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3b13eaf0ba
To pick the changes in:
7a078d2d18
("libbpf, hashmap: Fix undefined behavior in hash_bits")
That don't entail any changes in tools/perf.
This addresses this perf build warning:
Warning: Kernel ABI header at 'tools/perf/util/hashmap.h' differs from latest version at 'tools/lib/bpf/hashmap.h'
diff -u tools/perf/util/hashmap.h tools/lib/bpf/hashmap.h
Not a kernel ABI, its just that this uses the mechanism in place for
checking kernel ABI files drift.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
196 lines
5.8 KiB
C
196 lines
5.8 KiB
C
/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
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/*
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* Generic non-thread safe hash map implementation.
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*
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* Copyright (c) 2019 Facebook
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*/
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#ifndef __LIBBPF_HASHMAP_H
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#define __LIBBPF_HASHMAP_H
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#include <stdbool.h>
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#include <stddef.h>
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#include <limits.h>
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static inline size_t hash_bits(size_t h, int bits)
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{
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/* shuffle bits and return requested number of upper bits */
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if (bits == 0)
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return 0;
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#if (__SIZEOF_SIZE_T__ == __SIZEOF_LONG_LONG__)
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/* LP64 case */
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return (h * 11400714819323198485llu) >> (__SIZEOF_LONG_LONG__ * 8 - bits);
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#elif (__SIZEOF_SIZE_T__ <= __SIZEOF_LONG__)
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return (h * 2654435769lu) >> (__SIZEOF_LONG__ * 8 - bits);
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#else
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# error "Unsupported size_t size"
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#endif
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}
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/* generic C-string hashing function */
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static inline size_t str_hash(const char *s)
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{
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size_t h = 0;
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while (*s) {
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h = h * 31 + *s;
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s++;
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}
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return h;
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}
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typedef size_t (*hashmap_hash_fn)(const void *key, void *ctx);
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typedef bool (*hashmap_equal_fn)(const void *key1, const void *key2, void *ctx);
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struct hashmap_entry {
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const void *key;
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void *value;
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struct hashmap_entry *next;
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};
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struct hashmap {
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hashmap_hash_fn hash_fn;
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hashmap_equal_fn equal_fn;
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void *ctx;
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struct hashmap_entry **buckets;
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size_t cap;
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size_t cap_bits;
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size_t sz;
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};
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#define HASHMAP_INIT(hash_fn, equal_fn, ctx) { \
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.hash_fn = (hash_fn), \
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.equal_fn = (equal_fn), \
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.ctx = (ctx), \
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.buckets = NULL, \
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.cap = 0, \
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.cap_bits = 0, \
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.sz = 0, \
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}
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void hashmap__init(struct hashmap *map, hashmap_hash_fn hash_fn,
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hashmap_equal_fn equal_fn, void *ctx);
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struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
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hashmap_equal_fn equal_fn,
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void *ctx);
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void hashmap__clear(struct hashmap *map);
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void hashmap__free(struct hashmap *map);
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size_t hashmap__size(const struct hashmap *map);
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size_t hashmap__capacity(const struct hashmap *map);
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/*
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* Hashmap insertion strategy:
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* - HASHMAP_ADD - only add key/value if key doesn't exist yet;
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* - HASHMAP_SET - add key/value pair if key doesn't exist yet; otherwise,
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* update value;
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* - HASHMAP_UPDATE - update value, if key already exists; otherwise, do
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* nothing and return -ENOENT;
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* - HASHMAP_APPEND - always add key/value pair, even if key already exists.
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* This turns hashmap into a multimap by allowing multiple values to be
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* associated with the same key. Most useful read API for such hashmap is
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* hashmap__for_each_key_entry() iteration. If hashmap__find() is still
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* used, it will return last inserted key/value entry (first in a bucket
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* chain).
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*/
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enum hashmap_insert_strategy {
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HASHMAP_ADD,
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HASHMAP_SET,
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HASHMAP_UPDATE,
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HASHMAP_APPEND,
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};
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/*
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* hashmap__insert() adds key/value entry w/ various semantics, depending on
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* provided strategy value. If a given key/value pair replaced already
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* existing key/value pair, both old key and old value will be returned
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* through old_key and old_value to allow calling code do proper memory
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* management.
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*/
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int hashmap__insert(struct hashmap *map, const void *key, void *value,
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enum hashmap_insert_strategy strategy,
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const void **old_key, void **old_value);
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static inline int hashmap__add(struct hashmap *map,
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const void *key, void *value)
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{
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return hashmap__insert(map, key, value, HASHMAP_ADD, NULL, NULL);
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}
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static inline int hashmap__set(struct hashmap *map,
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const void *key, void *value,
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const void **old_key, void **old_value)
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{
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return hashmap__insert(map, key, value, HASHMAP_SET,
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old_key, old_value);
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}
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static inline int hashmap__update(struct hashmap *map,
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const void *key, void *value,
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const void **old_key, void **old_value)
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{
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return hashmap__insert(map, key, value, HASHMAP_UPDATE,
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old_key, old_value);
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}
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static inline int hashmap__append(struct hashmap *map,
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const void *key, void *value)
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{
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return hashmap__insert(map, key, value, HASHMAP_APPEND, NULL, NULL);
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}
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bool hashmap__delete(struct hashmap *map, const void *key,
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const void **old_key, void **old_value);
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bool hashmap__find(const struct hashmap *map, const void *key, void **value);
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/*
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* hashmap__for_each_entry - iterate over all entries in hashmap
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* @map: hashmap to iterate
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* @cur: struct hashmap_entry * used as a loop cursor
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* @bkt: integer used as a bucket loop cursor
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*/
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#define hashmap__for_each_entry(map, cur, bkt) \
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for (bkt = 0; bkt < map->cap; bkt++) \
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for (cur = map->buckets[bkt]; cur; cur = cur->next)
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/*
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* hashmap__for_each_entry_safe - iterate over all entries in hashmap, safe
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* against removals
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* @map: hashmap to iterate
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* @cur: struct hashmap_entry * used as a loop cursor
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* @tmp: struct hashmap_entry * used as a temporary next cursor storage
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* @bkt: integer used as a bucket loop cursor
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*/
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#define hashmap__for_each_entry_safe(map, cur, tmp, bkt) \
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for (bkt = 0; bkt < map->cap; bkt++) \
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for (cur = map->buckets[bkt]; \
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cur && ({tmp = cur->next; true; }); \
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cur = tmp)
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/*
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* hashmap__for_each_key_entry - iterate over entries associated with given key
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* @map: hashmap to iterate
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* @cur: struct hashmap_entry * used as a loop cursor
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* @key: key to iterate entries for
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*/
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#define hashmap__for_each_key_entry(map, cur, _key) \
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for (cur = map->buckets \
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? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \
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: NULL; \
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cur; \
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cur = cur->next) \
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if (map->equal_fn(cur->key, (_key), map->ctx))
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#define hashmap__for_each_key_entry_safe(map, cur, tmp, _key) \
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for (cur = map->buckets \
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? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \
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: NULL; \
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cur && ({ tmp = cur->next; true; }); \
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cur = tmp) \
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if (map->equal_fn(cur->key, (_key), map->ctx))
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#endif /* __LIBBPF_HASHMAP_H */
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