Update streaming example with new implementation

1 files changed, 457 insertions, 35 deletions

diff --git a/examples/cxx/tree/streaming/serializer.cxx b/examples/cxx/tree/streaming/serializer.cxx
index 04d2db4..0ce8156 100644
--- a/examples/cxx/tree/streaming/serializer.cxx
+++ b/examples/cxx/tree/streaming/serializer.cxx
@@ -1,9 +1,11 @@
-// file      : examples/cxx/tree/streaming/serializer.cxx
-// copyright : not copyrighted - public domain
+#include <vector>
+#include <cassert>
+#include <cstddef>
 
 #include <xercesc/util/XMLUni.hpp>
 
 #include <xercesc/dom/DOM.hpp>
+#include <xercesc/dom/impl/DOMLSSerializerImpl.hpp>
 
 #include <xsd/cxx/xml/string.hxx>
 #include <xsd/cxx/xml/dom/bits/error-handler-proxy.hxx>
@@ -20,6 +22,319 @@ using namespace xercesc;
 namespace xml = xsd::cxx::xml;
 namespace tree = xsd::cxx::tree;
 
+static const XMLCh  gEOLSeq[] =
+{
+  chLF, chNull
+};
+
+static const XMLCh  gUTF8[] =
+{
+  chLatin_U, chLatin_T, chLatin_F, chDash, chDigit_8, chNull
+};
+
+static const XMLCh  gEndElement[] =
+{
+  chOpenAngle, chForwardSlash, chNull
+};
+
+static const int DISCARD_DEFAULT_CONTENT_ID       = 0x1;
+static const int ENTITIES_ID                      = 0x2;
+static const int FORMAT_PRETTY_PRINT_1ST_LEVEL_ID = 0xA;
+
+class StreamingDOMSerializer: public DOMLSSerializerImpl
+{
+public:
+  StreamingDOMSerializer (MemoryManager* manager)
+    : DOMLSSerializerImpl (manager)
+  {
+  }
+
+  bool
+  startOpen (const DOMElement* e, DOMLSOutput* const destination)
+  {
+    const DOMDocument* docu (e->getOwnerDocument ());
+    assert (docu != 0);
+
+    // Code adapted from DOMLSSerializerImpl::write().
+    //
+    target_ = destination->getByteStream();
+
+    fEncodingUsed = gUTF8;
+
+    const XMLCh* lsEncoding=destination->getEncoding();
+    if (lsEncoding && *lsEncoding)
+    {
+      fEncodingUsed = lsEncoding;
+    }
+    else if (docu)
+    {
+      const XMLCh* tmpEncoding = docu->getInputEncoding();
+
+      if ( tmpEncoding && *tmpEncoding)
+      {
+        fEncodingUsed = tmpEncoding;
+      }
+      else
+      {
+        tmpEncoding = docu->getXmlEncoding();
+
+        if ( tmpEncoding && *tmpEncoding)
+        {
+          fEncodingUsed = tmpEncoding;
+        }
+      }
+    }
+
+    fNewLineUsed = (fNewLine && *fNewLine)? fNewLine : gEOLSeq;
+
+    fDocumentVersion = (docu->getXmlVersion() && *(docu->getXmlVersion()))
+      ? docu->getXmlVersion()
+      : XMLUni::fgVersion1_0;
+
+    fErrorCount = 0;
+
+    fLineFeedInTextNodePrinted = false;
+    fLastWhiteSpaceInTextNode = 0;
+
+    level_ = 0;
+    namespace_map_.clear ();
+
+    fFormatter = new (fMemoryManager) XMLFormatter( fEncodingUsed
+                                                    ,fDocumentVersion
+                                                    ,target_
+                                                    ,XMLFormatter::NoEscapes
+                                                    ,XMLFormatter::UnRep_CharRef
+                                                    ,fMemoryManager);
+    formatter_.reset (fFormatter);
+
+    // Write out the XML declaration, etc. Here we assume that the document
+    // has no children (i.e., no root element).
+    //
+    processNode (docu, 0);
+    fLineFeedInTextNodePrinted = true;
+
+    return writeOpen (e);
+  }
+
+  bool
+  writeOpen (const DOMElement* e)
+  {
+    // Code adapted from the first part of ELEMENT_NODE case in
