From: Ben Pfaff Date: Wed, 30 Mar 2011 20:44:10 +0000 (-0700) Subject: sset: New data type for a set of strings. X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f391294fde05ecae7c9a1ff8752f872a1db94f3a;p=openvswitch sset: New data type for a set of strings. Many uses of "shash" or "svec" data structures really call for a "set of strings" data type. This commit introduces such a data structure. Later commits convert inappropriate uses of shash and svec to use sset instead. --- diff --git a/lib/automake.mk b/lib/automake.mk index 78a45ea2..60d030e5 100644 --- a/lib/automake.mk +++ b/lib/automake.mk @@ -126,6 +126,8 @@ lib_libopenvswitch_a_SOURCES = \ lib/socket-util.h \ lib/sort.c \ lib/sort.h \ + lib/sset.c \ + lib/sset.h \ lib/stream-fd.c \ lib/stream-fd.h \ lib/stream-provider.h \ diff --git a/lib/sset.c b/lib/sset.c new file mode 100644 index 00000000..9a0936b2 --- /dev/null +++ b/lib/sset.c @@ -0,0 +1,253 @@ +/* + * Copyright (c) 2011 Nicira Networks. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include + +#include "sset.h" + +#include + +#include "hash.h" + +static uint32_t +hash_name__(const char *name, size_t length) +{ + return hash_bytes(name, length, 0); +} + +static uint32_t +hash_name(const char *name) +{ + return hash_name__(name, strlen(name)); +} + +static struct sset_node * +sset_find__(const struct sset *set, const char *name, size_t hash) +{ + struct sset_node *node; + + HMAP_FOR_EACH_WITH_HASH (node, hmap_node, hash, &set->map) { + if (!strcmp(node->name, name)) { + return node; + } + } + return NULL; +} + +static struct sset_node * +sset_add__(struct sset *set, const char *name, size_t length, size_t hash) +{ + struct sset_node *node = xmalloc(length + sizeof *node); + memcpy(node->name, name, length + 1); + hmap_insert(&set->map, &node->hmap_node, hash); + return node; +} + +/* Initializes 'set' as an empty set of strings. */ +void +sset_init(struct sset *set) +{ + hmap_init(&set->map); +} + +/* Destroys 'sets'. */ +void +sset_destroy(struct sset *set) +{ + if (set) { + sset_clear(set); + hmap_destroy(&set->map); + } +} + +/* Initializes 'set' to contain the same strings as 'orig'. */ +void +sset_clone(struct sset *set, const struct sset *orig) +{ + struct sset_node *node; + + sset_init(set); + HMAP_FOR_EACH (node, hmap_node, &orig->map) { + sset_add__(set, node->name, strlen(node->name), + node->hmap_node.hash); + } +} + +/* Exchanges the contents of 'a' and 'b'. */ +void +sset_swap(struct sset *a, struct sset *b) +{ + hmap_swap(&a->map, &b->map); +} + +/* Adjusts 'set' so that it is still valid after it has been moved around in + * memory (e.g. due to realloc()). */ +void +sset_moved(struct sset *set) +{ + hmap_moved(&set->map); +} + +/* Returns true if 'set' contains no strings, false if it contains at least one + * string. */ +bool +sset_is_empty(const struct sset *set) +{ + return hmap_is_empty(&set->map); +} + +/* Returns the number of strings in 'set'. */ +size_t +sset_count(const struct sset *set) +{ + return hmap_count(&set->map); +} + +/* Adds 'name' to 'set'. If 'name' is new, returns the new sset_node; + * otherwise (if a copy of 'name' already existed in 'set'), returns NULL. */ +struct sset_node * +sset_add(struct sset *set, const char *name) +{ + size_t length = strlen(name); + uint32_t hash = hash_name__(name, length); + + return (sset_find__(set, name, hash) + ? NULL + : sset_add__(set, name, length, hash)); +} + +/* Adds a copy of 'name' to 'set' and frees 'name'. + * + * If 'name' is new, returns the new sset_node; otherwise (if a copy of 'name' + * already existed in 'set'), returns NULL. */ +struct sset_node * +sset_add_and_free(struct sset *set, char *name) +{ + struct sset_node *node = sset_add(set, name); + free(name); + return node; +} + +/* Adds 'name' to 'set'. Assert-fails if a copy of 'name' was already in + * 'set'. */ +void +sset_add_assert(struct sset *set, const char *name) +{ + bool added OVS_UNUSED = sset_add(set, name); + assert(added); +} + +/* Adds a copy of each of the 'n' names in 'names' to 'set'. */ +void +sset_add_array(struct sset *set, char **names, size_t n) +{ + size_t i; + + for (i = 0; i < n; i++) { + sset_add(set, names[i]); + } +} + +/* Removes all of the strings from 'set'. */ +void +sset_clear(struct sset *set) +{ + const char *name, *next; + + SSET_FOR_EACH_SAFE (name, next, set) { + sset_delete(set, SSET_NODE_FROM_NAME(name)); + } +} + +/* Deletes 'node' from 'set' and frees 