29 lines
1.3 KiB
Plaintext
29 lines
1.3 KiB
Plaintext
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Technical choices for Cache_Lite...
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To begin, the main goals of Cache_Lite :
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- performances
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- safe use (even on very high traffic or with NFS (file locking doesn't work
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with NFS))
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- flexibility (can be used by the end user or as a part of a larger script)
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For speed reasons, it has been decided to focus on the file container (the
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faster one). So, cache is only stored in files. The class is optimized for that.
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If you want to use a different cache container, have a look to PEAR/Cache.
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For speed reasons too, the class 'Cache_Lite' has do be independant (so no
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'require_once' at all in 'Cache_Lite.php'). But, a conditional include_once
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is allowed. For example, when an error is detected, the class include dynamicaly
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the PEAR base class 'PEAR.php' to be able to use PEAR::raiseError(). But, in
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most cases, PEAR.php isn't included.
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For the second goal (safe use), there is three (optional) mecanisms :
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- File Locking : seems to work fine (but not with distributed file system
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like NFS...)
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- WriteControl : the cache is read and compared just after being stored
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(efficient but not perfect)
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- ReadControl : a control key (crc32(), md5() ou strlen()) is embeded is the
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cache file and compared just after reading (the most efficient
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but the slowest)
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