CFStorage.h

   1 /*
   2  * Copyright (c) 2014 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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  23
  24 /*      CFStorage.h
  25         Copyright (c) 1999-2013, Apple Inc. All rights reserved.
  26 */
  27 /*!
  28         @header CFStorage
  29 CFStorage stores an array of arbitrary-sized values. There are no callbacks;
  30 all that is provided about the values is the size, and the appropriate number
  31 of bytes are copied in and out of the CFStorage.
  32
  33 CFStorage uses a balanced tree to store the values, and is most appropriate
  34 for situations where potentially a large number values (more than a hundred
  35 bytes' worth) will be stored and there will be a lot of editing (insertions and deletions).
  36
  37 Getting to an item is O(log n), although caching the last result often reduces this
  38 to a constant time.
  39
  40 The overhead of CFStorage is 48 bytes. There is no per item overhead; the
  41 non-leaf nodes in the tree cost 20 bytes each, and the worst case extra
  42 capacity (unused space in the leaves) is 12%, typically much less.
  43
  44 Because CFStorage does not necessarily use a single block of memory to store the values,
  45 when you ask for a value, you get back the pointer to the value and optionally
  46 the range of other values that are consecutive and thus reachable as if the
  47 storage was a single block.
  48 */
  49
  50 #if !defined(__COREFOUNDATION_CFSTORAGE__)
  51 #define __COREFOUNDATION_CFSTORAGE__ 1
  52
  53 #include <CoreFoundation/CFBase.h>
  54
  55 typedef CF_OPTIONS(CFOptionFlags, CFStorageEnumerationOptionFlags) {
  56         kCFStorageEnumerationConcurrent = (1UL << 0) /* Allow enumeration to proceed concurrently */
  57 };
  58
  59 CF_EXTERN_C_BEGIN
  60
  61 /*!
  62         @typedef CFStorageRef
  63         This is the type of a reference to a CFStorage instance.
  64 */
  65 typedef struct __CFStorage *CFStorageRef;
  66
  67 /*!
  68         @typedef CFStorageApplierFunction
  69         Type of the callback function used by the apply functions of
  70                 CFStorage.
  71         @param value The current value from the storage.
  72         @param context The user-defined context parameter given to the apply
  73                 function.
  74 */
  75 typedef void (*CFStorageApplierFunction)(const void *val, void *context);
  76
  77 /*!
  78         @typedef CFStorageRangeApplierBlock
  79         Type of the callback block used by the apply functions of
  80             CFStorage
  81         @param val  A pointer to a range of values, numbering range.length
  82         @param range The range of values.  This will always be a subrange of the range
  83             passed to the apply function.  Do not try to modify the contents of the vals pointer, because
  84             there is no guarantee it points into the contents of the CFStorage object.
  85          @param stop An "out" parameter that, if set to true from within the block, indicates that the enumeration may stop.
  86
  87 */
  88 #if __BLOCKS__
  89 typedef void (^CFStorageApplierBlock)(const void *vals, CFRange range, bool *stop);
  90 #endif
  91
  92 /*!
  93         @function CFStorageGetTypeID
  94         Returns the type identifier of all CFStorage instances.
  95 */
  96 CF_EXPORT CFTypeID CFStorageGetTypeID(void);
  97
  98 /*!
  99         @function CFStorageCreate
 100         Creates a new mutable storage with elements of the given size.
 101         @param alloc The CFAllocator which should be used to allocate
 102                 memory for the set and its storage for values. This
 103                 parameter may be NULL in which case the current default
 104                 CFAllocator is used. If this reference is not a valid
 105                 CFAllocator, the behavior is undefined.
 106         @param valueSizeInBytes The size in bytes of each of the elements
 107                 to be stored in the storage.  If this value is zero or
 108                 negative, the result is undefined.
 109         @result A reference to the new CFStorage instance.
 110 */
 111 CF_EXPORT CFStorageRef CFStorageCreate(CFAllocatorRef alloc, CFIndex valueSizeInBytes);
 112
 113 /*!
 114         @function CFStorageInsertValues
 115         Allocates space for range.length values at location range.location.  Use
 116          CFStorageReplaceValues() to set those values.
 117         @param storage The storage to which the values are to be inserted.
 118                 If this parameter is not a valid CFStorage, the behavior is undefined.
 119         @param range The range of values within the storage to insert. The
 120                 range location must be at least zero and not exceed the count of the storage.
 121                 Values at indexes equal to or greater than the range location have their indexes
 122                 increased by the length of the range.  Thus this creates a gap in the storage
 123                  equal to the length of the given range.  If the range length is negative, the
 124                 behavior is undefined. The range may be empty (length 0),
 125                  in which case there is no effect.
 126
 127 */
 128 CF_EXPORT void CFStorageInsertValues(CFStorageRef storage, CFRange range);
 129
 130 /*!
