[2674] | 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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