From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 6 Apr 2010 00:38:43 +0000 (+0200)
Subject: hashmap,set: add new accessors that cannot fail on OOM
X-Git-Tag: v1~660
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=101d8e630eab1281a0e126a78433cf6d5bed4cb4

hashmap,set: add new accessors that cannot fail on OOM
---

diff --git a/hashmap.c b/hashmap.c
index 28256bd35..2102db8b2 100644
--- a/hashmap.c
+++ b/hashmap.c
@@ -96,7 +96,34 @@ int hashmap_ensure_allocated(Hashmap **h, hash_func_t hash_func, compare_func_t
         return 0;
 }
 
-static void remove_entry(Hashmap *h, struct hashmap_entry *e) {
+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);
 
@@ -117,17 +144,25 @@ 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)
@@ -180,27 +215,7 @@ 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;
-
-        /* 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);
+        link_entry(h, e, hash);
 
         return 0;
 }
@@ -214,6 +229,7 @@ int hashmap_replace(Hashmap *h, const void *key, void *value) {
         hash = h->hash_func(key) % NBUCKETS;
 
         if ((e = hash_scan(h, hash, key))) {
+                e->key = key;
                 e->value = value;
                 return 0;
         }
@@ -255,6 +271,31 @@ void* hashmap_remove(Hashmap *h, const void *key) {
         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;
+}
+
 void* hashmap_remove_value(Hashmap *h, const void *key, void *value) {
         struct hashmap_entry *e;
         unsigned hash;
@@ -434,6 +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;
 
diff --git a/hashmap.h b/hashmap.h
index bd57bca24..9cdd7016b 100644
--- a/hashmap.h
+++ b/hashmap.h
@@ -55,8 +55,11 @@ int hashmap_replace(Hashmap *h, const void *key, void *value);
 void* hashmap_get(Hashmap *h, const void *key);
 void* hashmap_remove(Hashmap *h, const void *key);
 void* hashmap_remove_value(Hashmap *h, const void *key, void *value);
+int hashmap_remove_and_put(Hashmap *h, const void *old_key, const void *new_key, void *value);
 
 int hashmap_merge(Hashmap *h, Hashmap *other);
+void hashmap_move(Hashmap *h, Hashmap *other);
+int hashmap_move_one(Hashmap *h, Hashmap *other, const void *key);
 
 unsigned hashmap_size(Hashmap *h);
 bool hashmap_isempty(Hashmap *h);
diff --git a/set.c b/set.c
index 708f12a94..efd20db53 100644
--- a/set.c
+++ b/set.c
@@ -57,6 +57,10 @@ void *set_remove(Set *s, void *value) {
         return hashmap_remove(MAKE_HASHMAP(s), value);
 }
 
+int set_remove_and_put(Set *s, void *old_value, void *new_value) {
+        return hashmap_remove_and_put(MAKE_HASHMAP(s), old_value, new_value, new_value);
+}
+
 unsigned set_size(Set *s) {
         return hashmap_size(MAKE_HASHMAP(s));
 }
@@ -93,6 +97,14 @@ int set_merge(Set *s, Set *other) {
         return hashmap_merge(MAKE_HASHMAP(s), MAKE_HASHMAP(other));
 }
 
+void set_move(Set *s, Set *other) {
+        return hashmap_move(MAKE_HASHMAP(s), MAKE_HASHMAP(other));
+}
+
+int set_move_one(Set *s, Set *other, void *value) {
+        return hashmap_move_one(MAKE_HASHMAP(s), MAKE_HASHMAP(other), value);
+}
+
 Set* set_copy(Set *s) {
         return MAKE_SET(hashmap_copy(MAKE_HASHMAP(s)));
 }
diff --git a/set.h b/set.h
index b0f2242c8..dd2e91dd1 100644
--- a/set.h
+++ b/set.h
@@ -41,8 +41,11 @@ int set_put(Set *s, void *value);
 int set_replace(Set *s, void *value);
 void *set_get(Set *s, void *value);
 void *set_remove(Set *s, void *value);
+int set_remove_and_put(Set *s, void *old_value, void *new_value);
 
 int set_merge(Set *s, Set *other);
+void set_move(Set *s, Set *other);
+int set_move_one(Set *s, Set *other, void *value);
 
 unsigned set_size(Set *s);
 bool set_isempty(Set *s);