Implemented DHT

lookup.c

@@ -0,0 +1,58 @@
+#include "lookup.h"
+
+void init_lookup_table()
+{
+    table = malloc(sizeof(lookup_head));
+    if (table == NULL) return;
+    table->head = NULL;
+}
+
+void push_lookup(lookup_request *request)
+{
+    if (free_space == 0)
+    {
+        lookup_table *infront = table->head;
+        while (infront->next != NULL && infront->next->next != NULL)
+        {
+            infront = infront->next;
+        }
+
+        free(infront->next->request);
+        free(infront->next);
+        infront->next = NULL;
+        // if malloc fails this does not leak space
+        free_space++;
+    }
+
+    lookup_table *new = (lookup_table*)malloc(sizeof(lookup_table));
+    if (new == NULL) return;
+    new->request = request;
+    new->next = table->head;
+    table->head = new;
+    free_space--;
+}
+
+lookup_request *find_lookup(const uint16_t hash_id)
+{
+    const lookup_table *current = table->head;
+    while (current != NULL && current->request->hash_id != hash_id)
+        current = current->next;
+    return current == NULL ? NULL : current->request;
+}
+
+void free_lookup_table()
+{
+    if (table == NULL) return;
+    lookup_table *current = table->head;
+
+    while (current != NULL)
+    {
+        lookup_table *temp = current;
+        current = current->next;
+        free(temp->request);
+        free(temp);
+    }
+    free(table);
+    table = NULL;
+    free_space = TABLE_SIZE;
+}