 131         @function CFStorageDeleteValues
 132         Deletes the values of the storage in the specified range.
 133         @param storage The storage from which the values are to be deleted.
 134                 If this parameter is not a valid CFStorage, the behavior is undefined.
 135         @param range The range of values within the storage to delete. If the
 136                 range location or end point (defined by the location plus
 137                 length minus 1) are outside the index space of the storage (0
 138                 to N inclusive, where N is the count of the storage), the
 139                 behavior is undefined. If the range length is negative, the
 140                 behavior is undefined. The range may be empty (length 0),
 141                 in which case no values are deleted.
 142 */
 143 CF_EXPORT void CFStorageDeleteValues(CFStorageRef storage, CFRange range);
 144
 145 /*!
 146         @function CFStorageGetCount
 147         Returns the number of values currently in the storage.
 148         @param storage The storage to be queried. If this parameter is not a valid
 149                 CFStorage, the behavior is undefined.
 150         @result The number of values in the storage.
 151 */
 152 CF_EXPORT CFIndex CFStorageGetCount(CFStorageRef storage);
 153
 154 /*!
 155         @function CFStorageGetValueAtIndex
 156                 Returns a pointer to the specified value.  The pointer is mutable and may be used to
 157                 get or set the value.  This is considered to be a mutating function, and so calling this
 158                 while accessing the CFStorage from another thread is undefined behavior,
 159                 even if you do not set a value.  To access the CFStorage in a non-mutating
 160                 manner, use the more efficient CFStorageGetConstValueAtIndex().
 161         @param storage The storage to be queried. If this parameter is not a
 162                 valid CFStorage, the behavior is undefined.
 163         @param idx The index of the value to retrieve. If the index is
 164                 outside the index space of the storage (0 to N-1 inclusive,
 165                 where N is the count of the storage), the behavior is
 166                 undefined.
 167         @param validConsecutiveValueRange This parameter is a C pointer to a CFRange.
 168                 If NULL is specified, this argument is ignored; otherwise, the range
 169                 is set to the range of values that may be accessed via an offset from the result pointer.
 170                 The range location is set to the index of the lowest consecutive
 171                 value and the range length is set to the count of consecutive values.
 172         @result The value with the given index in the storage.
 173 */
 174 CF_EXPORT void *CFStorageGetValueAtIndex(CFStorageRef storage, CFIndex idx, CFRange *validConsecutiveValueRange);
 175
 176 /*!
 177         @function CFStorageGetConstValueAtIndex
 178                 Returns a pointer to the specified value.  The pointer is immutable and may
 179                 only be used to get the value.  This is not considered to be a mutating function,
 180                 so it is safe to call this concurrently with other non-mutating functions.  Furthermore,
 181                 this is often more efficient than CFStorageGetValueAtIndex(), so it should be used
 182                 in preference to that function when possible.
 183         @param storage The storage to be queried. If this parameter is not a
 184                 valid CFStorage, the behavior is undefined.
 185         @param idx The index of the value to retrieve. If the index is
 186                 outside the index space of the storage (0 to N-1 inclusive,
 187                 where N is the count of the storage), the behavior is
 188                 undefined.
 189         @param validConsecutiveValueRange This parameter is a C pointer to a CFRange.
 190                 If NULL is specified, this argument is ignored; otherwise, the range
 191                 is set to the range of values that may be accessed via an offset from the result pointer.
 192                 The range location is set to the index of the lowest consecutive
 193                 value and the range length is set to the count of consecutive values.
 194         @result The value with the given index in the storage.
 195 */
 196 CF_EXPORT const void *CFStorageGetConstValueAtIndex(CFStorageRef storage, CFIndex idx, CFRange *validConsecutiveValueRange);
 197
 198 /*!
 199         @function CFStorageGetValues
 200         Fills the buffer with values from the storage.
 201         @param storage The storage to be queried. If this parameter is not a
 202                 valid CFStorage, the behavior is undefined.
 203         @param range The range of values within the storage to retrieve. If
 204                 the range location or end point (defined by the location
 205                 plus length minus 1) are outside the index space of the
 206                 storage (0 to N-1 inclusive, where N is the count of the
 207                 storage), the behavior is undefined. If the range length is
 208                 negative, the behavior is undefined. The range may be empty
 209                 (length 0), in which case no values are put into the buffer.
 210         @param values A C array of to be filled with values from the storage.
 211                 The values in the C array are ordered
 212                 in the same order in which they appear in the storage. If this
 213                 parameter is not a valid pointer to a C array of at least
 214                 range.length pointers, the behavior is undefined.
 215 */
 216 CF_EXPORT void CFStorageGetValues(CFStorageRef storage, CFRange range, void *values);
 217
 218 /*!
