From 36350a57f4fe6a70f139c0cbb01984cc1692e353 Mon Sep 17 00:00:00 2001
From: Bruce Cowan <bruce.cowan@strath.ac.uk>
Date: Sun, 22 Dec 2019 14:56:05 +0000
Subject: [PATCH] Change hashtable to use arrays rather than linked lists
---
lib/types/hashtable.c | 69 +++++++++++++++++++++++++++----------------
lib/types/hashtable.h | 2 --
2 files changed, 43 insertions(+), 28 deletions(-)
diff --git a/lib/types/hashtable.c b/lib/types/hashtable.c
index a55e447..00803b3 100644
--- a/lib/types/hashtable.c
+++ b/lib/types/hashtable.c
@@ -1,3 +1,4 @@
+#include "array.h"
#include "hashtable.h"
#include "mem.h"
@@ -19,10 +20,20 @@ typedef struct
*/
struct _HashTable
{
- SList **array;
- size_t size;
+ Array **buckets;
+ size_t size;
};
+static void
+key_value_free (void *element)
+{
+ KeyValue *kv = (KeyValue *) element;
+
+ free (kv->key);
+ free (kv->value);
+ free (kv);
+}
+
/**
* hash_table_new:
* @size: Number of buckets to use.
@@ -32,23 +43,23 @@ struct _HashTable
HashTable *
hash_table_new (size_t size)
{
- HashTable *new = malloc (sizeof (HashTable));
- new->array = calloc (size, sizeof (SList *));
- new->size = size;
+ HashTable *new = malloc (sizeof (HashTable));
+ new->buckets = calloc (size, sizeof (Array *));
+ new->size = size;
- return new;
+ return new;
}
static unsigned
strhash (const char *string)
{
- unsigned h = 5381;
- char c;
+ unsigned h = 5381;
+ char c;
- while ((c = *string++))
- h = (h << 5) + h + c;
+ while ((c = *string++))
+ h = (h << 5) + h + c;
- return h;
+ return h;
}
/**
@@ -66,14 +77,17 @@ hash_table_insert (HashTable *table,
const char *key,
const char *value)
{
- unsigned index = strhash (key) % table->size;
+ unsigned index = strhash (key) % table->size;
KeyValue *kv = check_malloc (sizeof (KeyValue));
kv->key = strdup (key);
kv->value = strdup (value);
- SList *list = slist_prepend (table->array[index], kv);
- table->array[index] = list;
+ // Only create array if needed
+ if (!table->buckets[index])
+ table->buckets[index] = array_new (key_value_free);
+
+ array_add (table->buckets[index], kv);
}
/**
@@ -86,16 +100,19 @@ hash_table_insert (HashTable *table,
void
hash_table_print_all (HashTable *table)
{
- for (size_t i = 0; i < table->size; i++)
- {
- SList *bucket = table->array[i];
- if (bucket == NULL)
- continue;
-
- for (SList *list = bucket; list; list = list->next)
- {
- KeyValue *kv = list->data;
- printf ("%s:%s\n", kv->key, kv->value);
- }
- }
+ for (size_t i = 0; i < table->size; i++)
+ {
+ Array *bucket = table->buckets[i];
+
+ if (!bucket)
+ continue;
+
+ size_t length = array_get_length (bucket);
+
+ for (size_t j = 0; j < length; j++)
+ {
+ KeyValue *kv = (KeyValue *) array_get (bucket, j);
+ printf ("%s:%s\n", kv->key, kv->value);
+ }
+ }
}
diff --git a/lib/types/hashtable.h b/lib/types/hashtable.h
index 03d02f4..d2b9e92 100644
--- a/lib/types/hashtable.h
+++ b/lib/types/hashtable.h
@@ -2,8 +2,6 @@
#include <stddef.h>
-#include "slist.h"
-
typedef struct _HashTable HashTable;
HashTable * hash_table_new (size_t size);
--
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