CFBinaryHeap.h

   1 /*
   2  * Copyright (c) 2009 Apple 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 /*      CFBinaryHeap.h
  24         Copyright (c) 1998-2009, Apple Inc. All rights reserved.
  25 */
  26 /*!
  27         @header CFBinaryHeap
  28         CFBinaryHeap implements a container which stores values sorted using
  29         a binary search algorithm.  CFBinaryHeaps can be useful as priority
  30         queues.
  31 */
  32
  33 #if !defined(__COREFOUNDATION_CFBINARYHEAP__)
  34 #define __COREFOUNDATION_CFBINARYHEAP__ 1
  35
  36 #include <CoreFoundation/CFBase.h>
  37
  38 CF_EXTERN_C_BEGIN
  39
  40 typedef struct {
  41     CFIndex     version;
  42     void *      info;
  43     const void *(*retain)(const void *info);
  44     void        (*release)(const void *info);
  45     CFStringRef (*copyDescription)(const void *info);
  46 } CFBinaryHeapCompareContext;
  47
  48 /*!
  49         @typedef CFBinaryHeapCallBacks
  50         Structure containing the callbacks for values of a CFBinaryHeap.
  51         @field version The version number of the structure type being passed
  52                 in as a parameter to the CFBinaryHeap creation functions.
  53                 This structure is version 0.
  54         @field retain The callback used to add a retain for the binary heap
  55                 on values as they are put into the binary heap.
  56                 This callback returns the value to use as the value in the
  57                 binary heap, which is usually the value parameter passed to
  58                 this callback, but may be a different value if a different
  59                 value should be added to the binary heap. The binary heap's
  60                 allocator is passed as the first argument.
  61         @field release The callback used to remove a retain previously added
  62                 for the binary heap from values as they are removed from
  63                 the binary heap. The binary heap's allocator is passed as the
  64                 first argument.
  65         @field copyDescription The callback used to create a descriptive
  66                 string representation of each value in the binary heap. This
  67                 is used by the CFCopyDescription() function.
  68         @field compare The callback used to compare values in the binary heap for
  69                 equality in some operations.
  70 */
  71 typedef struct {
  72     CFIndex     version;
  73     const void *(*retain)(CFAllocatorRef allocator, const void *ptr);
  74     void        (*release)(CFAllocatorRef allocator, const void *ptr);
  75     CFStringRef (*copyDescription)(const void *ptr);
  76     CFComparisonResult  (*compare)(const void *ptr1, const void *ptr2, void *context);
  77 } CFBinaryHeapCallBacks;
  78
  79 /*!
  80         @constant kCFStringBinaryHeapCallBacks
  81         Predefined CFBinaryHeapCallBacks structure containing a set
  82         of callbacks appropriate for use when the values in a CFBinaryHeap
  83         are all CFString types.
  84 */
  85 CF_EXPORT const CFBinaryHeapCallBacks kCFStringBinaryHeapCallBacks;
  86
  87 /*!
  88         @typedef CFBinaryHeapApplierFunction
  89         Type of the callback function used by the apply functions of
  90                 CFBinaryHeap.
  91         @param value The current value from the binary heap.
  92         @param context The user-defined context parameter given to the apply
  93                 function.
  94 */
  95 typedef void (*CFBinaryHeapApplierFunction)(const void *val, void *context);
  96
  97 /*!
  98         @typedef CFBinaryHeapRef
  99         This is the type of a reference to CFBinaryHeaps.
 100 */
 101 typedef struct __CFBinaryHeap * CFBinaryHeapRef;
 102
 103 /*!
 104         @function CFBinaryHeapGetTypeID
 105         Returns the type identifier of all CFBinaryHeap instances.
 106 */
 107 CF_EXPORT CFTypeID      CFBinaryHeapGetTypeID(void);
 108
 109 /*!
 110         @function CFBinaryHeapCreate
 111         Creates a new mutable binary heap with the given values.
 112         @param allocator The CFAllocator which should be used to allocate
 113                 memory for the binary heap and its storage for values. This
 114                 parameter may be NULL in which case the current default
 115                 CFAllocator is used. If this reference is not a valid
 116                 CFAllocator, the behavior is undefined.
 117         @param capacity A hint about the number of values that will be held
 118                 by the CFBinaryHeap. Pass 0 for no hint. The implementation may
 119                 ignore this hint, or may use it to optimize various
 120                 operations. A heap's actual capacity is only limited by
 121                 address space and available memory constraints). If this
 122                 parameter is negative, the behavior is undefined.
