fostore20/src/java/org/apache/jdo/impl/fostore/FOStoreModel.java - db-jdo - Git at Google

 /*
  * Copyright 2005 The Apache Software Foundation.
  *
  * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package org.apache.jdo.impl.fostore;

 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
 import java.security.AccessController;
 import java.security.PrivilegedAction;

 import javax.jdo.JDOFatalInternalException;

 import javax.jdo.spi.PersistenceCapable;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;

 import org.apache.jdo.impl.model.java.runtime.RuntimeJavaModelFactory;
 import org.apache.jdo.model.ModelException;
 import org.apache.jdo.model.jdo.JDOClass;
 import org.apache.jdo.model.jdo.JDOField;
 import org.apache.jdo.model.jdo.JDOIdentityType;
 import org.apache.jdo.model.jdo.JDOModel;
 import org.apache.jdo.pm.PersistenceManagerFactoryInternal;
 import org.apache.jdo.pm.PersistenceManagerInternal;
 import org.apache.jdo.util.I18NHelper;

 /**
 * Provides model information required by fostore: mapping between CLID's and
 * the java.lang.Class's.
 *
 * @author Dave Bristor
 */
 class FOStoreModel {
     // Maps from java.lang.Class to CLID.
     private HashMap clids = new HashMap();

     /** Maps from provisional CLID's to java.lang.Class's.  See updateCLID
     * and getClass.
     */
     private HashMap provisionalCLIDs = new HashMap();

     /** Map from jdoClass to an array of FOStoreTranscribers. */
     private final HashMap transcribers = new HashMap();

     /** Convenience; so that we don't have to getInstance() all the time. */
     // XXX We may want to rethink how transcribers are accessed.
     private final FOStoreTranscriberFactory transcriberFactory =
         FOStoreTranscriberFactory.getInstance();

     /** RuntimeJavaModelFactory. */
     private static final RuntimeJavaModelFactory javaModelFactory =
         (RuntimeJavaModelFactory) AccessController.doPrivileged(
             new PrivilegedAction () {
                 public Object run () {
                     return RuntimeJavaModelFactory.getInstance();
                 }
             }
         );

     /** I18N support. */
     private static final I18NHelper msg = I18NHelper.getInstance(
         I18N.NAME, FOStoreModel.class.getClassLoader());

     /** Logger */
     static final Log logger = LogFactory.getFactory().getInstance(
         "org.apache.jdo.impl.fostore"); // NOI18N

     /** Constructor */
     FOStoreModel() { }

     /**
      * Provides the class id for the given class.
      * @param cls The class for which the corresponding class id is needed.
      * @return CLID for the given class, or null if there is no metadata for
      * that class.
      */
    CLID getCLID(Class cls) {
        // First check if cls has a well-known CLID.  If not, get  metadata for
        // cls and get the CLID for that.  If still no CLID, create one and map
        // it in the clids table.
        CLID rc = CLID.getKnownCLID(cls);
        if (null == rc) {
            synchronized(clids) {
                rc = (CLID)clids.get(cls);
                if (null == rc) {
                    rc = CLID.createProvisional();
                    clids.put(cls, rc);
                    if (logger.isDebugEnabled()) {
                        logger.debug(
                          "FOM.getCLID (new): " + cls + " -> " + rc); // NOI18N
                    }
                }
            }
        }
        return rc;
     }

     /**
     * Add a mapping from ClassMetaData to CLID.
     */
     synchronized void put(Class cls, CLID clid) {
         clids.put(cls, clid);
     }

     /**
     * Causes the given class mapped to an OID.
     * @param cls Class to be mapped.
     * @param type JDOIdentityType as an int.
     * @param pc PersistenceCapable instance to copy fields from if available.
     * @param oid Object Id instance to copy fields from if available.
     * @param pm PersistenceManagerInternal that requested the operation.
     * @param pmf FOStorePMF that requested the operation.
     * @return ObjectId corresponding to given class.
     */
     OID bind(Class cls, int type, PersistenceCapable pc,
              Object oid, PersistenceManagerInternal pm, FOStorePMF pmf) {
         OID rc = null;
         switch (type) {
             case JDOIdentityType.APPLICATION:
                 rc = AID.create(cls, pc, oid, pm, pmf);
                 break;
             case JDOIdentityType.DATASTORE:
                 CLID clid = getCLID(cls);
                 rc = OID.create(clid);
                 break;
             default:
                 break;
         }
         return rc;
     }

