1
0
mirror of https://github.com/systemd/systemd.git synced 2024-11-08 11:27:32 +03:00
systemd/src/shared/hashmap.c
Lennart Poettering fabe5c0e5f binfmt,tmpfiles,modules-load,sysctl: rework the various early-boot services that work on .d/ directories
This unifies much of the logic behind them:

- All four will now ofllow the rule that the earlier file and earlier
  assignment in the .d/ directories wins. Before, sysctl was the only
  outlier, where the later setting always won.

- All four now support getopt() and --help on the command line.

- All four can now handle specification of configuration file names on
  the command line to apply. The tools will automatically find them, and
  apply them. Previously only tmpfiles could do that. This is useful for
  %post scripts in RPMs and suchlike.

- This fixes various error path issues in conf_files_list()
2013-02-11 23:54:30 +01:00

863 lines
19 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "util.h"
#include "hashmap.h"
#include "macro.h"
#define NBUCKETS 127
struct hashmap_entry {
const void *key;
void *value;
struct hashmap_entry *bucket_next, *bucket_previous;
struct hashmap_entry *iterate_next, *iterate_previous;
};
struct Hashmap {
hash_func_t hash_func;
compare_func_t compare_func;
struct hashmap_entry *iterate_list_head, *iterate_list_tail;
unsigned n_entries;
bool from_pool;
};
#define BY_HASH(h) ((struct hashmap_entry**) ((uint8_t*) (h) + ALIGN(sizeof(Hashmap))))
struct pool {
struct pool *next;
unsigned n_tiles;
unsigned n_used;
};
static struct pool *first_hashmap_pool = NULL;
static void *first_hashmap_tile = NULL;
static struct pool *first_entry_pool = NULL;
static void *first_entry_tile = NULL;
static void* allocate_tile(struct pool **first_pool, void **first_tile, size_t tile_size) {
unsigned i;
if (*first_tile) {
void *r;
r = *first_tile;
*first_tile = * (void**) (*first_tile);
return r;
}
if (_unlikely_(!*first_pool) || _unlikely_((*first_pool)->n_used >= (*first_pool)->n_tiles)) {
unsigned n;
size_t size;
struct pool *p;
n = *first_pool ? (*first_pool)->n_tiles : 0;
n = MAX(512U, n * 2);
size = PAGE_ALIGN(ALIGN(sizeof(struct pool)) + n*tile_size);
n = (size - ALIGN(sizeof(struct pool))) / tile_size;
p = malloc(size);
if (!p)
return NULL;
p->next = *first_pool;
p->n_tiles = n;
p->n_used = 0;
*first_pool = p;
}
i = (*first_pool)->n_used++;
return ((uint8_t*) (*first_pool)) + ALIGN(sizeof(struct pool)) + i*tile_size;
}
static void deallocate_tile(void **first_tile, void *p) {
* (void**) p = *first_tile;
*first_tile = p;
}
#ifdef VALGRIND
static void drop_pool(struct pool *p) {
while (p) {
struct pool *n;
n = p->next;
free(p);
p = n;
}
}
__attribute__((destructor)) static void cleanup_pool(void) {
/* Be nice to valgrind */
drop_pool(first_hashmap_pool);
drop_pool(first_entry_pool);
}
#endif
unsigned string_hash_func(const void *p) {
unsigned hash = 5381;
const signed char *c;
/* DJB's hash function */
for (c = p; *c; c++)
hash = (hash << 5) + hash + (unsigned) *c;
return hash;
}
int string_compare_func(const void *a, const void *b) {
return strcmp(a, b);
}
unsigned trivial_hash_func(const void *p) {
return PTR_TO_UINT(p);
}
int trivial_compare_func(const void *a, const void *b) {
return a < b ? -1 : (a > b ? 1 : 0);
}
unsigned uint64_hash_func(const void *p) {
uint64_t u;
assert_cc(sizeof(uint64_t) == 2*sizeof(unsigned));
u = *(const uint64_t*) p;
return (unsigned) ((u >> 32) ^ u);
}
int uint64_compare_func(const void *_a, const void *_b) {
uint64_t a, b;
a = *(const uint64_t*) _a;
b = *(const uint64_t*) _b;
return a < b ? -1 : (a > b ? 1 : 0);
}
Hashmap *hashmap_new(hash_func_t hash_func, compare_func_t compare_func) {
