libkern/libkern/c++/OSCollection.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /* IOCollection.h created by gvdl on Thu 1998-10-22 */
  24
  25 #ifndef _OS_OSCOLLECTION_H
  26 #define _OS_OSCOLLECTION_H
  27
  28 #include <libkern/c++/OSObject.h>
  29
  30 class OSDictionary;
  31
  32 /*!
  33     @class OSCollection
  34     @abstract Abstract super class for all collections.
  35     @discussion
  36     OSCollection is the abstract super class for all OSObject derived collections and provides the necessary interfaces for managing storage space and iteration through a collection.
  37 */
  38 class OSCollection : public OSObject
  39 {
  40     friend class OSCollectionIterator;
  41
  42     OSDeclareAbstractStructors(OSCollection);
  43
  44     struct ExpansionData { };
  45
  46 protected:
  47     unsigned int updateStamp;
  48
  49 private:
  50     /* Reserved for future use.  (Internal use only)  */
  51     // ExpansionData *reserved;
  52     unsigned int fOptions;
  53
  54 protected:
  55     // Member functions used by the OSCollectionIterator class.
  56     /*
  57         @function iteratorSize
  58         @abstract A pure virtual member function to return the size of the iterator context.
  59         @result Returns an integer size for the storage space required to contain context necessary for iterating through a collection.
  60         @discussion
  61         This member function is called by an OSCollectionIterator object to allow it to allocate enough storage space for the iterator context.  This context contains the data necessary to iterate through the collection when getNextObjectForIterator() is called.
  62     */
  63     virtual unsigned int iteratorSize() const = 0;
  64     /*
  65         @function initIterator
  66         @abstract Pure virtual member function to allocate and initialize the iterator context data.
  67         @param iterator The iterator context.
  68         @result Returns true if initialization was successful, false otherwise.
  69     */
  70     virtual bool initIterator(void *iterator) const = 0;
  71     /*
  72         @function getNextObjectForIterator
  73         @abstract A pure virtual member function which returns the next member of a collection.
  74         @param iterator The iterator context.
  75         @param ret The object returned to the caller.
  76         @result Returns true if an object was found, false otherwise.
  77         @discussion
  78         This is the entry point used by an OSCollectionIterator object to advance to next object in the collection.  The iterator context is passed to the receiver to allow it to find the location of the current object and then advance the iterator context to the next object.
  79     */
  80     virtual bool getNextObjectForIterator(void *iterator, OSObject **ret) const = 0;
  81
  82     /*
  83         @function init
  84         @abstract A member function to initialize the OSCollection object.
  85         @result Returns true if an object was initialized successfully, false otherwise.
  86         @discussion
  87         This function is used to initialize state within a newly created OSCollection object.
  88     */
  89     virtual bool init();
  90
  91 public:
  92     enum {
  93         kImmutable = 0x00000001,
  94         kMASK      = (unsigned) -1
  95     };
  96
  97     /*
  98         @function haveUpdated
  99         @abstract A member function to track of all updates to the collection.
 100     */
 101     void haveUpdated();
 102
 103     /*
 104         @function getCount
 105         @abstract A pure virtual member function which returns the number of objects in the collection subclass.
 106         @results Returns the number objects in a collection.
 107      */
 108     virtual unsigned int getCount() const = 0;
 109     /*
 110         @function getCapacity
 111         @abstract A pure virtual member function which returns the storage space in the collection subclass.
 112         @results Returns the number objects in a collection.
 113      */
 114     virtual unsigned int getCapacity() const = 0;
 115     /*
 116         @function getCapacityIncrement
 117         @abstract A pure virtual member function which returns the growth factor of the collection subclass.
 118         @results Returns the size by which the collection subclass should grow.
 119      */
 120     virtual unsigned int getCapacityIncrement() const = 0;
 121     /*
 122         @function setCapacityIncrement
 123         @abstract A pure virtual member function which sets the growth factor of the collection subclass.
 124         @param increment The new size by which the capacity of the collection should grow.
 125         @results Returns the new capacity increment.
