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package Data::Dump::Trace;
$VERSION = "0.02";
# Todo:
# - prototypes
# in/out parameters key/value style
# - exception
# - wrap class
# - configurable colors
# - show call depth using indentation
# - show nested calls sensibly
# - time calls
use strict;
use base 'Exporter';
our @EXPORT_OK = qw(call mcall wrap autowrap trace);
use Carp qw(croak);
use overload ();
my %obj_name;
my %autowrap_class;
my %name_count;
sub autowrap {
while (@_) {
my $class = shift;
my $info = shift;
$info = { prefix => $info } unless ref($info);
for ($info->{prefix}) {
unless ($_) {
$_ = lc($class);
s/.*:://;
}
$_ = '$' . $_ unless /^\$/;
}
$autowrap_class{$class} = $info;
}
}
sub wrap {
my %arg = @_;
my $name = $arg{name} || "func";
my $func = $arg{func};
my $proto = $arg{proto};
return sub {
call($name, $func, $proto, @_);
} if $func;
if (my $obj = $arg{obj}) {
$name = '$' . $name unless $name =~ /^\$/;
$obj_name{overload::StrVal($obj)} = $name;
return bless {
name => $name,
obj => $obj,
proto => $arg{proto},
}, "Data::Dump::Trace::Wrapper";
}
croak("Either the 'func' or 'obj' option must be given");
}
sub trace {
my($symbol, $prototype) = @_;
no strict 'refs';
no warnings 'redefine';
*{$symbol} = wrap(name => $symbol, func => \&{$symbol}, proto => $prototype);
}
sub call {
my $name = shift;
my $func = shift;
my $proto = shift;
my $fmt = Data::Dump::Trace::Call->new($name, $proto, \@_);
if (!defined wantarray) {
$func->(@_);
return $fmt->return_void(\@_);
}
elsif (wantarray) {
return $fmt->return_list(\@_, $func->(@_));
}
else {
return $fmt->return_scalar(\@_, scalar $func->(@_));
}
}
sub mcall {
my $o = shift;
my $method = shift;
my $proto = shift;
return if $method eq "DESTROY" && !$o->can("DESTROY");
my $oname = ref($o) ? $obj_name{overload::StrVal($o)} || "\$o" : $o;
my $fmt = Data::Dump::Trace::Call->new("$oname->$method", $proto, \@_);
if (!defined wantarray) {
$o->$method(@_);
return $fmt->return_void(\@_);
}
elsif (wantarray) {
return $fmt->return_list(\@_, $o->$method(@_));
}
else {
return $fmt->return_scalar(\@_, scalar $o->$method(@_));
}
}
package Data::Dump::Trace::Wrapper;
sub AUTOLOAD {
my $self = shift;
our $AUTOLOAD;
my $method = substr($AUTOLOAD, rindex($AUTOLOAD, '::')+2);
Data::Dump::Trace::mcall($self->{obj}, $method, $self->{proto}{$method}, @_);
}
package Data::Dump::Trace::Call;
use Term::ANSIColor ();
use Data::Dump ();
*_dump = \&Data::Dump::dump;
our %COLOR = (
name => "yellow",
output => "cyan",
error => "red",
debug => "red",
);
%COLOR = () unless -t STDOUT;
sub _dumpav {
return "(" . _dump(@_) . ")" if @_ == 1;
return _dump(@_);
}
sub _dumpkv {
return _dumpav(@_) if @_ % 2;
my %h = @_;
my $str = _dump(\%h);
$str =~ s/^\{/(/ && $str =~ s/\}\z/)/;
return $str;
}
sub new {
my($class, $name, $proto, $input_args) = @_;
my $self = bless {
name => $name,
proto => $proto,
}, $class;
my $proto_arg = $self->proto_arg;
if ($proto_arg =~ /o/) {
for (@$input_args) {
push(@{$self->{input_av}}, _dump($_));
}
}
else {
$self->{input} = $proto_arg eq "%" ? _dumpkv(@$input_args) : _dumpav(@$input_args);
}
return $self;
}
sub proto_arg {
my $self = shift;
my($arg, $ret) = split(/\s*=\s*/, $self->{proto} || "");
$arg ||= '@';
return $arg;
}
sub proto_ret {
my $self = shift;
my($arg, $ret) = split(/\s*=\s*/, $self->{proto} || "");
$ret ||= '@';
return $ret;
}
sub color {
my($self, $category, $text) = @_;
return $text unless $COLOR{$category};
return Term::ANSIColor::colored($text, $COLOR{$category});
}
sub print_call {
my $self = shift;
my $outarg = shift;
print $self->color("name", "$self->{name}");
if (my $input = $self->{input}) {
$input = "" if $input eq "()" && $self->{name} =~ /->/;
print $self->color("input", $input);
}
else {
my $proto_arg = $self->proto_arg;
print "(";
my $i = 0;
for (@{$self->{input_av}}) {
print ", " if $i;
my $proto = substr($proto_arg, 0, 1, "");
if ($proto ne "o") {
print $self->color("input", $_);
}
if ($proto eq "o" || $proto eq "O") {
print " = " if $proto eq "O";
print $self->color("output", _dump($outarg->[$i]));
}
}
continue {
$i++;
}
print ")";
}
}
sub return_void {
my $self = shift;
my $arg = shift;
$self->print_call($arg);
print "\n";
return;
}
sub return_scalar {
my $self = shift;
my $arg = shift;
$self->print_call($arg);