     /**
      * Changes the class id by which this metadata is known.
      * @param pCLID The class id by which the class was previously known.
      * @param rCLID The class id by which the class should be known from now
      * on in this JVM.
      */
     void updateCLID(CLID pCLID, CLID rCLID) {
         Map.Entry entry = getEntry(pCLID);
         if (null != entry) {
             entry.setValue(rCLID);
             if (null == provisionalCLIDs.get(pCLID)) {
                 Class cls = (Class)entry.getKey();
                 provisionalCLIDs.put(pCLID, cls);
             }
         }
     }

     /**
     * Return the class corresponding to the given CLID.
     * @param clid The CLID for which a class is wanted.
     * @return The java.lang.Class corresponding to the given CLID, or null if
     * none is found.
     */
     Class getClass(CLID clid) {
         Class rc = null;
         Map.Entry entry = getEntry(clid);
         if (null != entry) {
             rc = (Class)entry.getKey();
         }

         // It is possible we did not find a mapping.  This can be the case if,
         // for example, 2 objects are created, and one is stored but not the
         // other.  The act of storing one will update the clids table via
         // updateCLID. So we have to look in this other table.
         if (null == rc && clid.isProvisional()) {
             rc = (Class)provisionalCLIDs.get(clid);
         }
         return rc;
     }


     // Provide the entry which represents the Class - CLID mapping.  While
     // this may seem time-wise expensive, we don't expect there to be all
     // *that* many classes (O(100)) per JVM.
     synchronized Map.Entry getEntry(CLID clid) {
         Map.Entry rc = null;
         Set entries = (Set)clids.entrySet();
         for (Iterator i = entries.iterator(); i.hasNext();) {
             Map.Entry entry = (Map.Entry)i.next();
             CLID aCLID = (CLID)entry.getValue();
             if (clid.equals(aCLID)) {
                 rc = entry;
                 break;
             }
         }
         return rc;
     }

     //
     // Provide access to the JDOModel
     //

     /** @param c Class whose corresponding JDOClass is needed.
     * @return The JDOClass for the given class.
     */
     JDOClass getJDOClass(Class c) {
         if (logger.isDebugEnabled()) {
             logger.debug("FOM.getJDOClass for " + c.getName()); // NOI18N
         }
         return javaModelFactory.getJavaType(c).getJDOClass();
     }

     /** Provides a transcriber for the field in the given JDOClass indicated
     * by fieldNum.
     * @param c JDOClass for which a transcriber is needed.
     * @param fieldNum The absolute fieldNumber in the class modeled by
     * jdoClass that is to be transcribed.
     * @return a FOStoreTranscriber appropriate for the type of field in the
     * class modeled by field fieldNum in the class corresponding to
     * jdoClass.
     */
     FOStoreTranscriber getTranscriber(Class c, int fieldNum) {
         FOStoreTranscriber t[] =
             (FOStoreTranscriber[])transcribers.get(c);
         if (null == t) {
             // Create transcribers for jdoClass
             JDOClass jdoClass = getJDOClass(c);
             // Use managed fields here to preserve correct fieldNum's.
             JDOField fields[] = jdoClass.getManagedFields();
             int length = fields.length;
             t = new FOStoreTranscriber[length];

             for (int i = 0; i < length; i++) {
                 if (fields[i].isPersistent()) {
                     t[i] = (FOStoreTranscriber)transcriberFactory.getTranscriber(
                         javaModelFactory.getJavaClass(fields[i].getType()))[0];
                 } else {
                     t[i] = DummyTranscriber.getInstance();
                 }
             }
             transcribers.put(c, t);
         }
         return t[fieldNum];
     }

     //
     // Debug support
     //

     void print(Object o) {
         print (o.getClass());
     }

     void print(Class c) {
         JDOModel m = null;
         try {
             ClassLoader cl = c.getClassLoader();
                 m = javaModelFactory.getJavaModel(cl).getJDOModel();
             org.apache.jdo.impl.model.jdo.util.PrintSupport.printJDOModel(m);
         } catch (Exception ex) {
             System.out.println("Cannot print model"); // NOI18N
         }
     }
 }
	/*
	* Copyright 2005 The Apache Software Foundation.
	*
	* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package org.apache.jdo.impl.fostore;

