[PATCH] optimization for hash tables and pool userdata

[Brian Pane]

This patch speeds up the apr_hash_t implementation's
handling of APR_HASH_KEY_STRING.

The original logic was:
 call strlen to get the length of the key;
 then iterate through the key to compute the hash;

This patch combines the two into a single pass.
It also changes apr_pool_userdata_get() to take
advantage of this optimization.

--Brian

Index: srclib/apr/tables/apr_hash.c
===================================================================
RCS file: /home/cvspublic/apr/tables/apr_hash.c,v
retrieving revision 1.27
diff -u -r1.27 apr_hash.c
--- srclib/apr/tables/apr_hash.c        2001/11/10 17:58:36     1.27
+++ srclib/apr/tables/apr_hash.c        2001/11/18 07:16:32
@@ -222,9 +222,6 @@
     int hash;
     apr_ssize_t i;
 
-    if (klen == APR_HASH_KEY_STRING)
-       klen = strlen(key);
-
     /*
      * This is the popular `times 33' hash algorithm which is used by
      * perl and also appears in Berkeley DB. This is one of the best
@@ -263,8 +260,17 @@
      *                  -- Ralf S. Engelschall <[EMAIL PROTECTED]>
      */
     hash = 0;
-    for (p = key, i = klen; i; i--, p++)
-       hash = hash * 33 + *p;
+    if (klen == APR_HASH_KEY_STRING) {
+        for (p = key; *p; p++) {
+            hash = hash * 33 + *p;
+        }
+        klen = p - (const unsigned char *)key;
+    }
+    else {
+        for (p = key, i = klen; i; i--, p++) {
+            hash = hash * 33 + *p;
+        }
+    }
     
     /* scan linked list */
     for (hep = &ht->array[hash & ht->max], he = *hep;
Index: srclib/apr/memory/unix/apr_pools.c
===================================================================
RCS file: /home/cvspublic/apr/memory/unix/apr_pools.c,v
retrieving revision 1.115
diff -u -r1.115 apr_pools.c
--- srclib/apr/memory/unix/apr_pools.c  2001/10/29 14:54:19     1.115
+++ srclib/apr/memory/unix/apr_pools.c  2001/11/18 07:16:33
@@ -1312,7 +1312,7 @@
     if (cont->prog_data == NULL)
         *data = NULL;
     else
-        *data = apr_hash_get(cont->prog_data, key, strlen(key));
+        *data = apr_hash_get(cont->prog_data, key, APR_HASH_KEY_STRING);
     return APR_SUCCESS;
 }