PERFORCE change 120765 for review

[Fredrik Lindberg]

http://perforce.freebsd.org/chv.cgi?CH=120765

Change 120765 by fli at fli_genesis on 2007/06/02 11:47:05

	- Only duplicate the key if explicitly instructed to do so, most of the
	  times the key is a part of the data object and it's simply unnecessary 
	  to duplicate it.
	- Add hashtbl_walk() which will traverse the hash table.
	- Some minor adjustments to comments.

Affected files ...

.. //depot/projects/soc2007/fli-mdns_sd/mdnsd/hash.c#4 edit
.. //depot/projects/soc2007/fli-mdns_sd/mdnsd/hash.h#4 edit

Differences ...

==== //depot/projects/soc2007/fli-mdns_sd/mdnsd/hash.c#4 (text+ko) ====

@@ -341,7 +341,8 @@
 
 	for (i = 0; i < ht->ht_tblsz; i++) {
 		TAILQ_FOREACH(he, &ht->ht_buckets[i].hb_table, he_next) {
-			free(he->he_key);
+			if (he->he_flags & HASHTBL_KEYDUP)
+				free(he->he_key);
 		}
 	}
 	SLIST_FOREACH_SAFE(hep, &ht->ht_new, hep_next, hep2) {
@@ -381,7 +382,7 @@
  * Returns 0 on success, on failure -1 is returned
  */
 int
-hashtbl_add(struct hashtbl *ht, void *key, size_t keylen, void *data)
+hashtbl_add(struct hashtbl *ht, void *key, size_t keylen, void *data, int flags)
 {
 	uint32_t hval;
 	struct hashentry *he;
@@ -395,9 +396,15 @@
 
 	he->he_hash = hval;
 	hval &= ht->ht_mask;
+	he->he_flags = flags;
 
-	he->he_key = malloc(keylen);
-	memcpy(he->he_key, key, keylen);
+	if (flags & HASHTBL_KEYDUP) {
+		he->he_key = malloc(keylen);
+		memcpy(he->he_key, key, keylen);
+	}
+	else {
+		he->he_key = key;
+	}
 	he->he_keylen = keylen;
 	he->he_data = data;
 	TAILQ_INSERT_TAIL(&ht->ht_buckets[hval].hb_table, he, he_next);
@@ -431,7 +438,8 @@
 	he = find(ht, hval, key, keylen);
 	if (he != NULL) {
 		TAILQ_REMOVE(&ht->ht_buckets[hval].hb_table, he, he_next);
-		free(he->he_key);
+		if (he->he_flags & HASHTBL_KEYDUP)
+			free(he->he_key);
 		free_he(ht, he);
 		return (0);
 	}
@@ -459,3 +467,21 @@
 	he = find(ht, hval, key, keylen);
 	return (he != NULL) ? he->he_data : NULL;
 }
+
+/*
+ * Walk the hash table, cb will be called for every entry
+ *   ht - hash table
+ *   cb - Callback function
+ */
+void
+hashtbl_walk(struct hashtbl *ht, hashtbl_cb cb)
+{
+	struct hashentry *he, *he2;
+	size_t i;
+
+	for (i = 0; i < ht->ht_tblsz; i++) {
+		TAILQ_FOREACH_SAFE(he, &ht->ht_buckets[i].hb_table, he_next, he2) {
+			cb(ht, he->he_key, he->he_keylen, he->he_data);
+		}
+	}
+}

==== //depot/projects/soc2007/fli-mdns_sd/mdnsd/hash.h#4 (text+ko) ====

@@ -34,9 +34,10 @@
  */
 struct hashentry {
 	TAILQ_ENTRY(hashentry) he_next; /* Next entry */
-	uint32_t he_hash; /* Hash key */
-	void *he_key;	/* Key */
-	size_t he_keylen;	/* Key length */
+	uint32_t he_hash; /* Computed hash */
+	int he_flags;
+	void *he_key;	/* Byte key */
+	size_t he_keylen;	/* Byte Key length */
 	void *he_data;	/* Data object pointer */
 };
 
@@ -72,10 +73,14 @@
 	SLIST_HEAD(, he_pool) ht_free; /* free hashentry objs */
 };
 
+#define HASHTBL_KEYDUP 0x01
+
+typedef void (hashtbl_cb)(struct hashtbl *, void *, size_t, void *);
 int hashtbl_init(struct hashtbl *, size_t, size_t, size_t);
 void hashtbl_destroy(struct hashtbl *);
-int hashtbl_add(struct hashtbl *, void *, size_t, void *);
+int hashtbl_add(struct hashtbl *, void *, size_t, void *, int);
 int hashtbl_del(struct hashtbl *, void *, size_t);
 void * hashtbl_find(struct hashtbl *, void *, size_t);
+void hashtbl_walk(struct hashtbl *, hashtbl_cb);
 
 #endif /* _HASH_H_ */