crm-rush/api/soft/smarty/4.5.2/docs/programmers/api-variables/variable-caching.md

$caching

This tells Smarty whether or not to cache the output of the templates to the $cache_dir. By default this is set to the constant Smarty::CACHING_OFF. If your templates consistently generate the same content, it is advisable to turn on $caching, as this may result in significant performance gains.

You can also have multiple caches for the same template.

• A constant value of Smarty::CACHING_LIFETIME_CURRENT or Smarty::CACHING_LIFETIME_SAVED enables caching.

• A value of Smarty::CACHING_LIFETIME_CURRENT tells Smarty to use the current $cache_lifetime variable to determine if the cache has expired.

• A value of Smarty::CACHING_LIFETIME_SAVED tells Smarty to use the $cache_lifetime value at the time the cache was generated. This way you can set the $cache_lifetime just before fetching the template to have granular control over when that particular cache expires. See also isCached().

• If $compile_check is enabled, the cached content will be regenerated if any of the templates or config files that are part of this cache are changed.

• If $force_compile is enabled, the cached content will always be regenerated.

See also $cache_dir, $cache_lifetime, $cache_modified_check, is_cached() and the caching section.