CFBinaryHeap.h

   1 /*
   2  * Copyright (c) 2015 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
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   8  * Version 2.0 (the 'License'). You may not use this file except in
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  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
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  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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  23
  24 /*      CFBinaryHeap.h
  25         Copyright (c) 1998-2014, 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_IMPLICIT_BRIDGING_ENABLED
  40 CF_EXTERN_C_BEGIN
  41
  42 typedef struct {
  43     CFIndex     version;
  44     void *      info;
  45     const void *(*retain)(const void *info);
  46     void        (*release)(const void *info);
  47     CFStringRef (*copyDescription)(const void *info);
  48 } CFBinaryHeapCompareContext;
  49
  50 /*!
  51         @typedef CFBinaryHeapCallBacks
  52         Structure containing the callbacks for values of a CFBinaryHeap.
  53         @field version The version number of the structure type being passed
  54                 in as a parameter to the CFBinaryHeap creation functions.
  55                 This structure is version 0.
  56         @field retain The callback used to add a retain for the binary heap
  57                 on values as they are put into the binary heap.
  58                 This callback returns the value to use as the value in the
  59                 binary heap, which is usually the value parameter passed to
  60                 this callback, but may be a different value if a different
  61                 value should be added to the binary heap. The binary heap's
  62                 allocator is passed as the first argument.
  63         @field release The callback used to remove a retain previously added
  64                 for the binary heap from values as they are removed from
  65                 the binary heap. The binary heap's allocator is passed as the
  66                 first argument.
  67         @field copyDescription The callback used to create a descriptive
  68                 string representation of each value in the binary heap. This
  69                 is used by the CFCopyDescription() function.
  70         @field compare The callback used to compare values in the binary heap for
  71                 equality in some operations.
  72 */
  73 typedef struct {
  74     CFIndex     version;
  75     const void *(*retain)(CFAllocatorRef allocator, const void *ptr);
  76     void        (*release)(CFAllocatorRef allocator, const void *ptr);
  77     CFStringRef (*copyDescription)(const void *ptr);
  78     CFComparisonResult  (*compare)(const void *ptr1, const void *ptr2, void *context);
  79 } CFBinaryHeapCallBacks;
  80
  81 /*!
  82         @constant kCFStringBinaryHeapCallBacks
  83         Predefined CFBinaryHeapCallBacks structure containing a set
  84         of callbacks appropriate for use when the values in a CFBinaryHeap
  85         are all CFString types.
  86 */
  87 CF_EXPORT const CFBinaryHeapCallBacks kCFStringBinaryHeapCallBacks;
  88
  89 /*!
  90         @typedef CFBinaryHeapApplierFunction
  91         Type of the callback function used by the apply functions of
  92                 CFBinaryHeap.
  93         @param value The current value from the binary heap.
  94         @param context The user-defined context parameter given to the apply
  95                 function.
  96 */
  97 typedef void (*CFBinaryHeapApplierFunction)(const void *val, void *context);
  98
  99 /*!
 100         @typedef CFBinaryHeapRef
 101         This is the type of a reference to CFBinaryHeaps.
 102 */
 103 typedef struct __CFBinaryHeap * CFBinaryHeapRef;
 104
 105 /*!
 106         @function CFBinaryHeapGetTypeID
 107         Returns the type identifier of all CFBinaryHeap instances.
 108 */
 109 CF_EXPORT CFTypeID      CFBinaryHeapGetTypeID(void);
 110
 111 /*!
 112         @function CFBinaryHeapCreate
 113         Creates a new mutable binary heap with the given values.
 114         @param allocator The CFAllocator which should be used to allocate
 115                 memory for the binary heap and its storage for values. This
 116                 parameter may be NULL in which case the current default
 117                 CFAllocator is used. If this reference is not a valid
 118                 CFAllocator, the behavior is undefined.
 119         @param capacity A hint about the number of values that will be held
 120                 by the CFBinaryHeap. Pass 0 for no hint. The implementation may
 121                 ignore this hint, or may use it to optimize various
 122                 operations. A heap's actual capacity is only limited by
 123                 address space and available memory constraints). If this
 124                 parameter is negative, the behavior is undefined.
