NAME
Data::RecordStore - Simple and fast record based data store
SYNPOSIS
use Data::RecordStore;
my $store = Data::RecordStore->open( $directory );
my $data = "TEXT DATA OR BYTES"; my $id = $store->stow( $data, $optionalID );
my $val = $store->fetch( $id );
my $new_or_recycled_id = $store->next_id;
$store->stow( "MORE DATA", $new_or_recycled_id );
my $has = $store->has_id( $someid );
$store->empty_recycler; $store->recycle( $dead_id );
DESCRIPTION
A simple and fast way to store arbitrary text or byte data. It is written entirely in perl with no non-core dependencies. It is designed to be both easy to set up and easy to use.
LIMITATIONS
Data::RecordStore is not meant to store huge amounts of data. It will fail if it tries to create a file size greater than the max allowed by the filesystem. This limitation may be removed in subsequent versions. This limitation is most important when working with sets of data that approach the max file size of the system in question.
This is not written with thread safety in mind, so unexpected behavior can occur when multiple Data::RecordStore objects open the same directory. Locking coordination is currently the responsibility of the implementation.
METHODS
open( directory )
Takes a single argument - a directory, and constructs the data store in it. The directory must be writeable or creatible. If a RecordStore already exists there, it opens it, otherwise it creates a new one.
entry_count
Returns how many entries are in this store.
ensure_entry_count( min_count )
This makes sure there there are at least min_count entries in this record store. This creates empty records if needed.
set_entry_count( min_count )
This makes sure there there are exactly entries in this record store. This creates empty records or removes existing ones as needed. Use with caution.
next_id
This sets up a new empty record and returns the id for it.
stow( data, optionalID )
This saves the text or byte data to the record store. If an id is passed in, this saves the data to the record for that id, overwriting what was there. If an id is not passed in, it creates a new record store.
Returns the id of the record written to.
has_id( id )
Returns true if an object with this db exists in the record store.empty_recycler()
Clears out all data from the recyclerrecycle( $id )
Ads the id to the recycler, so it will be returned when next_id is called.fetch( id )
Returns the record associated with the ID. If the ID has no record associated with it, undef is returned.
all_stores
Returns a list of all the stores created in this Data::RecordStore
convert( $source_dir, $dest_dir )
Copies the database from source dir into dest dir while converting it to version 2. This does nothing if the source dir database is already at version 2
HELPER PACKAGES
Data::RecordStore relies on two helper packages that are useful in their own right and are documented here.
HELPER PACKAGE
Data::RecordStore::FixedStore
DESCRIPTION
A fixed record store that uses perl pack and unpack templates to store identically sized sets of data and uses a single file to do so.
SYNOPSIS
my $template = "LII"; # perl pack template. See perl pack/unpack.
my $size; #required if the template does not have a definite size, like A*
my $store = Data::RecordStore::FixedStore->open( $template, $filename, $size );
my $new_id = $store->next_id;
$store->put_record( $id, [ 321421424243, 12, 345 ] );
my $more_data = $store->get_record( $other_id );
my $removed_last = $store->pop;
my $last_id = $store->push( $data_at_the_end );
my $entries = $store->entry_count;
if( $entries < $min ) {
$store->ensure_entry_count( $min );}
$store->emtpy;
$store->unlink_store;
METHODS
open( template, filename, size )
Opens or creates the file given as a fixed record length data store. If a size is not given, it calculates the size from the template, if it can. This will die if a zero byte record size is determined.
empty
This empties out the database, setting it to zero records.
ensure_entry_count( count )
Makes sure the data store has at least as many entries as the count given. This creates empty records if needed to rearch the target record count.
set_entry_count( count )
Sets the number of entries in this record store, growing or shrinking as necessary.
Returns the number of entries in this store. This is the same as the size of the file divided by the record size.
get_record( idx )
Returns an arrayref representing the record with the given id. The array in question is the unpacked template.
has_id( id )
Returns true if an object with this db exists in the record store.
next_id
adds an empty record and returns its id, starting with 1
pop
Remove the last record and return it.
last_entry
Return the last record.
push( data )
Add a record to the end of this store. Returns the id assigned to that record. The data must be a scalar or list reference. If a list reference, it should conform to the pack template assigned to this store.
push( idx, data )
Saves the data to the record and the record to the filesystem. The data must be a scalar or list reference. If a list reference, it should conform to the pack template assigned to this store.
unlink_store
Removes the file for this record store entirely from the file system.
AUTHOR Eric Wolf coyocanid@gmail.com
COPYRIGHT AND LICENSE
Copyright (c) 2015 Eric Wolf. All rights reserved. This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.