kernel/git - git - PowerEL Git System

Commit Graph

Author	SHA1	Message	Date
René Scharfe	ca56dadb4b	use CALLOC_ARRAY Add and apply a semantic patch for converting code that open-codes CALLOC_ARRAY to use it instead. It shortens the code and infers the element size automatically. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
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>	4 years ago
Elijah Newren	33f20d8217	hashmap: introduce a new hashmap_partial_clear() merge-ort is a heavy user of strmaps, which are built on hashmap.[ch]. clear_or_reinit_internal_opts() in merge-ort was taking about 12% of overall runtime in my testcase involving rebasing 35 patches of linux.git across a big rename. clear_or_reinit_internal_opts() was calling hashmap_free() followed by hashmap_init(), meaning that not only was it freeing all the memory associated with each of the strmaps just to immediately allocate a new array again, it was allocating a new array that was likely smaller than needed (thus resulting in later need to rehash things). The ending size of the map table on the previous commit was likely almost perfectly sized for the next commit we wanted to pick, and not dropping and reallocating the table immediately is a win. Add some new API to hashmap to clear a hashmap of entries without freeing map->table (and instead only zeroing it out like alloc_table() would do, along with zeroing the count of items in the table and the shrink_at field). Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Elijah Newren	b7879b0ba6	hashmap: allow re-use after hashmap_free() Previously, once map->table had been freed, any calls to hashmap_put(), hashmap_get(), or hashmap_remove() would cause a NULL pointer dereference (since hashmap_free_() also zeros the memory; without that zeroing, calling these functions would cause a use-after-free problem). Modify these functions to check for a NULL table and automatically allocate as needed. Also add a HASHMAP_INIT(fn, data) macro for initializing hashmaps on the stack without calling hashmap_init(). Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Elijah Newren	97a39a4a93	hashmap: adjust spacing to fix argument alignment No actual code changes; just whitespace adjustments. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	4 years ago
Elijah Newren	15beaaa3d1	Fix spelling errors in code comments Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
Eric Wong	f23a465132	hashmap_get{,_from_hash} return "struct hashmap_entry *" Update callers to use hashmap_get_entry, hashmap_get_entry_from_hash or container_of as appropriate. This is another step towards eliminating the requirement of hashmap_entry being the first field in 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>	5 years ago
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>	5 years ago
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>	5 years ago
Eric Wong	28ee794128	hashmap_remove 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>	5 years ago
Eric Wong	b6c5241606	hashmap_get 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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	5 years ago
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>	8 years ago
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>	8 years ago
Jeff Hostetler	0607e10009	hashmap: add disallow_rehash setting Teach hashmap to allow rehashes to be suppressed. This is useful when hashmaps are accessed by multiple threads. It still requires the caller to properly manage their locking. This just prevents unexpected rehashing during inserts and deletes. Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	8 years ago
Jeff Hostetler	f75619bd6d	hashmap: allow memihash computation to be continued Add variant of memihash() to allow the hash computation to be continued. There are times when we compute the hash on a full path and then the hash on just the path to the parent directory. This can be expensive on large repositories. With this, we can hash the parent directory first. And then continue the computation to include the "/filename". Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	8 years ago
Jeff King	96ffc06f72	convert trivial cases to FLEX_ARRAY macros Using FLEX_ARRAY macros reduces the amount of manual computation size we have to do. It also ensures we don't overflow size_t, and it makes sure we write the same number of bytes that we allocated. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	9 years ago
Karsten Blees	7b64d42d22	hashmap: add string interning API Interning short strings with high probability of duplicates can reduce the memory footprint and speed up comparisons. Add strintern() and memintern() APIs that use a hashmap to manage the pool of unique, interned strings. Note: strintern(getenv()) could be used to sanitize git's use of getenv(), in case we ever encounter a platform where a call to getenv() invalidates previous getenv() results (which is allowed by POSIX). Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	11 years ago
Karsten Blees	6a364ced49	add a hashtable implementation that supports O(1) removal The existing hashtable implementation (in hash.[ch]) uses open addressing (i.e. resolve hash collisions by distributing entries across the table). Thus, removal is difficult to implement with less than O(n) complexity. Resolving collisions of entries with identical hashes (e.g. via chaining) is left to the client code. Add a hashtable implementation that supports O(1) removal and is slightly easier to use due to builtin entry chaining. Supports all basic operations init, free, get, add, remove and iteration. Also includes ready-to-use hash functions based on the public domain FNV-1 algorithm (http://www.isthe.com/chongo/tech/comp/fnv). The per-entry data structure (hashmap_entry) is piggybacked in front of the client's data structure to save memory. See test-hashmap.c for usage examples. The hashtable is resized by a factor of four when 80% full. With these settings, average memory consumption is about 2/3 of hash.[ch], and insertion is about twice as fast due to less frequent resizing. Lookups are also slightly faster, because entries are strictly confined to their bucket (i.e. no data of other buckets needs to be traversed). Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	11 years ago

26 Commits (e54b2715295df8d7174fe5be67b4459fd5b438f8)