CFBinaryHeap.h

   1 /*
   2  * Copyright (c) 2011 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,
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  18  * Please see the License for the specific language governing rights and
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  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 /*      CFBinaryHeap.h
  25         Copyright (c) 1998-2011, Apple Inc. All rights reserved.
  26 */
  27 /*!
  28         @header CFBinaryHeap
  29         CFBinaryHeap implements a container which stores values sorted using
  30         a binary search algorithm.  CFBinaryHeaps can be useful as priority
  31         queues.
  32 */
  33
  34 #if !defined(__COREFOUNDATION_CFBINARYHEAP__)
  35 #define __COREFOUNDATION_CFBINARYHEAP__ 1
  36
  37 #include <CoreFoundation/CFBase.h>
  38
  39 CF_EXTERN_C_BEGIN
  40
  41 typedef struct {
  42     CFIndex     version;
  43     void *      info;
  44     const void *(*retain)(const void *info);
  45     void        (*release)(const void *info);
  46     CFStringRef (*copyDescription)(const void *info);
  47 } CFBinaryHeapCompareContext;
  48
  49 /*!
  50         @typedef CFBinaryHeapCallBacks
  51         Structure containing the callbacks for values of a CFBinaryHeap.
  52         @field version The version number of the structure type being passed
  53                 in as a parameter to the CFBinaryHeap creation functions.
  54                 This structure is version 0.
  55         @field retain The callback used to add a retain for the binary heap
  56                 on values as they are put into the binary heap.
  57                 This callback returns the value to use as the value in the
  58                 binary heap, which is usually the value parameter passed to
  59                 this callback, but may be a different value if a different
  60                 value should be added to the binary heap. The binary heap's
  61                 allocator is passed as the first argument.
  62         @field release The callback used to remove a retain previously added
  63                 for the binary heap from values as they are removed from
  64                 the binary heap. The binary heap's allocator is passed as the
  65                 first argument.
  66         @field copyDescription The callback used to create a descriptive
  67                 string representation of each value in the binary heap. This
  68                 is used by the CFCopyDescription() function.
  69         @field compare The callback used to compare values in the binary heap for
  70                 equality in some operations.
  71 */
  72 typedef struct {
  73     CFIndex     version;
  74     const void *(*retain)(CFAllocatorRef allocator, const void *ptr);
  75     void        (*release)(CFAllocatorRef allocator, const void *ptr);
  76     CFStringRef (*copyDescription)(const void *ptr);
  77     CFComparisonResult  (*compare)(const void *ptr1, const void *ptr2, void *context);
  78 } CFBinaryHeapCallBacks;
  79
  80 /*!
  81         @constant kCFStringBinaryHeapCallBacks
  82         Predefined CFBinaryHeapCallBacks structure containing a set
  83         of callbacks appropriate for use when the values in a CFBinaryHeap
  84         are all CFString types.
  85 */
  86 CF_EXPORT const CFBinaryHeapCallBacks kCFStringBinaryHeapCallBacks;
  87
  88 /*!
  89         @typedef CFBinaryHeapApplierFunction
  90         Type of the callback function used by the apply functions of
  91                 CFBinaryHeap.
  92         @param value The current value from the binary heap.
  93         @param context The user-defined context parameter given to the apply
  94                 function.
  95 */
  96 typedef void (*CFBinaryHeapApplierFunction)(const void *val, void *context);
  97
  98 /*!
  99         @typedef CFBinaryHeapRef
 100         This is the type of a reference to CFBinaryHeaps.
 101 */
 102 typedef struct __CFBinaryHeap * CFBinaryHeapRef;
 103
 104 /*!
 105         @function CFBinaryHeapGetTypeID
 106         Returns the type identifier of all CFBinaryHeap instances.
 107 */
 108 CF_EXPORT CFTypeID      CFBinaryHeapGetTypeID(void);
 109
 110 /*!
 111         @function CFBinaryHeapCreate
 112         Creates a new mutable binary heap with the given values.
 113         @param allocator The CFAllocator which should be used to allocate
 114                 memory for the binary heap and its storage for values. This
 115                 parameter may be NULL in which case the current default
 116                 CFAllocator is used. If this reference is not a valid
 117                 CFAllocator, the behavior is undefined.
 118         @param capacity A hint about the number of values that will be held
 119                 by the CFBinaryHeap. Pass 0 for no hint. The implementation may
 120                 ignore this hint, or may use it to optimize various
 121                 operations. A heap's actual capacity is only limited by
 122                 address space and available memory constraints). If this
 123                 parameter is negative, the behavior is undefined.
