NAME
Devel::Walk::Unstorable - Find locations in complex structures that can't be serialized with Storable.
SYNOPSIS
use Devel::Walk::Unstorable;
my @list = unstorable( $suspect, '$suspect' );
die "Can't store ", join "\n", @list if @list;DESCRIPTION
This module uses Devel::Walk to find all the locations of objects that can't be stored with "freeze" in Storable.
If you are like me, you regularly try to serialize large objects and save them in a session file for your web application. Storable's freeze is ideal for this, except when it isn't. You forgot to close a DBI handle somewhere deep in your object. Storable just reports this as a CODE reference, but doesn't tell you what part of your structure is holding that reference. You can use unstorable to walk your object structure to find the location.
It is highly recomended to only do this in a development environment, and only if freeze has failed.
my $data = eval { freeze( $obj ) };
if( $@ ) {
warn $@;
my @list = unstorable( $obj, '$obj' );
die "Unstorable reference at ", join "\n", @list;
}
# now you can write $data to you session DB.unstorable
my @bad = unstorable( $obj, $basename );Walks $obj and finds all the locations that can't be stored with "freeze" in Storable. Returns the list of locations, if any.
$basename may be omited and defaults to '$o'.
OBJECT
You might want to customize the behaviour of this module. If so, you can subclass Devel::Walk::Unstorable and overload one of the worker modules.
my $walker = Devel::Walk::Unstorable->new;
$walker->walk( $obj, $name );
my @bad = $walker->list;new
my $walker = Devel::Walk::Unstorable->new;walk
$walker->walk( $struct, '$basename' );Recursely walks through $suspect, invoking "check" on each element of each structure. $basename is updated with each recursion to be. Only walks through ARRAY, HASH, SCALAR and REF references.
All locations that fail "check" will be accumulated in a list. The list will only contain the deepest locations.
If $basename is empty, '$o' is used as a default.
list
my @bad = $walker->list;Returns the list of location that failed "check".
check
my $ok = $walker->check( $loc, $obj );By default, check will return true if $obj is a reference that fails to be serialized with "freeze" in Storable. Returns false if $obj is not a reference, or if it's a reference that can be sucessfully serialized with "freeze" in Storable.
SEE ALSO
AUTHOR
Philip Gwyn, <perl -at- pied.nu>
COPYRIGHT AND LICENSE
Copyright (C) 2025 by Philip Gwyn
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.26.3 or, at your option, any later version of Perl 5 you may have available.