Robert Iakobashvili re-arranged the internal hash code to work with a custom

hash function for different hashes, and also expanded the default size for
the socket hash table used in multi handles to greatly enhance speed when
very many connections are added and the socket API is used.

1 files changed, 59 insertions, 40 deletions

diff --git a/lib/hash.c b/lib/hash.c
index e00462778..ec4a759f8 100644
--- a/lib/hash.c
+++ b/lib/hash.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2006, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -33,20 +33,6 @@
 /* this must be the last include file */
 #include "memdebug.h"
 
-static unsigned long
-hash_str(const char *key, size_t key_length)
-{
-  char *end = (char *) key + key_length;
-  unsigned long h = 5381;
-
-  while (key < end) {
-    h += h << 5;
-    h ^= (unsigned long) *key++;
-  }
-
-  return h;
-}
-
 static void
 hash_element_dtor(void *user, void *element)
 {
@@ -63,10 +49,20 @@ hash_element_dtor(void *user, void *element)
 
 /* return 1 on error, 0 is fine */
 int
-Curl_hash_init(struct curl_hash *h, int slots, curl_hash_dtor dtor)
+Curl_hash_init(struct curl_hash *h,
+               int slots,
+               hash_function hfunc,
+               comp_function comparator,
+               curl_hash_dtor dtor)
 {
   int i;
 
+  if (!slots || !hfunc || !comparator ||!dtor) {
+    return 1; /* failure */
+  }
+
+  h->hash_func = hfunc;
+  h->comp_func = comparator;
   h->dtor = dtor;
   h->size = 0;
   h->slots = slots;
@@ -89,13 +85,20 @@ Curl_hash_init(struct curl_hash *h, int slots, curl_hash_dtor dtor)
 }
 
 struct curl_hash *
-Curl_hash_alloc(int slots, curl_hash_dtor dtor)
+Curl_hash_alloc(int slots,
+                hash_function hfunc,
+                comp_function comparator,
+                curl_hash_dtor dtor)
 {
   struct curl_hash *h;
 
+  if (!slots || !hfunc || !comparator ||!dtor) {
+    return NULL; /* failure */
+  }
+
   h = (struct curl_hash *) malloc(sizeof(struct curl_hash));
   if (h) {
-    if(Curl_hash_init(h, slots, dtor)) {
+    if(Curl_hash_init(h, slots, hfunc, comparator, dtor)) {
       /* failure */
       free(h);
       h = NULL;
@@ -105,26 +108,16 @@ Curl_hash_alloc(int slots, curl_hash_dtor dtor)
   return h;
 }
 
-static int
-hash_key_compare(char *key1, size_t key1_len, char *key2, size_t key2_len)
-{
-  if (key1_len == key2_len &&
-      *key1 == *key2 &&
-      memcmp(key1, key2, key1_len) == 0) {
-    return 1;
-  }
 
-  return 0;
-}
 
 static struct curl_hash_element *
-mk_hash_element(char *key, size_t key_len, const void *p)
+mk_hash_element(void *key, size_t key_len, const void *p)
 {
   struct curl_hash_element *he =
     (struct curl_hash_element *) malloc(sizeof(struct curl_hash_element));
 
   if(he) {
-    char *dup = malloc(key_len);
+    void *dup = malloc(key_len);
     if(dup) {
       /* copy the key */
       memcpy(dup, key, key_len);
@@ -142,22 +135,20 @@ mk_hash_element(char *key, size_t key_len, const void *p)
   return he;
 }
 
-#define find_slot(__h, __k, __k_len) (hash_str(__k, __k_len) % (__h)->slots)
-
-#define FETCH_LIST(x,y,z) x->table[find_slot(x, y, z)]
+#define FETCH_LIST(x,y,z) x->table[x->hash_func(y, z, x->slots)]
 
 /* Return the data in the hash. If there already was a match in the hash,
    that data is returned. */
 void *
-Curl_hash_add(struct curl_hash *h, char *key, size_t key_len, void *p)
+Curl_hash_add(struct curl_hash *h, void *key, size_t key_len, void *p)
 {
   struct curl_hash_element  *he;
   struct curl_llist_element *le;
-  struct curl_llist *l = FETCH_LIST(h, key, key_len);
+  struct curl_llist *l = FETCH_LIST (h, key, key_len);
 
   for (le = l->head; le; le = le->next) {
     he = (struct curl_hash_element *) le->ptr;
-    if (hash_key_compare(he->key, he->key_len, key, key_len)) {
+    if (h->comp_func(he->key, he->key_len, key, key_len)) {
       h->dtor(p);     /* remove the NEW entry */
       return he->ptr; /* return the EXISTING entry */
     }
@@ -183,7 +174,7 @@ Curl_hash_add(struct curl_hash *h, char *key, size_t key_len, void *p)
 }
 
 /* remove the identified hash entry, returns non-zero on failure */
-int Curl_hash_delete(struct curl_hash *h, char *key, size_t key_len)
+int Curl_hash_delete(struct curl_hash *h, void *key, size_t key_len)
 {
   struct curl_llist_element *le;
   struct curl_hash_element  *he;
@@ -191,7 +182,7 @@ int Curl_hash_delete(struct curl_hash *h, char *key, size_t key_len)
 
   for (le = l->head; le; le = le->next) {
     he = le->ptr;
-    if (hash_key_compare(he->key, he->key_len, key, key_len)) {
+    if (h->comp_func(he->key, he->key_len, key, key_len)) {
       Curl_llist_remove(l, le, (void *) h);
       return 0;
     }
@@ -200,7 +191,7 @@ int Curl_hash_delete(struct curl_hash *h, char *key, size_t key_len)
 }
 
 void *
-Curl_hash_pick(struct curl_hash *h, char *key, size_t key_len)
+Curl_hash_pick(struct curl_hash *h, void *key, size_t key_len)
 {
   struct curl_llist_element *le;
   struct curl_hash_element  *he;
@@ -208,7 +199,7 @@ Curl_hash_pick(struct curl_hash *h, char *key, size_t key_len)
 
   for (le = l->head; le; le = le->next) {
     he = le->ptr;
-    if (hash_key_compare(he->key, he->key_len, key, key_len)) {
+    if (h->comp_func(he->key, he->key_len, key, key_len)) {
       return he->ptr;
     }
   }
@@ -282,6 +273,34 @@ Curl_hash_destroy(struct curl_hash *h)
   free(h);
 }
 
+size_t Curl_hash_str(void* key, size_t key_length, size_t slots_num)
+{
+  char* key_str = (char *) key;
+  char *end = (char *) key_str + key_length;
+  unsigned long h = 5381;
+
+  while (key_str < end) {
+    h += h << 5;
+    h ^= (unsigned long) *key_str++;
+  }
+
+  return (h % slots_num);
+}
+
+size_t Curl_str_key_compare(void*k1, size_t key1_len, void*k2, size_t key2_len)
+{
+  char *key1 = (char *)k1;
+  char *key2 = (char *)k2;
+
+  if (key1_len == key2_len &&
+      *key1 == *key2 &&
+      memcmp(key1, key2, key1_len) == 0) {
+    return 1;
+  }
+
+  return 0;
+}
+
 #if 0 /* useful function for debugging hashes and their contents */
 void Curl_hash_print(struct curl_hash *h,
                      void (*func)(void *))