documentmodel.cpp

OSB-PIK-OpenVXI-3.0.0源代码 “中国XML论坛 - 专业的XML技术讨论区--XML在语音技术中的应用”

 /****************License************************************************
  *
  * Copyright 2000-2003.  ScanSoft, Inc.    
  *
  * Use of this software is subject to notices and obligations set forth 
  * in the SpeechWorks Public License - Software Version 1.2 which is 
  * included with this software. 
  *
  * ScanSoft is a registered trademark of ScanSoft, Inc., and OpenSpeech, 
  * SpeechWorks and the SpeechWorks logo are registered trademarks or 
  * trademarks of SpeechWorks International, Inc. in the United States 
  * and other countries.
  *
  ***********************************************************************/
 

 #include "VXMLDocumentRep.hpp"
 #include "VXMLDocument.hpp"
 #include <sstream>                     // by CreateHiddenVariable()
 #include <list>                        // by VXMLElementRef
 #include <iostream>
 
 //#############################################################################
 // One mutex is shared across all the VXMLNodes.  The small performance
 // reduction is offset by the large number of mutexes which would be otherwise
 // created.
 
 #include "InternalMutex.hpp"                    // by VXMLNodeRef
 static InternalMutex * mutex = NULL;
 
 
 bool VXMLDocumentModel::Initialize()
 {
   mutex = new InternalMutex();
   return !(mutex == NULL || mutex->IsBad());
 }
 
 
 void VXMLDocumentModel::Deinitialize()
 {
   if (mutex != NULL) delete mutex;
   mutex = NULL;
 }
 
 //#############################################################################
 
 static const VXIchar * const HIDDEN_VAR_PREFIX   = L"$_internalName_";
 
 // The cautious reader will notice that this routine is not thread safe.  This
 // perfectly acceptible.  We don't really care what the numbers are so long
 // as they keep incrementing.
 //
 // The 'dangerous' line is indicated with the asterisk.  A context switch
 // would need to happen between the comparison and the assignment but only when
 // the threshold is exceeded.  Even on those architectures which permit this
 // context switch, the risk is near zero.
 //
 void VXMLDocumentModel::CreateHiddenVariable(vxistring & v)
 {
   static long internalCount = 31415;
 
   // Increment counter or reset if necessary (LONG_MAX must be larger).
   long count = ++internalCount;
   if (internalCount > 2141234567) internalCount = 271828;  // *
 
   std::basic_stringstream<VXIchar> name;
   name << HIDDEN_VAR_PREFIX << count;
 
   v = name.str();
 }
 
 
 // As long as HIDDEN_VAR_PREFIX is sufficiently obscure, this should be good
 // enough.
 bool VXMLDocumentModel::IsHiddenVariable(const vxistring & v)
 {
   return (v.find(HIDDEN_VAR_PREFIX) == 0);
 }
 
 //#############################################################################
 // This defines the reference counted data for VXMLNodes.
 
 class VXMLNodeRef {
 public:
   const VXMLNodeRef * GetParent() const         { return parent; }
   VXMLNode::VXMLNodeType GetType() const        { return type; }
 
   virtual ~VXMLNodeRef() { }
 
 protected:
   VXMLNodeRef(const VXMLNodeRef * p, VXMLNode::VXMLNodeType t)
     : parent(p), type(t) { }
 
   const VXMLNodeRef * parent;
   VXMLNode::VXMLNodeType type;
 };
 
 //#############################################################################
 // Content nodes are simple - they consist of a block of data.
 
 class VXMLContentRef : public VXMLNodeRef {
 public:
   vxistring data;
 
   VXMLContentRef(const VXMLNodeRef * p)
     : VXMLNodeRef(p, VXMLNode::Type_VXMLContent) { }
 
   virtual ~VXMLContentRef() { }
 };
 
 //#############################################################################
 
 class VXMLElementRef : public VXMLNodeRef {
 public:
   class VXMLElementAttribute {
   public:
     VXMLAttributeType key;
     vxistring value;
 
     VXMLElementAttribute() { }
     VXMLElementAttribute(VXMLAttributeType k, const vxistring & attr)
       : key(k), value(attr) { }
   };
 
   typedef std::list<VXMLNodeRef *> CHILDREN;
   typedef std::list<VXMLElementAttribute> ATTRIBUTES;
 
   VXMLElementType name;
   ATTRIBUTES attributes;
   CHILDREN   children;
 
   bool GetAttribute(VXMLAttributeType key, vxistring & attr) const;
 
   VXMLElementRef(const VXMLNodeRef * p, VXMLElementType n)
     : VXMLNodeRef(p, VXMLNode::Type_VXMLElement), name(n) { }
 
   virtual ~VXMLElementRef() {
     for (CHILDREN::iterator i = children.begin(); i != children.end(); ++i)
       delete (*i);
   }
 };
 
 
 bool VXMLElementRef::GetAttribute(VXMLAttributeType key,
                                   vxistring & attr) const
 {
   ATTRIBUTES::const_iterator i;
   for (i = attributes.begin(); i != attributes.end(); ++i) {
     if ((*i).key == key) {
       attr = (*i).value;
       return true;
     }
   }
 
   attr.erase();
   return false;
 }
 
 //#############################################################################
 
 class VXMLNodeIteratorData {
 public:
   const VXMLElementRef & ref;
   VXMLElementRef::CHILDREN::const_iterator i;
 
