patch 8.1.1752: resizing hashtable is inefficient
Problem: Resizing hashtable is inefficient.
Solution: Avoid resizing when the final size is predictable.
diff --git a/src/hashtab.c b/src/hashtab.c
index ad01857..450cf98 100644
--- a/src/hashtab.c
+++ b/src/hashtab.c
@@ -286,7 +286,6 @@
++ht->ht_locked;
}
-#if 0 /* currently not used */
/*
* Lock a hashtable at the specified number of entries.
* Caller must make sure no more than "size" entries will be added.
@@ -298,7 +297,6 @@
(void)hash_may_resize(ht, size);
++ht->ht_locked;
}
-#endif
/*
* Unlock a hashtable: allow ht_array changes again.
@@ -368,10 +366,10 @@
}
else
{
- /* Use specified size. */
- if ((long_u)minitems < ht->ht_used) /* just in case... */
+ // Use specified size.
+ if ((long_u)minitems < ht->ht_used) // just in case...
minitems = (int)ht->ht_used;
- minsize = minitems * 3 / 2; /* array is up to 2/3 full */
+ minsize = (minitems * 3 + 1) / 2; // array is up to 2/3 full
}
newsize = HT_INIT_SIZE;