1 | /* |
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2 | * Licensed to the Apache Software Foundation (ASF) under one or more |
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3 | * contributor license agreements. See the NOTICE file distributed with |
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4 | * this work for additional information regarding copyright ownership. |
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5 | * The ASF licenses this file to You under the Apache License, Version 2.0 |
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6 | * (the "License"); you may not use this file except in compliance with |
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7 | * the License. You may obtain a copy of the License at |
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8 | * |
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9 | * http://www.apache.org/licenses/LICENSE-2.0 |
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10 | * |
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11 | * Unless required by applicable law or agreed to in writing, software |
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12 | * distributed under the License is distributed on an "AS IS" BASIS, |
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13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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14 | * See the License for the specific language governing permissions and |
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15 | * limitations under the License. |
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16 | */ |
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17 | |
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18 | /* |
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19 | * $Id: MemBufInputSource.hpp 568078 2007-08-21 11:43:25Z amassari $ |
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20 | */ |
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21 | |
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22 | |
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23 | #if !defined(MEMBUFINPUTSOURCE_HPP) |
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24 | #define MEMBUFINPUTSOURCE_HPP |
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25 | |
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26 | #include <xercesc/sax/InputSource.hpp> |
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27 | |
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28 | XERCES_CPP_NAMESPACE_BEGIN |
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29 | |
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30 | class BinInputStream; |
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31 | |
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32 | |
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33 | /** |
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34 | * This class is a derivative of the standard InputSource class. It provides |
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35 | * for the parser access to data stored in a memory buffer. The type of |
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36 | * buffer and its host specific attributes are of little concern here. The |
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37 | * only real requirement is that the memory be readable by the current |
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38 | * process. |
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39 | * |
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40 | * Note that the memory buffer size is expressed in <b>bytes</b>, not in |
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41 | * characters. If you pass it text data, you must account for the bytes |
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42 | * per character when indicating the buffer size. |
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43 | * |
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44 | * As with all InputSource derivatives. The primary objective of an input |
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45 | * source is to create an input stream via which the parser can spool in |
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46 | * data from the referenced source. In this case, there are two options |
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47 | * available. |
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48 | * |
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49 | * The passed buffer can be adopted or merely referenced. If it is adopted, |
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50 | * then it must be dynamically allocated and will be destroyed when the |
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51 | * input source is destroyed (no reference counting!.) If not adopted, the |
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52 | * caller must insure that it remains valid until the input source object |
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53 | * is destroyed. |
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54 | * |
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55 | * The other option indicates whether each stream created for this input |
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56 | * source should get its own copy of the data, or whether it should just |
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57 | * stream the data directly from this object's copy of the data. The same |
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58 | * rules apply here, in that the buffer must either be copied by the |
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59 | * stream or it must remain valid until the stream is destroyed. |
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60 | */ |
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61 | class XMLPARSER_EXPORT MemBufInputSource : public InputSource |
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62 | { |
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63 | public : |
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64 | // ----------------------------------------------------------------------- |
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65 | // Constructors and Destructor |
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66 | // ----------------------------------------------------------------------- |
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67 | |
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68 | /** @name Constructors */ |
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69 | //@{ |
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70 | |
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71 | /** |
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72 | * A memory buffer input source is constructed from a buffer of byte |
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73 | * data, and the count of bytes in that buffer. The parser will parse |
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74 | * from this memory buffer until it has eaten the indicated number of |
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75 | * bytes. |
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76 | * |
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77 | * Note that the system id provided serves two purposes. Firstly it is |
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78 | * going to be displayed in error messages as the source of the error. |
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79 | * And secondly, any entities which are refered to from this entity |
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80 | * via relative paths/URLs will be relative to this fake system id. |
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81 | * |
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82 | * @param srcDocBytes The actual data buffer to be parsed from. |
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83 | * @param byteCount The count of bytes (not characters, bytes!) |
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84 | * in the buffer. |
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85 | * @param bufId A fake system id for the buffer. |
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86 | * @param adoptBuffer Indicates whether this object should adopt |
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87 | * the buffer (i.e. become responsible for |
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88 | * deletion) or just |
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89 | * use it in place. |
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90 | * @param manager Pointer to the memory manager to be used to |
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91 | * allocate objects. |
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92 | */ |
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93 | MemBufInputSource |
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94 | ( |
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95 | const XMLByte* const srcDocBytes |
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96 | , const unsigned int byteCount |
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97 | , const XMLCh* const bufId |
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98 | , const bool adoptBuffer = false |
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99 | , MemoryManager* const manager = XMLPlatformUtils::fgMemoryManager |
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100 | ); |
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101 | |
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102 | /** |
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103 | * This constructor is identical to the previous one, except that it takes |
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104 | * the fake system id in local code page form and transcodes it internally. |
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105 | */ |
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106 | MemBufInputSource |
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107 | ( |
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108 | const XMLByte* const srcDocBytes |
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109 | , const unsigned int byteCount |
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110 | , const char* const bufId |
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111 | , const bool adoptBuffer = false |
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112 | , MemoryManager* const manager = XMLPlatformUtils::fgMemoryManager |