 125         @param callBacks A pointer to a CFBinaryHeapCallBacks structure
 126                 initialized with the callbacks for the binary heap to use on
 127                 each value in the binary heap. A copy of the contents of the
 128                 callbacks structure is made, so that a pointer to a structure
 129                 on the stack can be passed in, or can be reused for multiple
 130                 binary heap creations. If the version field of this callbacks
 131                 structure is not one of the defined ones for CFBinaryHeap, the
 132                 behavior is undefined. The retain field may be NULL, in which
 133                 case the CFBinaryHeap will do nothing to add a retain to values
 134                 as they are put into the binary heap. The release field may be
 135                 NULL, in which case the CFBinaryHeap will do nothing to remove
 136                 the binary heap's retain (if any) on the values when the
 137                 heap is destroyed or a key-value pair is removed. If the
 138                 copyDescription field is NULL, the binary heap will create a
 139                 simple description for a value. If the equal field is NULL, the
 140                 binary heap will use pointer equality to test for equality of
 141                 values. This callbacks parameter itself may be NULL, which is
 142                 treated as if a valid structure of version 0 with all fields
 143                 NULL had been passed in. Otherwise,
 144                 if any of the fields are not valid pointers to functions
 145                 of the correct type, or this parameter is not a valid
 146                 pointer to a CFBinaryHeapCallBacks callbacks structure,
 147                 the behavior is undefined. If any of the values put into the
 148                 binary heap is not one understood by one of the callback functions
 149                 the behavior when that callback function is used is undefined.
 150         @param compareContext A pointer to a CFBinaryHeapCompareContext structure.
 151         @result A reference to the new CFBinaryHeap.
 152 */
 153 CF_EXPORT CFBinaryHeapRef       CFBinaryHeapCreate(CFAllocatorRef allocator, CFIndex capacity, const CFBinaryHeapCallBacks *callBacks, const CFBinaryHeapCompareContext *compareContext);
 154
 155 /*!
 156         @function CFBinaryHeapCreateCopy
 157         Creates a new mutable binary heap with the values from the given binary heap.
 158         @param allocator The CFAllocator which should be used to allocate
 159                 memory for the binary heap and its storage for values. This
 160                 parameter may be NULL in which case the current default
 161                 CFAllocator is used. If this reference is not a valid
 162                 CFAllocator, the behavior is undefined.
 163         @param capacity A hint about the number of values that will be held
 164                 by the CFBinaryHeap. Pass 0 for no hint. The implementation may
 165                 ignore this hint, or may use it to optimize various
 166                 operations. A heap's actual capacity is only limited by
 167                 address space and available memory constraints).
 168                 This parameter must be greater than or equal
 169                 to the count of the heap which is to be copied, or the
 170                 behavior is undefined. If this parameter is negative, the
 171                 behavior is undefined.
 172         @param heap The binary heap which is to be copied. The values from the
 173                 binary heap are copied as pointers into the new binary heap (that is,
 174                 the values themselves are copied, not that which the values
 175                 point to, if anything). However, the values are also
 176                 retained by the new binary heap. The count of the new binary will
 177                 be the same as the given binary heap. The new binary heap uses the same
 178                 callbacks as the binary heap to be copied. If this parameter is
 179                 not a valid CFBinaryHeap, the behavior is undefined.
 180         @result A reference to the new mutable binary heap.
 181 */
 182 CF_EXPORT CFBinaryHeapRef       CFBinaryHeapCreateCopy(CFAllocatorRef allocator, CFIndex capacity, CFBinaryHeapRef heap);
 183
 184 /*!
 185         @function CFBinaryHeapGetCount
 186         Returns the number of values currently in the binary heap.
 187         @param heap The binary heap to be queried. If this parameter is not a valid
 188                 CFBinaryHeap, the behavior is undefined.
 189         @result The number of values in the binary heap.
 190 */
 191 CF_EXPORT CFIndex       CFBinaryHeapGetCount(CFBinaryHeapRef heap);
 192
 193 /*!
 194         @function CFBinaryHeapGetCountOfValue
 195         Counts the number of times the given value occurs in the binary heap.
 196         @param heap The binary heap to be searched. If this parameter is not a
 197                 valid CFBinaryHeap, the behavior is undefined.
 198         @param value The value for which to find matches in the binary heap. The
 199                 compare() callback provided when the binary heap was created is
 200                 used to compare. If the compare() callback was NULL, pointer
 201                 equality (in C, ==) is used. If value, or any of the values
 202                 in the binary heap, are not understood by the compare() callback,
 203                 the behavior is undefined.
 204         @result The number of times the given value occurs in the binary heap.
 205 */
 206 CF_EXPORT CFIndex       CFBinaryHeapGetCountOfValue(CFBinaryHeapRef heap, const void *value);
 207
 208 /*!
 209         @function CFBinaryHeapContainsValue
 210         Reports whether or not the value is in the binary heap.
 211         @param heap The binary heap to be searched. If this parameter is not a
 212                 valid CFBinaryHeap, the behavior is undefined.
 213         @param value The value for which to find matches in the binary heap. The
 214                 compare() callback provided when the binary heap was created is
 215                 used to compare. If the compare() callback was NULL, pointer
 216                 equality (in C, ==) is used. If value, or any of the values
 217                 in the binary heap, are not understood by the compare() callback,
 218                 the behavior is undefined.
 219         @result true, if the value is in the specified binary heap, otherwise false.
