CFStorage.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
  24 /*      CFStorage.h
  25         Copyright (c) 1999-2009, 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 CF_EXTERN_C_BEGIN
  56
  57 /*!
  58         @typedef CFStorageRef
  59         This is the type of a reference to a CFStorage instance.
  60 */
  61 typedef struct __CFStorage *CFStorageRef;
  62
  63 /*!
  64         @typedef CFStorageApplierFunction
  65         Type of the callback function used by the apply functions of
  66                 CFStorage.
  67         @param value The current value from the storage.
  68         @param context The user-defined context parameter given to the apply
  69                 function.
  70 */
  71 typedef void (*CFStorageApplierFunction)(const void *val, void *context);
  72
  73 /*!
  74         @function CFStorageGetTypeID
  75         Returns the type identifier of all CFStorage instances.
  76 */
  77 CF_EXPORT CFTypeID CFStorageGetTypeID(void);
  78
  79 /*!
  80         @function CFStorageCreate
  81         Creates a new mutable storage with elements of the given size.
  82         @param alloc The CFAllocator which should be used to allocate
  83                 memory for the set and its storage for values. This
  84                 parameter may be NULL in which case the current default
  85                 CFAllocator is used. If this reference is not a valid
  86                 CFAllocator, the behavior is undefined.
  87         @param valueSizeInBytes The size in bytes of each of the elements
  88                 to be stored in the storage.  If this value is zero or
  89                 negative, the result is undefined.
  90         @result A reference to the new CFStorage instance.
  91 */
  92 CF_EXPORT CFStorageRef CFStorageCreate(CFAllocatorRef alloc, CFIndex valueSizeInBytes);
  93
  94 /*!
  95         @function CFStorageInsertValues
  96         Allocates space for range.length values at location range.location.  Use
  97         CFStorageReplaceValues() to set those values.
  98         @param storage The storage to which the values are to be inserted.
  99                 If this parameter is not a valid CFStorage, the behavior is undefined.
 100         @param range The range of values within the storage to delete. If the
 101                 range location or end point (defined by the location plus
 102                 length minus 1) are outside the index space of the storage (0
 103                 to N inclusive, where N is the count of the storage), the
 104                 behavior is undefined. If the range length is negative, the
 105                 behavior is undefined. The range may be empty (length 0),
 106                 in which case the no values are inserted.
 107 */
 108 CF_EXPORT void CFStorageInsertValues(CFStorageRef storage, CFRange range);
 109
 110 /*!
 111         @function CFStorageDeleteValues
 112         Deletes the values of the storage in the specified range.
 113         @param storage The storage from which the values are to be deleted.
 114                 If this parameter is not a valid CFStorage, the behavior is undefined.
 115         @param range The range of values within the storage to delete. If the
 116                 range location or end point (defined by the location plus
 117                 length minus 1) are outside the index space of the storage (0
 118                 to N inclusive, where N is the count of the storage), the
 119                 behavior is undefined. If the range length is negative, the
 120                 behavior is undefined. The range may be empty (length 0),
 121                 in which case the no values are deleted.
 122 */
 123 CF_EXPORT void CFStorageDeleteValues(CFStorageRef storage, CFRange range);
 124
 125 /*!
 126         @function CFStorageGetCount
 127         Returns the number of values currently in the storage.
 128         @param storage The storage to be queried. If this parameter is not a valid
 129                 CFStorage, the behavior is undefined.
 130         @result The number of values in the storage.
 131 */
 132 CF_EXPORT CFIndex CFStorageGetCount(CFStorageRef storage);
 133
 134 /*!
 135         @function CFStorageGetValueAtIndex
 136         Returns a pointer to the specified value.  The pointer is mutable and may be used to
 137         get or set the value.
 138         @param storage The storage to be queried. If this parameter is not a
 139                 valid CFStorage, the behavior is undefined.
 140         @param idx The index of the value to retrieve. If the index is
 141                 outside the index space of the storage (0 to N-1 inclusive,
 142                 where N is the count of the storage), the behavior is
 143                 undefined.
 144         @param validConsecutiveValueRange This parameter is a C pointer to a CFRange.
 145                 If NULL is specified, this argument is ignored; otherwise, the range
 146                 is set to the range of values that may be accessed via an offset from the result pointer.
