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1 /* |
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2 * Copyright (c) 2000 - 2001 Nokia Corporation and/or its subsidiary(-ies). |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of the License "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - initial contribution. |
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11 * |
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12 * Contributors: |
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13 * |
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14 * Description: |
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15 * |
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16 */ |
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17 |
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18 |
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19 /** ----------------------------------------------------------------------- ** |
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20 @package: NW_TinyTree |
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21 |
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22 @synopsis: default |
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23 |
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24 @description: default |
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25 |
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26 ** ----------------------------------------------------------------------- **/ |
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27 |
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28 #ifndef NW_TINYTREE_EBUFFER_H |
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29 #define NW_TINYTREE_EBUFFER_H |
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30 |
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31 #include "cxml_proj.h" |
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32 |
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33 #ifdef __cplusplus |
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34 extern "C" { |
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35 #endif /* __cplusplus */ |
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36 |
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37 /* ----------------------------------------------------------------------- ** |
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38 EBuffers (expandable buffers) provide storage blocks of bytes that |
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39 can be accessed by index. Tiny trees use these to store serialized |
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40 tree data. Node source offsets are stored as ebuffer indexes. EBuffers |
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41 are similar to segmented vectors, but with variable segment sizes so |
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42 that continuous byte blocks of different sizes can be stored efficiently. |
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43 Unlike vectors, EBuffers store only byte data, so alignment calculations |
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44 are not needed. Also, EBuffers support appending, but not insertion and |
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45 deletion. These simplifications make it much easier to deal with |
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46 variable segment sizes while guaranteeing that continuous blocks remain |
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47 continuous. |
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48 ** ----------------------------------------------------------------------- **/ |
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49 |
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50 /* ------------------------------------------------------------------------- */ |
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51 |
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52 #define NW_TINY_TREE_BLOCK_SIZE_DEFAULT ((CXML_Vector_Metric_t) 256) |
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53 |
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54 |
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55 /** ----------------------------------------------------------------------- ** |
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56 @struct: NW_TinyTree_Segment |
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57 |
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58 @synopsis: Tiny tree data segment. |
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59 |
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60 @scope: public |
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61 @variables: |
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62 NW_Uint8* storage |
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63 Data storage. |
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64 |
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65 CXML_Vector_Metric_t segmentSize |
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66 Size of segment. |
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67 |
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68 CXML_Vector_Metric_t freeOffset |
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69 Free offset. |
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70 |
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71 @description: Tiny tree data segment. |
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72 ** ----------------------------------------------------------------------- **/ |
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73 typedef struct NW_TinyTree_Segment_s { |
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74 NW_Uint8* storage; |
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75 NW_TinyTree_Offset_t segmentSize; |
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76 NW_TinyTree_Offset_t freeOffset; |
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77 } NW_TinyTree_Segment_t; |
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78 |
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79 |
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80 /** ----------------------------------------------------------------------- ** |
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81 @struct: NW_TinyTree_EBuffer |
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82 |
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83 @synopsis: Tiny tree E buffer. |
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84 |
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85 @scope: public |
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86 @variables: |
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87 NW_Bool ownFirstBlock |
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88 Ownership flag. |
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89 |
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90 CXML_Vector_Metric_t blockSize |
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91 Size of block, |
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92 |
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93 NW_TinyTree_Segment_t* segmentList |
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94 List of segments. |
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95 |
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96 CXML_Vector_Metric_t segmentListSize |
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97 Size of segment list. |
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98 |
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99 CXML_Vector_Metric_t numSegments |
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100 Number of segments. |
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101 |
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102 @description: EBuffers (expandable buffers) provide storage blocks |
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103 of bytes that can be accessed by index. Tiny trees use |
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104 these to store serialized tree data. Node source |
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105 offsets are stored as ebuffer indexes. EBuffers are |
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106 similar to segmented vectors, but with variable |
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107 segment sizes so that continuous byte blocks of |
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108 different sizes can be stored efficiently. Unlike |
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109 vectors, EBuffers store only byte data, so alignment |
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110 calculations are not needed. Also, EBuffers support |
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111 appending, but not insertion and deletion. These |
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112 simplifications make it much easier to deal with |
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113 variable segment sizes while guaranteeing that |
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114 continuous blocks remain continuous. |
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115 |
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116 ** ----------------------------------------------------------------------- **/ |
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117 typedef struct NW_TinyTree_EBuffer_s { |
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118 NW_Bool ownFirstBlock; |
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119 CXML_Vector_Metric_t blockSize; |
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120 NW_TinyTree_Segment_t* segmentList; |
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121 CXML_Vector_Metric_t segmentListSize; |
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122 CXML_Vector_Metric_t numSegments; |
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123 } NW_TinyTree_EBuffer_t; |
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124 |
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125 /* ------------------------------------------------------------------------- * |
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126 public methods |
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127 * ------------------------------------------------------------------------- */ |
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128 |
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129 NW_TinyTree_EBuffer_t* |
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130 NW_TinyTree_EBuffer_Construct (NW_Uint8* initialBuffer, |
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131 NW_TinyTree_Offset_t initBuffSize, |
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132 NW_TinyTree_Offset_t blockSize, |
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133 NW_Bool freeBuff); |
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134 |
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135 void |
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136 NW_TinyTree_EBuffer_Destruct (NW_TinyTree_EBuffer_t* thisObj); |
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137 |
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138 extern |
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139 NW_Uint8* |
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140 NW_TinyTree_EBuffer_GetWritableBlock(NW_TinyTree_EBuffer_t* ebuffer, |
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141 NW_TinyTree_Offset_t size, |
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142 NW_TinyTree_Offset_t* index); |
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143 |
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144 |
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145 extern |
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146 NW_Status_t |
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147 NW_TinyTree_EBuffer_GetSegmentAndOffset(NW_TinyTree_EBuffer_t* ebuffer, |
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148 NW_TinyTree_Offset_t index, |
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149 NW_Uint8** segment, /* OUT */ |
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150 NW_TinyTree_Offset_t* segSize, /* OUT */ |
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151 NW_TinyTree_Offset_t* offset); /* OUT */ |
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152 |
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153 extern |
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154 NW_Status_t |
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155 NW_TinyTree_EBuffer_GetIndex(NW_TinyTree_EBuffer_t* ebuffer, |
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156 NW_Uint8* segmentAddr, |
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157 NW_TinyTree_Offset_t offset, |
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158 NW_TinyTree_Offset_t * index); /* OUT */ |
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159 |
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160 extern |
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161 NW_Uint8* |
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162 NW_TinyTree_EBuffer_AddressAt(NW_TinyTree_EBuffer_t* ebuffer, |
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163 NW_TinyTree_Offset_t index); |
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164 |
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165 |
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166 #ifdef __cplusplus |
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167 } /* extern "C" { */ |
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168 #endif /* __cplusplus */ |
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169 |
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170 #endif /* NW_TINYTREE_EBUFFER_H */ |