'node'. */ +void +sset_delete(struct sset *set, struct sset_node *node) +{ + hmap_remove(&set->map, &node->hmap_node); + free(node); +} + +/* Searches for 'name' in 'set'. If found, deletes it and returns true. If + * not found, returns false without modifying 'set'. */ +bool +sset_find_and_delete(struct sset *set, const char *name) +{ + struct sset_node *node = sset_find(set, name); + if (node) { + sset_delete(set, node); + } + return node != NULL; +} + +/* Searches for 'name' in 'set' and deletes it. Assert-fails if 'name' is not + * in 'set'. */ +void +sset_find_and_delete_assert(struct sset *set, const char *name) +{ + bool deleted OVS_UNUSED = sset_find_and_delete(set, name); + assert(deleted); +} + +/* Removes a string from 'set' and returns a copy of it. The caller must free + * the returned string (with free()). + * + * 'set' must not be empty. + * + * This is not a very good way to iterate through an sset: it copies each name + * and it takes O(n**2) time to remove all the names. Use SSET_FOR_EACH_SAFE + * instead, if you can. */ +char * +sset_pop(struct sset *set) +{ + const char *name = SSET_FIRST(set); + char *copy = xstrdup(name); + sset_delete(set, SSET_NODE_FROM_NAME(name)); + return copy; +} + +/* Searches for 'name' in 'set'. Returns its node, if found, otherwise a null + * pointer. */ +struct sset_node * +sset_find(const struct sset *set, const char *name) +{ + return sset_find__(set, name, hash_name(name)); +} + +/* Returns true if 'set' contains a copy of 'name', false otherwise. */ +bool +sset_contains(const struct sset *set, const char *name) +{ + return sset_find(set, name) != NULL; +} + +/* Returns true if 'a' and 'b' contain the same strings, false otherwise. */ +bool +sset_equals(const struct sset *a, const struct sset *b) +{ + struct sset_node *node; + + if (sset_count(a) != sset_count(b)) { + return false; + } + + HMAP_FOR_EACH (node, hmap_node, &a->map) { + if (!sset_find__(b, node->name, node->hmap_node.hash)) { + return false; + } + } + + return true; +} diff --git a/lib/sset.h b/lib/sset.h new file mode 100644 index 00000000..88100673 --- /dev/null +++ b/lib/sset.h @@ -0,0 +1,88 @@ +/* + * Copyright (c) 2011 Nicira Networks. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef SSET_H +#define SSET_H + +#include "hmap.h" + +struct sset_node { + struct hmap_node hmap_node; + char name[1]; +}; + +/* A set of strings. */ +struct sset { + struct hmap map; +}; + +#define SSET_INITIALIZER(SSET) { HMAP_INITIALIZER(&(SSET)->map) } + +/* Basics. */ +void sset_init(struct sset *); +void sset_destroy(struct sset *); +void sset_clone(struct sset *, const struct sset *); +void sset_swap(struct sset *, struct sset *); +void sset_moved(struct sset *); + +/* Count. */ +bool sset_is_empty(const struct sset *); +size_t sset_count(const struct sset *); + +/* Insertion. */ +struct sset_node *sset_add(struct sset *, const char *); +struct sset_node *sset_add_and_free(struct sset *, char *); +void sset_add_assert(struct sset *, const char *); +void sset_add_array(struct sset *, char **, size_t n); + +/* Deletion. */ +void sset_clear(struct sset *); +void sset_delete(struct sset *, struct sset_node *); +bool sset_find_and_delete(struct sset *, const char *); +void sset_find_and_delete_assert(struct sset *, const char *); +char *sset_pop(struct sset *); + +/* Search. */ +struct sset_node *sset_find(const struct sset *, const char *); +bool sset_contains(const struct sset *, const char *); +bool sset_equals(const struct sset *, const struct sset *); + +/* Iteration macros. */ +#define SSET_FOR_EACH(NAME, SSET) \ + for ((NAME) = SSET_FIRST(SSET); \ + SSET_NODE_FROM_NAME(NAME) != NULL; \ + (NAME) = SSET_NEXT(SSET, NAME)) + +#define SSET_FOR_EACH_SAFE(NAME, NEXT, SSET) \ + for ((NAME) = SSET_FIRST(SSET); \ + (SSET_NODE_FROM_NAME(NAME) != NULL \ + ? (NEXT) = SSET_NEXT(SSET, NAME), true \ + : false); \ + (NAME) = (NEXT)) + +/* Implementation helper macros. */ + +#define SSET_NODE_FROM_HMAP_NODE(HMAP_NODE) \ + CONTAINER_OF(HMAP_NODE, struct sset_node, hmap_node) +#define SSET_NAME_FROM_HMAP_NODE(HMAP_NODE) \ + ((const char *) (SSET_NODE_FROM_HMAP_NODE(HMAP_NODE)->name)) +#define SSET_NODE_FROM_NAME(NAME) CONTAINER_OF(NAME, struct sset_node, name) +#define SSET_FIRST(SSET) SSET_NAME_FROM_HMAP_NODE(hmap_first(&(SSET)->map)) +#define SSET_NEXT(SSET, NAME) \ + SSET_NAME_FROM_HMAP_NODE( \ + hmap_next(&(SSET)->map, &SSET_NODE_FROM_NAME(NAME)->hmap_node)) + +#endif /* sset.h */