 220 */
 221 CF_EXPORT Boolean       CFBinaryHeapContainsValue(CFBinaryHeapRef heap, const void *value);
 222
 223 /*!
 224         @function CFBinaryHeapGetMinimum
 225         Returns the minimum value is in the binary heap.  If the heap contains several equal
 226                 minimum values, any one may be returned.
 227         @param heap The binary heap to be searched. If this parameter is not a
 228                 valid CFBinaryHeap, the behavior is undefined.
 229         @result A reference to the minimum value in the binary heap, or NULL if the
 230                 binary heap contains no values.
 231 */
 232 CF_EXPORT const void *  CFBinaryHeapGetMinimum(CFBinaryHeapRef heap);
 233
 234 /*!
 235         @function CFBinaryHeapGetMinimumIfPresent
 236         Returns the minimum value is in the binary heap, if present.  If the heap contains several equal
 237                 minimum values, any one may be returned.
 238         @param heap The binary heap to be searched. If this parameter is not a
 239                 valid CFBinaryHeap, the behavior is undefined.
 240         @param value A C pointer to pointer-sized storage to be filled with the minimum value in
 241                 the binary heap.  If this value is not a valid C pointer to a pointer-sized block
 242                 of storage, the result is undefined.  If the result of the function is false, the value
 243                 stored at this address is undefined.
 244         @result true, if a minimum value was found in the specified binary heap, otherwise false.
 245 */
 246 CF_EXPORT Boolean       CFBinaryHeapGetMinimumIfPresent(CFBinaryHeapRef heap, const void **value);
 247
 248 /*!
 249         @function CFBinaryHeapGetValues
 250         Fills the buffer with values from the binary heap.
 251         @param heap The binary heap to be queried. If this parameter is not a
 252                 valid CFBinaryHeap, the behavior is undefined.
 253         @param values A C array of pointer-sized values to be filled with
 254                 values from the binary heap. The values in the C array are ordered
 255                 from least to greatest. If this parameter is not a valid pointer to a
 256                 C array of at least CFBinaryHeapGetCount() pointers, the behavior is undefined.
 257 */
 258 CF_EXPORT void          CFBinaryHeapGetValues(CFBinaryHeapRef heap, const void **values);
 259
 260 /*!
 261         @function CFBinaryHeapApplyFunction
 262         Calls a function once for each value in the binary heap.
 263         @param heap The binary heap to be operated upon. If this parameter is not a
 264                 valid CFBinaryHeap, the behavior is undefined.
 265         @param applier The callback function to call once for each value in
 266                 the given binary heap. If this parameter is not a
 267                 pointer to a function of the correct prototype, the behavior
 268                 is undefined. If there are values in the binary heap which the
 269                 applier function does not expect or cannot properly apply
 270                 to, the behavior is undefined.
 271         @param context A pointer-sized user-defined value, which is passed
 272                 as the second parameter to the applier function, but is
 273                 otherwise unused by this function. If the context is not
 274                 what is expected by the applier function, the behavior is
 275                 undefined.
 276 */
 277 CF_EXPORT void          CFBinaryHeapApplyFunction(CFBinaryHeapRef heap, CFBinaryHeapApplierFunction applier, void *context);
 278
 279 /*!
 280         @function CFBinaryHeapAddValue
 281         Adds the value to the binary heap.
 282         @param heap The binary heap to which the value is to be added. If this parameter is not a
 283                 valid mutable CFBinaryHeap, the behavior is undefined.
 284         @param value The value to add to the binary heap. The value is retained by
 285                 the binary heap using the retain callback provided when the binary heap
 286                 was created. If the value is not of the sort expected by the
 287                 retain callback, the behavior is undefined.
 288 */
 289 CF_EXPORT void          CFBinaryHeapAddValue(CFBinaryHeapRef heap, const void *value);
 290
 291 /*!
 292         @function CFBinaryHeapRemoveMinimumValue
 293         Removes the minimum value from the binary heap.
 294         @param heap The binary heap from which the minimum value is to be removed. If this
 295                 parameter is not a valid mutable CFBinaryHeap, the behavior is undefined.
 296 */
 297 CF_EXPORT void          CFBinaryHeapRemoveMinimumValue(CFBinaryHeapRef heap);
 298
 299 /*!
 300         @function CFBinaryHeapRemoveAllValues
 301         Removes all the values from the binary heap, making it empty.
 302         @param heap The binary heap from which all of the values are to be
 303                 removed. If this parameter is not a valid mutable CFBinaryHeap,
 304                 the behavior is undefined.
 305 */
 306 CF_EXPORT void          CFBinaryHeapRemoveAllValues(CFBinaryHeapRef heap);
 307
 308 CF_EXTERN_C_END
 309 CF_IMPLICIT_BRIDGING_DISABLED
 310
 311 #endif /* ! __COREFOUNDATION_CFBINARYHEAP__ */
 312