	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.Map;
	import java.util.Set;
	import java.security.AccessController;
	import java.security.PrivilegedAction;

	import javax.jdo.JDOFatalInternalException;

	import javax.jdo.spi.PersistenceCapable;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;

	import org.apache.jdo.impl.model.java.runtime.RuntimeJavaModelFactory;
	import org.apache.jdo.model.ModelException;
	import org.apache.jdo.model.jdo.JDOClass;
	import org.apache.jdo.model.jdo.JDOField;
	import org.apache.jdo.model.jdo.JDOIdentityType;
	import org.apache.jdo.model.jdo.JDOModel;
	import org.apache.jdo.pm.PersistenceManagerFactoryInternal;
	import org.apache.jdo.pm.PersistenceManagerInternal;
	import org.apache.jdo.util.I18NHelper;

	/**
	* Provides model information required by fostore: mapping between CLID's and
	* the java.lang.Class's.
	*
	* @author Dave Bristor
	*/
	class FOStoreModel {
	// Maps from java.lang.Class to CLID.
	private HashMap clids = new HashMap();

	/** Maps from provisional CLID's to java.lang.Class's. See updateCLID
	* and getClass.
	*/
	private HashMap provisionalCLIDs = new HashMap();

	/** Map from jdoClass to an array of FOStoreTranscribers. */
	private final HashMap transcribers = new HashMap();

	/** Convenience; so that we don't have to getInstance() all the time. */
	// XXX We may want to rethink how transcribers are accessed.
	private final FOStoreTranscriberFactory transcriberFactory =
	FOStoreTranscriberFactory.getInstance();

	/** RuntimeJavaModelFactory. */
	private static final RuntimeJavaModelFactory javaModelFactory =
	(RuntimeJavaModelFactory) AccessController.doPrivileged(
	new PrivilegedAction () {
	public Object run () {
	return RuntimeJavaModelFactory.getInstance();
	}
	}
	);

	/** I18N support. */
	private static final I18NHelper msg = I18NHelper.getInstance(
	I18N.NAME, FOStoreModel.class.getClassLoader());

	/** Logger */
	static final Log logger = LogFactory.getFactory().getInstance(
	"org.apache.jdo.impl.fostore"); // NOI18N

	/** Constructor */
	FOStoreModel() { }

	/**
	* Provides the class id for the given class.
	* @param cls The class for which the corresponding class id is needed.
	* @return CLID for the given class, or null if there is no metadata for
	* that class.
	*/
	CLID getCLID(Class cls) {
	// First check if cls has a well-known CLID. If not, get metadata for
	// cls and get the CLID for that. If still no CLID, create one and map
	// it in the clids table.
	CLID rc = CLID.getKnownCLID(cls);
	if (null == rc) {
	synchronized(clids) {
	rc = (CLID)clids.get(cls);
	if (null == rc) {
	rc = CLID.createProvisional();
	clids.put(cls, rc);
	if (logger.isDebugEnabled()) {
	logger.debug(
	"FOM.getCLID (new): " + cls + " -> " + rc); // NOI18N
	}
	}
	}
	}
	return rc;
	}

	/**
	* Add a mapping from ClassMetaData to CLID.
	*/
	synchronized void put(Class cls, CLID clid) {
	clids.put(cls, clid);
	}

	/**
	* Causes the given class mapped to an OID.
	* @param cls Class to be mapped.
	* @param type JDOIdentityType as an int.
	* @param pc PersistenceCapable instance to copy fields from if available.
	* @param oid Object Id instance to copy fields from if available.
	* @param pm PersistenceManagerInternal that requested the operation.
	* @param pmf FOStorePMF that requested the operation.
	* @return ObjectId corresponding to given class.
	*/
	OID bind(Class cls, int type, PersistenceCapable pc,
	Object oid, PersistenceManagerInternal pm, FOStorePMF pmf) {
	OID rc = null;
	switch (type) {
	case JDOIdentityType.APPLICATION:
	rc = AID.create(cls, pc, oid, pm, pmf);
	break;
	case JDOIdentityType.DATASTORE:
	CLID clid = getCLID(cls);
	rc = OID.create(clid);
	break;
	default:
	break;
	}
	return rc;
	}