my $s = shift;
my $name;
my $proto_ret = $self->proto_ret;
my $wrap = $autowrap_class{ref($s)};
if ($proto_ret =~ /^\$\w+\z/ && ref($s) && ref($s) !~ /^(?:ARRAY|HASH|CODE|GLOB)\z/) {
$name = $proto_ret;
}
else {
$name = $wrap->{prefix} if $wrap;
}
if ($name) {
$name .= $name_count{$name} if $name_count{$name}++;
print " = ", $self->color("output", $name), "\n";
$s = Data::Dump::Trace::wrap(name => $name, obj => $s, proto => $wrap->{proto});
}
else {
print " = ", $self->color("output", _dump($s));
if (!$s && $proto_ret =~ /!/ && $!) {
print " ", $self->color("error", errno($!));
}
print "\n";
}
return $s;
}
sub return_list {
my $self = shift;
my $arg = shift;
$self->print_call($arg);
print " = ", $self->color("output", $self->proto_ret eq "%" ? _dumpkv(@_) : _dumpav(@_)), "\n";
return @_;
}
sub errno {
my $t = "";
for (keys %!) {
if ($!{$_}) {
$t = $_;
last;
}
}
my $n = int($!);
return "$t($n) $!";
}
1;
__END__
=head1 NAME
Data::Dump::Trace - Helpers to trace function and method calls
=head1 SYNOPSIS
use Data::Dump::Trace qw(autowrap mcall);
autowrap("LWP::UserAgent" => "ua", "HTTP::Response" => "res");
use LWP::UserAgent;
$ua = mcall(LWP::UserAgent => "new"); # instead of LWP::UserAgent->new;
$ua->get("http://www.example.com")->dump;
=head1 DESCRIPTION
The following functions are provided:
=over
=item autowrap( $class )
=item autowrap( $class => $prefix )
=item autowrap( $class1 => $prefix1, $class2 => $prefix2, ... )
=item autowrap( $class1 => \%info1, $class2 => \%info2, ... )
Register classes whose objects are automatically wrapped when
returned by one of the call functions below. If $prefix is provided
it will be used as to name the objects.
Alternative is to pass an %info hash for each class. The recognized keys are:
=over
=item prefix => $string
The prefix string used to name objects of this type.
=item proto => \%hash
A hash of prototypes to use for the methods when an object is wrapped.
=back
=item wrap( name => $str, func => \&func, proto => $proto )
=item wrap( name => $str, obj => $obj, proto => \%hash )
Returns a wrapped function or object. When a wrapped function is
invoked then a trace is printed after the underlying function has returned.
When a method on a wrapped object is invoked then a trace is printed
after the methods on the underlying objects has returned.
See L</"Prototypes"> for description of the C<proto> argument.
=item call( $name, \&func, $proto, @ARGS )
Calls the given function with the given arguments. The trace will use
$name as the name of the function.
See L</"Prototypes"> for description of the $proto argument.
=item mcall( $class, $method, $proto, @ARGS )
=item mcall( $object, $method, $proto, @ARGS )
Calls the given method with the given arguments.
See L</"Prototypes"> for description of the $proto argument.
=item trace( $symbol, $prototype )
Replaces the function given by $symbol with a wrapped function.
=back
=head2 Prototypes
B<Note: The prototype string syntax described here is experimental and
likely to change in revisions of this interface>.
The $proto argument to call() and mcall() can optionally provide a
prototype for the function call. This give the tracer hints about how
to best format the argument lists and if there are I<in/out> or I<out>
arguments. The general form for the prototype string is:
<arguments> = <return_value>
The default prototype is "@ = @"; list of values as input and list of
values as output.
The value '%' can be used for both arguments and return value to say
that key/value pair style lists are used.
Alternatively, individual positional arguments can be listed each
represented by a letter:
=over
=item C<i>
input argument
=item C<o>
output argument
=item C<O>
both input and output argument
=back
If the return value prototype has C<!> appended, then it signals that
this function sets errno ($!) when it returns a false value. The
trace will display the current value of errno in that case.
If the return value prototype looks like a variable name (with C<$>
prefix), and the function returns a blessed object, then the variable
name will be used as prefix and the returned object automatically
traced.
=head1 SEE ALSO
L<Data::Dump>
=head1 AUTHOR
Copyright 2009 Gisle Aas.
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
=cut
Mini Shell