   VXMLNodeIteratorData(const VXMLElementRef & r) : ref(r)
     { i = ref.children.begin(); }
 };
 
 VXMLNodeIterator::VXMLNodeIterator(const VXMLNode & n) : data(NULL)
 {
   if (n.internals == NULL ||
       n.internals->GetType() != VXMLNode::Type_VXMLElement)  return;
   
   const VXMLElementRef * tmp = static_cast<const VXMLElementRef*>(n.internals);
 
   data = new VXMLNodeIteratorData(*tmp);
 }
 
 
 VXMLNodeIterator::~VXMLNodeIterator()
 {
   if (data != NULL) delete data;
 }
 
 
 void VXMLNodeIterator::operator++()
 {
   if (data != NULL) ++data->i;
 }
 
 
 void VXMLNodeIterator::reset()
 {
   if (data != NULL) data->i = data->ref.children.begin();
 }
 
 
 VXMLNode VXMLNodeIterator::operator*() const
 {
   if (data == NULL) return VXMLNode();
   return *(data->i);
 }
 
 
 VXMLNodeIterator::operator const void *() const
 {
   if (data == NULL || data->i == data->ref.children.end()) return NULL;
   return reinterpret_cast<void *>(1);
 }
 
 //#############################################################################
 
 void VXMLDocumentRep::AddRef(VXMLDocumentRep * t)
 {
   if (t == NULL) return;
 
   mutex->Lock();
   ++t->count;
   mutex->Unlock();
 }
 
 
 void VXMLDocumentRep::Release(VXMLDocumentRep * & t)
 {
   if (t == NULL) return;
 
   mutex->Lock();
   --t->count;
   mutex->Unlock();
 
   if (t->count == 0) delete t;
 
   t = NULL;
 }
 
 
 VXMLDocumentRep::VXMLDocumentRep()
   : root(NULL), pos(NULL), posType(VXMLNode::Type_VXMLNode), count(1)
 {
 }
 
 
 VXMLDocumentRep::~VXMLDocumentRep()
 {
   if (root != NULL) delete root;
 }
 
 
 void VXMLDocumentRep::AddContent(const VXIchar * c, unsigned int len)
 {
   // (0) Parameter check.
   if (c == NULL || len == 0) return;
 
   // (1) Handle the case where we're just appending content to an existing node
   if (posType == VXMLNode::Type_VXMLContent) {
     (static_cast<VXMLContentRef *>(pos))->data += vxistring(c, len);
     return;
   }
 
   // (2) Create new content node.
   VXMLContentRef * temp = new VXMLContentRef(pos);
   if (temp == NULL) throw VXMLDocumentModel::OutOfMemory();
   temp->data = vxistring(c, len);
 
   AddChild(temp);
   pos = temp;
   posType = VXMLNode::Type_VXMLContent;
 }
 
 
 void VXMLDocumentRep::StartElement(VXMLElementType n)
 {
   if (root != NULL) {
     if (pos == NULL)
       throw VXMLDocumentModel::InternalError();
 
     else if (posType == VXMLNode::Type_VXMLContent) {
       pos = const_cast<VXMLNodeRef *>(pos->GetParent());
       posType = pos->GetType();
     }
   }
 
   VXMLElementRef * temp = new VXMLElementRef(pos, n);
   if (temp == NULL) throw VXMLDocumentModel::OutOfMemory();
 
   AddChild(temp);
   pos = temp;
   posType = VXMLNode::Type_VXMLElement;
 }
 
 
 void VXMLDocumentRep::PruneWhitespace()
 {
   // Set start to the current element.
   VXMLNodeRef * temp = pos;
   if (posType == VXMLNode::Type_VXMLContent)
     temp = const_cast<VXMLNodeRef *>(pos->GetParent());
   VXMLElementRef * start = static_cast<VXMLElementRef *>(temp);
 
   for (VXMLElementRef::CHILDREN::const_iterator j = start->children.begin();
        j != start->children.end(); ++j)
   {
     if ((*j)->GetType() != VXMLNode::Type_VXMLContent) continue;
 
     // Set up a very helpful reference...
     vxistring & str = reinterpret_cast<VXMLContentRef *>(*j)->data;
     vxistring::size_type len = str.length();
     if (len == 0) continue;
 
     // Convert all whitespace to spaces.
     unsigned int i;
     for (i = 0; i < len; ++i)
       if (str[i] == '\r' || str[i] == '\n' || str[i] == '\t')  str[i] = ' ';
 
     // Eliminate trailing and double spaces
     bool lastWasSpace = true;
     for (i = len; i > 0; --i) {
       if (str[i-1] != ' ') {
         lastWasSpace = false;
         continue;
       }
       if (lastWasSpace)
         str.erase(i-1, 1);
       else 
         lastWasSpace = true;
     }
 
     // Eliminate space at very beginning.
     if (str[0] == ' ') str.erase(0, 1);
   }
 }
 
 
 void VXMLDocumentRep::EndElement()
 {
   if (pos == NULL)
     throw VXMLDocumentModel::InternalError();
 
   if (posType == VXMLNode::Type_VXMLContent) {
     posType = pos->GetType();
     pos = const_cast<VXMLNodeRef *>(pos->GetParent());
   }
 
   if (pos == NULL)