 126      */
 127     virtual unsigned int setCapacityIncrement(unsigned increment) = 0;
 128
 129     /*
 130         @function ensureCapacity
 131         @abstract A pure virtual member function which
 132         @param newCapacity
 133         @result
 134      */
 135     virtual unsigned int ensureCapacity(unsigned int newCapacity) = 0;
 136
 137     /*
 138         @function flushCollection
 139         @abstract A pure virtual member function which
 140      */
 141     virtual void flushCollection() = 0;
 142
 143     /*!
 144         @function setOptions
 145         @abstract This function is used to recursively set option bits in this collection and all child collections.
 146         @discussion setOptions is a recursive function but the OSCollection class itself does not know the structure of the particular collection.  This means that all derived classes are expected to override this method and recurse if the old value of the option was NOT set, which is why the old value is returned.  As this function is a reserved function override it is very multi purpose.  It can be used to get & set the options,
 147         @param options Set the (options & mask) bits.
 148         @param mask The mask of bits which need to be set, 0 to get the current value.
 149         @result The options before the set operation, NB setOptions(?,0) returns the current value of this collection.
 150      */
 151     OSMetaClassDeclareReservedUsed(OSCollection, 0);
 152     virtual unsigned setOptions(unsigned options, unsigned mask, void * = 0);
 153
 154     /*!
 155         @function copyCollection
 156         @abstract Do a deep copy of a collection tree.
 157         @discussion This function copies this collection and all of the contained collections recursively.  Objects that don't derive from OSContainter are NOT copied, that is objects like OSString and OSData.  To a derive from OSConnection::copyCollection some code is required to be implemented in the derived class, below is the skeleton pseudo code to copy a collection.
 158
 159 OSCollection * <MyCollection>::copyCollection(OSDictionary *inCycleDict)
 160 {
 161     bool allocDict = !cycleDict;
 162     OSCollection *ret = 0;
 163     <MyCollection> *newMyColl = 0;
 164
 165     if (allocDict)
 166         cycleDict = OSDictionary::withCapacity(16);
 167     if (!cycleDict)
 168         return 0;
 169
 170     do {
 171         // Check to see if we already have a copy of the new dictionary
 172         ret = super::copyCollection(cycleDict);
 173         if (ret)
 174             continue;
 175
 176         // Your code goes here to copy your collection,
 177         // see OSArray & OSDictionary for examples.
 178         newMyColl = <MyCollection>::with<MyCollection>(this);
 179         if (!newMyColl)
 180             continue;
 181
 182         // Insert object into cycle Dictionary
 183         cycleDict->setObject((const OSSymbol *) this, newMyColl);
 184
 185         // Duplicate any collections in us
 186         for (unsigned int i = 0; i < count; i++) {
 187             OSObject *obj = getObject(i);
 188             OSCollection *coll = OSDynamicCast(OSCollection, obj);
 189
 190             if (coll) {
 191                 OSCollection *newColl = coll->copyCollection(cycleDict);
 192                 if (!newColl)
 193                     goto abortCopy;
 194
 195                 newMyColl->replaceObject(i, newColl);
 196                 newColl->release();
 197             };
 198         };
 199
 200         ret = newMyColl;
 201         newMyColl = 0;
 202
 203     } while (false);
 204
 205 abortCopy:
 206     if (newMyColl)
 207         newMyColl->release();
 208
 209     if (allocDict)
 210         cycleDict->release();
 211
 212     return ret;
 213 }
 214
 215         @param cycleDict Is a dictionary of all of the collections that have been, to start the copy at the top level just leave this field 0.
 216         @result The newly copied collecton or 0 if insufficient memory
 217     */
 218     virtual OSCollection *copyCollection(OSDictionary *cycleDict = 0);
 219     OSMetaClassDeclareReservedUsed(OSCollection, 1);
 220
 221     OSMetaClassDeclareReservedUnused(OSCollection, 2);
 222     OSMetaClassDeclareReservedUnused(OSCollection, 3);
 223     OSMetaClassDeclareReservedUnused(OSCollection, 4);
 224     OSMetaClassDeclareReservedUnused(OSCollection, 5);
 225     OSMetaClassDeclareReservedUnused(OSCollection, 6);
 226     OSMetaClassDeclareReservedUnused(OSCollection, 7);
 227 };
 228
 229 #endif /* !_OS_OSCOLLECTION_H */