(file) Return to InheritanceTree.h CVS log (file) (dir) Up to [Pegasus] / pegasus / src / Pegasus / Repository

File: [Pegasus] / pegasus / src / Pegasus / Repository / InheritanceTree.h (download)
Revision: 1.9, Sat May 5 23:09:12 2001 UTC (23 years, 1 month ago) by mike
Branch: MAIN
CVS Tags: version_0_96, version_0_95, stable_0_95, stable
Changes since 1.8: +6 -0 lines
Implemented enumerateInstances().

//%/////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2000 The Open Group, BMC Software, Tivoli Systems, IBM
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
//==============================================================================
//
// Author: Mike Brasher (mbrasher@bmc.com)
//
// Modified By:
//
//%/////////////////////////////////////////////////////////////////////////////

#ifndef Pegasus_InheritanceTree_h
#define Pegasus_InheritanceTree_h

#include <iostream>
#include <Pegasus/Common/Config.h>
#include <Pegasus/Common/String.h>
#include <Pegasus/Common/Exception.h>

PEGASUS_NAMESPACE_BEGIN

struct InheritanceTreeRep;

/** The InheritanceTree class tracks inheritance relationships of CIM classes.

    This class is a memory resident version of the repository's persistent 
    inheritance information (represented using file names). The InheritanceTree 
    provides O(1) access (via hashing) to any class in the inheritance tree.

    The inheritance tree provides methods for interrogating certain kinds of
    information about a class, including:

	<ul>
	<li>the superclass</li>
	<li>the subclasses</li>
	<li>the descendent classes</li>
	</ul>

    The insert() method is used to build up an InheritanceTree. The insert()
    method is called for each class-subclass relationship. For example, consider
    the following list of class-subclass pairs:

	<pre>
	{ "D", "B" }
	{ "E", "B" }
	{ "B", "A" }
	{ "C", "A" }
	{ "F", "C" }
	</pre>

    These pairs specify the following inheritance tree:

	<pre>
              A
            /   \
           B     C
         /   \     \
        D     E     F
	</pre>

    The pairs above may be used to build a class tree as follows:

	<pre>
	InheritanceTree it;
	it.insert("D", "B");
	it.insert("E", "B");
	it.insert("B", "A");
	it.insert("C", "A");
	it.insert("F", "C");
	it.insert("A", "");
	it.check();
	</pre>

    The check() method determines whether insert() was called for every class
    used as a superclass. In the following example, check() would fail (and
    throw and exception) since the "B" class is passed as a superclass (second
    argument) in two insert() calls but was never passed as the class itself
    (first argument) in any insert() call:

	<pre>
	InheritanceTree it;
	it.insert("D", "B");
	it.insert("E", "B");
	it.insert("C", "A");
	it.insert("F", "C");
	it.insert("A", "");
	it.check();
	</pre>

    In this case, check() throws an InvalidInheritanceTree exception.

    The InheritanceTree may be printed by calling the print() method.

    The insertFromPath() method is used to build up an InheritanceTree from
    the file names in a certain directory as used by the CIMRepository. The
    CIMRepository contains a disk file per class and the name has this form:

	<pre>
	<ClassName>.<SuperClassName>
	</pre>

    For example, a class called "ThisClass" with super class "ThatClass" 
    has this name:

	<pre>
	ThisClass.ThisClass
	</pre>

    The file or course contains the XML encoding of the ThisClass class (which 
    is irrelevant for the InheritanceTree). A root class (with no superclass
    has the following form):

	<pre>
	<ClassName>.#
	</pre>

    Suppose that ThatClass is a root class; then its file name is:

	<pre>
	ThatClass.#
	</pre>

    It must be obvious by now that the insertFromPath() method just scans
    the file names in a directory and calls insert() for each one (splitting
    the class name from superclass name and translating '#' to an empty string).

    The insertFromPath() method does NOT call check(), so it still must be 
    called to verify the InheritanceTree.
*/
class PEGASUS_REPOSITORY_LINKAGE InheritanceTree
{
public:

    /** Default constructor. */
    InheritanceTree();

    /** Destructor. */
    ~InheritanceTree();

    /** Inserts a class-subclass relationship into the inheritance three.
	Note that a class CAN be inserted before its superclass, in which case
	a provisional entry is made for the superclass and flagged as such; 
	when the superclass is later inserted, the provisional flag is cleared.
	@param className - name of class being inserted.
	@param superClassName - name of super class of class.
    */
    void insert(const String& className, const String& superClassName);

    /** Scan directory for file names of the form <ClassName>.<SuperClass> and
	call insert on insert for each one. Note that root classes (classes with
	no superclass) will use "#" for a SuperClass name.
	@param path - directory that contains files describing inheritance 
	    infoformation.
	@exception throws CannotOpenDirectory is invalid path specifies an
	    invalid directory.
    */
    void insertFromPath(const String& path);

    /** Checks that every superClassName passed to insert() was also passed
	as a className argument to insert(). In other words, it checks that
	there are no provisional entries as described in the insert() method.
	@exception InvalidInheritanceTree
    */
    void check() const;

    /** Get subclass names of the given class.
	@param className - class whose subclass names will be gotten. If
	    className is empty, all classnames are returned.
	@param deepInheritance - if true all descendent classes of class
	    are returned. If className is empty, only root classes are returned.
	@param subClassNames - output argument to hold subclass names.
	@return true on success. False if no such class.
    */
    Boolean getSubClassNames(
	const String& className,
	Boolean deepInheritance,
	Array<String>& subClassNames) const;

    /** Get the names of all superclasses of this class (direct and indirect).
    */
    Boolean getSuperClassNames(
	const String& className,
	Array<String>& subClassNames) const;

    /** Get the superclass of the given class.
	@param className name of class.
	@param superClassName name of superclass upon return.
	@return true if class was found; false otherwise.
    */
    Boolean getSuperClass(
	const String& className,
	String& superClassName) const;

    /** Returns true if the given class has sub-classes. */
    Boolean hasSubClasses(
	const String& className,
	Boolean& hasSubClasses) const;

    /** Returns true if this inhertance tree contains the given class. */
    Boolean containsClass(const String& className) const;

    /** Removes the given class from the class graph. 
	@exception CIMException(CIMException::CLASS_HAS_CHILDREN)
	@exception CIMException(CIMException::INVALID_CLASS)
    */
    void remove(const String& className);

    /** Prints the class */
    void print(std::ostream& os) const;

private:

    InheritanceTree(const InheritanceTree&) { }

    InheritanceTree& operator=(const InheritanceTree&) { return *this; }

    InheritanceTreeRep* _rep;
};

/** The InvalidInheritanceTree exception is thrown when the
    InheritanceTreeRep::check() method determines that an inheritance tree
    was not fully specified (when any class was passed as a superClassName
    argument to insert() but never as a className argument.
*/
class InvalidInheritanceTree : public Exception
{
public:

    InvalidInheritanceTree(const String& className) 
	: Exception("Invalid inheritance tree: unknown class: " + className) { }
};

PEGASUS_NAMESPACE_END

#endif /* Pegasus_InheritanceTree_h */

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