.\" Automatically generated by Pod::Man 4.09 (Pod::Simple 3.35) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .if !\nF .nr F 0 .if \nF>0 \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} .\} .\" ======================================================================== .\" .IX Title "CHI::Driver::File 3pm" .TH CHI::Driver::File 3pm "2017-07-31" "perl v5.26.0" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" CHI::Driver::File \- File\-based cache using one file per entry in a multi\-level directory structure .SH "VERSION" .IX Header "VERSION" version 0.60 .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& use CHI; \& \& my $cache = CHI\->new( \& driver => \*(AqFile\*(Aq, \& root_dir => \*(Aq/path/to/cache/root\*(Aq, \& depth => 3, \& max_key_length => 64 \& ); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" This cache driver stores data on the filesystem, so that it can be shared between processes on a single machine, or even on multiple machines if using \&\s-1NFS.\s0 .PP Each item is stored in its own file. By default, during a set, a temporary file is created and then atomically renamed to the proper file. While not the most efficient, it eliminates the need for locking (with multiple overlapping sets, the last one \*(L"wins\*(R") and makes this cache usable in environments like \s-1NFS\s0 where locking might normally be undesirable. .PP By default, the base filename is the key itself, with unsafe characters escaped similar to \s-1URL\s0 escaping. If the escaped key is larger than \*(L"max_key_length\*(R" (default 248 characters), it will be digested. You may want to lower \*(L"max_key_length\*(R" if you are storing a lot of items as long filenames can be more expensive to work with. .PP The files are evenly distributed within a multi-level directory structure with a customizable \*(L"depth\*(R", to minimize the time needed to search for a given entry. .SH "CONSTRUCTOR OPTIONS" .IX Header "CONSTRUCTOR OPTIONS" When using this driver, the following options can be passed to \s-1CHI\-\s0>\fInew()\fR in addition to the \s-1CHI\s0. .IP "root_dir" 4 .IX Item "root_dir" The location in the filesystem that will hold the root of the cache. Defaults to a directory called 'chi\-driver\-file' under the \s-1OS\s0 default temp directory (e.g. '/tmp' on \s-1UNIX\s0). This directory will be created as needed on the first cache set. .IP "depth" 4 .IX Item "depth" The number of subdirectories deep to place cache files. Defaults to 2. This should be large enough that no leaf directory has more than a few hundred files. Each non-leaf directory contains up to 16 subdirectories (0\-9, A\-F). .IP "dir_create_mode" 4 .IX Item "dir_create_mode" Permissions mode to use when creating directories. Defaults to 0775. .IP "file_create_mode" 4 .IX Item "file_create_mode" Permissions mode to use when creating files, modified by the current umask. Defaults to 0666. .IP "file_extension" 4 .IX Item "file_extension" Extension to append to filename. Default is \f(CW\*(C`.dat\*(C'\fR. .SH "METHODS" .IX Header "METHODS" .ie n .IP "path_to_key ( $key )" 4 .el .IP "path_to_key ( \f(CW$key\fR )" 4 .IX Item "path_to_key ( $key )" Returns the full path to the cache file representing \f(CW$key\fR, whether or not that entry exists. Returns the empty list if a valid path cannot be computed, for example if the key is too long. .IP "path_to_namespace" 4 .IX Item "path_to_namespace" Returns the full path to the directory representing this cache's namespace, whether or not it has any entries. .SH "TEMPORARY FILE RENAME" .IX Header "TEMPORARY FILE RENAME" By default, during a set, a temporary file is created and then atomically renamed to the proper file. This eliminates the need for locking. You can subclass and override method \fIgenerate_temporary_filename\fR to either change the path of the temporary filename, or skip the temporary file and rename altogether by having it return undef. .SH "SEE ALSO" .IX Header "SEE ALSO" \&\s-1CHI\s0 .SH "AUTHOR" .IX Header "AUTHOR" Jonathan Swartz .SH "COPYRIGHT AND LICENSE" .IX Header "COPYRIGHT AND LICENSE" This software is copyright (c) 2012 by Jonathan Swartz. .PP This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.