[NEEDS CLEAN-UP]: Working O(n) Cache

src/include/pgagroal.h

@@ -253,6 +253,11 @@ extern void* prometheus_cache_shmem;
  * response cache.
  */
 extern void* query_cache_shmem;
+/**
+ * Shared memory used to contain the Prometheus
+ * response cache.
+ */
+extern void* client_server_shmem;
 
 /** @struct
  * Defines a server
@@ -359,6 +364,13 @@ struct prometheus_cache
    size_t size;          /**< size of the cache */
    char data[];          /**< the payload */
 } __attribute__ ((aligned (64)));
+struct client_server_cache
+{
+   char kind;
+   atomic_schar lock;
+   size_t key_length;
+   char key[];
+} __attribute__ ((aligned (64)));
 
 /** @struct
  * Defines the Prometheus metrics
@@ -424,6 +436,13 @@ struct query_cache
    atomic_schar lock;    /**< lock to protect the cache */
    size_t size;          /**< size of the cache */
    struct hashTable* table;
+   struct cachev2
+   {
+      struct hashEntry* key;
+      struct hashEntry* data;
+   } cache[100000];
+   int max_elements;
+
 } __attribute__ ((aligned (64)));
 
 struct hashTable
@@ -437,6 +456,7 @@ struct hashEntry
 {
    void* value;
    size_t length;
+   char key[];
 } __attribute__ ((aligned (64)));
 
 /** @struct

src/include/query_cache.h

@@ -80,7 +80,7 @@ pgagroal_query_cache_init(size_t* p_size, void** p_shmem);
  *
  * @warning The caller should ensure the validity of the 'Table' pointer and the 'key' pointer.
  */
-struct hashTable*
+struct hashEntry*
 pgagroal_query_cache_get(struct query_cache* cache, struct hashTable** Table, struct hashEntry* key);
 
 /**