Redis php逐个处理数组（可能内存不足）
问题描述：
For example i have list in redis with some data, this list can be really large so if i use
getList method i can run out of memory.
//getList
$Data = Rediska()->getList('example_list_of_data');
foreach ($Data as $value) {
if (in_array($someValue, $value)) {
//delete element from list
Rediska()->popFromList('example_list_of_data', $value);
}
}
I dont want to get full list from Redis, i want to get data part by part(for exmaple of 50 pieces). Like so:
get 50 first items
->try to find element
->if so delete it and stop iteration
->if did not find iterate next 50 etc...
how can i achive this? i can get list size with LLEN
答
i have found solution, get list part by part, tested it with microtime and memory usage. It takes a little bit more time, but much less memory on list with 1000000 records.
public static function processRedisList($Start, $End, $ListName
$ElementToFind, $Found = false, $Part
){
while($Found != true) {
//
$Data = NoSQL_Singleton::Rediska()->getList($ListName, $Start, $End);
if (!empty($Data)) {
foreach ($Data as $Key => $Value) {
//process List here
//do what you want
$Found = true;
return $Found;
}
$Start = $Start + $Part;
$End = $End + $Part;
}
}
return false;
}
答
You could try to use the toArray method of the Rediska_Key_List. It gets elements from the list. The first parameter of this method is the start index, the second the end index. From the documentation:
array toArray ([integer $start = 0], [integer $end = -1], [ $responseIterator = false], boolean $responseIterator[optional])
integer $start: Start index
integer $end: End index
boolean $responseIterator[optional]: If true - command return iterator which read from socket buffer. Important: new connection will be created
$responseIterator