PHP GUID generation functions and Classes _php tutorial

Source: Internet
Author: User
I. Introduction of GUIDs
GUID: The globally unique Identifier (globally unique identifier) is also known as the UUID (universally unique Identifier). A GUID is a 128-bit numeric identifier produced by a particular algorithm that indicates the uniqueness of the product. GUIDs are primarily used to assign identifiers that must be unique in a network or system that has multiple nodes, multiple computers, and more than one computer.
On the Windows platform, GUIDs are widely used in Microsoft products to identify objects such as registry keys, class and interface identifiers, databases, system catalogs, and so on.
The format of the GUID is "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", where each x is a 32-bit hexadecimal number in the range of 0-9 or a-f. For example, 6F9619FF-8B86-D011-B42D-00C04FC964FF is a valid GUID value.
second, the advantages of the GUID
The 1.GUID is unique in space and time, ensuring that the numbers produced at different places at the same time are different.
2. No two computers in the world will generate duplicate GUID values.
3. When a GUID is required, it can be automatically generated by the algorithm and does not require an authoritative authority to manage it.
The 4.GUID is fixed in length and relatively short, and is ideal for sorting, labeling, and storage.
third, GUID generation function
Copy CodeThe code is as follows:
function Create_guid () {
$charid = Strtoupper (MD5 (Uniqid (Mt_rand (), true));
$hyphen = Chr (45);//"-"
$uuid = Chr (123)//"{"
. substr ($charid, 0, 8). $hyphen
. substr ($charid, 8, 4). $hyphen
. substr ($charid, 4). $hyphen
. substr ($charid, 4). $hyphen
. substr ($charid, 20,12)
. chr (125);//"}"
return $uuid;
}

third, GUID generation class
PHP Gets the GUID class: guid_class.php
Copy CodeThe code is as follows:
Class System
{
function Currenttimemillis ()
{
List ($usec, $sec) = Explode ("", Microtime ());
Return $sec. substr ($usec, 2, 3);
}
}
Class Netaddress
{
var $Name = ' localhost ';
var $IP = ' 127.0.0.1 ';
function Getlocalhost ()//static
{
$address = new Netaddress ();
$address->name = $_env["COMPUTERNAME"];
$address->ip = $_server["Server_addr"];
return $address;
}
function toString ()
{
Return Strtolower ($this->name. ' /'. $this->ip);
}
}
Class Random
{
function Nextlong ()
{
$tmp = rand (0,1)? ' -':'';
Return $tmp. Rand (9999). RAND (9999, 9999) rand (+, 999). RAND (100, 999);
}
}
Three sections
A section of a microsecond is an address, a random number.
Class Guid
{
var $valueBeforeMD 5;
var $valueAfterMD 5;
function Guid ()
{
$this->getguid ();
}
//
function GetGuid ()
{
$address = Netaddress::getlocalhost ();
$this->valuebeforemd5 = $address->tostring (). ': '. System::currenttimemillis (). ': '. Random::nextlong ();
$this->VALUEAFTERMD5 = MD5 ($this->valuebeforemd5);
}
function NewGuid ()
{
$Guid = new Guid ();
return $Guid;
}
function toString ()
{
$raw = Strtoupper ($this->valueaftermd5);
Return substr ($raw, 0,8). ' -'. substr ($raw, 8,4). ' -'. substr ($raw, 12,4). ' -'. substr ($raw, 16,4). ' -'. substr ($raw, 20);
}
}

How to use the GUID class:
Copy the Code code as follows:
Require_once ("guid.class.php");
$Guid = new Guid ();
Print $Guid->tostring ();

http://www.bkjia.com/PHPjc/739779.html www.bkjia.com true http://www.bkjia.com/PHPjc/739779.html techarticle First, GUID introduction GUID: That is, globally unique Identifier (Global unique identifier) is also known as the UUID (universally unique Identifier). A GUID is a binary length produced by a particular algorithm ...

  • Related Article

    Contact Us

    The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

    If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

    A Free Trial That Lets You Build Big!

    Start building with 50+ products and up to 12 months usage for Elastic Compute Service

    • Sales Support

      1 on 1 presale consultation

    • After-Sales Support

      24/7 Technical Support 6 Free Tickets per Quarter Faster Response

    • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.