What is buffering? Let's talk about php's buffering mechanism and closing method

This article will elaborate on the following aspects:

1. What is buffering
2. What is the PHP buffering mechanism
3. Why should we turn off buffering
4. How to turn off PHP buffering

Text:

1. What is buffering

Buffering is a mechanism in the computer system that can temporarily store data. These data are then output to the user. The existence of buffering can make data processing more efficient, because buffering can avoid repeated calculations and reading data, improving the running speed of the program.

2. What is the PHP buffering mechanism?

The PHP buffering mechanism stores a certain amount of data in the memory when the program is executed, and does not output it temporarily. When the cache reaches a certain size or is When the program is executed, it is output to the client together. PHP can implement caching through functions such as ob_start(), ob_flush(), and ob_end_flush().

3. Why should you turn off the buffering

By default, the PHP buffering mechanism is turned on, but in some cases it is necessary to turn off the buffering.

1. Since the PHP buffering mechanism temporarily stores a certain amount of data in the memory, this will lead to excessive memory consumption. When the buffer accumulates too much data or is not cleared for a long time, it will lead to Insufficient memory occurs, causing program crashes or even server downtime.
2. The default output method of the PHP buffering mechanism is block type, which means that the data is not output in one go, but in blocks. This may lead to incomplete rendering of the client page, horizontal scroll bars, etc. situation, affecting user experience.
3. In some application scenarios, the PHP program is required to output the contents in the cache at one time according to a specific point in time. Otherwise, the program execution process will be affected and errors will occur.

4. How to turn off PHP buffering

There are many ways to turn off buffering in PHP programs.

1. Make modifications directly in the php.ini file. Find the output_buffering option in the php.ini file and set it to 0 or turn it off.
2. Close via PHP function. Use the ob_end_clean() or ob_end_flush() function to force the cache to be cleared, and then close the cache.
3. Use the parameters of the ob_start() function to automatically close the cache when the PHP program is executed to the specified location. For example, ob_start(null,0,true) means that the cache is turned off, and it also means that the cache content is not subject to the cache area size limit, and the cache method is output to a string.

Summary:

PHP buffering mechanism can improve the processing efficiency of the program, but in some special cases, buffering needs to be turned off. Developers can choose different ways to turn off caching based on actual needs. At the same time, after turning off the cache, you also need to pay attention to the memory consumption and output effects of the program to avoid unnecessary problems.

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