CFStorage.h

   1 /*
   2  * Copyright (c) 2008 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 /*      CFStorage.h
  24         Copyright (c) 1999-2007, Apple Inc. All rights reserved.
  25 */
  26 /*!
  27         @header CFStorage
  28 CFStorage stores an array of arbitrary-sized values. There are no callbacks;
  29 all that is provided about the values is the size, and the appropriate number
  30 of bytes are copied in and out of the CFStorage.
  31
  32 CFStorage uses a balanced tree to store the values, and is most appropriate
  33 for situations where potentially a large number values (more than a hundred
  34 bytes' worth) will be stored and there will be a lot of editing (insertions and deletions).
  35
  36 Getting to an item is O(log n), although caching the last result often reduces this
  37 to a constant time.
  38
  39 The overhead of CFStorage is 48 bytes. There is no per item overhead; the
  40 non-leaf nodes in the tree cost 20 bytes each, and the worst case extra
  41 capacity (unused space in the leaves) is 12%, typically much less.
  42
  43 Because CFStorage does not necessarily use a single block of memory to store the values,
  44 when you ask for a value, you get back the pointer to the value and optionally
  45 the range of other values that are consecutive and thus reachable as if the
  46 storage was a single block.
  47 */
  48
  49 #if !defined(__COREFOUNDATION_CFSTORAGE__)
  50 #define __COREFOUNDATION_CFSTORAGE__ 1
  51
  52 #include <CoreFoundation/CFBase.h>
  53
  54 CF_EXTERN_C_BEGIN
  55
  56 /*!
  57         @typedef CFStorageRef
  58         This is the type of a reference to a CFStorage instance.
  59 */
  60 typedef struct __CFStorage *CFStorageRef;
  61
  62 /*!
  63         @typedef CFStorageApplierFunction
  64         Type of the callback function used by the apply functions of
  65                 CFStorage.
  66         @param value The current value from the storage.
  67         @param context The user-defined context parameter given to the apply
  68                 function.
  69 */
  70 typedef void (*CFStorageApplierFunction)(const void *val, void *context);
  71
  72 /*!
  73         @function CFStorageGetTypeID
  74         Returns the type identifier of all CFStorage instances.
  75 */
  76 CF_EXPORT CFTypeID CFStorageGetTypeID(void);
  77
  78 /*!
  79         @function CFStorageCreate
  80         Creates a new mutable storage with elements of the given size.
  81         @param alloc The CFAllocator which should be used to allocate
  82                 memory for the set and its storage for values. This
  83                 parameter may be NULL in which case the current default
  84                 CFAllocator is used. If this reference is not a valid
  85                 CFAllocator, the behavior is undefined.
  86         @param valueSizeInBytes The size in bytes of each of the elements
  87                 to be stored in the storage.  If this value is zero or
  88                 negative, the result is undefined.
  89         @result A reference to the new CFStorage instance.
  90 */
  91 CF_EXPORT CFStorageRef CFStorageCreate(CFAllocatorRef alloc, CFIndex valueSizeInBytes);
  92
  93 /*!
  94         @function CFStorageInsertValues
  95         Allocates space for range.length values at location range.location.  Use
  96         CFStorageReplaceValues() to set those values.
  97         @param storage The storage to which the values are to be inserted.
  98                 If this parameter is not a valid CFStorage, the behavior is undefined.
  99         @param range The range of values within the storage to delete. If the
 100                 range location or end point (defined by the location plus
 101                 length minus 1) are outside the index space of the storage (0
 102                 to N inclusive, where N is the count of the storage), the
 103                 behavior is undefined. If the range length is negative, the
 104                 behavior is undefined. The range may be empty (length 0),
 105                 in which case the no values are inserted.
 106 */
 107 CF_EXPORT void CFStorageInsertValues(CFStorageRef storage, CFRange range);
 108
 109 /*!
 110         @function CFStorageDeleteValues
 111         Deletes the values of the storage in the specified range.
 112         @param storage The storage from which the values are to be deleted.
 113                 If this parameter is not a valid CFStorage, the behavior is undefined.
 114         @param range The range of values within the storage to delete. If the
 115                 range location or end point (defined by the location plus
 116                 length minus 1) are outside the index space of the storage (0
 117                 to N inclusive, where N is the count of the storage), the
 118                 behavior is undefined. If the range length is negative, the
 119                 behavior is undefined. The range may be empty (length 0),
 120                 in which case the no values are deleted.
 121 */
 122 CF_EXPORT void CFStorageDeleteValues(CFStorageRef storage, CFRange range);
 123
 124 /*!
 125         @function CFStorageGetCount
 126         Returns the number of values currently in the storage.
 127         @param storage The storage to be queried. If this parameter is not a valid
 128                 CFStorage, the behavior is undefined.
 129         @result The number of values in the storage.
 130 */
 131 CF_EXPORT CFIndex CFStorageGetCount(CFStorageRef storage);
 132
 133 /*!
