hashmap_get_next returns "struct hashmap_entry *" hashmap-wip-v1

This is a step towards removing the requirement for
hashmap_entry being the first field of a struct.

Signed-off-by: Eric Wong <e@80x24.org>

6 files changed, 39 insertions, 23 deletions

diff --git a/diff.c b/diff.c
index 72d3c6aa19..663b5d01f8 100644
--- a/diff.c
+++ b/diff.c
@@ -1035,8 +1035,10 @@ static void pmb_advance_or_null_multi_match(struct diff_options *o,
 {
         int i;
         char *got_match = xcalloc(1, pmb_nr);
+        struct hashmap_entry *ent = &match->ent;
 
-        for (; match; match = hashmap_get_next(hm, &match->ent)) {
+        for (; ent; ent = hashmap_get_next(hm, ent)) {
+                match = container_of(ent, struct moved_entry, ent);
                 for (i = 0; i < pmb_nr; i++) {
                         struct moved_entry *prev = pmb[i].match;
                         struct moved_entry *cur = (prev && prev->next_line) ?
@@ -1135,8 +1137,9 @@ static void mark_color_as_moved(struct diff_options *o,
 
         for (n = 0; n < o->emitted_symbols->nr; n++) {
                 struct hashmap *hm = NULL;
+                struct hashmap_entry *ent = NULL;
                 struct moved_entry *key;
-                struct moved_entry *match = NULL;
+                struct moved_entry *match;
                 struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
                 enum diff_symbol last_symbol = 0;
 
@@ -1144,20 +1147,20 @@ static void mark_color_as_moved(struct diff_options *o,
                 case DIFF_SYMBOL_PLUS:
                         hm = del_lines;
                         key = prepare_entry(o, n);
-                        match = hashmap_get(hm, &key->ent, NULL);
+                        ent = hashmap_get(hm, &key->ent, NULL);
                         free(key);
                         break;
                 case DIFF_SYMBOL_MINUS:
                         hm = add_lines;
                         key = prepare_entry(o, n);
-                        match = hashmap_get(hm, &key->ent, NULL);
+                        ent = hashmap_get(hm, &key->ent, NULL);
                         free(key);
                         break;
                 default:
                         flipped_block = 0;
                 }
 
-                if (!match) {
+                if (!ent) {
                         int i;
 
                         adjust_last_block(o, n, block_length);
@@ -1169,6 +1172,7 @@ static void mark_color_as_moved(struct diff_options *o,
                         last_symbol = l->s;
                         continue;
                 }
+                match = container_of(ent, struct moved_entry, ent);
 
                 if (o->color_moved == COLOR_MOVED_PLAIN) {
                         last_symbol = l->s;
@@ -1189,8 +1193,9 @@ static void mark_color_as_moved(struct diff_options *o,
                          * The current line is the start of a new block.
                          * Setup the set of potential blocks.
                          */
-                        for (; match; match = hashmap_get_next(hm,
-                                                                &match->ent)) {
+                        for (; ent; ent = hashmap_get_next(hm, ent)) {
+                                match = container_of(ent, struct moved_entry,
+                                                        ent);
                                 ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
                                 if (o->color_moved_ws_handling &
                                     COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
diff --git a/diffcore-rename.c b/diffcore-rename.c
index 4670a40179..71aa240a68 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -274,7 +274,7 @@ static int find_identical_files(struct hashmap *srcs,
                                 struct diff_options *options)
 {
         int renames = 0;
-
+        struct hashmap_entry *ent;
         struct diff_filespec *target = rename_dst[dst_index].two;
         struct file_similarity *p, *best = NULL;
         int i = 100, best_score = -1;
@@ -282,12 +282,15 @@ static int find_identical_files(struct hashmap *srcs,
         /*
          * Find the best source match for specified destination.
          */
-        p = hashmap_get_from_hash(srcs,
+        ent = hashmap_get_from_hash(srcs,
                                   hash_filespec(options->repo, target),
                                   NULL);
-        for (; p; p = hashmap_get_next(srcs, &p->entry)) {
+        for (; ent; ent = hashmap_get_next(srcs, ent)) {
                 int score;
-                struct diff_filespec *source = p->filespec;
+                struct diff_filespec *source;
+
+                p = container_of(ent, struct file_similarity, entry);
+                source = p->filespec;
 