bool b;
Hashmap *h;
size_t size;
b = is_main_thread();
size = ALIGN(sizeof(Hashmap)) + NBUCKETS * sizeof(struct hashmap_entry*);
if (b) {
h = allocate_tile(&first_hashmap_pool, &first_hashmap_tile, size);
if (!h)
return NULL;
memset(h, 0, size);
} else {
h = malloc0(size);
if (!h)
return NULL;
}
h->hash_func = hash_func ? hash_func : trivial_hash_func;
h->compare_func = compare_func ? compare_func : trivial_compare_func;
h->n_entries = 0;
h->iterate_list_head = h->iterate_list_tail = NULL;
h->from_pool = b;
return h;
}
int hashmap_ensure_allocated(Hashmap **h, hash_func_t hash_func, compare_func_t compare_func) {
assert(h);
if (*h)
return 0;
if (!(*h = hashmap_new(hash_func, compare_func)))
return -ENOMEM;
return 0;
}
static void link_entry(Hashmap *h, struct hashmap_entry *e, unsigned hash) {
assert(h);
assert(e);
/* Insert into hash table */
e->bucket_next = BY_HASH(h)[hash];
e->bucket_previous = NULL;
if (BY_HASH(h)[hash])
BY_HASH(h)[hash]->bucket_previous = e;
BY_HASH(h)[hash] = e;
/* Insert into iteration list */
e->iterate_previous = h->iterate_list_tail;
e->iterate_next = NULL;
if (h->iterate_list_tail) {
assert(h->iterate_list_head);
h->iterate_list_tail->iterate_next = e;
} else {
assert(!h->iterate_list_head);
h->iterate_list_head = e;
}
h->iterate_list_tail = e;
h->n_entries++;
assert(h->n_entries >= 1);
}
static void unlink_entry(Hashmap *h, struct hashmap_entry *e, unsigned hash) {
assert(h);
assert(e);
/* Remove from iteration list */
if (e->iterate_next)
e->iterate_next->iterate_previous = e->iterate_previous;
else
h->iterate_list_tail = e->iterate_previous;
if (e->iterate_previous)
e->iterate_previous->iterate_next = e->iterate_next;
else
h->iterate_list_head = e->iterate_next;
/* Remove from hash table bucket list */
if (e->bucket_next)
e->bucket_next->bucket_previous = e->bucket_previous;
if (e->bucket_previous)
e->bucket_previous->bucket_next = e->bucket_next;
else
BY_HASH(h)[hash] = e->bucket_next;
assert(h->n_entries >= 1);
h->n_entries--;
}
static void remove_entry(Hashmap *h, struct hashmap_entry *e) {
unsigned hash;
assert(h);
assert(e);
hash = h->hash_func(e->key) % NBUCKETS;
unlink_entry(h, e, hash);
if (h->from_pool)
deallocate_tile(&first_entry_tile, e);
else
free(e);
}
void hashmap_free(Hashmap*h) {
/* Free the hashmap, but nothing in it */
if (!h)
return;
hashmap_clear(h);
if (h->from_pool)
deallocate_tile(&first_hashmap_tile, h);
else
free(h);
}
void hashmap_free_free(Hashmap *h) {
/* Free the hashmap and all data objects in it, but not the
* keys */
if (!h)
return;
hashmap_clear_free(h);
hashmap_free(h);
}
void hashmap_free_free_free(Hashmap *h) {
/* Free the hashmap and all data and key objects in it */
if (!h)
return;
hashmap_clear_free_free(h);
hashmap_free(h);
}
void hashmap_clear(Hashmap *h) {
if (!h)
return;
while (h->iterate_list_head)
remove_entry(h, h->iterate_list_head);
}
void hashmap_clear_free(Hashmap *h) {
void *p;
if (!h)
return;
while ((p = hashmap_steal_first(h)))
free(p);
}
void hashmap_clear_free_free(Hashmap *h) {
if (!h)
return;
while (h->iterate_list_head) {
void *a, *b;
a = h->iterate_list_head->value;
b = (void*) h->iterate_list_head->key;
remove_entry(h, h->iterate_list_head);
free(a);
free(b);
}
}
static struct hashmap_entry *hash_scan(Hashmap *h, unsigned hash, const void *key) {
struct hashmap_entry *e;
assert(h);
assert(hash < NBUCKETS);
for (e = BY_HASH(h)[hash]; e; e = e->bucket_next)
if (h->compare_func(e->key, key) == 0)
return e;
return NULL;
}
int hashmap_put(Hashmap *h, const void *key, void *value) {
struct hashmap_entry *e;
unsigned hash;
assert(h);