+    // DOMLSSerializerImpl::processNode().
+    //
+
+    if (!fLineFeedInTextNodePrinted)
+    {
+      if(level_ == 1 && getFeature(FORMAT_PRETTY_PRINT_1ST_LEVEL_ID))
+        printNewLine();
+
+      printNewLine();
+    }
+    else
+    {
+      fLineFeedInTextNodePrinted = false;
+    }
+
+    printIndent(level_);
+
+    RefHashTableOf<XMLCh>* namespaceMap = NULL;
+
+    *fFormatter  << XMLFormatter::NoEscapes << chOpenAngle <<
+      e->getNodeName ();
+
+    setURCharRef();
+    DOMNamedNodeMap *attributes = e->getAttributes();
+    XMLSize_t attrCount = attributes->getLength();
+
+    const XMLCh* prefix = e->getPrefix();
+    const XMLCh* uri = e->getNamespaceURI();
+    if((uri && uri[0]) ||
+       ((prefix==0 || prefix[0]==0) && isDefaultNamespacePrefixDeclared()))
+    {
+      if(prefix==0 || prefix[0]==0)
+        prefix=XMLUni::fgZeroLenString;
+      if(!isNamespaceBindingActive(prefix, uri))
+      {
+        if(namespaceMap==NULL)
+        {
+          namespaceMap=new (fMemoryManager) RefHashTableOf<XMLCh>(12, false, fMemoryManager);
+          fNamespaceStack->addElement(namespaceMap);
+        }
+        namespaceMap->put((void*)prefix,(XMLCh*)uri);
+        *fFormatter  << XMLFormatter::NoEscapes
+                     << chSpace << XMLUni::fgXMLNSString;
+
+        if(!XMLString::equals(prefix,XMLUni::fgZeroLenString))
+          *fFormatter  << chColon << prefix;
+
+        *fFormatter  << chEqual << chDoubleQuote
+                     << XMLFormatter::AttrEscapes
+                     << uri
+                     << XMLFormatter::NoEscapes
+                     << chDoubleQuote;
+      }
+    }
+
+    bool discard = getFeature(DISCARD_DEFAULT_CONTENT_ID);
+    for (XMLSize_t i = 0; i < attrCount; i++)
+    {
+      DOMAttr*  attribute = (DOMAttr*)attributes->item(i);
+
+      if (discard && !((DOMAttr*)attribute )->getSpecified())
+        continue;
+
+      // if this attribute is a namespace declaration, add it to the namespace map for the current level
+      const XMLCh* ns = attribute->getNamespaceURI();
+      if (ns != 0 )
+      {
+        if(XMLString::equals(ns, XMLUni::fgXMLNSURIName))
+        {
+          if(namespaceMap==NULL)
+          {
+            namespaceMap=new (fMemoryManager) RefHashTableOf<XMLCh>(12, false, fMemoryManager);
+            fNamespaceStack->addElement(namespaceMap);
+          }
+          const XMLCh* nsPrefix = attribute->getLocalName();
+          if(XMLString::equals(attribute->getNodeName(),XMLUni::fgXMLNSString))
+            nsPrefix = XMLUni::fgZeroLenString;
+          if(namespaceMap->containsKey((void*)nsPrefix))
+            continue;
+          namespaceMap->put((void*)attribute->getLocalName(),(XMLCh*)attribute->getNodeValue());
+        }
+        else if(!XMLString::equals(ns, XMLUni::fgXMLURIName))
+        {
+          // check if the namespace for the current node is already defined
+          const XMLCh* prefix = attribute->getPrefix();
+          if(prefix && prefix[0])
+          {
+            const XMLCh* uri = attribute->getNamespaceURI();
+            if(!isNamespaceBindingActive(prefix, uri))
+            {
+              if(namespaceMap==NULL)
+              {
+                namespaceMap=new (fMemoryManager) RefHashTableOf<XMLCh>(12, false, fMemoryManager);
+                fNamespaceStack->addElement(namespaceMap);