 123         @param callBacks A pointer to a CFBinaryHeapCallBacks structure
 124                 initialized with the callbacks for the binary heap to use on
 125                 each value in the binary heap. A copy of the contents of the
 126                 callbacks structure is made, so that a pointer to a structure
 127                 on the stack can be passed in, or can be reused for multiple
 128                 binary heap creations. If the version field of this callbacks
 129                 structure is not one of the defined ones for CFBinaryHeap, the
 130                 behavior is undefined. The retain field may be NULL, in which
 131                 case the CFBinaryHeap will do nothing to add a retain to values
 132                 as they are put into the binary heap. The release field may be
 133                 NULL, in which case the CFBinaryHeap will do nothing to remove
 134                 the binary heap's retain (if any) on the values when the
 135                 heap is destroyed or a key-value pair is removed. If the
 136                 copyDescription field is NULL, the binary heap will create a
 137                 simple description for a value. If the equal field is NULL, the
 138                 binary heap will use pointer equality to test for equality of
 139                 values. This callbacks parameter itself may be NULL, which is
 140                 treated as if a valid structure of version 0 with all fields
 141                 NULL had been passed in. Otherwise,
 142                 if any of the fields are not valid pointers to functions
 143                 of the correct type, or this parameter is not a valid
 144                 pointer to a CFBinaryHeapCallBacks callbacks structure,
 145                 the behavior is undefined. If any of the values put into the
 146                 binary heap is not one understood by one of the callback functions
 147                 the behavior when that callback function is used is undefined.
 148         @param compareContext A pointer to a CFBinaryHeapCompareContext structure.
 149         @result A reference to the new CFBinaryHeap.
 150 */
 151 CF_EXPORT CFBinaryHeapRef       CFBinaryHeapCreate(CFAllocatorRef allocator, CFIndex capacity, const CFBinaryHeapCallBacks *callBacks, const CFBinaryHeapCompareContext *compareContext);
 152
 153 /*!
 154         @function CFBinaryHeapCreateCopy
 155         Creates a new mutable binary heap with the values from the given binary heap.
 156         @param allocator The CFAllocator which should be used to allocate
 157                 memory for the binary heap and its storage for values. This
 158                 parameter may be NULL in which case the current default
 159                 CFAllocator is used. If this reference is not a valid
 160                 CFAllocator, the behavior is undefined.
 161         @param capacity A hint about the number of values that will be held
 162                 by the CFBinaryHeap. Pass 0 for no hint. The implementation may
 163                 ignore this hint, or may use it to optimize various
 164                 operations. A heap's actual capacity is only limited by
 165                 address space and available memory constraints).
 166                 This parameter must be greater than or equal
 167                 to the count of the heap which is to be copied, or the
 168                 behavior is undefined. If this parameter is negative, the
 169                 behavior is undefined.
 170         @param heap The binary heap which is to be copied. The values from the
 171                 binary heap are copied as pointers into the new binary heap (that is,
 172                 the values themselves are copied, not that which the values
 173                 point to, if anything). However, the values are also
 174                 retained by the new binary heap. The count of the new binary will
 175                 be the same as the given binary heap. The new binary heap uses the same
 176                 callbacks as the binary heap to be copied. If this parameter is
 177                 not a valid CFBinaryHeap, the behavior is undefined.
 178         @result A reference to the new mutable binary heap.
 179 */
 180 CF_EXPORT CFBinaryHeapRef       CFBinaryHeapCreateCopy(CFAllocatorRef allocator, CFIndex capacity, CFBinaryHeapRef heap);
 181
 182 /*!
 183         @function CFBinaryHeapGetCount
 184         Returns the number of values currently in the binary heap.
 185         @param heap The binary heap to be queried. If this parameter is not a valid
 186                 CFBinaryHeap, the behavior is undefined.
 187         @result The number of values in the binary heap.
 188 */
 189 CF_EXPORT CFIndex       CFBinaryHeapGetCount(CFBinaryHeapRef heap);
 190
 191 /*!
 192         @function CFBinaryHeapGetCountOfValue
 193         Counts the number of times the given value occurs in the binary heap.
 194         @param heap The binary heap to be searched. If this parameter is not a
 195                 valid CFBinaryHeap, the behavior is undefined.
 196         @param value The value for which to find matches in the binary heap. The
 197                 compare() callback provided when the binary heap was created is
 198                 used to compare. If the compare() callback was NULL, pointer
 199                 equality (in C, ==) is used. If value, or any of the values
 200                 in the binary heap, are not understood by the compare() callback,
 201                 the behavior is undefined.
 202         @result The number of times the given value occurs in the binary heap.
 203 */
 204 CF_EXPORT CFIndex       CFBinaryHeapGetCountOfValue(CFBinaryHeapRef heap, const void *value);
 205
 206 /*!
 207         @function CFBinaryHeapContainsValue
 208         Reports whether or not the value is in the binary heap.
 209         @param heap The binary heap to be searched. If this parameter is not a
 210                 valid CFBinaryHeap, the behavior is undefined.
 211         @param value The value for which to find matches in the binary heap. The
 212                 compare() callback provided when the binary heap was created is
 213                 used to compare. If the compare() callback was NULL, pointer
 214                 equality (in C, ==) is used. If value, or any of the values
 215                 in the binary heap, are not understood by the compare() callback,
 216                 the behavior is undefined.
