Good morning,
I have a little problem with a php script which uses really lots of
memory. Until now, I have thought that PHP will free variable memory
after the end of a function. But it seems, that this is not true.
simple variables:
function readData() {
$data = file_get_contents("C:/phpProjekte/map1000.db");
$data2 = $data;
}
function readData2() {
$data = file_get_contents("C:/phpProjekte/map1000.db");
$data2 = $data;
unset($data);
unset($data2);
}
These two functions need no memory, it works fine.
recordsets (sqlite):
function readData() {
$db = sqlite_open('C:/phpProjekte/map1000.db', 0666);
$rs = sqlite_query($db, 'Select * from Node');
sqlite_close($db);
}
function readData2() {
$db = sqlite_open('C:/phpProjekte/map1000.db', 0666);
$rs = sqlite_query($db, 'Select * from Node');
sqlite_close($db);
unset($rs);
}
With these functions, you will see a difference in memory usage. But
there is no sqlite_free_result, which would imply, that you have free
your memory. I think, this is a bug. The memory should be freed after
the end of the script automatically.
arrays:
function readData() {
$arr = array();
for ($i=1; $i<500; $i++) {
$arr[$i] = 5;
}
}
function readData2() {
$arr = array();
for ($i=1; $i<500; $i++) {
$arr[$i] = new test();
}
unset($arr);
}
There is no difference. The memory is freed correctly.
Objects:
class test {
public $t = 3;
}
function readData() {
$arr = array();
for ($i=1; $i<500; $i++) {
$arr[$i] = new test();
}
}
function readData2() {
$arr = array();
for ($i=1; $i<500; $i++) {
$arr[$i] = new test();
}
unset($arr);
}
There is a difference: The memory is not freed correctly. I also think
this is a bug.
Of course, PHP will free used memory after the end of the script, but
because PHP could also be used in complex scripts, it would be
important, that the garbage collector will do what it promises.
I have found the error by creating a squarified cushion treemap. The
algo really works good in PHP. But if you have large trees, than PHP
needs to much memory.
Mathias