Asat 14 maggio 2009: Sono passato all'utilizzo di un approccio ibrido ... vedere il codice di seguito.
Questa versione ha la maggior parte dei vantaggi di entrambi:
* XmlReader/XmlTextReader (efficienza della memoria -> velocità); e
* XmlSerializer (code-gen -> sviluppo expediancy e flessibilità).
Utilizza XmlTextReader per scorrere il documento e crea "doclet" che deserializza utilizzando le classi XmlSerializer e "XML binding" generate con XSD.EXE.
Immagino che questa ricetta sia universalmente applicabile, ed è veloce ... Sto analizzando un documento XML da 201 MB contenente 56.000 funzionalità GML in circa 7 secondi ... la vecchia implementazione VB6 di questa applicazione ha richiesto alcuni minuti (o addirittura ore) per analizzare grandi estratti ... quindi sto cercando di andare.
Ancora una volta, un BIG Grazie ai forum per donare il tuo tempo prezioso. Lo apprezzo molto.
Saluti tutti. Keith.
using System;
using System.Reflection;
using System.Xml;
using System.Xml.Serialization;
using System.IO;
using System.Collections.Generic;
using nrw_rime_extract.utils;
using nrw_rime_extract.xml.generated_bindings;
namespace nrw_rime_extract.xml
{
internal interface ExtractXmlReader
{
rimeType read(string xmlFilename);
}
/// <summary>
/// RimeExtractXml provides bindings to the RIME Extract XML as defined by
/// $/Release 2.7/Documentation/Technical/SCHEMA and DTDs/nrw-rime-extract.xsd
/// </summary>
internal class ExtractXmlReader_XmlSerializerImpl : ExtractXmlReader
{
private Log log = Log.getInstance();
public rimeType read(string xmlFilename)
{
log.write(
string.Format(
"DEBUG: ExtractXmlReader_XmlSerializerImpl.read({0})",
xmlFilename));
using (Stream stream = new FileStream(xmlFilename, FileMode.Open))
{
return read(stream);
}
}
internal rimeType read(Stream xmlInputStream)
{
// create an instance of the XmlSerializer class,
// specifying the type of object to be deserialized.
XmlSerializer serializer = new XmlSerializer(typeof(rimeType));
serializer.UnknownNode += new XmlNodeEventHandler(handleUnknownNode);
serializer.UnknownAttribute +=
new XmlAttributeEventHandler(handleUnknownAttribute);
// use the Deserialize method to restore the object's state
// with data from the XML document.
return (rimeType)serializer.Deserialize(xmlInputStream);
}
protected void handleUnknownNode(object sender, XmlNodeEventArgs e)
{
log.write(
string.Format(
"XML_ERROR: Unknown Node at line {0} position {1} : {2}\t{3}",
e.LineNumber, e.LinePosition, e.Name, e.Text));
}
protected void handleUnknownAttribute(object sender, XmlAttributeEventArgs e)
{
log.write(
string.Format(
"XML_ERROR: Unknown Attribute at line {0} position {1} : {2}='{3}'",
e.LineNumber, e.LinePosition, e.Attr.Name, e.Attr.Value));
}
}
/// <summary>
/// xtractXmlReader provides bindings to the extract.xml
/// returned by the RIME server; as defined by:
/// $/Release X/Documentation/Technical/SCHEMA and
/// DTDs/nrw-rime-extract.xsd
/// </summary>
internal class ExtractXmlReader_XmlTextReaderXmlSerializerHybridImpl :
ExtractXmlReader
{
private Log log = Log.getInstance();
public rimeType read(string xmlFilename)
{
log.write(
string.Format(
"DEBUG: ExtractXmlReader_XmlTextReaderXmlSerializerHybridImpl." +
"read({0})",
xmlFilename));
using (XmlReader reader = XmlReader.Create(xmlFilename))
{
return read(reader);
}
}
public rimeType read(XmlReader reader)
{
rimeType result = new rimeType();
// a deserializer for featureClass, feature, etc, "doclets"
Dictionary<Type, XmlSerializer> serializers =
new Dictionary<Type, XmlSerializer>();
serializers.Add(typeof(featureClassType),
newSerializer(typeof(featureClassType)));
serializers.Add(typeof(featureType),
newSerializer(typeof(featureType)));
List<featureClassType> featureClasses = new List<featureClassType>();
List<featureType> features = new List<featureType>();
while (!reader.EOF)
{
if (reader.MoveToContent() != XmlNodeType.Element)
{
reader.Read(); // skip non-element-nodes and unknown-elements.
continue;
}
// skip junk nodes.
if (reader.Name.Equals("featureClass"))
{
using (
StringReader elementReader =
new StringReader(reader.ReadOuterXml()))
{
XmlSerializer deserializer =
serializers[typeof (featureClassType)];
featureClasses.Add(
(featureClassType)
deserializer.Deserialize(elementReader));
}
continue;
// ReadOuterXml advances the reader, so don't read again.
}
if (reader.Name.Equals("feature"))
{
using (
StringReader elementReader =
new StringReader(reader.ReadOuterXml()))
{
XmlSerializer deserializer =
serializers[typeof (featureType)];
features.Add(
(featureType)
deserializer.Deserialize(elementReader));
}
continue;
// ReadOuterXml advances the reader, so don't read again.
}
log.write(
"WARNING: unknown element '" + reader.Name +
"' was skipped during parsing.");
reader.Read(); // skip non-element-nodes and unknown-elements.
}
result.featureClasses = featureClasses.ToArray();
result.features = features.ToArray();
return result;
}
private XmlSerializer newSerializer(Type elementType)
{
XmlSerializer serializer = new XmlSerializer(elementType);
serializer.UnknownNode += new XmlNodeEventHandler(handleUnknownNode);
serializer.UnknownAttribute +=
new XmlAttributeEventHandler(handleUnknownAttribute);
return serializer;
}
protected void handleUnknownNode(object sender, XmlNodeEventArgs e)
{
log.write(
string.Format(
"XML_ERROR: Unknown Node at line {0} position {1} : {2}\t{3}",
e.LineNumber, e.LinePosition, e.Name, e.Text));
}
protected void handleUnknownAttribute(object sender, XmlAttributeEventArgs e)
{
log.write(
string.Format(
"XML_ERROR: Unknown Attribute at line {0} position {1} : {2}='{3}'",
e.LineNumber, e.LinePosition, e.Attr.Name, e.Attr.Value));
}
}
}
una risposta un po 'in ritardo: SAX/L'analisi dello streaming Stax è limitata nell'utilità, prova vtd-xml, che usa 1/5 di DOM –