Merge pull request #3507 from masatake/libutil-htable-update

libutil: revise functions for updating the value for a given key

Author: masatake

dsl/optscript.c

@@ -2129,7 +2129,11 @@ dict_op_def (EsObject* dict, EsObject *key, EsObject *val)
 	key = es_object_ref (key);
 	val = es_object_ref (val);
 
-	hashTableUpdateItem (t, key, val);
+	if (hashTableUpdateOrPutItem (t, key, val))
+	{
+		/* A key in the hashtable is reused. */
+		es_object_unref (key);
+	}
 }
 
 static bool

extra-cmds/utiltest.c

@@ -8,15 +8,33 @@
 #include "general.h"
 
 #include "acutest.h"
+#include "htable.h"
 #include "routines.h"
 #include <string.h>
 
+void test_htable_update(void)
+{
+	hashTable *htable = hashTableNew (3, hashCstrhash, hashCstreq,
+									  eFree, NULL);
+	TEST_CHECK(htable != NULL);
+
+	hashTablePutItem (htable, strdup("a"), "A");
+	TEST_CHECK (hashTableUpdateItem (htable,  "a", "B") == true);
+	TEST_CHECK (hashTableUpdateItem (htable,  "b", "B") == false);
+	TEST_CHECK (strcmp (hashTableGetItem (htable, "a"), "B") == 0);
+	TEST_CHECK (hashTableUpdateOrPutItem (htable,  "a", "C") == true);
+	TEST_CHECK (hashTableUpdateOrPutItem (htable,  strdup("x"), "X") == false);
+	TEST_CHECK (strcmp (hashTableGetItem (htable, "x"), "X") == 0);
+	hashTableDelete(htable);
+}
+
 void test_routines_strrstr(void)
 {
 	TEST_CHECK(strcmp(strrstr("abcdcdb", "cd"), "cdb") == 0);
 }
 
 TEST_LIST = {
+   { "htable/update",    test_htable_update    },
    { "routines/strrstr", test_routines_strrstr },
    { NULL, NULL }     /* zeroed record marking the end of the list */
 };

main/htable.c

@@ -81,7 +81,9 @@ static void entry_reset  (hentry* entry,
 		keyfreefn (entry->key);
 	if (valfreefn)
 		valfreefn (entry->value);
-	entry->key = newkey;
+
+	if (keyfreefn)
+		entry->key = newkey;
 	entry->value = newval;
 }
 
@@ -346,14 +348,25 @@ extern bool     hashTableDeleteItem (hashTable *htable, const void *key)
 	return r;
 }
 
-extern bool    hashTableUpdateItem (hashTable *htable, void *key, void *value)
+extern bool    hashTableUpdateItem (hashTable *htable, const void *key, void *value)
+{
+	unsigned int h, i;
+
+	h = htable->hashfn (key);
+	i = h % htable->size;
+	bool r = entry_update(htable->table[i], (void *)key, value,
+						  htable->equalfn, NULL, htable->valfreefn);
+	return r;
+}
+
+extern bool    hashTableUpdateOrPutItem (hashTable *htable, void *key, void *value)
 {
 	unsigned int h, i;
 
 	h = htable->hashfn (key);
 	i = h % htable->size;
 	bool r = entry_update(htable->table[i], key, value,
-						  htable->equalfn, htable->keyfreefn, htable->valfreefn);
+						  htable->equalfn, NULL, htable->valfreefn);
 	if (!r)
 		hashTablePutItem0(htable, key, value, h);
 

main/htable.h

@@ -70,7 +70,19 @@ extern void       hashTablePutItem     (hashTable *htable, void *key, void *valu
 extern void*      hashTableGetItem     (hashTable *htable, const void * key);
 extern bool    hashTableHasItem     (hashTable * htable, const void * key);
 extern bool    hashTableDeleteItem  (hashTable *htable, const void *key);
-extern bool       hashTableUpdateItem  (hashTable *htable, void *key, void *value);
+
+/* If KEY is found, this function updates the value for KEY and returns true.
+ * If KEY is not found, this function just returns false.
+ *
+ * KEY is just referred. The HTABLE takes the ownership of VALUE when KEY is found. */
+extern bool       hashTableUpdateItem  (hashTable *htable, const void *key, void *value);
+
+/* If KEY is found, this function updates the value for KEY and returns true.
+ * If KEY is not found, this function adds KEY and VALUE and returns false.
+ *
+ * The HTABLE takes the ownership of KEY only if KEY is not found.
+ * The HTABLE takes the ownership of VALUE either when KEY is found or not. */
+extern bool       hashTableUpdateOrPutItem  (hashTable *htable, void *key, void *value);
 
 /* Return true if proc never returns false; proc returns true for all
  * the items, or htable holds no item.