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      1 /*
      2  * libjingle
      3  * Copyright 2004--2005, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include "talk/xmllite/xmlparser.h"
     29 
     30 #include <string>
     31 #include <vector>
     32 
     33 #include "talk/base/common.h"
     34 #include "talk/xmllite/xmlconstants.h"
     35 #include "talk/xmllite/xmlelement.h"
     36 #include "talk/xmllite/xmlnsstack.h"
     37 #include "talk/xmllite/xmlnsstack.h"
     38 
     39 namespace buzz {
     40 
     41 
     42 static void
     43 StartElementCallback(void * userData, const char *name, const char **atts) {
     44   (static_cast<XmlParser *>(userData))->ExpatStartElement(name, atts);
     45 }
     46 
     47 static void
     48 EndElementCallback(void * userData, const char *name) {
     49   (static_cast<XmlParser *>(userData))->ExpatEndElement(name);
     50 }
     51 
     52 static void
     53 CharacterDataCallback(void * userData, const char *text, int len) {
     54   (static_cast<XmlParser *>(userData))->ExpatCharacterData(text, len);
     55 }
     56 
     57 static void
     58 XmlDeclCallback(void * userData, const char * ver, const char * enc, int st) {
     59   (static_cast<XmlParser *>(userData))->ExpatXmlDecl(ver, enc, st);
     60 }
     61 
     62 XmlParser::XmlParser(XmlParseHandler *pxph) :
     63     context_(this), pxph_(pxph), sentError_(false) {
     64   expat_ = XML_ParserCreate(NULL);
     65   XML_SetUserData(expat_, this);
     66   XML_SetElementHandler(expat_, StartElementCallback, EndElementCallback);
     67   XML_SetCharacterDataHandler(expat_, CharacterDataCallback);
     68   XML_SetXmlDeclHandler(expat_, XmlDeclCallback);
     69 }
     70 
     71 void
     72 XmlParser::Reset() {
     73   if (!XML_ParserReset(expat_, NULL)) {
     74     XML_ParserFree(expat_);
     75     expat_ = XML_ParserCreate(NULL);
     76   }
     77   XML_SetUserData(expat_, this);
     78   XML_SetElementHandler(expat_, StartElementCallback, EndElementCallback);
     79   XML_SetCharacterDataHandler(expat_, CharacterDataCallback);
     80   XML_SetXmlDeclHandler(expat_, XmlDeclCallback);
     81   context_.Reset();
     82   sentError_ = false;
     83 }
     84 
     85 static bool
     86 XmlParser_StartsWithXmlns(const char *name) {
     87   return name[0] == 'x' &&
     88          name[1] == 'm' &&
     89          name[2] == 'l' &&
     90          name[3] == 'n' &&
     91          name[4] == 's';
     92 }
     93 
     94 void
     95 XmlParser::ExpatStartElement(const char *name, const char **atts) {
     96   if (context_.RaisedError() != XML_ERROR_NONE)
     97     return;
     98   const char **att;
     99   context_.StartElement();
    100   for (att = atts; *att; att += 2) {
    101     if (XmlParser_StartsWithXmlns(*att)) {
    102       if ((*att)[5] == '\0') {
    103         context_.StartNamespace("", *(att + 1));
    104       }
    105       else if ((*att)[5] == ':') {
    106         if (**(att + 1) == '\0') {
    107           // In XML 1.0 empty namespace illegal with prefix (not in 1.1)
    108           context_.RaiseError(XML_ERROR_SYNTAX);
    109           return;
    110         }
    111         context_.StartNamespace((*att) + 6, *(att + 1));
    112       }
    113     }
    114   }
    115   context_.SetPosition(XML_GetCurrentLineNumber(expat_),
    116                        XML_GetCurrentColumnNumber(expat_),
    117                        XML_GetCurrentByteIndex(expat_));
    118   pxph_->StartElement(&context_, name, atts);
    119 }
    120 
    121 void
    122 XmlParser::ExpatEndElement(const char *name) {
    123   if (context_.RaisedError() != XML_ERROR_NONE)
    124     return;
    125   context_.EndElement();
    126   context_.SetPosition(XML_GetCurrentLineNumber(expat_),
    127                        XML_GetCurrentColumnNumber(expat_),
    128                        XML_GetCurrentByteIndex(expat_));
    129   pxph_->EndElement(&context_, name);
    130 }
    131 
    132 void
    133 XmlParser::ExpatCharacterData(const char *text, int len) {
    134   if (context_.RaisedError() != XML_ERROR_NONE)
    135     return;
    136   context_.SetPosition(XML_GetCurrentLineNumber(expat_),
    137                        XML_GetCurrentColumnNumber(expat_),
    138                        XML_GetCurrentByteIndex(expat_));
    139   pxph_->CharacterData(&context_, text, len);
