Commit graph

29 commits

Author SHA1 Message Date
Taylor Blau
826f0e33ab t/helper/test-hashmap.c: avoid using strtok()
Avoid using the non-reentrant `strtok()` to separate the parts of each
incoming command. Instead of replacing it with `strtok_r()`, let's
instead use the more friendly pair of `string_list_split_in_place()` and
`string_list_remove_empty_items()`.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-24 16:01:28 -07:00
Elijah Newren
b19315d8ab Use new HASHMAP_INIT macro to simplify hashmap initialization
Now that hashamp has lazy initialization and a HASHMAP_INIT macro,
hashmaps allocated on the stack can be initialized without a call to
hashmap_init() and in some cases makes the code a bit shorter.  Convert
some callsites over to take advantage of this.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 12:55:27 -08:00
Elijah Newren
6da1a25814 hashmap: provide deallocation function names
hashmap_free(), hashmap_free_entries(), and hashmap_free_() have existed
for a while, but aren't necessarily the clearest names, especially with
hashmap_partial_clear() being added to the mix and lazy-initialization
now being supported.  Peff suggested we adopt the following names[1]:

  - hashmap_clear() - remove all entries and de-allocate any
    hashmap-specific data, but be ready for reuse

  - hashmap_clear_and_free() - ditto, but free the entries themselves

  - hashmap_partial_clear() - remove all entries but don't deallocate
    table

  - hashmap_partial_clear_and_free() - ditto, but free the entries

This patch provides the new names and converts all existing callers over
to the new naming scheme.

[1] https://lore.kernel.org/git/20201030125059.GA3277724@coredump.intra.peff.net/

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-02 12:15:50 -08:00
Eric Wong
e2b5038d87 hashmap_entry: remove first member requirement from docs
Comments stating that "struct hashmap_entry" must be the first
member in a struct are no longer valid.

Suggested-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:12 +09:00
Eric Wong
404ab78e39 hashmap: remove type arg from hashmap_{get,put,remove}_entry
Since these macros already take a `keyvar' pointer of a known type,
we can rely on OFFSETOF_VAR to get the correct offset without
relying on non-portable `__typeof__' and `offsetof'.

Argument order is also rearranged, so `keyvar' and `member' are
sequential as they are used as: `keyvar->member'

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:12 +09:00
Eric Wong
23dee69f53 OFFSETOF_VAR macro to simplify hashmap iterators
While we cannot rely on a `__typeof__' operator being portable
to use with `offsetof'; we can calculate the pointer offset
using an existing pointer and the address of a member using
pointer arithmetic for compilers without `__typeof__'.

This allows us to simplify usage of hashmap iterator macros
by not having to specify a type when a pointer of that type
is already given.

In the future, list iterator macros (e.g. list_for_each_entry)
may also be implemented using OFFSETOF_VAR to save hackers the
trouble of using container_of/list_entry macros and without
relying on non-portable `__typeof__'.

v3: use `__typeof__' to avoid clang warnings

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
c8e424c9c9 hashmap: introduce hashmap_free_entries
`hashmap_free_entries' behaves like `container_of' and passes
the offset of the hashmap_entry struct to the internal
`hashmap_free_' function, allowing the function to free any
struct pointer regardless of where the hashmap_entry field
is located.

`hashmap_free' no longer takes any arguments aside from
the hashmap itself.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
8a973d0bb3 hashmap: hashmap_{put,remove} return hashmap_entry *
And add *_entry variants to perform container_of as necessary
to simplify most callers.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
87571c3f71 hashmap: use *_entry APIs for iteration
Inspired by list_for_each_entry in the Linux kernel.
Once again, these are somewhat compromised usability-wise
by compilers lacking __typeof__ support.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
939af16eac hashmap_cmp_fn takes hashmap_entry params
Another step in eliminating the requirement of hashmap_entry
being the first member of a struct.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
f0e63c4113 hashmap: use *_entry APIs to wrap container_of
Using `container_of' can be verbose and choosing names for
intermediate "struct hashmap_entry" pointers is a hard problem.
So introduce "*_entry" APIs inspired by similar linked-list
APIs in the Linux kernel.

