xref: /onnv-gate/usr/src/cmd/perl/contrib/Sun/Solaris/Exacct/pod/Object.pod (revision 12388:1bc8d55b0dfd)

#
# Copyright (c) 2002, 2003, Oracle and/or its affiliates. All rights reserved.
#

#
# Sun::Solaris::Exacct::Object documentation.
#

=head1 NAME

Sun::Solaris::Exacct::Object - exacct object manipulation

=head1 SYNOPSIS

 use Sun::Solaris::Exacct::Object qw(:ALL);
 print($ea_obj->value(), "\n");

This module is used as a parent of the two possible types of Perl exacct
objects: Items and Groups. An Item is either a single data value such as the
number of seconds of user CPU time consumed by a process, an embedded Perl
exacct object, or a block of raw data. A Group is an ordered collection of
Perl exacct Items such as all of the resource usage values for a particular
process or task. If Groups need to be nested within each other, the inner
Groups can be stored as embedded Perl exacct objects inside the enclosing
Group.

This module contains methods that are common to both Perl exacct Items and
Groups. The attributes of C<Sun::Solaris::Exacct::Object> and all classes
derived from it are read-only after initial creation with new(). This behavior
prevents the inadvertent modification of the attributes that could produce
inconsistent catalog tags and data values. The only exception is the array
used to store the Items inside a Group object, which can be modified using the
normal Perl array operators. See the C<value()> method below.

=head2 Constants

C<EO_ERROR>, C<EO_NONE>, C<EO_ITEM>, and C<EO_GROUP>.

=head2 Functions

None.

=head2 Class methods

B<C<dump($object, $filehandle)>>

This method dumps formatted text representation of a Perl exacct object to the
supplied file handle. If no file handle is specified, the text representation
is dumped to C<STDOUT>. See EXAMPLES below for sample output.

=head2 Object methods

B<C<type()>>

This method returns the type field of the Perl exacct object. The value of the
type field is returned as a dual-typed scalar and is either C<EO_ITEM>,
C<EO_GROUP>, or C<EO_NONE>.

B<C<catalog()>>

This method returns the catalog field of the Perl exacct object. The value is
returned as a C<Sun::Solaris::Exacct::Catalog> object.

B<C<match_catalog($catalog)>>

This method matches the passed catalog tag against the object. C<true> is
returned of a match occurs. Otherwise C<false> is returned. This method has
the same behavior as the underlying C<ea_match_object_catalog(3EXACCT)>
function.

B<C<value()>>

This method returns the value of the Perl exacct object. In the case of an
Item, this object will normally be a Perl scalar, either a number or string.
For raw Items, the buffer contained inside the object is returned as a Perl
string that can be manipulated with the Perl C<unpack()> function. If the Item
contains either a nested Item or a nested Group, the enclosed Item is returned
as a reference to an object of the appropriate subtype of the
C<Sun::Solaris::Exacct::Object> class.

For Group objects, if C<value()> is called in a scalar context, the return
value is a reference to the underlying array used to store the component Items
of the Group. Since this array can be manipulated with the normal Perl array
indexing syntax and array operators, the objects inside the Group can be
manipulated. All objects in the array must be derived from the
C<Sun::Solaris::Exacct::Object> class. Any attempt to insert something else
into the array will generate a fatal runtime error that can be caught with an
C<eval { }> block.

If C<value()> is called in a list context for a Group object, it returns a
list of all the objects in the Group. Unlike the array reference returned in a
scalar context, this list cannot be manipulated to add or delete Items from a
Group. This mechanism is considerably faster than the array mechanism
described above and is the preferred mechanism if a Group is being examined in
a read-only manner.

=head2 Exports

By default nothing is exported from this module. The following tags can be
used to selectively import constants and functions defined in this module:

 :CONSTANTS   EO_ERROR, EO_NONE, EO_ITEM, and EO_GROUP

 :ALL         :CONSTANTS

=head1 EXAMPLES

The following is an example of output of the C<dump()> method for a Perl exacct
Group object.

 GROUP
   Catalog = EXT_GROUP|EXC_DEFAULT|EXD_GROUP_PROC_PARTIAL
   ITEM
     Catalog = EXT_UINT32|EXC_DEFAULT|EXD_PROC_PID
     Value = 3
    ITEM
      Catalog = EXT_UINT32|EXC_DEFAULT|EXD_PROC_UID
      Value = 0
    ITEM
      Catalog = EXT_UINT32|EXC_DEFAULT|EXD_PROC_GID
      Value = 0
    ITEM
      Catalog = EXT_UINT32|EXC_DEFAULT|EXD_PROC_PROJID
      Value = 0
    ITEM
      Catalog = EXT_UINT32|EXC_DEFAULT|EXD_PROC_TASKID
      Value = 0
    ITEM
      Catalog = EXT_STRING|EXC_DEFAULT|EXD_PROC_COMMAND
      Value = fsflush
 ENDGROUP

=head1 ATTRIBUTES

See C<attributes(5)> for descriptions of the following attributes:

  ___________________________________________________________
 |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
 |_____________________________|_____________________________|
 | Availability                | CPAN (http://www.cpan.org)  |
 |_____________________________|_____________________________|
 | Interface Stability         | Evolving                    |
 |_____________________________|_____________________________|

=head1 SEE ALSO

C<ea_match_object_catalog(3EXACCT)>, C<Sun::Solaris::Exacct(3)>,
C<Sun::Solaris::Exacct::Catalog(3)>, C<Sun::Solaris::Exacct::File(3)>,
C<Sun::Solaris::Exacct::Object::Group(3)>,
C<Sun::Solaris::Exacct::Object::Item(3)>, C<libexacct(3LIB)>, C<attributes(5)>