 147                 The range location is set to the index of the lowest consecutive
 148                 value and the range length is set to the count of consecutive values.
 149         @result The value with the given index in the storage.
 150 */
 151 CF_EXPORT void *CFStorageGetValueAtIndex(CFStorageRef storage, CFIndex idx, CFRange *validConsecutiveValueRange);
 152
 153 /*!
 154         @function CFStorageGetValues
 155         Fills the buffer with values from the storage.
 156         @param storage The storage to be queried. If this parameter is not a
 157                 valid CFStorage, the behavior is undefined.
 158         @param range The range of values within the storage to retrieve. If
 159                 the range location or end point (defined by the location
 160                 plus length minus 1) are outside the index space of the
 161                 storage (0 to N-1 inclusive, where N is the count of the
 162                 storage), the behavior is undefined. If the range length is
 163                 negative, the behavior is undefined. The range may be empty
 164                 (length 0), in which case no values are put into the buffer.
 165         @param values A C array of to be filled with values from the storage.
 166                 The values in the C array are ordered
 167                 in the same order in which they appear in the storage. If this
 168                 parameter is not a valid pointer to a C array of at least
 169                 range.length pointers, the behavior is undefined.
 170 */
 171 CF_EXPORT void CFStorageGetValues(CFStorageRef storage, CFRange range, void *values);
 172
 173 /*!
 174         @function CFStorageApplyFunction
 175         Calls a function once for each value in the set.
 176         @param storage The storage to be operated upon. If this parameter is not
 177                 a valid CFStorage, the behavior is undefined.
 178         @param range The range of values within the storage to operate on. If the
 179                 range location or end point (defined by the location plus
 180                 length minus 1) are outside the index space of the storage (0
 181                 to N inclusive, where N is the count of the storage), the
 182                 behavior is undefined. If the range length is negative, the
 183                 behavior is undefined. The range may be empty (length 0),
 184                 in which case the no values are operated on.
 185         @param applier The callback function to call once for each value in
 186                 the given storage. If this parameter is not a
 187                 pointer to a function of the correct prototype, the behavior
 188                 is undefined. If there are values in the storage which the
 189                 applier function does not expect or cannot properly apply
 190                 to, the behavior is undefined.
 191         @param context A pointer-sized user-defined value, which is passed
 192                 as the second parameter to the applier function, but is
 193                 otherwise unused by this function. If the context is not
 194                 what is expected by the applier function, the behavior is
 195                 undefined.
 196 */
 197 CF_EXPORT void CFStorageApplyFunction(CFStorageRef storage, CFRange range, CFStorageApplierFunction applier, void *context);
 198
 199 /*!
 200         @function CFStorageReplaceValues
 201         Replaces a range of values in the storage.
 202         @param storage The storage from which the specified values are to be
 203                 removed. If this parameter is not a valid CFStorage,
 204                 the behavior is undefined.
 205         @param range The range of values within the storage to replace. If the
 206                 range location or end point (defined by the location plus
 207                 length minus 1) are outside the index space of the storage (0
 208                 to N inclusive, where N is the count of the storage), the
 209                 behavior is undefined. If the range length is negative, the
 210                 behavior is undefined. The range may be empty (length 0),
 211                 in which case the new values are merely inserted at the
 212                 range location.
 213         @param values A C array of the values to be copied into the storage.
 214                 The new values in the storage are ordered in the same order
 215                 in which they appear in this C array. This parameter may be NULL
 216                 if the range length is 0.  This C array is not changed or freed by
 217                 this function. If this parameter is not a valid pointer to a C array of at least
 218                 range length pointers, the behavior is undefined.
 219 */
 220 CF_EXPORT void CFStorageReplaceValues(CFStorageRef storage, CFRange range, const void *values);
 221
 222 /* Private stuff...
 223 */
 224 CF_EXPORT CFIndex __CFStorageGetCapacity(CFStorageRef storage);
 225 CF_EXPORT CFIndex __CFStorageGetValueSize(CFStorageRef storage);
 226
 227
 228 CF_EXTERN_C_END
 229
 230 #endif /* ! __COREFOUNDATION_CFSTORAGE__ */
 231