laikaC_iterPeers now uses hashmap_iter

TODO:
- refactor codebase to use laikaC_iterPeersNext instead of laikaC_iterPeers where appropriate

cnc/src/cnc.c

@@ -451,28 +451,25 @@ void laikaC_sweepPeersTask(struct sLaika_taskService *service, struct sLaika_tas
 
 /* =======================================[[ Peer Iter ]]======================================= */
 
-struct sWrapperData
+bool laikaC_iterPeersNext(struct sLaika_cnc *cnc, size_t *i, struct sLaika_peer **peer)
 {
-    tLaika_peerIter iter;
-    void *uData;
-};
+    tCNC_PeerHashElem *elem;
 
-/* wrapper iterator */
-bool iterWrapper(const void *rawItem, void *uData)
-{
-    struct sWrapperData *data = (struct sWrapperData *)uData;
-    tCNC_PeerHashElem *item = (tCNC_PeerHashElem *)rawItem;
-    return data->iter(item->peer, data->uData);
+    if (hashmap_iter(cnc->peers, i, (void *)&elem)) {
+        *peer = elem->peer;
+        return true;
+    }
+
+    *peer = NULL;
+    return false;
 }
 
 void laikaC_iterPeers(struct sLaika_cnc *cnc, tLaika_peerIter iter, void *uData)
 {
-    struct sWrapperData wrapper;
-    wrapper.iter = iter;
-    wrapper.uData = uData;
+    size_t i = 0;
+    struct sLaika_peer *peer;
 
-    /* iterate over hashmap calling our iterWrapper, pass the *real* iterator to
-        itemWrapper so that it can call it. probably a better way to do this
-        but w/e lol */
-    hashmap_scan(cnc->peers, iterWrapper, &wrapper);
+    /* call iter for every peer in cnc->peers */
+    while (laikaC_iterPeersNext(cnc, &i, &peer))
+        iter(peer, uData);
 }

lib/include/hashmap.h

@@ -1,3 +1,4 @@
+// https://github.com/tidwall/hashmap.c
 // Copyright 2020 Joshua J Baker. All rights reserved.
 // Use of this source code is governed by an MIT-style
 // license that can be found in the LICENSE file.
@@ -11,44 +12,32 @@
 
 struct hashmap;
 
-struct hashmap *hashmap_new(size_t elsize, size_t cap, 
-                            uint64_t seed0, uint64_t seed1,
-                            uint64_t (*hash)(const void *item, 
-                                             uint64_t seed0, uint64_t seed1),
-                            int (*compare)(const void *a, const void *b, 
-                                           void *udata),
-                            void (*elfree)(void *item),
-                            void *udata);
-struct hashmap *hashmap_new_with_allocator(
-                            void *(*malloc)(size_t), 
-                            void *(*realloc)(void *, size_t), 
-                            void (*free)(void*),
-                            size_t elsize, size_t cap, 
-                            uint64_t seed0, uint64_t seed1,
-                            uint64_t (*hash)(const void *item, 
-                                             uint64_t seed0, uint64_t seed1),
-                            int (*compare)(const void *a, const void *b, 
-                                           void *udata),
-                            void (*elfree)(void *item),
-                            void *udata);
+struct hashmap *hashmap_new(size_t elsize, size_t cap, uint64_t seed0, uint64_t seed1,
+                            uint64_t (*hash)(const void *item, uint64_t seed0, uint64_t seed1),
+                            int (*compare)(const void *a, const void *b, void *udata),
+                            void (*elfree)(void *item), void *udata);
+struct hashmap *
+hashmap_new_with_allocator(void *(*malloc)(size_t), void *(*realloc)(void *, size_t),
+                           void (*free)(void *), size_t elsize, size_t cap, uint64_t seed0,
+                           uint64_t seed1,
+                           uint64_t (*hash)(const void *item, uint64_t seed0, uint64_t seed1),
+                           int (*compare)(const void *a, const void *b, void *udata),
+                           void (*elfree)(void *item), void *udata);
 void hashmap_free(struct hashmap *map);
 void hashmap_clear(struct hashmap *map, bool update_cap);
 size_t hashmap_count(struct hashmap *map);
 bool hashmap_oom(struct hashmap *map);
 void *hashmap_get(struct hashmap *map, const void *item);
-void *hashmap_set(struct hashmap *map, void *item);
+void *hashmap_set(struct hashmap *map, const void *item);
 void *hashmap_delete(struct hashmap *map, void *item);
 void *hashmap_probe(struct hashmap *map, uint64_t position);
-bool hashmap_scan(struct hashmap *map,
-                  bool (*iter)(const void *item, void *udata), void *udata);
-
-uint64_t hashmap_sip(const void *data, size_t len, 
-                     uint64_t seed0, uint64_t seed1);
-uint64_t hashmap_murmur(const void *data, size_t len, 
-                        uint64_t seed0, uint64_t seed1);
+bool hashmap_scan(struct hashmap *map, bool (*iter)(const void *item, void *udata), void *udata);
+bool hashmap_iter(struct hashmap *map, size_t *i, void **item);
 
