src/shared: refactor shared code

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

1 files changed, 75 insertions, 0 deletions

diff --git a/src/shared/hashmap.h b/src/shared/hashmap.h
new file mode 100644
index 0000000000..387c32243e
--- /dev/null
+++ b/src/shared/hashmap.h
@@ -0,0 +1,75 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  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 <stdbool.h>
+
+#include "macro.h"
+
+/* Pretty straightforward hash table implementation. As a minor
+ * optimization a NULL hashmap object will be treated as empty hashmap
+ * for all read operations. That way it is not necessary to
+ * instantiate an object for each Hashmap use. */
+
+#define HASH_KEY_SIZE 16
+
+typedef struct Hashmap Hashmap;
+typedef struct _IteratorStruct _IteratorStruct;
+typedef _IteratorStruct* Iterator;
+
+#define ITERATOR_FIRST ((Iterator) 0)
+#define ITERATOR_LAST ((Iterator) -1)
+
+typedef unsigned long (*hash_func_t)(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]);
+typedef int (*compare_func_t)(const void *a, const void *b);
+
+unsigned long string_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) _pure_;
+int string_compare_func(const void *a, const void *b) _pure_;
+
+/* This will compare the passed pointers directly, and will not
+ * dereference them. This is hence not useful for strings or
+ * suchlike. */
+unsigned long trivial_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) _pure_;
+int trivial_compare_func(const void *a, const void *b) _const_;
+
+Hashmap *hashmap_new(hash_func_t hash_func, compare_func_t compare_func);
+void hashmap_free(Hashmap *h);
+void hashmap_free_free(Hashmap *h);
+
+int hashmap_put(Hashmap *h, const void *key, void *value);
+void *hashmap_get(Hashmap *h, const void *key);
+bool hashmap_contains(Hashmap *h, const void *key);
+
+unsigned hashmap_size(Hashmap *h) _pure_;
+
+void *hashmap_iterate(Hashmap *h, Iterator *i, const void **key);
+void *hashmap_iterate_backwards(Hashmap *h, Iterator *i, const void **key);
+
+void hashmap_clear(Hashmap *h);
+void hashmap_clear_free(Hashmap *h);
+
+void *hashmap_steal_first(Hashmap *h);
+
+char **hashmap_get_strv(Hashmap *h);
+
+#define HASHMAP_FOREACH(e, h, i) \
+        for ((i) = ITERATOR_FIRST, (e) = hashmap_iterate((h), &(i), NULL); (e); (e) = hashmap_iterate((h), &(i), NULL))