Unfortunately, `__typeof__' is not portable C, so we need an
extra parameter to specify the type.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +09:00
Eric Wong
6bcbdfb277 hashmap_get_next returns "struct hashmap_entry *"
This is a step towards removing the requirement for
hashmap_entry being the first field of a struct.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +09:00
Eric Wong
26b455f21e hashmap_put takes "struct hashmap_entry *"
This is less error-prone than "void *" as the compiler now
detects invalid types being passed.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +09:00
Eric Wong
b94e5c1df6 hashmap_add takes "struct hashmap_entry *"
This is less error-prone than "void *" as the compiler now
detects invalid types being passed.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +09:00
Eric Wong
f6eb6bdcf2 hashmap_get_next takes "const struct hashmap_entry *"
This is less error-prone than "const void *" as the compiler
now detects invalid types being passed.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +09:00
Eric Wong
d22245a2e3 hashmap_entry_init takes "struct hashmap_entry *"
C compilers do type checking to make life easier for us.  So
rely on that and update all hashmap_entry_init callers to take
"struct hashmap_entry *" to avoid future bugs while improving
safety and readability.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:09 +09:00
Christian Couder
a1100d2cee test-hashmap: remove 'hash' command
If hashes like strhash() are updated, for example to use a different
hash algorithm, we should not have to be updating t0011 to change out
the hashes.

As long as hashmap can store and retrieve values, and that it performs
well, we should not care what are the values of the hashes. Let's just
focus on the externally visible behavior instead.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-17 18:11:42 -07:00
Nguyễn Thái Ngọc Duy
7c18cbd562 t/helper: merge test-hashmap into test-tool
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-27 08:45:47 -07:00
Jeff King
a6119f82b1 test-hashmap: use "unsigned int" for hash storage
The hashmap API always use an unsigned value for storing
and comparing hashes. Whereas this test code uses "int".
This works out in practice since one can typically
round-trip between "int" and "unsigned int". But since this
is essentially reference code for the hashmap API, we should
model using the correct types.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-14 10:31:10 -08:00
Jeff King
7daa825d67 test-hashmap: simplify alloc_test_entry
This function takes two ptr/len pairs, which implies that
they can be arbitrary buffers. But internally, it assumes
that each "ptr" is NUL-terminated at "len" (because we
memcpy an extra byte to pick up the NUL terminator).

In practice this works because each caller only ever passes
strlen(ptr) as the length. But let's drop the "len"
parameters to make our expectations clear.

Note that we can get rid of the "l1" and "l2" variables from
cmd_main() as a further cleanup, since they are now mostly
used to check whether the p1 and p2 arguments are present
(technically the length parameters conflated NULL with the
empty string, which we no longer do, but I think that is
actually an improvement).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-14 10:31:10 -08:00
Jeff King
7e8089c986 test-hashmap: use strbuf_getline rather than fgets
Using fgets() with a fixed-size buffer can lead to lines
being accidentally split across two calls if they are larger
than the buffer size.

As this is just a test helper, this is unlikely to be a
problem in practice. But since people may look at test
helpers as reference code, it's a good idea for them to
model the preferred behavior.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-14 10:31:10 -08:00
Jeff King
cbadf0ee37 test-hashmap: use xsnprintf rather than snprintf
In general, using a bare snprintf can truncate the resulting
buffer, leading to confusing results. In this case we know
that our buffer is sized large enough to accommodate our
loop, so there's no bug. However, we should use xsnprintf()
to document (and check) that assumption, and to model good
practice to people reading the code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-14 10:31:09 -08:00
Jeff King
b6c4380d6e test-hashmap: check allocation computation for overflow
When we allocate the test_entry flex-struct, we have to add
up all of the elements that go into the flex array. If these
were to overflow a size_t, this would allocate a too-small
buffer, which we would then overflow in our memcpy steps.

Since this is just a test-helper, it probably doesn't matter
in practice, but we should model the correct technique by
using the st_add() macros.

Unfortunately, we cannot use the FLEX_ALLOC() macros here,
because we are stuffing two different buffers into a single
flex array.

While we're here, let's also swap out "malloc" for our
error-checking "xmalloc", and use the preferred
"sizeof(*var)" instead of "sizeof(type)".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-14 10:31:09 -08:00
Jeff King
aef6cf1e50 test-hashmap: use ALLOC_ARRAY rather than bare malloc
These two array allocations have several minor flaws:

  - they use bare malloc, rather than our error-checking
    xmalloc

  - they do a bare multiplication to determine the total
    size (which in theory can overflow, though in this case
    the sizes are all constants)

  - they use sizeof(type), but the type in the second one
    doesn't match the actual array (though it's "int" versus
    "unsigned int", which are guaranteed by C99 to have the
    same size)

None of these are likely to be problems in practice, and
this is just a test helper. But since people often look at
test helpers as reference code, we should do our best to
model the recommended techniques.