+              }
+              namespaceMap->put((void*)prefix,(XMLCh*)uri);
+              *fFormatter  << XMLFormatter::NoEscapes
+                           << chSpace << XMLUni::fgXMLNSString << chColon << prefix
+                           << chEqual << chDoubleQuote
+                           << XMLFormatter::AttrEscapes
+                           << uri
+                           << XMLFormatter::NoEscapes
+                           << chDoubleQuote;
+            }
+          }
+        }
+      }
+
+      if (XMLString::equals(ns, XMLUni::fgXMLNSURIName) || checkFilter(attribute) == DOMNodeFilter::FILTER_ACCEPT)
+      {
+        *fFormatter  << XMLFormatter::NoEscapes
+                     << chSpace << attribute->getNodeName()
+                     << chEqual << chDoubleQuote
+                     << XMLFormatter::AttrEscapes;
+
+        if (getFeature(ENTITIES_ID))
+        {
+          DOMNode* child = attribute->getFirstChild();
+          while( child != 0)
+          {
+            if(child->getNodeType()==DOMNode::TEXT_NODE)
+              *fFormatter  << child->getNodeValue();
+            else if(child->getNodeType()==DOMNode::ENTITY_REFERENCE_NODE)
+              *fFormatter << XMLFormatter::NoEscapes
+                          << chAmpersand << child->getNodeName() << chSemiColon
+                          << XMLFormatter::AttrEscapes;
+            child = child->getNextSibling();
+          }
+        }
+        else
+          *fFormatter  << attribute->getNodeValue();
+
+        *fFormatter  << XMLFormatter::NoEscapes << chDoubleQuote;
+      }
+    }
+
+    *fFormatter << XMLFormatter::NoEscapes << chCloseAngle;
+
+    // Keep track of whether we have added a namespace map for this
+    // element. Used to pop it in writeClose().
+    //
+    namespace_map_.push_back (namespaceMap != 0);
+
+    level_++;
+
+    DOMNode* child = e->getFirstChild();
+    while (child != 0)
+    {
+      processNode (child, level_);
+      child = child->getNextSibling();
+    }
+
+    return fErrorCount == 0;
+  }
+
+  bool
+  writeClose (const XMLCh* name)
+  {
+    // Code adapted from the second part of ELEMENT_NODE case in
+    // DOMLSSerializerImpl::processNode().
+    //
+    level_--;
+
+    // Assume we are not on the same line (nodeLine != fCurrentLine).
+    //
+    {
+      if (!fLineFeedInTextNodePrinted)
+      {
+        printNewLine();
+      }
+      else
+      {
+        fLineFeedInTextNodePrinted = false;
+      }
+
+      if(level_ == 0 && getFeature(FORMAT_PRETTY_PRINT_1ST_LEVEL_ID))
+        printNewLine();
+
+      printIndent(level_);
+    }
+
+    *fFormatter << XMLFormatter::NoEscapes << gEndElement <<
+      name << chCloseAngle;
+
+    if (namespace_map_.back ())
+      fNamespaceStack->removeLastElement();
+
+    namespace_map_.pop_back ();
+
+    if (level_ == 0)
+    {
+      printNewLine();
+      target_->flush ();
+    }
+
+    return fErrorCount == 0;
+  }
+
+  bool
+  write (const DOMElement* e)
+  {
+    processNode (e, level_);
+    return fErrorCount == 0;
+  }
+
+  using DOMLSSerializerImpl::write; // Whole document.
+
+private:
+  XMLFormatTarget* target_;
+  std::auto_ptr<XMLFormatter> formatter_;
+  int level_;
+
+  std::vector<bool> namespace_map_;
+};
+
 class serializer_impl
 {
 public:
@@ -37,17 +352,25 @@ public:
   create (const string& ns, const string& qname, const namespace_infomap&);
 