 219         @function CFStorageApplyFunction
 220         Calls a function once for each value in the set.
 221         @param storage The storage to be operated upon. If this parameter is not
 222                 a valid CFStorage, the behavior is undefined.
 223         @param range The range of values within the storage to operate on. If the
 224                 range location or end point (defined by the location plus
 225                 length minus 1) are outside the index space of the storage (0
 226                 to N inclusive, where N is the count of the storage), the
 227                 behavior is undefined. If the range length is negative, the
 228                 behavior is undefined. The range may be empty (length 0),
 229                 in which case the no values are operated on.
 230         @param applier The callback function to call once for each value in
 231                 the given storage. If this parameter is not a
 232                 pointer to a function of the correct prototype, the behavior
 233                 is undefined. If there are values in the storage which the
 234                 applier function does not expect or cannot properly apply
 235                 to, the behavior is undefined.
 236         @param context A pointer-sized user-defined value, which is passed
 237                 as the second parameter to the applier function, but is
 238                 otherwise unused by this function. If the context is not
 239                 what is expected by the applier function, the behavior is
 240                 undefined.
 241 */
 242 CF_EXPORT void CFStorageApplyFunction(CFStorageRef storage, CFRange range, CFStorageApplierFunction applier, void *context);
 243
 244 /*!
 245         @function CFStorageApplyBlock
 246         Enumerates ranges of stored objects with a block.
 247         @param storage The storage to be operated upon. If this parameter is not
 248                 a valid CFStorage, the behavior is undefined.
 249          @param range The range of values within the storage to operate on. If the
 250                  sum of the range location and length is larger than the
 251                  count of the storage, the behavior is undefined.  If the
 252                  range location or length is negative, the behavior is undefined.
 253         @param options Options controlling how the enumeration may proceed.
 254         @param applier The callback block.  The block is passed a pointer to
 255                 a buffer of contiguous objects in the storage, and the range of stored
 256                 values represented by the buffer.  If the block modifies the
 257                 contents of the buffer, the behavior is undefined.  If the block modifies
 258                 the contents of the CFStorage, the behavior is undefined.
 259
 260  */
 261 #if __BLOCKS__
 262 CF_EXPORT void CFStorageApplyBlock(CFStorageRef storage, CFRange range, CFStorageEnumerationOptionFlags options, CFStorageApplierBlock applier);
 263 #endif
 264
 265
 266 /*!
 267         @function CFStorageCreateWithSubrange
 268         Returns a new CFStorage that contains a portion of an existing CFStorage.
 269         @param storage The storage to be operated upon. If this parameter is not
 270                 a valid CFStorage, the behavior is undefined.
 271          @param range The range of values within the storage to operate on. If the
 272                  sum of the range location and length is larger than the
 273                  count of the storage, the behavior is undefined.  If the
 274                  range location or length is negative, the behavior is undefined.
 275          @result A reference to a new CFStorage containing a byte-for-byte copy of
 276                  the objects in the range.  This may use copy-on-write techniques
 277                  to allow efficient implementation.
 278  */
 279 CF_EXPORT CFStorageRef CFStorageCreateWithSubrange(CFStorageRef storage, CFRange range);
 280
 281 /*!
 282         @function CFStorageReplaceValues
 283         Replaces a range of values in the storage.
 284         @param storage The storage from which the specified values are to be
 285                 removed. If this parameter is not a valid CFStorage,
 286                 the behavior is undefined.
 287         @param range The range of values within the storage to replace. If the
 288                 range location or end point (defined by the location plus
 289                 length minus 1) are outside the index space of the storage (0
 290                 to N inclusive, where N is the count of the storage), the
 291                 behavior is undefined. If the range length is negative, the
 292                 behavior is undefined. The range may be empty (length 0),
 293                 in which case the new values are merely inserted at the
 294                 range location.
 295         @param values A C array of the values to be copied into the storage.
 296                 The new values in the storage are ordered in the same order
 297                 in which they appear in this C array. This parameter may be NULL
 298                 if the range length is 0.  This C array is not changed or freed by
 299                 this function. If this parameter is not a valid pointer to a C array of at least
 300                 range length pointers, the behavior is undefined.
 301 */
 302 CF_EXPORT void CFStorageReplaceValues(CFStorageRef storage, CFRange range, const void *values);
 303
 304 /* Private stuff...
 305 */
 306 CF_EXPORT CFIndex __CFStorageGetCapacity(CFStorageRef storage);
 307 CF_EXPORT CFIndex __CFStorageGetValueSize(CFStorageRef storage);
 308 CF_EXPORT void __CFStorageSetAlwaysFrozen(CFStorageRef storage, bool alwaysFrozen);
 309
 310
 311 CF_EXTERN_C_END
 312
 313 #endif /* ! __COREFOUNDATION_CFSTORAGE__ */
 314