PHP queue usage instance, php queue instance _ PHP Tutorial

PHP queue usage instance, php queue instance. PHP queue usage example. php queue instance this article describes the PHP queue usage. Share it with you for your reference. The specific analysis is as follows: what is a queue, a first-in-first-out linear table, a PHP queue usage instance, and a php queue instance

This example describes the usage of PHP queues. Share it with you for your reference. The specific analysis is as follows:

What is a queue? it is a first-in-first-out linear table. in a specific application, linked lists or arrays are commonly used. a queue can only be inserted at the backend and deleted at the front end.

Under what circumstances will a queue be used? when concurrent requests are required to ensure transaction integrity, the queue will be used. of course, other better methods are not ruled out. I don't know what to say.

The queue can also be used to reduce the pressure on the database server. we can put non-instant data into the queue and execute it when the database is idle or after a period of time. For example, the access counter does not need to execute the SQL statement added for access in real time. the SQL statement is like this when the queue is not used. suppose there are five users who access the database:

Update table1 set count = count + 1 where id = 1
Update table1 set count = count + 1 where id = 1
Update table1 set count = count + 1 where id = 1
Update table1 set count = count + 1 where id = 1
Update table1 set count = count + 1 where id = 1

The queue can be used as follows:
Update table1 set count = count + 5 where id = 1

Reduce the number of SQL requests to reduce the pressure on the server. of course, this is not necessary for websites with low access traffic.
The following queue class:

The code is as follows:

/**
* Queue
*
* @ Author jaclon
*
*/
Class Queue
{
Private $ _ queue = array ();
Protected $ cache = null;
Protected $ queuecachename;

/**
* Constructor
* @ Param string $ queuename queue name
*/
Function _ construct ($ queuename)
{

$ This-> cache = & Cache: instance ();
$ This-> queuecachename = 'queue _ '. $ queuename;

$ Result = $ this-> cache-> get ($ this-> queuecachename );
If (is_array ($ result )){
$ This-> _ queue = $ result;
}
}

/**
* Put a unit at the end of the queue
* @ Param mixed $ value
*/
Function enQueue ($ value)
{
$ This-> _ queue [] = $ value;
$ This-> cache-> set ($ this-> queuecachename, $ this-> _ queue );

Return $ this;
}

/**
* Remove one or more units starting with the queue
* @ Param int $ num
*/
Function sliceQueue ($ num = 1)
{
If (count ($ this-> _ queue) <$ num ){
$ Num = count ($ this-> _ queue );
}
$ Output = array_splice ($ this-> _ queue, 0, $ num );
$ This-> cache-> set ($ this-> queuecachename, $ this-> _ queue );

Return $ output;
}

/**
* Remove the unit starting with the queue from the queue
*/
Function deQueue ()
{
$ Entry = array_shift ($ this-> _ queue );
$ This-> cache-> set ($ this-> queuecachename, $ this-> _ queue );

Return $ entry;
}

/**
* Return queue length
*/
Function size ()
{
Return count ($ this-> _ queue );
}

/**
* Returns the first unit in the queue.
*/
Function peek ()
{
Return $ this-> _ queue [0];
}

/**
* Return one or more units in the queue.
* @ Param int $ num
*/
Function peeks ($ num)
{
If (count ($ this-> _ queue) <$ num ){
$ Num = count ($ this-> _ queue );
}
Return array_slice ($ this-> _ queue, 0, $ num );
}

/**
* Destroy a queue
*/
Function destroy ()
{
$ This-> cache-> remove ($ this-> queuecachename );
}
}

I hope this article will help you with PHP programming.

Stack, queue, and two application instances respectively

Stack is the data first input and then output;
The queue is the first input data that is output first;
Can this be understood? The example is hard to say. for a long time, our teacher talked about two classes, on the stack and queue.
Hope to help you.

Summer

Implement a two-way queue using PHP

Unknown problem
 

The example in this article describes the PHP queue usage. Share it with you for your reference. The specific analysis is as follows: what is a queue? it is a first-in-first-out linear table ,...