php的memory_limit、upload_max_filesize和post_max_filesize的关系 [英] Relationship between php’s memory_limit, upload_max_filesize and post_max_filesize

问题描述

底线:
我需要关心设置 post_max_filesize >> memory_limit 吗?

详细信息:
这个答案表明上传的文件不需要适合 php 的 memory_limit.php 文档 建议整个帖子应该适合 php 的内存限制.

Details:
This answer suggests that uploaded files do not need to fit within php’s memory_limit. The php docs suggest that the entire post should fit within php’s memory limit.

我发现文档令人惊讶，我希望有人能详细说明.例如采用以下 php 配置:

I find the docs surprising and I’m hoping someone can elaborate. For example take the following php configs:

; config A
memory_limit = 50M
upload_max_filesize = 100M
post_max_filesize = 1000M
max_file_uploads = 10    

和

; config B
memory_limit = 50M
upload_max_filesize = 10M
post_max_filesize = 1000M
max_file_uploads = 100    

通过这些配置，我希望能够:

• 上传 10x100mb 文件到服务器 A，
• 上传 100x10mb 文件到服务器 B.

With these configurations I’d expect to be able to:

• upload 10x100mb files to server A,
• and 100x10mb files to server B.
• 处理上传到服务器 A 的 10 个文件中的任何一个都是一个问题(50M 包中有 100M 的文件......).
• 使用上传到服务器 B 的 100 个文件中的任何一个都可以(10 <50 个).
• Working with any one of the 10 files uploaded to server A is a problem (100Ms of file in a 50M bag…).
• Working with any 1 of the 100 files uploaded to server B is okay (10 < 50).

这个经验会让我说通常memory_limit应该大于upload_max_filesize"；相反，php docs 说:

This experience would lead me to say that "generally the memory_limit should be larger than the upload_max_filesize"; instead, the php docs say:

一般来说，memory_limit 应该大于post_max_size.

generally speaking, memory_limit should be larger than post_max_size.

为什么，如果不是，会发生什么?

Why and what happens if it isn't?

当我的 php 代码被执行时，我没有看到所有发布的文件都在内存中的证据.在我看来，我所拥有的只是一个 $_FILES 数组，其中包含专门在磁盘上找到的文件的路径.在我内省环境之前的某个时间点，php 是否将整个帖子保存在内存中?我需要关心设置 post_max_filesize >> memory_limit 吗?

When my php code is executed I see no evidence that all of the posted files are in memory. It seems to me that all I’ve got is a $_FILES array of paths to files found exclusively on disk. Is php holding the whole post in memory at some point prior to my ability to introspect the environment? Do I need to be concerned about setting post_max_filesize >> memory_limit?

旁白:
违反手册规则不会导致服务器严重损坏(使用 php5.3 apache2.2 debian 6).

Aside:
Violating the manual's rule does not result in a grossly broken server (w/ php5.3 apache2.2 debian 6).

推荐答案

PHP 将接受单个小于 upload_max_filesize 且合计小于 post_max_size 字节的上传文件.PHP 文档关于 memory_limit 是错误的，它不需要保存发布的文件内容.

PHP will accept uploaded files that are individually smaller than upload_max_filesize and together take less than post_max_size bytes. The PHP documentation is wrong with regard to memory_limit which does not need to hold the file contents posted.

以下配置适用于 Apache2 模块和 CGI​​，并接受小于 1G 的文件.

The following configuration works with both Apache2 module and CGI, and accepts files smaller than 1G.

 upload_max_filesize = 1G
 post_max_size = 1G
 memory_limit = 32M

这篇关于php的memory_limit、upload_max_filesize和post_max_filesize的关系的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！