NAME
Data::Dump::Trace - Helpers to trace function and method calls
SYNOPSIS
autowrap(
"LWP::UserAgent"
=>
"ua"
,
"HTTP::Response"
=>
"res"
);
use
LWP::UserAgent;
$ua
= mcall(LWP::
UserAgent
=>
"new"
);
# instead of LWP::UserAgent->new;
DESCRIPTION
The following functions are provided:
- autowrap( $class )
- autowrap( $class => $prefix )
- autowrap( $class1 => $prefix1, $class2 => $prefix2, ... )
- 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:
- wrap( name => $str, func => \&func, proto => $proto )
- 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 "Prototypes" for description of the
proto
argument. - 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 "Prototypes" for description of the $proto argument.
- mcall( $class, $method, $proto, @ARGS )
- mcall( $object, $method, $proto, @ARGS )
-
Calls the given method with the given arguments.
See "Prototypes" for description of the $proto argument.
- trace( $symbol, $prototype )
-
Replaces the function given by $symbol with a wrapped function.
Prototypes
Note: The prototype string syntax described here is experimental and likely to change in revisions of this interface.
The $proto argument to call() and mcall() can optionally provide a prototype for the function call. This give the tracer hints about how to best format the argument lists and if there are in/out or out arguments. The general form for the prototype string is:
<arguments> = <return_value>
The default prototype is "@ = @"; list of values as input and list of values as output.
The value '%' can be used for both arguments and return value to say that key/value pair style lists are used.
Alternatively, individual positional arguments can be listed each represented by a letter:
If the return value prototype has !
appended, then it signals that this function sets errno ($!) 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 $
prefix), and the function returns a blessed object, then the variable name will be used as prefix and the returned object automatically traced.