   void
-  serialize (DOMElement& e);
+  serialize (xml::dom::auto_ptr<DOMElement>);
+
+  void
+  serialize_open (xml::dom::auto_ptr<DOMElement>);
+
+  void
+  serialize_close (const string&);
 
 private:
   void
-  add_namespaces (xercesc::DOMElement*, const namespace_infomap&);
+  clear_document ();
 
 private:
+  bool start_;
+
   // Serializer.
   //
   xml::dom::auto_ptr<DOMLSOutput> out_;
-  xml::dom::auto_ptr<DOMLSSerializer> serializer_;
+  xml::dom::auto_ptr<StreamingDOMSerializer> serializer_;
 
   auto_ptr<xml::dom::ostream_format_target> oft_;
 
@@ -58,6 +381,10 @@ private:
   //
   DOMImplementation& dom_impl_;
   xml::dom::auto_ptr<DOMDocument> doc_;
+  vector<DOMElement*> element_stack_;
+
+  size_t element_count_; // Number of elements serialized using current doc.
+  static const size_t element_count_limit_ = 500;
 };
 
 const XMLCh ls[] = {chLatin_L, chLatin_S, chNull};
@@ -65,27 +392,35 @@ const XMLCh ls[] = {chLatin_L, chLatin_S, chNull};
 serializer_impl::
 serializer_impl ()
     : error_proxy_ (error_handler_),
-      dom_impl_ (*DOMImplementationRegistry::getDOMImplementation (ls)),
-      doc_ (dom_impl_.createDocument ())
+      dom_impl_ (*DOMImplementationRegistry::getDOMImplementation (ls))
 {
-  serializer_.reset (dom_impl_.createLSSerializer ());
-  DOMConfiguration* conf (serializer_->getDomConfig ());
+  serializer_.reset (
+    new (XMLPlatformUtils::fgMemoryManager)
+    StreamingDOMSerializer (XMLPlatformUtils::fgMemoryManager));
 
+  DOMConfiguration* conf (serializer_->getDomConfig ());
   conf->setParameter (XMLUni::fgDOMErrorHandler, &error_proxy_);
+  conf->setParameter (XMLUni::fgDOMXMLDeclaration, true);
   conf->setParameter (XMLUni::fgDOMWRTDiscardDefaultContent, true);
   conf->setParameter (XMLUni::fgDOMWRTFormatPrettyPrint, true);
-  conf->setParameter (XMLUni::fgDOMXMLDeclaration, false);
+  conf->setParameter (XMLUni::fgDOMWRTXercesPrettyPrint, false);
 }
 
 void serializer_impl::
 start (ostream& os, const string& encoding)
 {
+  element_stack_.clear ();
+  doc_.reset (dom_impl_.createDocument ());
+  element_count_ = 0;
+
   error_handler_.reset ();
   oft_.reset (new xml::dom::ostream_format_target (os));
 
   out_.reset (dom_impl_.createLSOutput ());
   out_->setEncoding (xml::string (encoding).c_str ());
   out_->setByteStream (oft_.get ());
+
+  start_ = true;
 }
 
 DOMElement* serializer_impl::
@@ -94,7 +429,13 @@ create (const string& name, const namespace_infomap& map)
   DOMElement* r (doc_->createElement (xml::string (name).c_str ()));
 
   if (!map.empty ())
-    add_namespaces (r, map);
+    xml::dom::add_namespaces<char> (*r, map);
+
+  // Add the element as the child of the stack "tip" so that it
+  // "sees" all the namespace declarations active from this point.
+  //
+  if (!element_stack_.empty ())
+    element_stack_.back ()->appendChild (r);
 
   return r;
 }
@@ -107,42 +448,111 @@ create (const string& ns, const string& qname, const namespace_infomap& map)
       xml::string (ns).c_str (), xml::string (qname).c_str ()));
 
   if (!map.empty ())
-    add_namespaces (r, map);
+    xml::dom::add_namespaces<char> (*r, map);
+
+  // Add the element as the child of the stack "tip" so that it
+  // "sees" all the namespace declarations active from this point.
+  //
+  if (!element_stack_.empty ())
+    element_stack_.back ()->appendChild (r);
 