 134         @function CFStorageGetValueAtIndex
 135         Returns a pointer to the specified value.  The pointer is mutable and may be used to
 136         get or set the value.
 137         @param storage The storage to be queried. If this parameter is not a
 138                 valid CFStorage, the behavior is undefined.
 139         @param idx The index of the value to retrieve. If the index is
 140                 outside the index space of the storage (0 to N-1 inclusive,
 141                 where N is the count of the storage), the behavior is
 142                 undefined.
 143         @param validConsecutiveValueRange This parameter is a C pointer to a CFRange.
 144                 If NULL is specified, this argument is ignored; otherwise, the range
 145                 is set to the range of values that may be accessed via an offset from the result pointer.
 146                 The range location is set to the index of the lowest consecutive
 147                 value and the range length is set to the count of consecutive values.
 148         @result The value with the given index in the storage.
 149 */
 150 CF_EXPORT void *CFStorageGetValueAtIndex(CFStorageRef storage, CFIndex idx, CFRange *validConsecutiveValueRange);
 151
 152 /*!
 153         @function CFStorageGetValues
 154         Fills the buffer with values from the storage.
 155         @param storage The storage to be queried. If this parameter is not a
 156                 valid CFStorage, the behavior is undefined.
 157         @param range The range of values within the storage to retrieve. If
 158                 the range location or end point (defined by the location
 159                 plus length minus 1) are outside the index space of the
 160                 storage (0 to N-1 inclusive, where N is the count of the
 161                 storage), the behavior is undefined. If the range length is
 162                 negative, the behavior is undefined. The range may be empty
 163                 (length 0), in which case no values are put into the buffer.
 164         @param values A C array of to be filled with values from the storage.
 165                 The values in the C array are ordered
 166                 in the same order in which they appear in the storage. If this
 167                 parameter is not a valid pointer to a C array of at least
 168                 range.length pointers, the behavior is undefined.
 169 */
 170 CF_EXPORT void CFStorageGetValues(CFStorageRef storage, CFRange range, void *values);
 171
 172 /*!
 173         @function CFStorageApplyFunction
 174         Calls a function once for each value in the set.
 175         @param storage The storage to be operated upon. If this parameter is not
 176                 a valid CFStorage, the behavior is undefined.
 177         @param range The range of values within the storage to operate on. If the
 178                 range location or end point (defined by the location plus
 179                 length minus 1) are outside the index space of the storage (0
 180                 to N inclusive, where N is the count of the storage), the
 181                 behavior is undefined. If the range length is negative, the
 182                 behavior is undefined. The range may be empty (length 0),
 183                 in which case the no values are operated on.
 184         @param applier The callback function to call once for each value in
 185                 the given storage. If this parameter is not a
 186                 pointer to a function of the correct prototype, the behavior
 187                 is undefined. If there are values in the storage which the
 188                 applier function does not expect or cannot properly apply
 189                 to, the behavior is undefined.
 190         @param context A pointer-sized user-defined value, which is passed
 191                 as the second parameter to the applier function, but is
 192                 otherwise unused by this function. If the context is not
 193                 what is expected by the applier function, the behavior is
 194                 undefined.
 195 */
 196 CF_EXPORT void CFStorageApplyFunction(CFStorageRef storage, CFRange range, CFStorageApplierFunction applier, void *context);
 197
 198 /*!
 199         @function CFStorageReplaceValues
 200         Replaces a range of values in the storage.
 201         @param storage The storage from which the specified values are to be
 202                 removed. If this parameter is not a valid CFStorage,
 203                 the behavior is undefined.
 204         @param range The range of values within the storage to replace. If the
 205                 range location or end point (defined by the location plus
 206                 length minus 1) are outside the index space of the storage (0
 207                 to N inclusive, where N is the count of the storage), the
 208                 behavior is undefined. If the range length is negative, the
 209                 behavior is undefined. The range may be empty (length 0),
 210                 in which case the new values are merely inserted at the
 211                 range location.
 212         @param values A C array of the values to be copied into the storage.
 213                 The new values in the storage are ordered in the same order
 214                 in which they appear in this C array. This parameter may be NULL
 215                 if the range length is 0.  This C array is not changed or freed by
 216                 this function. If this parameter is not a valid pointer to a C array of at least
 217                 range length pointers, the behavior is undefined.
 218 */
 219 CF_EXPORT void CFStorageReplaceValues(CFStorageRef storage, CFRange range, const void *values);
 220
 221 /* Private stuff...
 222 */
 223 CF_EXPORT CFIndex __CFStorageGetCapacity(CFStorageRef storage);
 224 CF_EXPORT CFIndex __CFStorageGetValueSize(CFStorageRef storage);
 225
 226
 227 CF_EXTERN_C_END
 228
 229 #endif /* ! __COREFOUNDATION_CFSTORAGE__ */
 230