                 /* False hash collision? */
                 if (!oideq(&source->oid, &target->oid))
diff --git a/hashmap.c b/hashmap.c
index 2dd9912e13..d6434d9ca4 100644
--- a/hashmap.c
+++ b/hashmap.c
@@ -192,7 +192,7 @@ void *hashmap_get(const struct hashmap *map, const struct hashmap_entry *key,
         return *find_entry_ptr(map, key, keydata);
 }
 
-void *hashmap_get_next(const struct hashmap *map,
+struct hashmap_entry *hashmap_get_next(const struct hashmap *map,
                         const struct hashmap_entry *entry)
 {
         struct hashmap_entry *e = entry->next;
diff --git a/hashmap.h b/hashmap.h
index b62ee2e7b9..25643dcdc4 100644
--- a/hashmap.h
+++ b/hashmap.h
@@ -55,15 +55,19 @@
  *
  *         if (!strcmp("print_all_by_key", action)) {
  *             struct long2string k, *e;
+ *             struct hashmap_entry *ent;
  *             hashmap_entry_init(&k->ent, memhash(&key, sizeof(long)));
  *             k.key = key;
  *
  *             flags &= ~COMPARE_VALUE;
- *             e = hashmap_get(&map, &k, NULL);
- *             if (e) {
+ *             ent = hashmap_get(&map, &k, NULL);
+ *             if (ent) {
+ *                 e = container_of(ent, struct long2string, ent);
  *                 printf("first: %ld %s\n", e->key, e->value);
- *                 while ((e = hashmap_get_next(&map, e)))
+ *                 while ((ent = hashmap_get_next(&map, ent))) {
+ *                     e = container_of(ent, struct long2string, ent);
  *                     printf("found more: %ld %s\n", e->key, e->value);
+ *                 }
  *             }
  *         }
  *
@@ -320,7 +324,7 @@ static inline void *hashmap_get_from_hash(const struct hashmap *map,
  * `entry` is the hashmap_entry to start the search from, obtained via a previous
  * call to `hashmap_get` or `hashmap_get_next`.
  */
-void *hashmap_get_next(const struct hashmap *map,
+struct hashmap_entry *hashmap_get_next(const struct hashmap *map,
                         const struct hashmap_entry *entry);
 
 /*
diff --git a/name-hash.c b/name-hash.c
index f64c52bfa2..6f2779934f 100644
--- a/name-hash.c
+++ b/name-hash.c
@@ -703,15 +703,17 @@ void adjust_dirname_case(struct index_state *istate, char *name)
 struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int icase)
 {
         struct cache_entry *ce;
+        struct hashmap_entry *ent;
 
         lazy_init_name_hash(istate);
 
-        ce = hashmap_get_from_hash(&istate->name_hash,
+        ent = hashmap_get_from_hash(&istate->name_hash,
                                    memihash(name, namelen), NULL);
-        while (ce) {
+        while (ent) {
+                ce = container_of(ent, struct cache_entry, ent);
                 if (same_name(ce, name, namelen, icase))
                         return ce;
-                ce = hashmap_get_next(&istate->name_hash, &ce->ent);
+                ent = hashmap_get_next(&istate->name_hash, ent);
         }
         return NULL;
 }
diff --git a/t/helper/test-hashmap.c b/t/helper/test-hashmap.c
index de2bd083b9..d85b8dc58e 100644
--- a/t/helper/test-hashmap.c
+++ b/t/helper/test-hashmap.c
@@ -194,16 +194,18 @@ int cmd__hashmap(int argc, const char **argv)
                         free(entry);
 
                 } else if (!strcmp("get", cmd) && p1) {
+                        struct hashmap_entry *e;
 
                         /* lookup entry in hashmap */
-                        entry = hashmap_get_from_hash(&map, hash, p1);
+                        e = hashmap_get_from_hash(&map, hash, p1);
 
                         /* print result */
-                        if (!entry)
+                        if (!e)
                                 puts("NULL");
-                        while (entry) {
+                        while (e) {
+                                entry = container_of(e, struct test_entry, ent);
                                 puts(get_value(entry));
-                                entry = hashmap_get_next(&map, &entry->ent);
+                                e = hashmap_get_next(&map, e);
                         }
 
                 } else if (!strcmp("remove", cmd) && p1) {