Increase array_rand() rehashing treshold

From 3/8 to 3/4. I was thinking in terms of nTableSize, where a
requirement > 1/2 is not tenable. However, we're actually working
with nNumUsed, in which case more than 1/4 tombstones should be
quite unusual.

diff --git a/ext/standard/array.c b/ext/standard/array.c
index 3ffced130ceee062710572430336e17bb5bc6d52..359bd978d40e59f2bd3fa712337a7be82d93e1e9 100644 (file)
--- a/ext/standard/array.c
+++ b/ext/standard/array.c
@@ -5056,8 +5056,8 @@ PHP_FUNCTION(array_rand)
        if (num_req == 1) {
                HashTable *ht = Z_ARRVAL_P(input);
 
-               /* Compact the hashtable if less than 3/8 of elements are used */
-               if (num_avail < ht->nNumUsed - (ht->nNumUsed>>1) - (ht->nNumUsed>>2)) {
+               /* Compact the hashtable if less than 3/4 of elements are used */
+               if (num_avail < ht->nNumUsed - (ht->nNumUsed>>2)) {
                        if (ht->u.flags & HASH_FLAG_PACKED) {
                                zend_hash_packed_to_hash(ht);
                        } else {
@@ -5066,9 +5066,9 @@ PHP_FUNCTION(array_rand)
                }
 
                /* Sample random buckets until we hit one that is not empty.
-                * The worst case probability of hitting an empty element is 1-3/8. The worst case
-                * probability of hitting N empty elements in a row is (1-3/8)**N.
-                * For N=10 this becomes smaller than 1%. */
+                * The worst case probability of hitting an empty element is 1-3/4. The worst case
+                * probability of hitting N empty elements in a row is (1-3/4)**N.
+                * For N=5 this becomes smaller than 0.1%. */
                do {
                        zend_long randval = php_mt_rand_range(0, ht->nNumUsed - 1);
                        Bucket *bucket = &ht->arData[randval];