hash = h->hash_func(key) % NBUCKETS;
e = hash_scan(h, hash, key);
if (e) {
if (e->value == value)
return 0;
return -EEXIST;
}
if (h->from_pool)
e = allocate_tile(&first_entry_pool, &first_entry_tile, sizeof(struct hashmap_entry));
else
e = new(struct hashmap_entry, 1);
if (!e)
return -ENOMEM;
e->key = key;
e->value = value;
link_entry(h, e, hash);
return 1;
}
int hashmap_replace(Hashmap *h, const void *key, void *value) {
struct hashmap_entry *e;
unsigned hash;
assert(h);
hash = h->hash_func(key) % NBUCKETS;
e = hash_scan(h, hash, key);
if (e) {
e->key = key;
e->value = value;
return 0;
}
return hashmap_put(h, key, value);
}
int hashmap_update(Hashmap *h, const void *key, void *value) {
struct hashmap_entry *e;
unsigned hash;
assert(h);
hash = h->hash_func(key) % NBUCKETS;
e = hash_scan(h, hash, key);
if (!e)
return -ENOENT;
e->value = value;
return 0;
}
void* hashmap_get(Hashmap *h, const void *key) {
unsigned hash;
struct hashmap_entry *e;
if (!h)
return NULL;
hash = h->hash_func(key) % NBUCKETS;
e = hash_scan(h, hash, key);
if (!e)
return NULL;
return e->value;
}
void* hashmap_get2(Hashmap *h, const void *key, void **key2) {
unsigned hash;
struct hashmap_entry *e;
if (!h)
return NULL;
hash = h->hash_func(key) % NBUCKETS;
e = hash_scan(h, hash, key);
if (!e)
return NULL;
if (key2)
*key2 = (void*) e->key;
return e->value;
}
bool hashmap_contains(Hashmap *h, const void *key) {
unsigned hash;
if (!h)
return false;
hash = h->hash_func(key) % NBUCKETS;
if (!hash_scan(h, hash, key))
return false;
return true;
}
void* hashmap_remove(Hashmap *h, const void *key) {
struct hashmap_entry *e;
unsigned hash;
void *data;
if (!h)
return NULL;
hash = h->hash_func(key) % NBUCKETS;
if (!(e = hash_scan(h, hash, key)))
return NULL;
data = e->value;
remove_entry(h, e);
return data;
}
int hashmap_remove_and_put(Hashmap *h, const void *old_key, const void *new_key, void *value) {
struct hashmap_entry *e;
unsigned old_hash, new_hash;
if (!h)
return -ENOENT;
old_hash = h->hash_func(old_key) % NBUCKETS;
if (!(e = hash_scan(h, old_hash, old_key)))
return -ENOENT;
new_hash = h->hash_func(new_key) % NBUCKETS;
if (hash_scan(h, new_hash, new_key))
return -EEXIST;
unlink_entry(h, e, old_hash);
e->key = new_key;
e->value = value;
link_entry(h, e, new_hash);
return 0;
}
int hashmap_remove_and_replace(Hashmap *h, const void *old_key, const void *new_key, void *value) {
struct hashmap_entry *e, *k;
unsigned old_hash, new_hash;
if (!h)
return -ENOENT;
old_hash = h->hash_func(old_key) % NBUCKETS;
if (!(e = hash_scan(h, old_hash, old_key)))
return -ENOENT;
new_hash = h->hash_func(new_key) % NBUCKETS;
if ((k = hash_scan(h, new_hash, new_key)))
if (e != k)
remove_entry(h, k);
unlink_entry(h, e, old_hash);
e->key = new_key;
e->value = value;
link_entry(h, e, new_hash);
return 0;
}
void* hashmap_remove_value(Hashmap *h, const void *key, void *value) {
struct hashmap_entry *e;
unsigned hash;
if (!h)
return NULL;
hash = h->hash_func(key) % NBUCKETS;
if (!(e = hash_scan(h, hash, key)))
return NULL;
if (e->value != value)
return NULL;
remove_entry(h, e);
return value;
}
void *hashmap_iterate(Hashmap *h, Iterator *i, const void **key) {
struct hashmap_entry *e;
assert(i);
if (!h)
goto at_end;
if (*i == ITERATOR_LAST)
goto at_end;
if (*i == ITERATOR_FIRST && !h->iterate_list_head)
goto at_end;
e = *i == ITERATOR_FIRST ? h->iterate_list_head : (struct hashmap_entry*) *i;
if (e->iterate_next)
*i = (Iterator) e->iterate_next;
else
*i = ITERATOR_LAST;
if (key)
*key = e->key;
return e->value;
at_end:
*i = ITERATOR_LAST;
if (key)
*key = NULL;
return NULL;
}
void *hashmap_iterate_backwards(Hashmap *h, Iterator *i, const void **key) {