+uint64_t hashmap_sip(const void *data, size_t len, uint64_t seed0, uint64_t seed1);
+uint64_t hashmap_murmur(const void *data, size_t len, uint64_t seed0, uint64_t seed1);
 
 // DEPRECATED: use `hashmap_new_with_allocator`
-void hashmap_set_allocator(void *(*malloc)(size_t), void (*free)(void*));
+void hashmap_set_allocator(void *(*malloc)(size_t), void (*free)(void *));
 
 #endif

lib/vendor/hashmap.c

@@ -2,13 +2,14 @@
 // Use of this source code is governed by an MIT-style
 // license that can be found in the LICENSE file.
 
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <stddef.h>
 #include "hashmap.h"
 
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
 static void *(*_malloc)(size_t) = NULL;
 static void *(*_realloc)(void *, size_t) = NULL;
 static void (*_free)(void *) = NULL;
@@ -23,7 +24,7 @@ void hashmap_set_allocator(void *(*malloc)(size_t), void (*free)(void*))
 }
 
 #define panic(_msg_) { \
-    /*fprintf(stderr, "panic: %s (%s:%d)\n", (_msg_), __FILE__, __LINE__);*/ \
+    fprintf(stderr, "panic: %s (%s:%d)\n", (_msg_), __FILE__, __LINE__); \
     exit(1); \
 }
 
@@ -248,7 +249,7 @@ static bool resize(struct hashmap *map, size_t new_cap) {
 // replaced then it is returned otherwise NULL is returned. This operation
 // may allocate memory. If the system is unable to allocate additional
 // memory then NULL is returned and hashmap_oom() returns true.
-void *hashmap_set(struct hashmap *map, void *item) {
+void *hashmap_set(struct hashmap *map, const void *item) {
     if (!item) {
         panic("item is null");
     }
@@ -408,6 +409,42 @@ bool hashmap_scan(struct hashmap *map,
     return true;
 }
 
+
+// hashmap_iter iterates one key at a time yielding a reference to an
+// entry at each iteration. Useful to write simple loops and avoid writing
+// dedicated callbacks and udata structures, as in hashmap_scan.
+//
+// map is a hash map handle. i is a pointer to a size_t cursor that
+// should be initialized to 0 at the beginning of the loop. item is a void
+// pointer pointer that is populated with the retrieved item. Note that this
+// is NOT a copy of the item stored in the hash map and can be directly
+// modified.
+//
+// Note that if hashmap_delete() is called on the hashmap being iterated,
+// the buckets are rearranged and the iterator must be reset to 0, otherwise
+// unexpected results may be returned after deletion.
+//
+// This function has not been tested for thread safety.
+//
+// The function returns true if an item was retrieved; false if the end of the
+// iteration has been reached.
+bool hashmap_iter(struct hashmap *map, size_t *i, void **item)
+{
+    struct bucket *bucket;
+
+    do {
+        if (*i >= map->nbuckets) return false;
+
+        bucket = bucket_at(map, *i);
+        (*i)++;
+    } while (!bucket->dib);
+
+    *item = bucket_item(bucket);
+
+    return true;
+}
+
+
 //-----------------------------------------------------------------------------
 // SipHash reference C implementation
 //
@@ -738,6 +775,13 @@ static void all() {
     while (!(vals2 = xmalloc(N * sizeof(int)))) {}
     memset(vals2, 0, N * sizeof(int));
     assert(hashmap_scan(map, iter_ints, &vals2));
+
+    // Test hashmap_iter. This does the same as hashmap_scan above.
+    size_t iter = 0;
+    void *iter_val;
+    while (hashmap_iter (map, &iter, &iter_val)) {
+        assert (iter_ints(iter_val, &vals2));
+    }
     for (int i = 0; i < N; i++) {
         assert(vals2[i] == 1);
     }