From 3c946d0a54ef321f995d9112d5265d28dc262a3b Mon Sep 17 00:00:00 2001
From: Nathan Fisher <jeang3nie@hitchhiker-linux.org>
Date: Sat, 12 Aug 2023 11:13:02 -0400
Subject: [PATCH] Add hashmap `deinit` and `get` functions

---
 hmap.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 59 insertions(+), 8 deletions(-)

diff --git a/hmap.c b/hmap.c
index b4342f8..1dafb92 100644
--- a/hmap.c
+++ b/hmap.c
@@ -33,6 +33,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 
@@ -70,7 +71,7 @@ typedef struct {
     hmap_node *buckets;
 } hmap;
 
-hmap_node* hmap_insert(hmap * map, void *key, size_t keysize, void *data);
+void* hmap_insert(hmap * map, void *key, void *data);
 
 hmap_node* hmap_node_init(void *key, size_t keysize, void *data) {
     hmap_node *node;
@@ -85,11 +86,20 @@ hmap_node* hmap_node_init(void *key, size_t keysize, void *data) {
     return node;
 }
 
-void* hmap_node_attach(hmap_node *root, hmap_node *leaf) {
+void hmap_node_deinit(hmap_node *node) {
+    hmap_node *current = node;
+    while (current != NULL) {
+        current = node->next;
+        free(node);
+        node = current;
+    }
+}
+
+void* hmap_node_attach(hmap_node *root, hmap_node *leaf, size_t keysize) {
     void *ret = NULL;
 
     while (1) {
-        if (root->key == leaf->key) {
+        if (memcmp(root->key, leaf->key, keysize) == 0) {
             ret = root->data;
             root->data = leaf->data;
             return ret;
@@ -104,6 +114,21 @@ void* hmap_node_attach(hmap_node *root, hmap_node *leaf) {
     // todo
 }
 
+void* hmap_node_search(hmap_node *root, void *key, size_t keysize) {
+    void *ret = NULL;
+
+    while (1) {
+        if (memcmp(root->key, key, keysize) == 0) {
+            ret = root->data;
+            return ret;
+        } else if (root->next == NULL) {
+            return NULL;
+        } else {
+            root = root->next;
+        }
+    }
+}
+
 hmap* hmap_init(size_t keysize) {
     hmap* map;
 
@@ -120,6 +145,18 @@ hmap* hmap_init(size_t keysize) {
     return map;
 }
 
+void hmap_deinit(hmap *map) {
+    int i;
+
+    for (i = 0; i < map->capacity; i++) {
+        if (map->buckets[i].next != NULL) {
+            hmap_node_deinit(map->buckets[i].next);
+        }
+    }
+    free(map->buckets);
+    free(map);
+}
+
 int hmap_expand(hmap *map) {
     hmap_node *old;
     hmap_node *new;
@@ -133,7 +170,7 @@ int hmap_expand(hmap *map) {
     for (i = 0; i < map->capacity; i++) {
         current = &old[i];
         while (current->key != NULL) {
-            hmap_insert(map, current->key, map->keysize, current->data);
+            hmap_insert(map, current->key, current->data);
             current = current->next;
         }
     }
@@ -141,7 +178,7 @@ int hmap_expand(hmap *map) {
     return 0;
 }
 
-hmap_node* hmap_insert(hmap * map, void *key, size_t keysize, void *data) {
+void* hmap_insert(hmap *map, void *key, void *data) {
     hmap_node *node;
     size_t idx;
     hmap_node *ret = NULL;
@@ -149,14 +186,28 @@ hmap_node* hmap_insert(hmap * map, void *key, size_t keysize, void *data) {
     if (map->len >= map->capacity / 2) {
         if (hmap_expand(map)) return NULL;
     }
-    node = hmap_node_init(key, keysize, data);
+    node = hmap_node_init(key, map->keysize, data);
     if (node == NULL) return NULL;
     idx = node->hash % map->capacity;
     if (map->buckets[idx].key == NULL) {
         map->buckets[idx] = *node;
     } else {
-        ret = hmap_node_attach(&map->buckets[idx], node);
+        ret = hmap_node_attach(&map->buckets[idx], node, map->keysize);
     }
-    // todo
+    map->len += 1;
+    if (ret == NULL)
+        return NULL;
+    else
+        return ret->data;
+}
+
+void* hmap_get(hmap *map, void *key) {
+    uint64_t hash;
+    size_t idx;
+    void *ret;
+
+    hash = hash_fnv1a_64(key, map->keysize);
+    idx = hash % map->capacity;
+    ret = hmap_node_search(&map->buckets[idx], key, map->keysize);
     return ret;
 }