   return r;
 }
 
 void serializer_impl::
-add_namespaces (DOMElement* e, const namespace_infomap& map)
+serialize (xml::dom::auto_ptr<DOMElement> p)
 {
-  for (namespace_infomap::const_iterator i (map.begin ()), end (map.end ());
-       i != end; ++i)
+  DOMElement* e (p.get ());
+
+  if (start_)
   {
-    if (i->first.empty ())
-    {
-      // Empty prefix.
-      //
-      if (!i->second.name.empty ())
-        e->setAttributeNS (
-          XMLUni::fgXMLNSURIName,
-          xml::string ("xmlns").c_str (),
-          xml::string (i->second.name).c_str ());
-    }
-    else
-    {
-      e->setAttributeNS (
-        XMLUni::fgXMLNSURIName,
-        xml::string ("xmlns:" + i->first).c_str (),
-        xml::string (i->second.name).c_str ());
-    }
+    serializer_->write (e, out_.get ());
+    start_ = false;
   }
+  else
+    serializer_->write (e);
+
+  error_handler_.throw_if_failed<tree::serialization<char> > ();
+
+  // Remove this element from its parent before we release.
+  //
+  if (!element_stack_.empty ())
+    element_stack_.back ()->removeChild (e);
+
+  p.reset (); // Release it before we may clear the document below.
+
+  if (element_count_++ > element_count_limit_)
+    clear_document ();
 }
 
 void serializer_impl::
-serialize (DOMElement& e)
+serialize_open (xml::dom::auto_ptr<DOMElement> p)
 {
-  serializer_->write (&e, out_.get ());
+  DOMElement* e (p.get ());
+
+  if (start_)
+  {
+    serializer_->startOpen (e, out_.get ());
+    start_ = false;
+  }
+  else
+    serializer_->writeOpen (e);
+
+  error_handler_.throw_if_failed<tree::serialization<char> > ();
+
+  // Add this element to the element stack. serialize_close() is
+  // responsible for its removal and releasing.
+  //
+  element_stack_.push_back (e);
+  p.release ();
+}
+
+void serializer_impl::
+serialize_close (const string& name)
+{
+  serializer_->writeClose (xml::string (name).c_str ());
   error_handler_.throw_if_failed<tree::serialization<char> > ();
+
+  // Release the element.
+  //
+  DOMElement* e (element_stack_.back ());
+  element_stack_.pop_back ();
+
+  if (!element_stack_.empty ())
+    element_stack_.back ()->removeChild (e);
+
+  e->release ();
+
+  if (element_count_++ > element_count_limit_)
+    clear_document ();
+}
+
+void serializer_impl::
+clear_document ()
+{
+  // Re-create the document in order to force deallocation of its
+  // internal heap. While Xerces-C++ DOM tries to re-use memory,
+  // it still accumulates no longer used memory blocks.
+  //
+  xml::dom::auto_ptr<DOMDocument> doc (dom_impl_.createDocument ());
+
+  if (!element_stack_.empty ())
+  {
+    DOMElement* e (
+      static_cast<DOMElement*> (
+        doc->importNode (element_stack_.front (), true)));
+
+    for (vector<DOMElement*>::iterator i (element_stack_.begin ());
+         i != element_stack_.end ();
+         ++i)
+    {
+      *i = e;
+      e = static_cast<DOMElement*> (e->getFirstChild ());
+    }
+  }
+
+  doc_ = doc;
+  element_count_ = 0;
 }
 
 //
@@ -179,7 +589,19 @@ create (const string& ns, const string& qname, const namespace_infomap& map)
 }
 
 void serializer::
-serialize (DOMElement& e)
+serialize (xml::dom::auto_ptr<DOMElement> e)
 {
   impl_->serialize (e);
 }
+
+void serializer::
+serialize_open (xml::dom::auto_ptr<DOMElement> e)
+{
+  impl_->serialize_open (e);
+}
+
+void serializer::
+serialize_close (const string& name)
+{
+  impl_->serialize_close (name);
+}