struct hashmap_entry *e;
assert(i);
if (!h)
goto at_beginning;
if (*i == ITERATOR_FIRST)
goto at_beginning;
if (*i == ITERATOR_LAST && !h->iterate_list_tail)
goto at_beginning;
e = *i == ITERATOR_LAST ? h->iterate_list_tail : (struct hashmap_entry*) *i;
if (e->iterate_previous)
*i = (Iterator) e->iterate_previous;
else
*i = ITERATOR_FIRST;
if (key)
*key = e->key;
return e->value;
at_beginning:
*i = ITERATOR_FIRST;
if (key)
*key = NULL;
return NULL;
}
void *hashmap_iterate_skip(Hashmap *h, const void *key, Iterator *i) {
unsigned hash;
struct hashmap_entry *e;
if (!h)
return NULL;
hash = h->hash_func(key) % NBUCKETS;
if (!(e = hash_scan(h, hash, key)))
return NULL;
*i = (Iterator) e;
return e->value;
}
void* hashmap_first(Hashmap *h) {
if (!h)
return NULL;
if (!h->iterate_list_head)
return NULL;
return h->iterate_list_head->value;
}
void* hashmap_first_key(Hashmap *h) {
if (!h)
return NULL;
if (!h->iterate_list_head)
return NULL;
return (void*) h->iterate_list_head->key;
}
void* hashmap_last(Hashmap *h) {
if (!h)
return NULL;
if (!h->iterate_list_tail)
return NULL;
return h->iterate_list_tail->value;
}
void* hashmap_steal_first(Hashmap *h) {
void *data;
if (!h)
return NULL;
if (!h->iterate_list_head)
return NULL;
data = h->iterate_list_head->value;
remove_entry(h, h->iterate_list_head);
return data;
}
void* hashmap_steal_first_key(Hashmap *h) {
void *key;
if (!h)
return NULL;
if (!h->iterate_list_head)
return NULL;
key = (void*) h->iterate_list_head->key;
remove_entry(h, h->iterate_list_head);
return key;
}
unsigned hashmap_size(Hashmap *h) {
if (!h)
return 0;
return h->n_entries;
}
bool hashmap_isempty(Hashmap *h) {
if (!h)
return true;
return h->n_entries == 0;
}
int hashmap_merge(Hashmap *h, Hashmap *other) {
struct hashmap_entry *e;
assert(h);
if (!other)
return 0;
for (e = other->iterate_list_head; e; e = e->iterate_next) {
int r;
if ((r = hashmap_put(h, e->key, e->value)) < 0)
if (r != -EEXIST)
return r;
}
return 0;
}
void hashmap_move(Hashmap *h, Hashmap *other) {
struct hashmap_entry *e, *n;
assert(h);
/* The same as hashmap_merge(), but every new item from other
* is moved to h. This function is guaranteed to succeed. */
if (!other)
return;
for (e = other->iterate_list_head; e; e = n) {
unsigned h_hash, other_hash;
n = e->iterate_next;
h_hash = h->hash_func(e->key) % NBUCKETS;
if (hash_scan(h, h_hash, e->key))
continue;
other_hash = other->hash_func(e->key) % NBUCKETS;
unlink_entry(other, e, other_hash);
link_entry(h, e, h_hash);
}
}
int hashmap_move_one(Hashmap *h, Hashmap *other, const void *key) {
unsigned h_hash, other_hash;
struct hashmap_entry *e;
if (!other)
return 0;
assert(h);
h_hash = h->hash_func(key) % NBUCKETS;
if (hash_scan(h, h_hash, key))
return -EEXIST;
other_hash = other->hash_func(key) % NBUCKETS;
if (!(e = hash_scan(other, other_hash, key)))
return -ENOENT;
unlink_entry(other, e, other_hash);
link_entry(h, e, h_hash);
return 0;
}
Hashmap *hashmap_copy(Hashmap *h) {
Hashmap *copy;
assert(h);
if (!(copy = hashmap_new(h->hash_func, h->compare_func)))
return NULL;
if (hashmap_merge(copy, h) < 0) {
hashmap_free(copy);
return NULL;
}
return copy;
}
char **hashmap_get_strv(Hashmap *h) {
char **sv;
Iterator it;
char *item;
int n;
sv = new(char*, h->n_entries+1);
if (!sv)
return NULL;
n = 0;
HASHMAP_FOREACH(item, h, it)
sv[n++] = item;
sv[n] = NULL;
return sv;
}
void *hashmap_next(Hashmap *h, const void *key) {
unsigned hash;
struct hashmap_entry *e;
assert(h);
assert(key);
if (!h)
return NULL;
hash = h->hash_func(key) % NBUCKETS;
e = hash_scan(h, hash, key);
if (!e)
return NULL;
e = e->iterate_next;
if (!e)
return NULL;
return e->value;
}