CRM-8393 Performance improvement in DataObject->fetch()

The fetch() method in DataObject calls str_replace() in a loop, in order to modify the keys of the array. This is an expensive operation, especially since fetch() is called in a loop itself when fetching records one row at a time.

The str_replace() function can perform its own iteration on arrays, so we can cut down drastically on the number of calls to str_replace() by re-writing the keys prior to entering the loop.

The code block starts on line 560.

The original code is:
foreach($array as $k=>$v) {
$kk = str_replace(array("."," "), "_", $k);
if (!empty($_DB_DATAOBJECT['CONFIG']['debug']))

{ $this->debug("$kk = ". $array[$k], "fetchrow LINE", 3); }

$this->$kk = $array[$k];
}

The new code is:
$keys = str_replace(array("."," "), "_", array_keys($array));
$i = 0;
foreach ($array as $val)

{ $key = $keys[$i++]; if (!empty($_DB_DATAOBJECT['CONFIG']['debug'])) $this->debug("$key = $val", "fetchrow LINE", 3); $this->$key = $val; }

We are using this modification, and are seeing performance improvements on all platforms.