Hello again,
once again top posting this this is fairly old ..
however for something that is sounding so promising I am wondering why
this hasnt been picked up ..
regards,
Lukas
On 20.10.2008, at 22:09, shire wrote:
On Oct 19, 2008, at 12:11 PM, Karoly Negyesi wrote:
Hi,
I think zend_hash_compare could get a healthy speed boost in some
cases if first it would check whether the two variables passed to it
are actually the same (because of "reference counting"). Sorry, my C
skills are way too rusty to write the patch which is likely to be
just
a few lines long.
A quick patch/test seems to agree with you, I'd be interested to
know if you/others are able to apply this patch and see any real-
world savings with your web application. The following was done
with a debug build of PHP so results are likely exaggerated. I'm
also using non-recursive array with 256 byte strings below, results
with numeric values are less significant of course (approx a 25%
gain)...
I'll also look into applying this to some other functions like
compare_function where it's likely to yield a larger savings in a
general application.
patch against php-5.2 CVS head
--------------------------
iff --git a/Zend/zend_hash.c b/Zend/zend_hash.c
index a1d7071..d11785f 100644
--- a/Zend/zend_hash.c
+++ b/Zend/zend_hash.c
@@ -1327,16 +1327,14 @@ ZEND_API int zend_hash_compare(HashTable
*ht1, HashTable *ht2, compare_func_t co
IS_CONSISTENT(ht1);
IS_CONSISTENT(ht2);
- HASH_PROTECT_RECURSION(ht1);
- HASH_PROTECT_RECURSION(ht2);
-
result = ht1->nNumOfElements - ht2->nNumOfElements;
- if (result!=0) {
- HASH_UNPROTECT_RECURSION(ht1);
- HASH_UNPROTECT_RECURSION(ht2);
+ if (ht1 == ht2 || result!=0) {
return result;
}
+ HASH_PROTECT_RECURSION(ht1);
+ HASH_PROTECT_RECURSION(ht2);
+
p1 = ht1->pListHead;
if (ordered) {
p2 = ht2->pListHead;
simple test script
-------------------------------
<?php
$arr1 = array();
for ($i=0; $i < 10000; $i++) {
$arr1[$i] = str_repeat('x', 256);
}
$arr2 = array();
for ($i=0; $i < 10000; $i++) {
$arr2[$i] = str_repeat('x', 256);
}
$arr3 = $arr1;
$count = 0;
$start = microtime(true);
for ($i = 0; $i < 1000; $i++) {
if ($arr1 == $arr2) {
$count++;
}
}
$stop = microtime(true);
echo "different array time: ".($stop-$start)."\n";
echo "count: $count \n";
$count = 0;
$start = microtime(true);
for ($i = 0; $i < 1000; $i++) {
if ($arr1 == $arr3) {
$count++;
}
}
$stop = microtime(true);
echo "identical array time: ".($stop-$start)."\n";
echo "count: $count \n";
-------------------------------
(un-patched php build)
[EMAIL PROTECTED]:~/data/php/git/php$ ./sapi/cli/php.vanilla test.php
different array time: 4.2019698619843
count: 1000
identical array time: 2.4957029819489
count: 1000
(patched build)
[EMAIL PROTECTED]:~/data/php/git/php$ ./sapi/cli/php test.php
different array time: 4.059928894043
count: 1000
identical array time: 0.00043511390686035
count: 1000
-shire
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Lukas Kahwe Smith
[EMAIL PROTECTED]
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