net.sf.saxon.om.DocumentPool Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of saxon9 Show documentation
Provides a basic XSLT 2.0 and XQuery 1.0 processor (W3C Recommendations, January 2007). Command line interfaces and implementations of several Java APIs (DOM, XPath, s9api) are also included.
The newest version!
package net.sf.saxon.om;
import java.util.HashMap;
import java.util.Iterator;
import java.io.Serializable;

/**
  * An object representing the collection of documents handled during
  * a single transformation.
  *
  * The function of allocating document numbers is performed
  * by the DocumentNumberAllocator in the Configuration, not by the DocumentPool. This has a
  * number of effects: in particular it allows operations involving multiple
  * documents (such as generateId() and document()) to occur in a free-standing
  * XPath environment.
  */

public final class DocumentPool implements Serializable {

    // The document pool ensures that the document()
    // function, when called twice with the same URI, returns the same document
    // each time. For this purpose we use a hashtable from
    // URI to DocumentInfo object.

    private HashMap documentNameMap = new HashMap(10);

    /**
    * Add a document to the pool
    * @param doc The DocumentInfo for the document in question
    * @param uri The document-uri property of the document.
    */

    public void add(DocumentInfo doc, String uri) {
        if (uri!=null) {
            documentNameMap.put(uri, doc);
        }
    }

    /**
    * Get the document with a given document-uri
    * @param uri The document-uri property of the document.
    * @return the DocumentInfo with the given document-uri property if it exists,
    * or null if it is not found.
    */

    public DocumentInfo find(String uri) {
        return (DocumentInfo)documentNameMap.get(uri);
    }

    /**
     * Get the URI for a given document node, if it is present in the pool. This supports the
     * document-uri() function.
     * @param doc The document node
     * @return The uri of the document node, if present in the pool, or the systemId of the document node otherwise
     */

    public String getDocumentURI(NodeInfo doc) {
        Iterator iter = documentNameMap.keySet().iterator();
        while (iter.hasNext()) {
            String uri = (String)iter.next();
            if (find(uri).isSameNodeInfo(doc)) {
                return uri;
            }
        }
        return null;
    }

    /**
     * Release a document from the document pool. This means that if the same document is
     * loaded again later, the source will need to be re-parsed, and nodes will get new identities.
     * @param doc the document to be discarded from the pool
     * @return the document supplied in the doc parameter
     */

    public DocumentInfo discard(DocumentInfo doc) {
        Iterator iter = documentNameMap.keySet().iterator();
        while (iter.hasNext()) {
            Object name = iter.next();
            DocumentInfo entry = (DocumentInfo) documentNameMap.get(name);
            if (entry == doc) {
                documentNameMap.remove(name);
                return doc;
            }
        }
        return doc;
    }

}

//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//