_PATH" where applicable
  t: provide a perl() function which uses $PERL_PATH
2013-11-04 14:58:02 -08:00
Jeff King
a0e0ec9f7d t: provide a perl() function which uses $PERL_PATH
Once upon a time, we assumed that calling a bare "perl" in
the test scripts was OK, because we would find the perl from
the user's PATH, and we were only asking that perl to do
basic operations that work even on old versions of perl.

Later, we found that some systems really prefer to use
$PERL_PATH even for these basic cases, because the system
perl misbehaves in some way (e.g., by handling line endings
differently). We then switched "perl" invocations to
"$PERL_PATH" to respect the user's choice.

Having to use "$PERL_PATH" is ugly and cumbersome, though.
Instead, let's provide a perl() shell function that tests
can use, which will transparently do the right thing.

Unfortunately, test writers still have to use $PERL_PATH in
certain situations, so we still need to keep the advice in
the README.

Note that this may fix test failures in t5004, t5503, t6002,
t6003, t6300, t8001, and t8002, depending on your system's
perl setup. All of these can be detected by running:

  ln -s /bin/false bin-wrappers/perl
  make test

which fails before this patch, and passes after.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-10-29 12:44:39 -07:00
Jonathan Nieder
f8fc0ee314 t/README: tests can use perl even with NO_PERL
The git build system supports a NO_PERL switch to avoid installing
perl bindings or other features (like "git add --patch") that rely on
perl on runtime, but even with NO_PERL it has not been possible for a
long time to run tests without perl.  Helpers such as

	nul_to_q () {
		"$PERL_PATH" -pe 'y/\000/Q/'
	}

use perl as a better tr or sed and are regularly used in tests without
worrying to add a PERL prerequisite.

Perl is portable enough that it seems fine to keep relying on it for
this kind of thing in tests (and more readable than the alternative of
trying to find POSIXy equivalents).  Update the test documentation to
clarify this.

Reported-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-10-28 12:32:18 -07:00
Junio C Hamano
04f2ddda84 Merge branch 'tr/test-v-and-v-subtest-only'
Allows N instances of tests run in parallel, each running 1/N parts
of the test suite under Valgrind, to speed things up.

* tr/test-v-and-v-subtest-only:
  perf-lib: fix start/stop of perf tests
  test-lib: support running tests under valgrind in parallel
  test-lib: allow prefixing a custom string before "ok N" etc.
  test-lib: valgrind for only tests matching a pattern
  test-lib: verbose mode for only tests matching a pattern
  test-lib: self-test that --verbose works
  test-lib: rearrange start/end of test_expect_* and test_skip
  test-lib: refactor $GIT_SKIP_TESTS matching
  test-lib: enable MALLOC_* for the actual tests
2013-07-05 01:15:48 -07:00
Thomas Rast
5dfc368f5e test-lib: valgrind for only tests matching a pattern
With the new --valgrind-only=<pattern> option, one can enable
--valgrind at a per-test granularity, exactly analogous to
--verbose-only from the previous commit.

The options are wired such that --valgrind implies --verbose (as
before), but --valgrind-only=<pattern> implies
--verbose-only=<pattern> unless --verbose is also in effect.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-23 12:24:06 -07:00
Thomas Rast
ff09af3fb8 test-lib: verbose mode for only tests matching a pattern
With the new --verbose-only=<pattern> option, one can enable --verbose
at a per-test granularity.  The pattern is matched against the test
number, e.g.

  ./t0000-basic.sh --verbose-only='2[0-2]'

to see only the full output of test 20-22, while showing the rest in the
one-liner format.

As suggested by Jeff King, this takes care to wrap the entire
test_expect_* block, but nothing else, in the verbose toggling.  We
can use the test_start/end functions from the previous commit for the
purpose.

This is arguably not *too* useful on its own, but makes the next patch
easier to follow.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-23 12:24:06 -07:00
Junio C Hamano
c0266ed275 Merge branch 'js/test-ln-s-add'
Many tests that check the behaviour of symbolic links stored in the
index or the tree objects do not have to be skipped on a filesystem
that lack symbolic link support.

* js/test-ln-s-add:
  t4011: remove SYMLINKS prerequisite
  t6035: use test_ln_s_add to remove SYMLINKS prerequisite
  t3509, t4023, t4114: use test_ln_s_add to remove SYMLINKS prerequisite
  t3100: use test_ln_s_add to remove SYMLINKS prerequisite
  t3030: use test_ln_s_add to remove SYMLINKS prerequisite
  t0000: use test_ln_s_add to remove SYMLINKS prerequisite
  tests: use test_ln_s_add to remove SYMLINKS prerequisite (trivial cases)
  tests: introduce test_ln_s_add
  t3010: modernize style
  test-chmtime: Fix exit code on Windows
2013-06-20 16:02:18 -07:00
Johannes Sixt
9ce415d972 tests: introduce test_ln_s_add
Add a new function that creates a symbolic link and adds it to the index
to be used in cases where a symbolic link is not required on the file
system. We will use it to remove many SYMLINKS prerequisites from test
cases.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-07 15:01:16 -07:00
Junio C Hamano
f445500e4d t/README: test_must_fail is for testing Git
When a test wants to make sure there is no <string> in an output
file, we should just say "! grep string output".

"test_must_fail" is there only to test Git command and catch unusual
deaths we know about (e.g. segv) as an error, not as an expected
failure.  "test_must_fail grep string output" is unnecessary, as
we are not making sure the system binaries do not dump core or
anything like that.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-04 13:36:54 -07:00
Junio C Hamano
e2af9e361b Merge branch 'maint'
* maint:
  Typo fix: replacing it's -> its
  t: make PIPE a standard test prerequisite
  archive: clarify explanation of --worktree-attributes
  t/README: --immediate skips cleanup commands for failed tests
2013-04-11 17:41:48 -07:00
Adam Spiers
200732744a t: make PIPE a standard test prerequisite
The 'PIPE' test prerequisite was already defined identically by t9010
and t9300, therefore it makes sense to make it a predefined
prerequisite.

Signed-off-by: Adam Spiers <git@adamspiers.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-11 17:39:05 -07:00
Simon Ruderich
13cb3bb7e6 t/README: --immediate skips cleanup commands for failed tests
Signed-off-by: Simon Ruderich <simon@ruderich.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-09 15:12:28 -07:00
Thomas Rast
95d9d5ec75 tests --valgrind: provide a mode without --track-origins
With --valgrind=memcheck-fast, the tests run under memcheck but
without the autodetected --track-origins.  If you just run valgrind to
see *if* there is any memory issue with your program, the extra
information is not needed, and it comes at a roughly 30% hit in
runtime.

While it is possible to achieve the same through GIT_VALGRIND_OPTIONS,
this should be more discoverable and hopefully encourage more users to
run their tests with valgrind.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-01 07:45:41 -07:00
Thomas Rast
952af3511c tests: parameterize --valgrind option
Running tests under helgrind and DRD recently proved useful in
tracking down thread interaction issues.  This can unfortunately not
be done through GIT_VALGRIND_OPTIONS because any tool other than
memcheck would complain about unknown options.

Let --valgrind take an optional parameter that describes the valgrind
tool to invoke.  The default mode is to run memcheck as before.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-01 07:45:37 -07:00
Thomas Rast
fd4fab894f t/README: --valgrind already implies -v
This was missed in 3da9365 (Tests: let --valgrind imply --verbose and
--tee, 2009-02-04).

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-01 07:45:30 -07:00