PHP make iteration through big array in steps-CodePudding

I load data from a huge XML-File into an array. That's fine for now, is the memory of the web server not overloaded. But as soon as I try to iterate through that array to work with the data, then I get a memory error. Setting memory-limit to -1 is not an option, obviously.

So, what I am trying to do, is iterating through the array step by step. Like the first 1,000 entries and then the next till there are no more entries left. Like this:

$i = 0;
foreach($entries as $entry) {
    // Do some stuff with the entries
    if (  $i == 1000) break;
}

I now want to iterate through the next 1.000 entries. My idea was to address the key of the array. Like doing the loop again but from entries[1000]. But I can't get the break from the loop and going back into the loop again going.

Is, what I try to achieve, even possible?

Thank you very much!

CodePudding user response：

The issue probably happens before your foreach loop is reached. You should take a look at the code parses the XML file and populates the array $entries. If you are using XMLParser then you should look at the handler functions (they are usually called startElements and endElements, if not look for xml_set_element_handler and the function names would be in its second and third parameters). In the handler functions, you are probably populating the array $entries. You should do your processing directly in the handlers and retrieve the relevant data w/o putting everything in the memory.

PS: If my theory turns out to be correct, you should change the title and rephrase the question

CodePudding user response：

Try this if your data is really Big and slow your web server:

for($i = 1;$i <= count($entries);$i  ) {       
   if($i % 1000 === 0) {
     // your code here        
   }
     usleep(100000); // delays execution for 0.1 second x 1000 entries
 }

CodePudding user response：

from what you did I think you should have done this instead

for ($i=0; $i>=1000; $i  ){

}

Note: the $i=0 is when you want it to start counting from zero but if you want it to count from 1 then replace the 0 with 1