iftop

hash.c

@@ -0,0 +1,112 @@
+/* hash table */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "hash.h"
+
+hash_status_enum hash_insert(hash_type* hash_table, void* key, void* rec) {
+    hash_node_type *p, *p0;
+    int bucket;
+
+   /************************************************
+    *  allocate node for data and insert in table  *
+    ************************************************/
+
+
+    /* insert node at beginning of list */
+    bucket = hash_table->hash(key);
+    if ((p = malloc(sizeof(hash_node_type))) == 0)
+        return HASH_STATUS_MEM_EXHAUSTED;
+    p0 = hash_table->table[bucket];
+    hash_table->table[bucket] = p;
+    p->next = p0;
+    p->key = hash_table->copy_key(key);
+    p->rec = rec;
+    return HASH_STATUS_OK;
+}
+
+hash_status_enum hash_delete(hash_type* hash_table, void* key) {
+    hash_node_type *p0, *p;
+    int bucket;
+
+   /********************************************
+    *  delete node containing data from table  *
+    ********************************************/
+
+    /* find node */
+    p0 = 0;
+    bucket = hash_table->hash(key);
+    p = hash_table->table[bucket];
+    while (p && !hash_table->compare(p->key, key)) {
+        p0 = p;
+        p = p->next;
+    }
+    if (!p) return HASH_STATUS_KEY_NOT_FOUND;
+
+    /* p designates node to delete, remove it from list */
+    if (p0)
+        /* not first node, p0 points to previous node */
+        p0->next = p->next;
+    else
+        /* first node on chain */
+        hash_table->table[bucket] = p->next;
+
+    hash_table->delete_key(p->key);
+    free (p);
+    return HASH_STATUS_OK;
+}
+
+hash_status_enum hash_find(hash_type* hash_table, void* key, void **rec) {
+    hash_node_type *p;
+
+   /*******************************
+    *  find node containing data  *
+    *******************************/
+    p = hash_table->table[hash_table->hash(key)];
+    while (p && !hash_table->compare(p->key, key)) 
+        p = p->next;
+    if (!p) return HASH_STATUS_KEY_NOT_FOUND;
+    *rec = p->rec;
+    return HASH_STATUS_OK;
+}
+
+hash_status_enum hash_next_item(hash_type* hash_table, hash_node_type** ppnode) {
+    int i;
+    if(*ppnode != NULL) {
+        if((*ppnode)->next != NULL) {
+            *ppnode = (*ppnode)->next;
+            return HASH_STATUS_OK;
+        }
+        i = hash_table->hash((*ppnode)->key) + 1;
+    }
+    else {
+        /* first node */
+        i = 0;
+    }
+    while(i < hash_table->size && hash_table->table[i] == NULL) {
+         i++; 
+    }
+    if(i == hash_table->size) {
+        *ppnode = NULL;
+        return HASH_STATUS_KEY_NOT_FOUND;
+    }
+    *ppnode = hash_table->table[i];
+    return HASH_STATUS_OK;
+}
+
+/*
+ * Allocate and return a hash
+ */
+hash_status_enum hash_initialise(hash_type* hash_table) {
+    if ((hash_table->table = calloc(hash_table->size, sizeof(hash_node_type *))) == 0) {
+        fprintf (stderr, "out of memory (hash_table)\n");
+        return HASH_STATUS_MEM_EXHAUSTED;
+    }
+    return HASH_STATUS_OK;
+}
+
+hash_status_enum hash_destroy(hash_type* hash_table) {
+    free(hash_table->table);
+    return HASH_STATUS_OK;
+}
+