NAME

VCP::DB_File - Persistant storage for vcp_state data

SYNOPSIS

    use base qw( VCP::DB_File );

DESCRIPTION

By default, most VCP::Dest::* drivers keep track of the relationship between the id field assigned by the (original) VCP::Source::* driver and the final name and rev_id (or whatever fields are important to it) in the destination repository so that the previous_id fields, which refer to the original id, may be resolved when backfilling or branching.

The VCP::*::revml drivers do not do this; they do not need to resolve id fields.

The intent for this file is to serve as a base class so that individual sites may write their own ", ref $self, " plugins to, for instance, store this state in a RDBMS table. This is not quite offered at this time; we need to add an option to the appropriate VCP::Dest::* modules to allow the appropriate ", ref $self, " file to be loaded.

To write your own ", ref $self, " file, see VCP::DB_File::sdbm.

Methods

new

   VCP::DB_File::foo->new(
      StoreLoc => $dir,  ## path to a dir to keep the state store in
   );

The "Store" field indicates where the ", ref $self, " should be stored, for instance a DBI specification string or a directory to place a "revmap.db" file in. There is no control over the filename, as different storage modes may need different conventions.

store_loc

Gets (does not set) the StoreLoc field as an absolute path.

delete_db

   $db->delete_db;

Deletes the persitent store. This should remove all files, lock files, etc. for filesystem stores and drop any tables for RDBMS stores.

Default action is to call close_db; subclasses should perform the deletion.

(subclasses should call "$self-"SUPER::delete_db before doing anything else in their delete_db() overrides).

open_db

   $db->open_db;

Creates a new or opens an existing db.

(subclasses should call "$self-"SUPER::open_db before doing anything else in their open_db() overrides).

close_db

   $db->close_db;

(subclasses should call "$self-"SUPER::close_db before doing anything else in their close_db() overrides).

set

   $db->set( $key, @values );

Sets the values for $key.

get

   my @values = $db->get( $key );

Gets the values for $key.

keys

   my @keys = $db->keys;

Returns a list of ARRAY references. Each ARRAY ref is a key.

HELPER METHODS

These are provided to make subclassing a tad easier

mkdir_store_loc

   $self->mkdir_store_loc;

A helper method for subclasses' open_db()s to create the directory referred to by store_loc and any missing parent dirs.

rmdir_store_loc

   $self->rmdir_store_loc;

A helper method for subclasses' delete_db()s to remove the directory referred to by store_loc.

pack_values

   my $v = $self->pack_values( @values );

Combines the parameters in to a single string.

upack_values

   my @v = $self->unpack_values( $v );

AUTHOR

Barrie Slaymaker <barries@slaysys.com>

COPYRIGHT

See VCP::License ("vcp help license") for the terms of use.