php 如何创建uuid

传统的创建uuid的方法是自己写个函数实现随机

<?php
function create_uuid($prefix="") {
    $chars = md5(uniqid(mt_rand(), true));
    $uuid = substr ( $chars, 0, 8 ) . '-'
        . substr ( $chars, 8, 4 ) . '-'
        . substr ( $chars, 12, 4 ) . '-'
        . substr ( $chars, 16, 4 ) . '-'
        . substr ( $chars, 20, 12 );
    return $prefix.$uuid ;
}

$uuid = create_uuid();
var_dump($uuid);

不过现在有扩展了就使用扩展吧

使用 apt search uuid 搜索一下

sudo apt search uuid

得到结果

然后就安装吧

使用命令

sudo apt-get install php7.4-uuid

安装

$ sudo apt-get install php7.4-uuid
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'php-uuid' instead of 'php7.4-uuid'
The following NEW packages will be installed:
  php-uuid
0 upgraded, 1 newly installed, 0 to remove and 95 not upgraded.
Need to get 8,520 B of archives.
After this operation, 51.2 kB of additional disk space will be used.
Get:1 http://cn.archive.ubuntu.com/ubuntu focal/universe amd64 php-uuid amd64 1.1.0-1build1 [8,520 B]
Fetched 8,520 B in 1s (14.4 kB/s)    
Selecting previously unselected package php-uuid.
(Reading database ... 222525 files and directories currently installed.)
Preparing to unpack .../php-uuid_1.1.0-1build1_amd64.deb ...
Unpacking php-uuid (1.1.0-1build1) ...
Setting up php-uuid (1.1.0-1build1) ...
Processing triggers for libapache2-mod-php7.4 (7.4.3-4ubuntu2.4) ...
Processing triggers for php7.4-cli (7.4.3-4ubuntu2.4) ...

可以看到此时扩展已经有了

$ php -m |grep uuid
uuid

web 端需要 sudo /etc/init.d/apache2 restart 一下

然后 phpinfo()

之后使用php 函数 uuid_create 即可。

<?php

$uuid = uuid_create(1);
var_dump($uuid);

cli 端得到

string(36) "a84f0c4e-a24b-11eb-87fd-9f2061574580"

web 端得到

经过测试发现还是扩展的方式实现更快。

传统方式实现uuid 100万次

代码

<?php
function create_uuid($prefix="") {
    $chars = md5(uniqid(mt_rand(), true));
    $uuid = substr ( $chars, 0, 8 ) . '-'
        . substr ( $chars, 8, 4 ) . '-'
        . substr ( $chars, 12, 4 ) . '-'
        . substr ( $chars, 16, 4 ) . '-'
        . substr ( $chars, 20, 12 );
    return $prefix.$uuid ;
}

$start_time = microtime(true);
for ($i=0; $i < 1000000; $i++) { 
    $uuid = create_uuid(1);
}
$end_time = microtime(true);
var_dump(($end_time-$start_time));
exit;

效果

扩展实现

<?php
$start_time = microtime(true);
for ($i=0; $i < 1000000; $i++) { 
    $uuid = uuid_create(1);
}
$end_time = microtime(true);
var_dump(($end_time-$start_time));
exit;

效率几乎提升一倍啊！看来还是扩展厉害啊，毕竟扩展都底层语言了嘛。

不过单次执行一次来看时间几乎可以忽略不计

传统方式得到的时间是 4.9829483032227E-5

扩展方式得到的时间是 2.6941299438477E-5

但是单次的这个耗时对比极不稳定，有时候传统方式用时反而短，这个扩展有时候时间也用的长，这说明单次其实两者并没有太大差异。而如果这个东西用到了百次、万次循环的时候，它使用扩展就很有用了。