Cache time consuming subroutines or paid api calls SYNOPSIS #!/usr/bin/perl use Cache::SimpleDir; my $key1 = Cache::SimpleDir->new( callback => 'GetWeather', cache_dir => '/tmp', expire_sec => 1800, verbose => 'false') or die $Cache::SimpleDir::ERROR; my $key2 = Cache::SimpleDir->new( callback => \&GetCountryInfo, cache_dir => '/tmp', expire_sec => 2592000, verbose => 'true') or die $Cache::SimpleDir::ERROR; my $where_are_my_data = $key1->get('a','b','c') or die $Cache::SimpleDir::ERROR; print "data are at: $where_are_my_data\n"; # How to get and cache new data sub GetWeather { my $dir = shift; open FILE, '>', "$dir/file.txt" or return undef; print FILE 'Example of callback. Arguments: ', join ',', @_; close FILE } sub GetCountryInfo { my $dir = shift; ... } DESCRIPTION Every time you use the "get" method, it returns only the cache directory where your files are stored. It is up to your code, to do something with these files. Read them, copy them or whatever. If the cache data are older than "expire_sec" then the "callback" subroutine is called automatically; new data are cached, while the old are deleted. So there is no need for a "set" method. Write at the "callback" subroutine the code, that generate new data. Its first argument is always the directory that you should write your cached files. Any optional argument used at the "get" is passed at the "callback" It is thread safe. ERROR HANDLING On error "get" returns FALSE. Sets the error message at the variable $Cache::SimpleDir::ERROR and at the property $obj->error_msg while the error code is at $obj->error METHODS new Generate and return a new cache object, while it initialize/overwrite the default properties cache_dir The root cache directory of your key callback Name or code reference, of the subroutine that caches new data expire_sec After how many seconds the record will be considered expired and a new one should cached using the callback verbose Verbose operation if TRUE or 1 There is not support for multiple cache keys at the same object. This is by design, because it must be fast and simple. If you want multiple keys, then create multiple objects with different properties e.g. my $key1 = SimpleDir->new(callback=>'Sub1', cache_dir=>'/tmp', expire_sec=>300); my $key2 = SimpleDir->new(callback=>'Sub2', cache_dir=>'/tmp', expire_sec=>800); ... get Returns the cache directory where your files/dirs are stored. If the the files/dirs are older than "expire_sec" seconds then are deleted and new one are cached by calling automatically the subroutine defined at the "callback" If your code at the B encount an error then you must return with FALSE. On success, at the end, your code must return TRUE. George Bouras george.mpouras@yandex.com