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Creating a Simple PHP Cache Script

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Cache is a programming concept that can be used in a various range of applications and for various purposes. A cache library can be used for storing database queries for later use, to store rendered pages to be served again without generating them again, or to save indexed pages in a crawler application to be processed by multiple modules.

    A cache mechanism is more simple that it might sound. It’s just a simple module that should implement 2 actions:
  • to store a value(identified by a key).
  • to retrieve a value if it’s not expired.
  • additionally it can offer a mechanism to invalidate a set of values or the entire cache.

In this tutorial we are going to create a disk cache script. It stores the string values in files, each value is stored in a file and it contains an additional file to store the expiration date. Performance wise, this is not the best approach, but the script is designed like that with a clear purpose: the additional file can be used to store additional attributes, beside the expiration date. Imagine an application that crawls pages, with different modules. Each time a module crawls the page, it adds it’s result to the additional file.
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Written by admin

March 3rd, 2010 at 1:42 am

Posted in api,howto,Util

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