Beginner's Portal: describes the core Zend_PHP of PHP4.

I. summary: The name of Zend Engine is a combination of the names of ZeevSuraski and AndiGutmans senior designers who work in PHP for core development. the developer aims to develop a new script execution mechanism, and PHP4 is the first implementation product of the new Zend Engine. In some special test environments, Zend (PHP $) is executed several times faster than PHP3 and ASP. overview:

The name of the Zend Engine is a combination of the names of two senior designers, Zeev Suraski and Andi Gutmans, who work as core developers in PHP. the developer aims to develop a new script execution mechanism, and PHP4 is the first implementation product of the new Zend Engine. In some special test environments, the execution speed of Zend (PHP $) is several to several hundred times faster than that of PHP3 and ASP, this also means that the website's backend CGI interface is not a PHP4 Zend. (Of course, technology is constantly improving. maybe a new engine will emerge one day .)

After more than two years of development, the Zend Engine has become a generalized programming environment similar to the VBA function. it not only has the traditional PHP function, but also adds the function of distributed object (COM, and can be executed on different operating platforms. With this potential, the Terminator of VBA is not Zend.

Zend makes the most complete commitment to the session with the biggest defect before PHP3 in PHP4, and adds some future functions, such as CyberCash... and so on.

In the opensource community, PHP/Zend is the best example of the only one that can maintain consistency, but has not yet been regarded as a competitor by Microsoft. It has completely lost ASP behind it and is developing towards the VBA environment. Microsoft only tries its best to deal with Linux and does not notice any threats from PHP/Zend.

The Web server finds that PHP requires parsing by the PHP engine (based on the file extension), so it is sent to the Zend Engine of PHP4.

The Zend Engine reads files from the hard disk and sends them to the Zend online Compiler (Run-time Compiler) for literal translation. (Online compilation may be omitted after Zend Compiler is released in the future .)

The online execution unit (Excutor) of the Zend Engine executes the compiled PHP program. When necessary, find the relevant modules to perform cooperative actions (such as XML, IMAP, ODBC ).

Zend organizes the execution results into HTML files and sends them to the Web server.

The Web server sends the results over the network to the user's browser.

Zend has the following four types of products:

Zend Engine: currently, Zend Engine is only a PHP4 product and provides functions similar to Microsoft VBA and cross-platform. The current popularity on the Internet has also given the best witness to the Zend Engine. Among Zend's four major products, this is currently the only mature product.

Zend Optimizer: The Zend Optimizer readjusts the PHP core to improve the efficiency of PHP program execution. It can speed up PHP code execution, reduce the CPU burden, and reduce the latent time.

Zend Cache: Zend Cache takes the PHP program to the memory of the Web server, so that the system no longer needs to read the PHP program from the hard disk, which can greatly shorten the system response time and reduce the network load. Data with Cache can be reduced without literal translation.

Zend Compiler: Zend Compiler is probably the most powerful weapon of Zend. it allows PHP program Code to exist in the form of Zend Intermediate Code (ZIC, Zend Intermediate Code) after compilation.

It can protect the source code of PHP and prevent users from seeing it. This ensures the security of the source code of PHP. The appearance of this product is expected to have a significant impact on the entire network. The PHP code library will be visible everywhere, and the software industry will also provide related function libraries or object libraries for PHP programmers. At that time, there may be PHP conflicts with Java.