cdsa/cdsa_utilities/MetaAttribute.cpp

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 //
  20 // MetaAttribute.cpp
  21 //
  22
  23 #include "MetaAttribute.h"
  24 #include "MetaRecord.h"
  25
  26 MetaAttribute::~MetaAttribute()
  27 {
  28 }
  29
  30 // Construct an instance of an appropriate subclass of MetaAttribute
  31 // based on the given format.
  32
  33 MetaAttribute *
  34 MetaAttribute::create(Format format, uint32 attributeIndex,
  35         uint32 attributeId)
  36 {
  37         switch (format)
  38         {
  39                 case CSSM_DB_ATTRIBUTE_FORMAT_STRING:
  40                         return new TypedMetaAttribute<StringValue>(format, attributeIndex, attributeId);
  41
  42                 case CSSM_DB_ATTRIBUTE_FORMAT_SINT32:
  43                         return new TypedMetaAttribute<SInt32Value>(format, attributeIndex, attributeId);
  44
  45                 case CSSM_DB_ATTRIBUTE_FORMAT_UINT32:
  46                         return new TypedMetaAttribute<UInt32Value>(format, attributeIndex, attributeId);
  47
  48                 case CSSM_DB_ATTRIBUTE_FORMAT_BIG_NUM:
  49                         return new TypedMetaAttribute<BigNumValue>(format, attributeIndex, attributeId);
  50
  51                 case CSSM_DB_ATTRIBUTE_FORMAT_REAL:
  52                         return new TypedMetaAttribute<DoubleValue>(format, attributeIndex, attributeId);
  53
  54                 case CSSM_DB_ATTRIBUTE_FORMAT_TIME_DATE:
  55                         return new TypedMetaAttribute<TimeDateValue>(format, attributeIndex, attributeId);
  56
  57                 case CSSM_DB_ATTRIBUTE_FORMAT_BLOB:
  58                         return new TypedMetaAttribute<BlobValue>(format, attributeIndex, attributeId);
  59
  60                 case CSSM_DB_ATTRIBUTE_FORMAT_MULTI_UINT32:
  61                         return new TypedMetaAttribute<MultiUInt32Value>(format, attributeIndex, attributeId);
  62
  63             case CSSM_DB_ATTRIBUTE_FORMAT_COMPLEX:
  64                 default:
  65                         CssmError::throwMe(CSSMERR_DL_UNSUPPORTED_FIELD_FORMAT);
  66         }
  67 }
  68
  69 void
  70 MetaAttribute::packNumberOfValues(WriteSection &ws, uint32 numValues, uint32 &valueOffset) const
  71 {
  72         uint32 offset = MetaRecord::OffsetAttributeOffsets + mAttributeIndex * AtomSize;
  73
  74         if (numValues == 0) {
  75                 // a zero offset means the attribute has no values
  76                 ws.put(offset, 0);
  77         }
  78         else if (numValues == 1) {
  79                 // setting the low bit of the offset means that there is exactly one value
  80                  ws.put(offset, valueOffset | 1);
  81         }
  82         else {
  83                 // write the offset, then write the number of values at that position
  84                 ws.put(offset, valueOffset);
  85                 valueOffset = ws.put(valueOffset, numValues);
  86         }
  87 }
  88
  89 void
  90 MetaAttribute::unpackNumberOfValues(const ReadSection &rs, uint32 &numValues,
  91         uint32 &valueOffset) const
  92 {
  93         uint32 offset = MetaRecord::OffsetAttributeOffsets + mAttributeIndex * AtomSize;
  94         valueOffset = rs[offset];
  95
  96         if (valueOffset == 0)
  97                 // a zero offset means no values
  98                 numValues = 0;
  99         else if (valueOffset & 1) {
 100                 // setting the LSB means exactly one value
 101                 valueOffset ^= 1;
 102                 numValues = 1;
 103         }
 104         else {
 105                 // otherwise, the number of values is at the offset, and the values follow
 106                 numValues = rs[valueOffset];
 107                 valueOffset += AtomSize;
 108         }
 109 }
 110
 111 void
 112 MetaAttribute::packAttribute(WriteSection &ws, uint32 &valueOffset, uint32 numValues,
 113         const CSSM_DATA *values) const
 114 {
 115         packNumberOfValues(ws, numValues, valueOffset);
 116         for (uint32 i = 0; i < numValues; i++)
 117                 packValue(ws, valueOffset, values[i]);
 118 }
 119
 120 void
 121 MetaAttribute::unpackAttribute(const ReadSection &rs, CssmAllocator &allocator,
 122         uint32 &numValues, CSSM_DATA *&values) const
 123 {
 124         uint32 valueOffset;
 125         unpackNumberOfValues(rs, numValues, valueOffset);
 126
 127         values = reinterpret_cast<CSSM_DATA *>(allocator.malloc(numValues * sizeof(CSSM_DATA)));
 128
 129         for (uint32 i = 0; i < numValues; i++)
 130                 unpackValue(rs, valueOffset, values[i], allocator);
 131 }
 132
 133 uint32
 134 MetaAttribute::getNumberOfValues(const ReadSection &rs) const
 135 {
 136         uint32 numValues, valueOffset;
 137         unpackNumberOfValues(rs, numValues, valueOffset);
 138         return numValues;
 139 }
 140
 141 void
 142 MetaAttribute::copyValueBytes(uint32 valueIndex, const ReadSection &rs, WriteSection &ws,
 143         uint32 &writeOffset) const
 144 {
 145         uint32 numValues, valueOffset;
 146         unpackNumberOfValues(rs, numValues, valueOffset);
 147
 148         // skip bytes before the desired value
 149         for (uint32 i = 0; i < valueIndex; i++)
 150                 skipValue(rs, valueOffset);
 151
 152         // copy the value bytes into the write section
 153         copyValue(rs, valueOffset, ws, writeOffset);
 154 }