Add appropriate 'const' qualifier to the parameters

The 'const' qualifier is useful for ensuring type safety. Specifically,
'const' can clarify pointer ownership. It is important to note that
'const' applied to the target of a pointer or reference does not imply
that the target is constant. Instead, it indicates a read-only view of
the object. This means that while the object can not be modified through
this particular reference or pointer, it may still be altered through
other means. An object is truly immutable only when 'const' is used in
its definition. The primary purpose of using 'const' is not to facilitate
compiler optimizations, but to safeguard against programming errors.

Author: jserv

src/cache.c

@@ -192,27 +192,26 @@ cache_t *cache_create(int size_bits)
     cache_t *cache = malloc(sizeof(cache_t));
     if (!cache)
         return NULL;
+
     cache_size_bits = size_bits;
     cache_size = 1 << size_bits;
     for (i = 0; i < THRESHOLD; i++) {
         cache->lists[i] = malloc(sizeof(struct list_head));
-        if (!cache->lists[i]) {
+        if (!cache->lists[i])
             goto free_lists;
-        }
         INIT_LIST_HEAD(cache->lists[i]);
     }
 
     cache->map = malloc(sizeof(hashtable_t));
-    if (!cache->map) {
+    if (!cache->map)
         goto free_lists;
-    }
+
     cache->map->ht_list_head = malloc(cache_size * sizeof(struct hlist_head));
-    if (!cache->map->ht_list_head) {
+    if (!cache->map->ht_list_head)
         goto free_map;
-    }
-    for (uint32_t i = 0; i < cache_size; i++) {
-        INIT_HLIST_HEAD(&cache->map->ht_list_head[i]);
-    }
+
+    for (size_t ii = 0; ii < cache_size; ii++)
+        INIT_HLIST_HEAD(&cache->map->ht_list_head[ii]);
     cache->list_size = 0;
     cache_mp =
         mpool_create(cache_size * sizeof(lfu_entry_t), sizeof(lfu_entry_t));
@@ -229,7 +228,7 @@ cache_t *cache_create(int size_bits)
     return NULL;
 }
 
-void *cache_get(cache_t *cache, uint32_t key)
+void *cache_get(const cache_t *cache, uint32_t key)
 {
     if (!cache->capacity ||
         hlist_empty(&cache->map->ht_list_head[cache_hash(key)]))
@@ -326,7 +325,7 @@ uint32_t cache_freq(struct cache *cache, uint32_t key)
 }
 
 #if RV32_HAS(JIT)
-bool cache_hot(struct cache *cache, uint32_t key)
+bool cache_hot(const struct cache *cache, uint32_t key)
 {
     if (!cache->capacity ||
         hlist_empty(&cache->map->ht_list_head[cache_hash(key)]))

src/cache.h

@@ -22,7 +22,7 @@ struct cache *cache_create(int size_bits);
  * @key: the key of the specified entry
  * @return: the specified entry or NULL
  */
-void *cache_get(struct cache *cache, uint32_t key);
+void *cache_get(const struct cache *cache, uint32_t key);
 
 /**
  * cache_put - insert a new entry into the cache
@@ -47,7 +47,7 @@ void cache_free(struct cache *cache);
  * @cache: a pointer points to target cache
  * @key: the key of the specified entry
  */
-bool cache_hot(struct cache *cache, uint32_t key);
+bool cache_hot(const struct cache *cache, uint32_t key);
 #endif
 
 uint32_t cache_freq(struct cache *cache, uint32_t key);