    140 }
    141 
    142 void
    143 XmlParser::ExpatXmlDecl(const char * ver, const char * enc, int standalone) {
    144   if (context_.RaisedError() != XML_ERROR_NONE)
    145     return;
    146 
    147   if (ver && std::string("1.0") != ver) {
    148     context_.RaiseError(XML_ERROR_SYNTAX);
    149     return;
    150   }
    151 
    152   if (standalone == 0) {
    153     context_.RaiseError(XML_ERROR_SYNTAX);
    154     return;
    155   }
    156 
    157   if (enc && !((enc[0] == 'U' || enc[0] == 'u') &&
    158                (enc[1] == 'T' || enc[1] == 't') &&
    159                (enc[2] == 'F' || enc[2] == 'f') &&
    160                 enc[3] == '-' && enc[4] =='8')) {
    161     context_.RaiseError(XML_ERROR_INCORRECT_ENCODING);
    162     return;
    163   }
    164 
    165 }
    166 
    167 bool
    168 XmlParser::Parse(const char *data, size_t len, bool isFinal) {
    169   if (sentError_)
    170     return false;
    171 
    172   if (XML_Parse(expat_, data, static_cast<int>(len), isFinal) !=
    173       XML_STATUS_OK) {
    174     context_.SetPosition(XML_GetCurrentLineNumber(expat_),
    175                          XML_GetCurrentColumnNumber(expat_),
    176                          XML_GetCurrentByteIndex(expat_));
    177     context_.RaiseError(XML_GetErrorCode(expat_));
    178   }
    179 
    180   if (context_.RaisedError() != XML_ERROR_NONE) {
    181     sentError_ = true;
    182     pxph_->Error(&context_, context_.RaisedError());
    183     return false;
    184   }
    185 
    186   return true;
    187 }
    188 
    189 XmlParser::~XmlParser() {
    190   XML_ParserFree(expat_);
    191 }
    192 
    193 void
    194 XmlParser::ParseXml(XmlParseHandler *pxph, std::string text) {
    195   XmlParser parser(pxph);
    196   parser.Parse(text.c_str(), text.length(), true);
    197 }
    198 
    199 XmlParser::ParseContext::ParseContext(XmlParser *parser) :
    200     parser_(parser),
    201     xmlnsstack_(),
    202     raised_(XML_ERROR_NONE),
    203     line_number_(0),
    204     column_number_(0),
    205     byte_index_(0) {
    206 }
    207 
    208 void
    209 XmlParser::ParseContext::StartNamespace(const char *prefix, const char *ns) {
    210   xmlnsstack_.AddXmlns(*prefix ? prefix : STR_EMPTY, ns);
    211 }
    212 
    213 void
    214 XmlParser::ParseContext::StartElement() {
    215   xmlnsstack_.PushFrame();
    216 }
    217 
    218 void
    219 XmlParser::ParseContext::EndElement() {
    220   xmlnsstack_.PopFrame();
    221 }
    222 
    223 QName
    224 XmlParser::ParseContext::ResolveQName(const char* qname, bool isAttr) {
    225   const char *c;
    226   for (c = qname; *c; ++c) {
    227     if (*c == ':') {
    228       const std::pair<std::string, bool> result =
    229           xmlnsstack_.NsForPrefix(std::string(qname, c - qname));
    230       if (!result.second)
    231         return QName();
    232       return QName(result.first, c + 1);
    233     }
    234   }
    235   if (isAttr)
    236     return QName(STR_EMPTY, qname);
    237 
    238   std::pair<std::string, bool> result = xmlnsstack_.NsForPrefix(STR_EMPTY);
    239   if (!result.second)
    240     return QName();
    241 
    242   return QName(result.first, qname);
    243 }
    244 
    245 void
    246 XmlParser::ParseContext::Reset() {
    247   xmlnsstack_.Reset();
    248   raised_ = XML_ERROR_NONE;
    249 }
    250 
    251 void
    252 XmlParser::ParseContext::SetPosition(int line, int column,
    253                                           long byte_index) {
    254   line_number_ = line;
    255   column_number_ = column;
    256   byte_index_ = byte_index;
    257 }
    258 
    259 void
    260 XmlParser::ParseContext::GetPosition(unsigned long * line,
    261                                      unsigned long * column,
    262                                      unsigned long * byte_index) {
    263   if (line != NULL) {
    264     *line = static_cast<unsigned long>(line_number_);
    265   }
    266 
    267   if (column != NULL) {
    268     *column = static_cast<unsigned long>(column_number_);
    269   }
    270 
    271   if (byte_index != NULL) {
    272     *byte_index = static_cast<unsigned long>(byte_index_);
    273   }
    274 }
    275 
    276 XmlParser::ParseContext::~ParseContext() {
    277 }
    278 
    279 }  // namespace buzz
    280