1 files changed, 121 insertions, 0 deletions
diff --git a/src/basic/hash-funcs.c b/src/basic/hash-funcs.c
new file mode 100644
index 0000000..5fac467
--- /dev/null
+++ b/src/basic/hash-funcs.c
@@ -0,0 +1,121 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <string.h>
+
+#include "hash-funcs.h"
+#include "path-util.h"
+#include "strv.h"
+
+void string_hash_func(const char *p, struct siphash *state) {
+        siphash24_compress(p, strlen(p) + 1, state);
+}
+
+DEFINE_HASH_OPS(string_hash_ops, char, string_hash_func, string_compare_func);
+DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(string_hash_ops_free,
+                                    char, string_hash_func, string_compare_func, free);
+DEFINE_HASH_OPS_FULL(string_hash_ops_free_free,
+                     char, string_hash_func, string_compare_func, free,
+                     void, free);
+DEFINE_HASH_OPS_FULL(string_hash_ops_free_strv_free,
+                     char, string_hash_func, string_compare_func, free,
+                     char*, strv_free);
+
+void path_hash_func(const char *q, struct siphash *state) {
+        bool add_slash = false;
+
+        assert(q);
+        assert(state);
+
+        /* Calculates a hash for a path in a way this duplicate inner slashes don't make a differences, and also
+         * whether there's a trailing slash or not. This fits well with the semantics of path_compare(), which does
+         * similar checks and also doesn't care for trailing slashes. Note that relative and absolute paths (i.e. those
+         * which begin in a slash or not) will hash differently though. */
+
+        /* if path is absolute, add one "/" to the hash. */
+        if (path_is_absolute(q))
+                siphash24_compress("/", 1, state);
+
+        for (;;) {
+                const char *e;
+                int r;
+
+                r = path_find_first_component(&q, true, &e);
+                if (r == 0)
+                        return;
+
+                if (add_slash)
+                        siphash24_compress_byte('/', state);
+
+                if (r < 0) {
+                        /* if a component is invalid, then add remaining part as a string. */
+                        string_hash_func(q, state);
+                        return;
+                }
+
+                /* Add this component to the hash. */
+                siphash24_compress(e, r, state);
+
+                add_slash = true;
+        }
+}
+
+DEFINE_HASH_OPS(path_hash_ops, char, path_hash_func, path_compare);
+DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(path_hash_ops_free,
+                                    char, path_hash_func, path_compare, free);
+DEFINE_HASH_OPS_FULL(path_hash_ops_free_free,
+                     char, path_hash_func, path_compare, free,
+                     void, free);
+
+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 CMP(a, b);
+}
+
+const struct hash_ops trivial_hash_ops = {
+        .hash = trivial_hash_func,
+        .compare = trivial_compare_func,
+};
+
+const struct hash_ops trivial_hash_ops_free = {
+        .hash = trivial_hash_func,
+        .compare = trivial_compare_func,
+        .free_key = free,
+};
+
+const struct hash_ops trivial_hash_ops_free_free = {
+        .hash = trivial_hash_func,
+        .compare = trivial_compare_func,
+        .free_key = free,
+        .free_value = free,
+};
+
+void uint64_hash_func(const uint64_t *p, struct siphash *state) {
+        siphash24_compress(p, sizeof(uint64_t), state);
+}
+
+int uint64_compare_func(const uint64_t *a, const uint64_t *b) {
+        return CMP(*a, *b);
+}
+
+DEFINE_HASH_OPS(uint64_hash_ops, uint64_t, uint64_hash_func, uint64_compare_func);
+
+#if SIZEOF_DEV_T != 8
+void devt_hash_func(const dev_t *p, struct siphash *state) {
+        siphash24_compress(p, sizeof(dev_t), state);
+}
+#endif
+
+int devt_compare_func(const dev_t *a, const dev_t *b) {
+        int r;
+
+        r = CMP(major(*a), major(*b));
+        if (r != 0)
+                return r;
+
+        return CMP(minor(*a), minor(*b));
+}
+
+DEFINE_HASH_OPS(devt_hash_ops, dev_t, devt_hash_func, devt_compare_func);