	/**
	* Changes the class id by which this metadata is known.
	* @param pCLID The class id by which the class was previously known.
	* @param rCLID The class id by which the class should be known from now
	* on in this JVM.
	*/
	void updateCLID(CLID pCLID, CLID rCLID) {
	Map.Entry entry = getEntry(pCLID);
	if (null != entry) {
	entry.setValue(rCLID);
	if (null == provisionalCLIDs.get(pCLID)) {
	Class cls = (Class)entry.getKey();
	provisionalCLIDs.put(pCLID, cls);
	}
	}
	}

	/**
	* Return the class corresponding to the given CLID.
	* @param clid The CLID for which a class is wanted.
	* @return The java.lang.Class corresponding to the given CLID, or null if
	* none is found.
	*/
	Class getClass(CLID clid) {
	Class rc = null;
	Map.Entry entry = getEntry(clid);
	if (null != entry) {
	rc = (Class)entry.getKey();
	}

	// It is possible we did not find a mapping. This can be the case if,
	// for example, 2 objects are created, and one is stored but not the
	// other. The act of storing one will update the clids table via
	// updateCLID. So we have to look in this other table.
	if (null == rc && clid.isProvisional()) {
	rc = (Class)provisionalCLIDs.get(clid);
	}
	return rc;
	}


	// Provide the entry which represents the Class - CLID mapping. While
	// this may seem time-wise expensive, we don't expect there to be all
	// that many classes (O(100)) per JVM.
	synchronized Map.Entry getEntry(CLID clid) {
	Map.Entry rc = null;
	Set entries = (Set)clids.entrySet();
	for (Iterator i = entries.iterator(); i.hasNext();) {
	Map.Entry entry = (Map.Entry)i.next();
	CLID aCLID = (CLID)entry.getValue();
	if (clid.equals(aCLID)) {
	rc = entry;
	break;
	}
	}
	return rc;
	}

	//
	// Provide access to the JDOModel
	//

	/** @param c Class whose corresponding JDOClass is needed.
	* @return The JDOClass for the given class.
	*/
	JDOClass getJDOClass(Class c) {
	if (logger.isDebugEnabled()) {
	logger.debug("FOM.getJDOClass for " + c.getName()); // NOI18N
	}
	return javaModelFactory.getJavaType(c).getJDOClass();
	}

	/** Provides a transcriber for the field in the given JDOClass indicated
	* by fieldNum.
	* @param c JDOClass for which a transcriber is needed.
	* @param fieldNum The absolute fieldNumber in the class modeled by
	* jdoClass that is to be transcribed.
	* @return a FOStoreTranscriber appropriate for the type of field in the
	* class modeled by field fieldNum in the class corresponding to
	* jdoClass.
	*/
	FOStoreTranscriber getTranscriber(Class c, int fieldNum) {
	FOStoreTranscriber t[] =
	(FOStoreTranscriber[])transcribers.get(c);
	if (null == t) {
	// Create transcribers for jdoClass
	JDOClass jdoClass = getJDOClass(c);
	// Use managed fields here to preserve correct fieldNum's.
	JDOField fields[] = jdoClass.getManagedFields();
	int length = fields.length;
	t = new FOStoreTranscriber[length];

	for (int i = 0; i < length; i++) {
	if (fields[i].isPersistent()) {
	t[i] = (FOStoreTranscriber)transcriberFactory.getTranscriber(
	javaModelFactory.getJavaClass(fields[i].getType()))[0];
	} else {
	t[i] = DummyTranscriber.getInstance();
	}
	}
	transcribers.put(c, t);
	}
	return t[fieldNum];
	}

	//
	// Debug support
	//

	void print(Object o) {
	print (o.getClass());
	}

	void print(Class c) {
	JDOModel m = null;
	try {
	ClassLoader cl = c.getClassLoader();
	m = javaModelFactory.getJavaModel(cl).getJDOModel();
	org.apache.jdo.impl.model.jdo.util.PrintSupport.printJDOModel(m);
	} catch (Exception ex) {
	System.out.println("Cannot print model"); // NOI18N
	}
	}
	}