 124         @param callBacks A pointer to a CFBinaryHeapCallBacks structure
 125                 initialized with the callbacks for the binary heap to use on
 126                 each value in the binary heap. A copy of the contents of the
 127                 callbacks structure is made, so that a pointer to a structure
 128                 on the stack can be passed in, or can be reused for multiple
 129                 binary heap creations. If the version field of this callbacks
 130                 structure is not one of the defined ones for CFBinaryHeap, the
 131                 behavior is undefined. The retain field may be NULL, in which
 132                 case the CFBinaryHeap will do nothing to add a retain to values
 133                 as they are put into the binary heap. The release field may be
 134                 NULL, in which case the CFBinaryHeap will do nothing to remove
 135                 the binary heap's retain (if any) on the values when the
 136                 heap is destroyed or a key-value pair is removed. If the
 137                 copyDescription field is NULL, the binary heap will create a
 138                 simple description for a value. If the equal field is NULL, the
 139                 binary heap will use pointer equality to test for equality of
 140                 values. This callbacks parameter itself may be NULL, which is
 141                 treated as if a valid structure of version 0 with all fields
 142                 NULL had been passed in. Otherwise,
 143                 if any of the fields are not valid pointers to functions
 144                 of the correct type, or this parameter is not a valid
 145                 pointer to a CFBinaryHeapCallBacks callbacks structure,
 146                 the behavior is undefined. If any of the values put into the
 147                 binary heap is not one understood by one of the callback functions
 148                 the behavior when that callback function is used is undefined.
 149         @param compareContext A pointer to a CFBinaryHeapCompareContext structure.
 150         @result A reference to the new CFBinaryHeap.
 151 */
 152 CF_EXPORT CFBinaryHeapRef       CFBinaryHeapCreate(CFAllocatorRef allocator, CFIndex capacity, const CFBinaryHeapCallBacks *callBacks, const CFBinaryHeapCompareContext *compareContext);
 153
 154 /*!
 155         @function CFBinaryHeapCreateCopy
 156         Creates a new mutable binary heap with the values from the given binary heap.
 157         @param allocator The CFAllocator which should be used to allocate
 158                 memory for the binary heap and its storage for values. This
 159                 parameter may be NULL in which case the current default
 160                 CFAllocator is used. If this reference is not a valid
 161                 CFAllocator, the behavior is undefined.
 162         @param capacity A hint about the number of values that will be held
 163                 by the CFBinaryHeap. Pass 0 for no hint. The implementation may
 164                 ignore this hint, or may use it to optimize various
 165                 operations. A heap's actual capacity is only limited by
 166                 address space and available memory constraints).
 167                 This parameter must be greater than or equal
 168                 to the count of the heap which is to be copied, or the
 169                 behavior is undefined. If this parameter is negative, the
 170                 behavior is undefined.
 171         @param heap The binary heap which is to be copied. The values from the
 172                 binary heap are copied as pointers into the new binary heap (that is,
 173                 the values themselves are copied, not that which the values
 174                 point to, if anything). However, the values are also
 175                 retained by the new binary heap. The count of the new binary will
 176                 be the same as the given binary heap. The new binary heap uses the same
 177                 callbacks as the binary heap to be copied. If this parameter is
 178                 not a valid CFBinaryHeap, the behavior is undefined.
 179         @result A reference to the new mutable binary heap.
 180 */
 181 CF_EXPORT CFBinaryHeapRef       CFBinaryHeapCreateCopy(CFAllocatorRef allocator, CFIndex capacity, CFBinaryHeapRef heap);
 182
 183 /*!
 184         @function CFBinaryHeapGetCount
 185         Returns the number of values currently in the binary heap.
 186         @param heap The binary heap to be queried. If this parameter is not a valid
 187                 CFBinaryHeap, the behavior is undefined.
 188         @result The number of values in the binary heap.
 189 */
 190 CF_EXPORT CFIndex       CFBinaryHeapGetCount(CFBinaryHeapRef heap);
 191
 192 /*!
 193         @function CFBinaryHeapGetCountOfValue
 194         Counts the number of times the given value occurs in the binary heap.
 195         @param heap The binary heap to be searched. If this parameter is not a
 196                 valid CFBinaryHeap, the behavior is undefined.
 197         @param value The value for which to find matches in the binary heap. The
 198                 compare() callback provided when the binary heap was created is
 199                 used to compare. If the compare() callback was NULL, pointer
 200                 equality (in C, ==) is used. If value, or any of the values
 201                 in the binary heap, are not understood by the compare() callback,
 202                 the behavior is undefined.
 203         @result The number of times the given value occurs in the binary heap.
 204 */
 205 CF_EXPORT CFIndex       CFBinaryHeapGetCountOfValue(CFBinaryHeapRef heap, const void *value);
 206
 207 /*!
 208         @function CFBinaryHeapContainsValue
 209         Reports whether or not the value is in the binary heap.
 210         @param heap The binary heap to be searched. If this parameter is not a
 211                 valid CFBinaryHeap, the behavior is undefined.
 212         @param value The value for which to find matches in the binary heap. The
 213                 compare() callback provided when the binary heap was created is
 214                 used to compare. If the compare() callback was NULL, pointer
 215                 equality (in C, ==) is used. If value, or any of the values
 216                 in the binary heap, are not understood by the compare() callback,
 217                 the behavior is undefined.