 217         @result true, if the value is in the specified binary heap, otherwise false.
 218 */
 219 CF_EXPORT Boolean       CFBinaryHeapContainsValue(CFBinaryHeapRef heap, const void *value);
 220
 221 /*!
 222         @function CFBinaryHeapGetMinimum
 223         Returns the minimum value is in the binary heap.  If the heap contains several equal
 224                 minimum values, any one may be returned.
 225         @param heap The binary heap to be searched. If this parameter is not a
 226                 valid CFBinaryHeap, the behavior is undefined.
 227         @result A reference to the minimum value in the binary heap, or NULL if the
 228                 binary heap contains no values.
 229 */
 230 CF_EXPORT const void *  CFBinaryHeapGetMinimum(CFBinaryHeapRef heap);
 231
 232 /*!
 233         @function CFBinaryHeapGetMinimumIfPresent
 234         Returns the minimum value is in the binary heap, if present.  If the heap contains several equal
 235                 minimum values, any one may be returned.
 236         @param heap The binary heap to be searched. If this parameter is not a
 237                 valid CFBinaryHeap, the behavior is undefined.
 238         @param value A C pointer to pointer-sized storage to be filled with the minimum value in
 239                 the binary heap.  If this value is not a valid C pointer to a pointer-sized block
 240                 of storage, the result is undefined.  If the result of the function is false, the value
 241                 stored at this address is undefined.
 242         @result true, if a minimum value was found in the specified binary heap, otherwise false.
 243 */
 244 CF_EXPORT Boolean       CFBinaryHeapGetMinimumIfPresent(CFBinaryHeapRef heap, const void **value);
 245
 246 /*!
 247         @function CFBinaryHeapGetValues
 248         Fills the buffer with values from the binary heap.
 249         @param heap The binary heap to be queried. If this parameter is not a
 250                 valid CFBinaryHeap, the behavior is undefined.
 251         @param values A C array of pointer-sized values to be filled with
 252                 values from the binary heap. The values in the C array are ordered
 253                 from least to greatest. If this parameter is not a valid pointer to a
 254                 C array of at least CFBinaryHeapGetCount() pointers, the behavior is undefined.
 255 */
 256 CF_EXPORT void          CFBinaryHeapGetValues(CFBinaryHeapRef heap, const void **values);
 257
 258 /*!
 259         @function CFBinaryHeapApplyFunction
 260         Calls a function once for each value in the binary heap.
 261         @param heap The binary heap to be operated upon. If this parameter is not a
 262                 valid CFBinaryHeap, the behavior is undefined.
 263         @param applier The callback function to call once for each value in
 264                 the given binary heap. If this parameter is not a
 265                 pointer to a function of the correct prototype, the behavior
 266                 is undefined. If there are values in the binary heap which the
 267                 applier function does not expect or cannot properly apply
 268                 to, the behavior is undefined.
 269         @param context A pointer-sized user-defined value, which is passed
 270                 as the second parameter to the applier function, but is
 271                 otherwise unused by this function. If the context is not
 272                 what is expected by the applier function, the behavior is
 273                 undefined.
 274 */
 275 CF_EXPORT void          CFBinaryHeapApplyFunction(CFBinaryHeapRef heap, CFBinaryHeapApplierFunction applier, void *context);
 276
 277 /*!
 278         @function CFBinaryHeapAddValue
 279         Adds the value to the binary heap.
 280         @param heap The binary heap to which the value is to be added. If this parameter is not a
 281                 valid mutable CFBinaryHeap, the behavior is undefined.
 282         @param value The value to add to the binary heap. The value is retained by
 283                 the binary heap using the retain callback provided when the binary heap
 284                 was created. If the value is not of the sort expected by the
 285                 retain callback, the behavior is undefined.
 286 */
 287 CF_EXPORT void          CFBinaryHeapAddValue(CFBinaryHeapRef heap, const void *value);
 288
 289 /*!
 290         @function CFBinaryHeapRemoveMinimumValue
 291         Removes the minimum value from the binary heap.
 292         @param heap The binary heap from which the minimum value is to be removed. If this
 293                 parameter is not a valid mutable CFBinaryHeap, the behavior is undefined.
 294 */
 295 CF_EXPORT void          CFBinaryHeapRemoveMinimumValue(CFBinaryHeapRef heap);
 296
 297 /*!
 298         @function CFBinaryHeapRemoveAllValues
 299         Removes all the values from the binary heap, making it empty.
 300         @param heap The binary heap from which all of the values are to be
 301                 removed. If this parameter is not a valid mutable CFBinaryHeap,
 302                 the behavior is undefined.
 303 */
 304 CF_EXPORT void          CFBinaryHeapRemoveAllValues(CFBinaryHeapRef heap);
 305
 306 CF_EXTERN_C_END
 307
 308 #endif /* ! __COREFOUNDATION_CFBINARYHEAP__ */
 309