Switching to ALLOC_ARRAY fixes all three.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-14 10:31:09 -08:00
Jeff Hostetler
8b604d1951 hashmap: add API to disable item counting when threaded
This is to address concerns raised by ThreadSanitizer on the mailing list
about threaded unprotected R/W access to map.size with my previous "disallow
rehash" change (0607e10009).

See:
https://public-inbox.org/git/adb37b70139fd1e2bac18bfd22c8b96683ae18eb.1502780344.git.martin.agren@gmail.com/

Add API to hashmap to disable item counting and thus automatic rehashing.
Also include API to later re-enable them.

When item counting is disabled, the map.size field is invalid.  So to
prevent accidents, the field has been renamed and an accessor function
hashmap_get_size() has been added.  All direct references to this
field have been been updated.  And the name of the field changed
to map.private_size to communicate this.

Here is the relevant output from ThreadSanitizer showing the problem:

WARNING: ThreadSanitizer: data race (pid=10554)
  Read of size 4 at 0x00000082d488 by thread T2 (mutexes: write M16):
    #0 hashmap_add hashmap.c:209
    #1 hash_dir_entry_with_parent_and_prefix name-hash.c:302
    #2 handle_range_dir name-hash.c:347
    #3 handle_range_1 name-hash.c:415
    #4 lazy_dir_thread_proc name-hash.c:471
    #5 <null> <null>

  Previous write of size 4 at 0x00000082d488 by thread T1 (mutexes: write M31):
    #0 hashmap_add hashmap.c:209
    #1 hash_dir_entry_with_parent_and_prefix name-hash.c:302
    #2 handle_range_dir name-hash.c:347
    #3 handle_range_1 name-hash.c:415
    #4 handle_range_dir name-hash.c:380
    #5 handle_range_1 name-hash.c:415
    #6 lazy_dir_thread_proc name-hash.c:471
    #7 <null> <null>

Martin gives instructions for running TSan on test t3008 in this post:
https://public-inbox.org/git/CAN0heSoJDL9pWELD6ciLTmWf-a=oyxe4EXXOmCKvsG5MSuzxsA@mail.gmail.com/

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-07 09:42:02 +09:00
Stefan Beller
6815d11431 t/helper/test-hashmap: use custom data instead of duplicate cmp functions
With the new field that is passed to the compare function, we can pass
through flags there instead of having multiple compare functions.
Also drop the cast to hashmap_cmp_fn.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-07-05 13:53:12 -07:00
Stefan Beller
7663cdc86c hashmap.h: compare function has access to a data field
When using the hashmap a common need is to have access to caller provided
data in the compare function. A couple of times we abuse the keydata field
to pass in the data needed. This happens for example in patch-ids.c.

This patch changes the function signature of the compare function
to have one more void pointer available. The pointer given for each
invocation of the compare function must be defined in the init function
of the hashmap and is just passed through.

Documentation of this new feature is deferred to a later patch.
This is a rather mechanical conversion, just adding the new pass-through
parameter.  However while at it improve the naming of the fields of all
compare functions used by hashmaps by ensuring unused parameters are
prefixed with 'unused_' and naming the parameters what they are (instead
of 'unused' make it 'unused_keydata').

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 12:49:28 -07:00
Junio C Hamano
de61cebde7 Merge branch 'jk/common-main-2.8' into jk/common-main
* jk/common-main-2.8:
  mingw: declare main()'s argv as const
  common-main: call git_setup_gettext()
  common-main: call restore_sigpipe_to_default()
  common-main: call sanitize_stdfds()
  common-main: call git_extract_argv0_path()
  add an extra level of indirection to main()
2016-07-06 10:02:57 -07:00
Nguyễn Thái Ngọc Duy
e6e7530d10 test helpers: move test-* to t/helper/ subdirectory
This keeps top dir a bit less crowded. And because these programs are
for testing purposes, it makes sense that they stay somewhere in t/

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-04-15 10:12:19 -07:00
Renamed from test-hashmap.c (Browse further)