object: hashmap: implement integer-based hashmap keys

rather than always interpreting a b_hashmap_key as a buffer to be hashed,
b_hashmap can now be told to consider the value of the key_data pointer itself
as the key, treating it as a buffer of size sizeof(void*).

object/hashmap.c

@@ -38,6 +38,45 @@ static uint64_t hash_data(const void *p, size_t size)
 	return hash;
 }
 
+static uint64_t hash_key(const struct b_hashmap_key *key)
+{
+	if (key->key_flags & B_HASHMAP_KEY_F_INTVALUE) {
+		return hash_data(&key->key_data, sizeof key->key_data);
+	} else {
+		return hash_data(key->key_data, key->key_size);
+	}
+}
+
+static bool compare_key(
+	const struct b_hashmap_key *a, const struct b_hashmap_key *b)
+{
+	const void *a_data = NULL, *b_data = NULL;
+	size_t a_len = 0, b_len = 0;
+
+	if (a->key_flags & B_HASHMAP_KEY_F_INTVALUE) {
+		a_data = &a->key_data;
+		a_len = sizeof a->key_data;
+	} else {
+		a_data = a->key_data;
+		a_len = a->key_size;
+	}
+
+	if (b->key_flags & B_HASHMAP_KEY_F_INTVALUE) {
+		b_data = &b->key_data;
+		b_len = sizeof b->key_data;
+	} else {
+		b_data = b->key_data;
+		b_len = b->key_size;
+	}
+
+	if (a_len != b_len) {
+		return false;
+	}
+
+	size_t cmp_len = a_len;
+	return memcmp(a_data, b_data, cmp_len) == 0;
+}
+
 static void hashmap_release(struct b_object *obj);
 
 static struct b_object_type hashmap_type = {
@@ -101,7 +140,7 @@ b_status b_hashmap_put(
 	struct b_hashmap *hashmap, const b_hashmap_key *key,
 	const b_hashmap_value *value)
 {
-	uint64_t hash = hash_data(key->key_data, key->key_size);
+	uint64_t hash = hash_key(key);
 	struct b_hashmap_bucket *bucket = get_bucket(&hashmap->h_buckets, hash);
 
 	if (!bucket) {
@@ -119,12 +158,9 @@ b_status b_hashmap_put(
 		struct b_hashmap_bucket_item *item = b_unbox(
 			struct b_hashmap_bucket_item, it.entry, bi_entry);
 
-		if (item->bi_key.key_size != key->key_size) {
-			continue;
-		}
-
-		if (!memcmp(item->bi_key.key_data, key->key_data, key->key_size)) {
-			return B_ERR_NAME_EXISTS;
+		if (compare_key(&item->bi_key, key)) {
+			memcpy(&item->bi_value, value, sizeof *value);
+			return B_SUCCESS;
 		}
 	}
 
@@ -144,7 +180,8 @@ b_status b_hashmap_put(
 const struct b_hashmap_value *b_hashmap_get(
 	const struct b_hashmap *hashmap, const struct b_hashmap_key *key)
 {
-	uint64_t hash = hash_data(key->key_data, key->key_size);
+	uint64_t hash = hash_key(key);
+
 	struct b_hashmap_bucket *bucket = get_bucket(&hashmap->h_buckets, hash);
 	if (!bucket) {
 		return NULL;
@@ -155,11 +192,7 @@ const struct b_hashmap_value *b_hashmap_get(
 		struct b_hashmap_bucket_item *item = b_unbox(
 			struct b_hashmap_bucket_item, it.entry, bi_entry);
 
-		if (item->bi_key.key_size != key->key_size) {
-			continue;
-		}
-
-		if (!memcmp(item->bi_key.key_data, key->key_data, key->key_size)) {
+		if (compare_key(&item->bi_key, key)) {
 			return &item->bi_value;
 		}
 	}
@@ -169,7 +202,7 @@ const struct b_hashmap_value *b_hashmap_get(
 
 bool b_hashmap_has_key(const struct b_hashmap *hashmap, const b_hashmap_key *key)
 {
-	uint64_t hash = hash_data(key->key_data, key->key_size);
+	uint64_t hash = hash_key(key);
 	struct b_hashmap_bucket *bucket = get_bucket(&hashmap->h_buckets, hash);
 	if (!bucket) {
 		return false;
@@ -180,11 +213,7 @@ bool b_hashmap_has_key(const struct b_hashmap *hashmap, const b_hashmap_key *key
 		struct b_hashmap_bucket_item *item = b_unbox(
 			struct b_hashmap_bucket_item, it.entry, bi_entry);
 
-		if (item->bi_key.key_size != key->key_size) {
-			continue;
-		}
-
-		if (!memcmp(item->bi_key.key_data, key->key_data, key->key_size)) {
+		if (compare_key(&item->bi_key, key)) {
 			return true;
 		}
 	}

object/include/blue/object/hashmap.h

@@ -7,6 +7,7 @@
 #include <blue/core/status.h>
 #include <blue/object/object.h>
 #include <blue/object/type.h>
+#include <stddef.h>
 
 #define B_HASHMAP(p) ((b_hashmap *)(p))
 
@@ -38,7 +39,12 @@ typedef struct b_hashmap b_hashmap;
 typedef void (*b_hashmap_key_destructor)(void *);
 typedef void (*b_hashmap_value_destructor)(void *);
 
+typedef enum b_hashmap_key_flags {
+	B_HASHMAP_KEY_F_INTVALUE = 0x01u,
+} b_hashmap_key_flags;
+
 typedef struct b_hashmap_key {
+	b_hashmap_key_flags key_flags;
 	const void *key_data;
 	size_t key_size;
 } b_hashmap_key;