 218         @result true, if the value is in the specified binary heap, otherwise false.
 219 */
 220 CF_EXPORT Boolean       CFBinaryHeapContainsValue(CFBinaryHeapRef heap, const void *value);
 221
 222 /*!
 223         @function CFBinaryHeapGetMinimum
 224         Returns the minimum value is in the binary heap.  If the heap contains several equal
 225                 minimum values, any one may be returned.
 226         @param heap The binary heap to be searched. If this parameter is not a
 227                 valid CFBinaryHeap, the behavior is undefined.
 228         @result A reference to the minimum value in the binary heap, or NULL if the
 229                 binary heap contains no values.
 230 */
 231 CF_EXPORT const void *  CFBinaryHeapGetMinimum(CFBinaryHeapRef heap);
 232
 233 /*!
 234         @function CFBinaryHeapGetMinimumIfPresent
 235         Returns the minimum value is in the binary heap, if present.  If the heap contains several equal
 236                 minimum values, any one may be returned.
 237         @param heap The binary heap to be searched. If this parameter is not a
 238                 valid CFBinaryHeap, the behavior is undefined.
 239         @param value A C pointer to pointer-sized storage to be filled with the minimum value in
 240                 the binary heap.  If this value is not a valid C pointer to a pointer-sized block
 241                 of storage, the result is undefined.  If the result of the function is false, the value
 242                 stored at this address is undefined.
 243         @result true, if a minimum value was found in the specified binary heap, otherwise false.
 244 */
 245 CF_EXPORT Boolean       CFBinaryHeapGetMinimumIfPresent(CFBinaryHeapRef heap, const void **value);
 246
 247 /*!
 248         @function CFBinaryHeapGetValues
 249         Fills the buffer with values from the binary heap.
 250         @param heap The binary heap to be queried. If this parameter is not a
 251                 valid CFBinaryHeap, the behavior is undefined.
 252         @param values A C array of pointer-sized values to be filled with
 253                 values from the binary heap. The values in the C array are ordered
 254                 from least to greatest. If this parameter is not a valid pointer to a
 255                 C array of at least CFBinaryHeapGetCount() pointers, the behavior is undefined.
 256 */
 257 CF_EXPORT void          CFBinaryHeapGetValues(CFBinaryHeapRef heap, const void **values);
 258
 259 /*!
 260         @function CFBinaryHeapApplyFunction
 261         Calls a function once for each value in the binary heap.
 262         @param heap The binary heap to be operated upon. If this parameter is not a
 263                 valid CFBinaryHeap, the behavior is undefined.
 264         @param applier The callback function to call once for each value in
 265                 the given binary heap. If this parameter is not a
 266                 pointer to a function of the correct prototype, the behavior
 267                 is undefined. If there are values in the binary heap which the
 268                 applier function does not expect or cannot properly apply
 269                 to, the behavior is undefined.
 270         @param context A pointer-sized user-defined value, which is passed
 271                 as the second parameter to the applier function, but is
 272                 otherwise unused by this function. If the context is not
 273                 what is expected by the applier function, the behavior is
 274                 undefined.
 275 */
 276 CF_EXPORT void          CFBinaryHeapApplyFunction(CFBinaryHeapRef heap, CFBinaryHeapApplierFunction applier, void *context);
 277
 278 /*!
 279         @function CFBinaryHeapAddValue
 280         Adds the value to the binary heap.
 281         @param heap The binary heap to which the value is to be added. If this parameter is not a
 282                 valid mutable CFBinaryHeap, the behavior is undefined.
 283         @param value The value to add to the binary heap. The value is retained by
 284                 the binary heap using the retain callback provided when the binary heap
 285                 was created. If the value is not of the sort expected by the
 286                 retain callback, the behavior is undefined.
 287 */
 288 CF_EXPORT void          CFBinaryHeapAddValue(CFBinaryHeapRef heap, const void *value);
 289
 290 /*!
 291         @function CFBinaryHeapRemoveMinimumValue
 292         Removes the minimum value from the binary heap.
 293         @param heap The binary heap from which the minimum value is to be removed. If this
 294                 parameter is not a valid mutable CFBinaryHeap, the behavior is undefined.
 295 */
 296 CF_EXPORT void          CFBinaryHeapRemoveMinimumValue(CFBinaryHeapRef heap);
 297
 298 /*!
 299         @function CFBinaryHeapRemoveAllValues
 300         Removes all the values from the binary heap, making it empty.
 301         @param heap The binary heap from which all of the values are to be
 302                 removed. If this parameter is not a valid mutable CFBinaryHeap,
 303                 the behavior is undefined.
 304 */
 305 CF_EXPORT void          CFBinaryHeapRemoveAllValues(CFBinaryHeapRef heap);
 306
 307 CF_EXTERN_C_END
 308
 309 #endif /* ! __COREFOUNDATION_CFBINARYHEAP__ */
 310