php-cache-zero

This class provides a simple caching system for PHP pages. It was inspired by Cache_Lite.

Compatibility

PHP 5 only (tested with 5.4.4).

Usage Examples

Please see files in the 'examples' directory.

Constructor Options

The constructor takes an associative array with options as key value pairs.

string cacheDir (default: 'cache')

Path to directory that will contain the cache files. This must be within $_SERVER['DOCUMENT_ROOT']. Do not add slash at the beginning or the end.

bool caching (default: true)

Enable / disable caching (e.g. for debugging, or error handling)

bool fileLocking (default: true)

Use flock() before writitng to cache file. Note that this may not work so well of you are writing to an NFS export.

int hashedDirectoryLevel (default: 0)

Create nested subdirectories for cache files based on the first n characters of id. Useful if you envisage creating a massive number of files on a filesystem that doesn't like that sort of thing.

int lifeTime (default: 3600)

Lifetime of cache in seconds. Note that this only affects the validity of the cache - stale files are not deleted for performance reasons.

int modeFile (default: 0600)

File mode used by chmod().

int modeDir (default: 0700)

Directory mode used by mkdir().

bool exitOnError (default: true)

Configures the behaviour of the error handler. If set to false, it prints an error message and disables caching but does not terminate the script.

bool protectID (default: true)

Hash the id with md5 before use. If set to false, characters that are not alpha-numeric or [-_?&=.] will be removed.

bool protectGroup (default: false)

Hash the group with md5 before use. If set to false, characters that are not alpha-numeric or [-_?&=.] will be removed.

bool verify (default: true)

Verify integrity of cache file. A checksum is added at the top of the file on write and is used to verify the data on read.

string verifyMethod (default: 'crc32')

Method for producing the checksum. Acceptable values are 'crc32', 'md5', or 'strlen'.

Public Methods

CacheZero::get(string $id, string $group = 'default', boolean $expiredOK = false)

Get cache content, if available and valid.

• $id - cache object ID (e.g. $_SERVER['REQUEST_URI'])
• $group - optional group
• $expiredOK - optional, if set to true will return cache content even if expired

CacheZero::save(string $data, string $id, string $group = 'default')

Save content to cache.

• $data - data to go in the cache
• $id - cache object ID (e.g. $_SERVER['REQUEST_URI'])
• $group - optional group

CacheZero::start(string $id, string $group = 'default')

Start capture of output buffer (e.g. echo).

• $id - cache object ID (e.g. $_SERVER['REQUEST_URI'])
• $group - optional group

CacheZero::finish()

Finish capture of output buffer, save to cache file and print buffer contents.