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113 | ); |
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114 | //@} |
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115 | |
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116 | /** @name Destructor */ |
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117 | //@{ |
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118 | /** |
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119 | * If the buffer was adopted, the copy made during construction is deleted |
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120 | * at this point. |
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121 | */ |
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122 | ~MemBufInputSource(); |
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123 | //@} |
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124 | |
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125 | |
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126 | // ----------------------------------------------------------------------- |
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127 | // Virtual input source interface |
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128 | // ----------------------------------------------------------------------- |
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129 | |
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130 | /** @name Virtual methods */ |
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131 | //@{ |
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132 | |
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133 | /** |
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134 | * This method will return a binary input stream derivative that will |
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135 | * parse from the memory buffer. If setCopyBufToStream() has been set, |
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136 | * then the stream will make its own copy. Otherwise, it will use the |
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137 | * buffer as is (in which case it must remain valid until the stream |
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138 | * is no longer in use, i.e. the parse completes.) |
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139 | * |
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140 | * @return A dynamically allocated binary input stream derivative that |
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141 | * can parse from the memory buffer. |
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142 | */ |
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143 | BinInputStream* makeStream() const; |
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144 | |
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145 | //@} |
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146 | |
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147 | |
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148 | // ----------------------------------------------------------------------- |
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149 | // Setter methods |
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150 | // ----------------------------------------------------------------------- |
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151 | |
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152 | /** @name Setter methods */ |
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153 | |
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154 | //@{ |
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155 | |
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156 | /** |
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157 | * By default, for safety's sake, each newly created stream from this |
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158 | * input source will make its own copy of the buffer to stream from. This |
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159 | * avoids having to deal with aliasing of the buffer for simple work. But, |
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160 | * for higher performance applications or for large buffers, this is |
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161 | * obviously not optimal. |
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162 | * |
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163 | * In such cases, you can call this method to turn off that default |
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164 | * action. Once turned off, the streams will just get a pointer to the |
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165 | * buffer and parse directly from that. In this case, you must insure that |
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166 | * the buffer remains valid for as long as any parse events are still |
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167 | * using it. |
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168 | * |
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169 | * @param newState The new boolean flag state to set. |
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170 | */ |
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171 | void setCopyBufToStream(const bool newState); |
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172 | |
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173 | /** |
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174 | * This methods allows the MemBufInputSource to be used for more than |
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175 | * one input source, instead of destructing/constructing another |
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176 | * MemBufInputSource. |
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177 | * |
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178 | * @param srcDocBytes The actual data buffer to be parsed from. |
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179 | * @param byteCount The count of bytes (not characters, bytes!) |
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180 | * in the buffer. |
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181 | */ |
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182 | void resetMemBufInputSource(const XMLByte* const srcDocBytes |
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183 | , const unsigned int byteCount); |
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184 | //@} |
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185 | |
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186 | |
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187 | private : |
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188 | // ----------------------------------------------------------------------- |
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189 | // Unimplemented constructors and operators |
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190 | // ----------------------------------------------------------------------- |
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191 | MemBufInputSource(const MemBufInputSource&); |
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192 | MemBufInputSource& operator=(const MemBufInputSource&); |
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193 | |
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194 | // ----------------------------------------------------------------------- |
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195 | // Private data members |
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196 | // |
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197 | // fAdopted |
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198 | // Indicates whether the buffer is adopted or not. If so, then it |
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199 | // is destroyed when the input source is destroyed. |
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200 | // |
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201 | // fByteCount |
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202 | // The size of the source document. |
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203 | // |
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204 | // fCopyBufToStream |
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205 | // This defaults to true (the safe option), which causes it to |
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206 | // give a copy of the buffer to any streams it creates. If you set |
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207 | // it to false, it will allow the streams to just reference the |
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208 | // buffer (in which case this input source must stay alive as long |
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209 | // as the buffer is in use by the stream.) |
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210 | // |
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211 | // fSrcBytes |
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212 | // The source memory buffer that is being spooled from. Whether it |
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213 | // belongs to the this input source or not is controlled by the |
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214 | // fAdopted flag. |
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215 | // ----------------------------------------------------------------------- |
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216 | bool fAdopted; |
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217 | unsigned int fByteCount; |
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218 | bool fCopyBufToStream; |
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219 | const XMLByte* fSrcBytes; |
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220 | }; |
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221 | |
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222 | |
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223 | inline void MemBufInputSource::setCopyBufToStream(const bool newState) |
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224 | { |
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225 | fCopyBufToStream = newState; |
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226 | } |
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227 | |
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228 | XERCES_CPP_NAMESPACE_END |
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229 | |
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230 | #endif |
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