X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=hashmap.c;h=5a993b6e4761a36ba410c1f9b1cbba7a5de95a58;hp=4db61732fae566011e06af51ae0b9de24ba37f74;hb=bff7c062a40379c0797c34f0f3d159e3c6126a29;hpb=91cdde8a7a08c6797995cc67f4b55ac43780cdd8

diff --git a/hashmap.c b/hashmap.c
index 4db61732f..5a993b6e4 100644
--- a/hashmap.c
+++ b/hashmap.c
@@ -1,8 +1,23 @@
 /*-*- Mode: C; c-basic-offset: 8 -*-*/
 
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
+/***
+  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 General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
 
 #include <assert.h>
 #include <stdlib.h>
@@ -69,7 +84,46 @@ Hashmap *hashmap_new(hash_func_t hash_func, compare_func_t compare_func) {
         return h;
 }
 
-static void remove_entry(Hashmap *h, struct hashmap_entry *e) {
+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);
 
@@ -90,28 +144,43 @@ static void remove_entry(Hashmap *h, struct hashmap_entry *e) {
 
         if (e->bucket_previous)
                 e->bucket_previous->bucket_next = e->bucket_next;
-        else {
-                unsigned hash = h->hash_func(e->key) % NBUCKETS;
+        else
                 BY_HASH(h)[hash] = e->bucket_next;
-        }
-
-        free(e);
 
         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);
+        free(e);
+}
+
 void hashmap_free(Hashmap*h) {
 
         if (!h)
                 return;
 
-        while (h->iterate_list_head)
-                remove_entry(h, h->iterate_list_head);
+        hashmap_clear(h);
 
         free(h);
 }
 
+void hashmap_clear(Hashmap *h) {
+        if (!h)
+                return;
+
+        while (h->iterate_list_head)
+                remove_entry(h, h->iterate_list_head);
+}
+
 static struct hashmap_entry *hash_scan(Hashmap *h, unsigned hash, const void *key) {
         struct hashmap_entry *e;
         assert(h);
@@ -132,8 +201,13 @@ int hashmap_put(Hashmap *h, const void *key, void *value) {
 
         hash = h->hash_func(key) % NBUCKETS;
 
-        if (hash_scan(h, hash, key))
+        if ((e = hash_scan(h, hash, key))) {
+
+                if (e->value == value)
+                        return 0;
+
                 return -EEXIST;
+        }
 
         if (!(e = new(struct hashmap_entry, 1)))
                 return -ENOMEM;
@@ -141,29 +215,26 @@ int hashmap_put(Hashmap *h, const void *key, void *value) {
         e->key = key;
         e->value = value;
 
-        /* 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;
+        link_entry(h, e, hash);
 
-        /* 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;
+        return 1;
+}
 
-        h->n_entries++;
-        assert(h->n_entries >= 1);
+int hashmap_replace(Hashmap *h, const void *key, void *value) {
+        struct hashmap_entry *e;
+        unsigned hash;
 
-        return 0;
+        assert(h);
+
+        hash = h->hash_func(key) % NBUCKETS;
+
+        if ((e = hash_scan(h, hash, key))) {
+                e->key = key;
+                e->value = value;
+                return 0;
+        }
+
+        return hashmap_put(h, key, value);
 }
 
 void* hashmap_get(Hashmap *h, const void *key) {
@@ -200,26 +271,71 @@ void* hashmap_remove(Hashmap *h, const void *key) {
         return data;
 }
 
-void *hashmap_iterate(Hashmap *h, void **state, const void **key) {
+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);
 
-        assert(state);
+        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 (*state == (void*) -1)
+        if (*i == ITERATOR_LAST)
                 goto at_end;
 
-        if (!*state && !h->iterate_list_head)
+        if (*i == ITERATOR_FIRST && !h->iterate_list_head)
                 goto at_end;
 
-        e = *state ? *state : h->iterate_list_head;
+        e = *i == ITERATOR_FIRST ? h->iterate_list_head : (struct hashmap_entry*) *i;
 
         if (e->iterate_next)
-                *state = e->iterate_next;
+                *i = (Iterator) e->iterate_next;
         else
-                *state = (void*) -1;
+                *i = ITERATOR_LAST;
 
         if (key)
                 *key = e->key;
@@ -227,7 +343,7 @@ void *hashmap_iterate(Hashmap *h, void **state, const void **key) {
         return e->value;
 
 at_end:
-        *state = (void *) -1;
+        *i = ITERATOR_LAST;
 
         if (key)
                 *key = NULL;
@@ -235,26 +351,26 @@ at_end:
         return NULL;
 }
 
-void *hashmap_iterate_backwards(Hashmap *h, void **state, const void **key) {
+void *hashmap_iterate_backwards(Hashmap *h, Iterator *i, const void **key) {
         struct hashmap_entry *e;
 
-        assert(state);
+        assert(i);
 
         if (!h)
                 goto at_beginning;
 
-        if (*state == (void*) -1)
+        if (*i == ITERATOR_FIRST)
                 goto at_beginning;
 
-        if (!*state && !h->iterate_list_tail)
+        if (*i == ITERATOR_LAST && !h->iterate_list_tail)
                 goto at_beginning;
 
-        e = *state ? *state : h->iterate_list_tail;
+        e = *i == ITERATOR_LAST ? h->iterate_list_tail : (struct hashmap_entry*) *i;
 
         if (e->iterate_previous)
-                *state = e->iterate_previous;
+                *i = (Iterator) e->iterate_previous;
         else
-                *state = (void*) -1;
+                *i = ITERATOR_FIRST;
 
         if (key)
                 *key = e->key;
@@ -262,7 +378,7 @@ void *hashmap_iterate_backwards(Hashmap *h, void **state, const void **key) {
         return e->value;
 
 at_beginning:
-        *state = (void *) -1;
+        *i = ITERATOR_FIRST;
 
         if (key)
                 *key = NULL;
@@ -270,6 +386,23 @@ at_beginning:
         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)
@@ -342,6 +475,57 @@ int hashmap_merge(Hashmap *h, Hashmap *other) {
         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;