From: Ari Johnson <ari@theari.com>
Date: Tue, 10 May 2011 23:42:04 +0000 (-0400)
Subject: Update to latest PennMUSH hashtab code, with one bugfix.
X-Git-Url: https://git.theari.com/?a=commitdiff_plain;h=71958e114d118392a1db807962381b632b0e0615;p=cobramush.git

Update to latest PennMUSH hashtab code, with one bugfix.

refs #235
---

diff --git a/src/htab.c b/src/htab.c
index 0d8a347..5835e65 100644
--- a/src/htab.c
+++ b/src/htab.c
@@ -7,7 +7,7 @@
  * to resolve collisions. This gives an O(1) worse-case performance
  * (As well as best, of course), compared to the worst-case O(N) of
  * chained or linear probing tables.
- * 
+ *
  * A lookup will require at most X hash functions and string
  * comparisions.  The old tables had, with data used by Penn, 1 hash
  * function and up to 6 or 7 comparisions in the worst case. Best case
@@ -53,7 +53,7 @@
 #endif
 #include "conf.h"
 #include "externs.h"
-
+#include "log.h"
 #include "htab.h"
 #include "mymalloc.h"
 
@@ -266,7 +266,7 @@ penn_hash(const char *key, int len)
   return hash;
 }
 
-typedef uint32_t (*hash_func) (const char *, int);
+typedef uint32_t(*hash_func) (const char *, int);
 
 hash_func hash_functions[] = {
   hsieh_hash,
@@ -419,7 +419,6 @@ next_prime_after(unsigned int val)
 /** Initialize a hashtable.
  * \param htab pointer to hash table to initialize.
  * \param size size of hashtable.
- * \param data_size size of an individual datum to store in the table.
  */
 void
 hash_init(HASHTAB *htab, int size, void (*free_data) (void *))
@@ -503,7 +502,8 @@ hash_insert(HASHTAB *htab, const char *key, void *data)
 
   /* At this point, we've bumped BUMP_LIMIT times. Probably in a
      loop. Find the first empty bucket, add the last bumped to, and
-     return failure. */
+     return failure. The table will have to be resized now to restore
+     the hash. */
   for (n = 0; n < htab->hashsize; n++)
     if (htab->buckets[n].key == NULL) {
       htab->buckets[n] = bump;
@@ -554,9 +554,7 @@ real_hash_resize(HASHTAB *htab, int newsize, int hashfunc_offset)
   htab->hashsize = newsize;
   htab->hashfunc_offset = hashfunc_offset;
   for (i = 0; i < oldsize; i++) {
-
     if (oldarr[i].key) {
-
       if (!hash_insert(htab, oldarr[i].key, oldarr[i].data)) {
         /* Couldn't fit an element in. Try with different hash functions. */
         mush_free(htab->buckets, "hash.buckets");
@@ -596,34 +594,29 @@ hash_resize(HASHTAB *htab, int size)
  * \param htab pointer to hash table.
  * \param key key string to store data under.
  * \param hashdata void pointer to data to be stored.
- * \param extra_size unused.
  * \retval false failure.
  * \retval true success.
  */
 bool
 hash_add(HASHTAB *htab, const char *key, void *hashdata)
 {
-  const char *keycopy;
+  char *keycopy;
 
   if (hash_find(htab, key) != NULL)
     return false;
 
-  htab->entries += 1;
-
   keycopy = mush_strdup(key, "hash.key");
 
+  if (htab->entries == htab->hashsize)
+    real_hash_resize(htab, next_prime_after(floor(htab->hashsize * 1.15)),
+                     htab->hashfunc_offset);
 
-  while (1) {
-    if (!hash_insert(htab, keycopy, hashdata)) {
-      first_offset = -1;
-      resize_calls = 0;
-      if (!real_hash_resize(htab, htab->hashsize,
-			    (htab->hashfunc_offset + 1) % NHASH_MOD)) {
-	htab->entries -= 1;
-	return false;
-      }
-    } else
-      break;
+  htab->entries += 1;
+  if (!hash_insert(htab, keycopy, hashdata)) {
+    first_offset = -1;
+    resize_calls = 0;
+    real_hash_resize(htab, htab->hashsize,
+                     (htab->hashfunc_offset + 1) % NHASH_MOD);
   }
   return true;
 }
@@ -675,7 +668,7 @@ hash_flush(HASHTAB *htab, int size)
 }
 
 /** Return the first entry of a hash table.
- * This function is used with hash_nextentry() to iterate through a 
+ * This function is used with hash_nextentry() to iterate through a
  * hash table.
  * \param htab pointer to hash table.
  * \return first hash table entry.
@@ -694,7 +687,7 @@ hash_firstentry(HASHTAB *htab)
 }
 
 /** Return the first key of a hash table.
- * This function is used with hash_nextentry_key() to iterate through a 
+ * This function is used with hash_nextentry_key() to iterate through a
  * hash table.
  * \param htab pointer to hash table.
  * \return first hash table key.
@@ -713,7 +706,7 @@ hash_firstentry_key(HASHTAB *htab)
 }
 
 /** Return the next entry of a hash table.
- * This function is used with hash_firstentry() to iterate through a 
+ * This function is used with hash_firstentry() to iterate through a
  * hash table. hash_firstentry() must be called before calling
  * this function.
  * \param htab pointer to hash table.
@@ -734,7 +727,7 @@ hash_nextentry(HASHTAB *htab)
 }
 
 /** Return the next key of a hash table.
- * This function is used with hash_firstentry{,_key}() to iterate through a 
+ * This function is used with hash_firstentry{,_key}() to iterate through a
  * hash table. hash_firstentry{,_key}() must be called before calling
  * this function.
  * \param htab pointer to hash table.
@@ -772,7 +765,7 @@ hash_stats_header(dbref player)
 void
 hash_stats(dbref player, HASHTAB *htab, const char *hname)
 {
-  int n;
+  int n, entries = 0;
   size_t bytes;
   unsigned int compares[3] = { 0, 0, 0 };
 
@@ -787,6 +780,7 @@ hash_stats(dbref player, HASHTAB *htab, const char *hname)
       int i;
       int len = strlen(htab->buckets[n].key);
       bytes += len + 1;
+      entries += 1;
       for (i = 0; i < 3; i++) {
         hash_func hash =
           hash_functions[(i + htab->hashfunc_offset) % NHASH_MOD];
@@ -801,4 +795,7 @@ hash_stats(dbref player, HASHTAB *htab, const char *hname)
                 "%-11s %7d %7d %7u %7u %7u %7u",
                 hname, htab->hashsize, htab->entries, compares[0], compares[1],
                 compares[2], (unsigned int) bytes);
+  if (entries != htab->entries)
+    notify_format(player, "Mismatch in size: %d expected, %d found!",
+                  htab->entries, entries);
 }