NAME

Data::Trace - Trace when a data structure gets updated.

SYNOPSIS

Variable change trace:

use Data::Trace;

my $data = {a => [0, {complex => 1}]};

sub BadCall{ $data->{a}[0] = 1 }

Trace($data);

BadCall();  # Shows stack trace of where data was changed.

Stack trace:

use Data::Trace;
Trace();    # 1 level.
Trace(5);   # 5 levels.

DESCRIPTION

This module provides a convienient way to find out when a data structure has been updated.

It is a debugging/tracing aid for complex systems to identify unintentional alteration to data structures which should be treated as read-only.

Probably can also create a variable as read-only in Moose and see where its been changed, but this module is without Moose support.

SUBROUTINES/METHODS

Trace

Watch a reference for changes:

Trace( \$scalar, @OPTIONS );
Trace( \@array , @OPTIONS );
Trace( \@hash , @OPTIONS );
Trace( $complex_data , @OPTIONS );

Just a stack trace with no watching:

Trace( @OPTIONS );

Options:

-clone => 0,    # Disable auto tying after a Storable dclone.

-var => REF,    # Variable to watch.
REF             # Same as passing a reference.

-levels => NUM  # How many scope levels to show.
NUM             # Same as passing a decimal.

-raw => 1,      # Include Internal call like Moose,
                # and Class::MOP in a trace.
-NUM            # Same as passing negative number.

-message => STR # Message to use for a normal (non-
                # tie stack trace).
STR             # Same as passing anything else.

-methods => STR   # Monitors only specific methods.
-methods => [STR] #

_ProcessArgs

Allows calling Trace like:
Trace() and Trace(-levels => 1) to
mean the same.

AUTHOR

Tim Potapov, <tim.potapov at gmail.com>

BUGS

Please report any bugs or feature requests to https://github.com/poti1/data-trace/issues.

Currently only detect STORE operations. Expand this to also detect PUSH, POP, DELETE, etc.

TODO

Consider adding an option to have a warn message anytime a structure is FETCHed.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc Data::Trace

You can also look for information at:

https://metacpan.org/pod/Data::Trace

https://github.com/poti1/data-trace

LICENSE AND COPYRIGHT

This software is Copyright (c) 2024 by Tim Potapov.

This is free software, licensed under:

The Artistic License 2.0 (GPL Compatible)