basic: split hash functions into their own header files

The hash operations are not really that specific to hashmaps, hence split them into a .c module of their own.

3 files changed, 150 insertions, 60 deletions

diff --git a/src/basic/hash-funcs.c b/src/basic/hash-funcs.c
new file mode 100644
index 000000000..8d39915ba
--- /dev/null
+++ b/src/basic/hash-funcs.c
@@ -0,0 +1,83 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of elogind.
+
+  Copyright 2010 Lennart Poettering
+  Copyright 2014 Michal Schmidt
+
+  elogind 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.
+
+  elogind 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 elogind; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "hash-funcs.h"
+
+void string_hash_func(const void *p, struct siphash *state) {
+        siphash24_compress(p, strlen(p) + 1, state);
+}
+
+int string_compare_func(const void *a, const void *b) {
+        return strcmp(a, b);
+}
+
+const struct hash_ops string_hash_ops = {
+        .hash = string_hash_func,
+        .compare = string_compare_func
+};
+
+void trivial_hash_func(const void *p, struct siphash *state) {
+        siphash24_compress(&p, sizeof(p), state);
+}
+
+int trivial_compare_func(const void *a, const void *b) {
+        return a < b ? -1 : (a > b ? 1 : 0);
+}
+
+const struct hash_ops trivial_hash_ops = {
+        .hash = trivial_hash_func,
+        .compare = trivial_compare_func
+};
+
+void uint64_hash_func(const void *p, struct siphash *state) {
+        siphash24_compress(p, sizeof(uint64_t), state);
+}
+
+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);
+}
+
+const struct hash_ops uint64_hash_ops = {
+        .hash = uint64_hash_func,
+        .compare = uint64_compare_func
+};
+
+#if SIZEOF_DEV_T != 8
+void devt_hash_func(const void *p, struct siphash *state) {
+        siphash24_compress(p, sizeof(dev_t), state);
+}
+
+int devt_compare_func(const void *_a, const void *_b) {
+        dev_t a, b;
+        a = *(const dev_t*) _a;
+        b = *(const dev_t*) _b;
+        return a < b ? -1 : (a > b ? 1 : 0);
+}
+
+const struct hash_ops devt_hash_ops = {
+        .hash = devt_hash_func,
+        .compare = devt_compare_func
+};
+#endif
diff --git a/src/basic/hash-funcs.h b/src/basic/hash-funcs.h
new file mode 100644
index 000000000..b085054ee
--- /dev/null
+++ b/src/basic/hash-funcs.h
@@ -0,0 +1,67 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of elogind.
+
+  Copyright 2010 Lennart Poettering
+  Copyright 2014 Michal Schmidt
+
+  elogind 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.
+
+  elogind 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 elogind; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "macro.h"
+#include "siphash24.h"
+
+typedef void (*hash_func_t)(const void *p, struct siphash *state);
+typedef int (*compare_func_t)(const void *a, const void *b);
+
+struct hash_ops {
+        hash_func_t hash;
+        compare_func_t compare;
+};
+
+void string_hash_func(const void *p, struct siphash *state);
+int string_compare_func(const void *a, const void *b) _pure_;
+extern const struct hash_ops string_hash_ops;
+
+/* This will compare the passed pointers directly, and will not
+ * dereference them. This is hence not useful for strings or
+ * suchlike. */
+void trivial_hash_func(const void *p, struct siphash *state);
+int trivial_compare_func(const void *a, const void *b) _const_;
+extern const struct hash_ops trivial_hash_ops;
+
+/* 32bit values we can always just embed in the pointer itself, but
+ * in order to support 32bit archs we need store 64bit values
+ * indirectly, since they don't fit in a pointer. */
+void uint64_hash_func(const void *p, struct siphash *state);
+int uint64_compare_func(const void *a, const void *b) _pure_;
+extern const struct hash_ops uint64_hash_ops;
+
+/* On some archs dev_t is 32bit, and on others 64bit. And sometimes
+ * it's 64bit on 32bit archs, and sometimes 32bit on 64bit archs. Yuck! */
+#if SIZEOF_DEV_T != 8
+void devt_hash_func(const void *p, struct siphash *state) _pure_;
+int devt_compare_func(const void *a, const void *b) _pure_;
+extern const struct hash_ops devt_hash_ops = {
+        .hash = devt_hash_func,
+        .compare = devt_compare_func
+};
+#else
+#define devt_hash_func uint64_hash_func
+#define devt_compare_func uint64_compare_func
+#define devt_hash_ops uint64_hash_ops
+#endif
diff --git a/src/basic/hashmap.c b/src/basic/hashmap.c
index 0e46716c5..f8d331637 100644
--- a/src/basic/hashmap.c
+++ b/src/basic/hashmap.c
@@ -280,66 +280,6 @@ static const struct hashmap_type_info hashmap_type_info[_HASHMAP_TYPE_MAX] = {
         },
 };
 
-void string_hash_func(const void *p, struct siphash *state) {
-        siphash24_compress(p, strlen(p) + 1, state);
-}
-
-int string_compare_func(const void *a, const void *b) {
-        return strcmp(a, b);
-}
-
-const struct hash_ops string_hash_ops = {
-        .hash = string_hash_func,
-        .compare = string_compare_func
-};
-
-void trivial_hash_func(const void *p, struct siphash *state) {
-        siphash24_compress(&p, sizeof(p), state);
-}
-
-int trivial_compare_func(const void *a, const void *b) {
-        return a < b ? -1 : (a > b ? 1 : 0);
-}
-
-const struct hash_ops trivial_hash_ops = {
-        .hash = trivial_hash_func,
-        .compare = trivial_compare_func
-};
-
-void uint64_hash_func(const void *p, struct siphash *state) {
-        siphash24_compress(p, sizeof(uint64_t), state);
-}
-
-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);
-}
-
-const struct hash_ops uint64_hash_ops = {
-        .hash = uint64_hash_func,
-        .compare = uint64_compare_func
-};
-
-#if SIZEOF_DEV_T != 8
-void devt_hash_func(const void *p, struct siphash *state) {
-        siphash24_compress(p, sizeof(dev_t), state);
-}
-
-int devt_compare_func(const void *_a, const void *_b) {
-        dev_t a, b;
-        a = *(const dev_t*) _a;
-        b = *(const dev_t*) _b;
-        return a < b ? -1 : (a > b ? 1 : 0);
-}
-
-const struct hash_ops devt_hash_ops = {
-        .hash = devt_hash_func,
-        .compare = devt_compare_func
-};
-#endif
-
 static unsigned n_buckets(HashmapBase *h) {
         return h->has_indirect ? h->indirect.n_buckets
                                : hashmap_type_info[h->type].n_direct_buckets;