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[apple/xnu.git] / libkern / libkern / c++ / OSCollectionIterator.h

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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 */
/* IOCollectionIterator.h created by gvdl on Fri 1998-10-30 */

#ifndef _OS_OSCOLLECTIONITERATOR_H
#define _OS_OSCOLLECTIONITERATOR_H

#include <libkern/c++/OSIterator.h>

class OSCollection;

/*!
    @class OSCollectionIterator
    @discussion
    OSCollectionIterator objects provide a consistent mechanism to iterate through all OSCollection derived collections.
*/
class OSCollectionIterator : public OSIterator
{
    OSDeclareDefaultStructors(OSCollectionIterator)

protected:
    const OSCollection *collection;
    void *collIterator;
    unsigned int initialUpdateStamp;
    bool valid;

public:
    /*!
        @function withCollection
        @abstract A static constructor function which creates and initializes an instance of OSCollectionIterator for the provided collection object.
        @param inColl The OSCollection derived collection object to be iteratated.
        @result Returns a new instance of OSCollection or 0 on failure.
    */
    static OSCollectionIterator *withCollection(const OSCollection *inColl);

    /*!
        @function withCollection
        @abstract A member function to initialize the intance of OSCollectionIterator with the provided colleciton object.
        @param inColl The OSCollection derived collection object to be iteratated.
        @result Returns true if the initialization was successful or false on failure.
    */
    virtual bool initWithCollection(const OSCollection *inColl);
    /*!
        @function free
        @abstract A member function to release and deallocate all resources created or used by the OSCollectionIterator object.
        @discussion This function should not be called directly, use release() instead.
    */
    virtual void free();

    /*!
        @function reset
        @abstract A member function which resets the iterator to begin the next iteration from the beginning of the collection.
    */
    virtual void reset();

    /*!
        @function isValid
        @abstract A member function for determining if the collection was modified during iteration.
    */
    virtual bool isValid();

    /*!
        @function getNextObject
        @abstract A member function to get the next object in the collection being iterated.
        @result Returns the next object in the collection or 0 when the end has been reached.
    */
    virtual OSObject *getNextObject();
};

#endif /* !_OS_OSCOLLECTIONITERATOR_H */