for_each_hash: allow passing a 'void *data' pointer to callback

For the find_exact_renames() function, this allows us to pass the
diff_options structure pointer to the low-level routines.  We will use
that to distinguish between the "rename" and "copy" cases.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/describe.c

@@ -63,7 +63,7 @@ static inline struct commit_name *find_commit_name(const unsigned char *peeled)
 	return n;
 }
 
-static int set_util(void *chain)
+static int set_util(void *chain, void *data)
 {
 	struct commit_name *n;
 	for (n = chain; n; n = n->next) {
@@ -289,7 +289,7 @@ static void describe(const char *arg, int last_one)
 		fprintf(stderr, "searching to describe %s\n", arg);
 
 	if (!have_util) {
-		for_each_hash(&names, set_util);
+		for_each_hash(&names, set_util, NULL);
 		have_util = 1;
 	}
 

diffcore-rename.c

@@ -247,7 +247,8 @@ struct file_similarity {
 };
 
 static int find_identical_files(struct file_similarity *src,
-				struct file_similarity *dst)
+				struct file_similarity *dst,
+				struct diff_options *options)
 {
 	int renames = 0;
 
@@ -306,11 +307,12 @@ static void free_similarity_list(struct file_similarity *p)
 	}
 }
 
-static int find_same_files(void *ptr)
+static int find_same_files(void *ptr, void *data)
 {
 	int ret;
 	struct file_similarity *p = ptr;
 	struct file_similarity *src = NULL, *dst = NULL;
+	struct diff_options *options = data;
 
 	/* Split the hash list up into sources and destinations */
 	do {
@@ -329,7 +331,7 @@ static int find_same_files(void *ptr)
 	 * If we have both sources *and* destinations, see if
 	 * we can match them up
 	 */
-	ret = (src && dst) ? find_identical_files(src, dst) : 0;
+	ret = (src && dst) ? find_identical_files(src, dst, options) : 0;
 
 	/* Free the hashes and return the number of renames found */
 	free_similarity_list(src);
@@ -377,7 +379,7 @@ static void insert_file_table(struct hash_table *table, int src_dst, int index,
  * and then during the second round we try to match
  * cache-dirty entries as well.
  */
-static int find_exact_renames(void)
+static int find_exact_renames(struct diff_options *options)
 {
 	int i;
 	struct hash_table file_table;
@@ -390,7 +392,7 @@ static int find_exact_renames(void)
 		insert_file_table(&file_table, 1, i, rename_dst[i].two);
 
 	/* Find the renames */
-	i = for_each_hash(&file_table, find_same_files);
+	i = for_each_hash(&file_table, find_same_files, options);
 
 	/* .. and free the hash data structure */
 	free_hash(&file_table);
@@ -467,7 +469,7 @@ void diffcore_rename(struct diff_options *options)
 	 * We really want to cull the candidates list early
 	 * with cheap tests in order to avoid doing deltas.
 	 */
-	rename_count = find_exact_renames();
+	rename_count = find_exact_renames(options);
 
 	/* Did we only want exact renames? */
 	if (minimum_score == MAX_SCORE)

hash.c

@@ -81,7 +81,7 @@ void **insert_hash(unsigned int hash, void *ptr, struct hash_table *table)
 	return insert_hash_entry(hash, ptr, table);
 }
 
-int for_each_hash(const struct hash_table *table, int (*fn)(void *))
+int for_each_hash(const struct hash_table *table, int (*fn)(void *, void *), void *data)
 {
 	int sum = 0;
 	unsigned int i;
@@ -92,7 +92,7 @@ int for_each_hash(const struct hash_table *table, int (*fn)(void *))
 		void *ptr = array->ptr;
 		array++;
 		if (ptr) {
-			int val = fn(ptr);
+			int val = fn(ptr, data);
 			if (val < 0)
 				return val;
 			sum += val;

hash.h

@@ -30,7 +30,7 @@ struct hash_table {
 
 extern void *lookup_hash(unsigned int hash, const struct hash_table *table);
 extern void **insert_hash(unsigned int hash, void *ptr, struct hash_table *table);
-extern int for_each_hash(const struct hash_table *table, int (*fn)(void *));
+extern int for_each_hash(const struct hash_table *table, int (*fn)(void *, void *), void *data);
 extern void free_hash(struct hash_table *table);
 
 static inline void init_hash(struct hash_table *table)