Introduce the concept of a PropertyStore. The PropertyStore is where all the properties are stored (oh der!) and it is where things like immutability, scoping and so forth are controlled from.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@272257 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/src/java/org/apache/myrmidon/components/store/DefaultPropertyStore.java

@@ -0,0 +1,251 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.store;
+
+import java.io.File;
+import java.util.HashMap;
+import java.util.Hashtable;
+import java.util.Map;
+import org.apache.avalon.excalibur.i18n.ResourceManager;
+import org.apache.avalon.excalibur.i18n.Resources;
+import org.apache.myrmidon.api.TaskContext;
+import org.apache.myrmidon.api.TaskException;
+import org.apache.myrmidon.interfaces.model.DefaultNameValidator;
+import org.apache.myrmidon.interfaces.model.NameValidator;
+import org.apache.myrmidon.interfaces.store.PropertyStore;
+
+/**
+ * This is the Default implementation of PropertyStore. It follows
+ * the following rules;
+ *
+ * <ul>
+ *   <li>The property names must pass DefaultNameValidator checks</li>
+ *   <li>The store is mutable</li>
+ *   <li>If the key is TaskContext.NAME then value must be a string.</li>
+ *   <li>If the key is TaskContext.BASE_DIRECTORY then value must be a key.</li>
+ * </ul>
+ *
+ * @author <a href="mailto:peter@apache.org">Peter Donald</a>
+ * @version $Revision$ $Date$
+ * @see PropertyStore
+ */
+public class DefaultPropertyStore
+    implements PropertyStore
+{
+    private final static Resources REZ =
+        ResourceManager.getPackageResources( DefaultPropertyStore.class );
+
+    /**
+     * The parent store (may be null).
+     */
+    private final PropertyStore m_parent;
+
+    /**
+     * The name validator to check property names against.
+     */
+    private final NameValidator m_validator;
+
+    /**
+     * The underlying map where propertys are actually stored.
+     */
+    private final Map m_contextData = new Hashtable();
+
+    /**
+     * Construct a PropertyStore with no parent and
+     * default name-validator.
+     */
+    public DefaultPropertyStore()
+    {
+        this( null, null );
+    }
+
+    /**
+     * Construct a PropertyStore with specified parent.
+     *
+     * @param parent the parent PropertyStore (may be null)
+     */
+    public DefaultPropertyStore( final PropertyStore parent,
+                                 final NameValidator validator )
+    {
+        m_parent = parent;
+
+        NameValidator candidateValidator = validator;
+        if( null == candidateValidator )
+        {
+            candidateValidator = createDefaultNameValidator();
+        }
+
+        m_validator = candidateValidator;
+
+    }
+
+    /**
+     * Set the property with specified name to specified value.
+     * The specific implementation will apply various rules
+     * before setting the property.
+     *
+     * @param name the name of property
+     * @param value the value of property
+     * @throws Exception if property can not be set
+     */
+    public void setProperty( final String name, final Object value )
+        throws Exception
+    {
+        checkPropertyName( name );
+        checkPropertyValid( name, value );
+
+        if ( value == null )
+        {
+            m_contextData.remove( name );
+        }
+        else
+        {
+            m_contextData.put( name, value );
+        }
+    }
+
+    /**
+     * Return <code>true</code> if the specified property is set.
+     *
+     * @param name the name of property
+     */
+    public boolean isPropertySet( final String name )
+    {
+        try
+        {
+            final Object value = getProperty( name );
+            if( null != value )
+            {
+                return true;
+            }
+        }
+        catch( Exception e )
+        {
+        }
+        return false;
+    }
+
+    /**
+     * Retrieve the value of specified property.
+     * Will return null if no such property exists.
+     *
+     * @param name the name of the property
+     * @return the value of the property, or null if no such property
+     * @throws Exception if theres an error retrieving property, such
+     *         as an invalid property name
+     */
+    public Object getProperty( String name )
+        throws Exception
+    {
+        Object value = m_contextData.get( name );
+        if( value == null && m_parent != null )
+        {
+            value = m_parent.getProperty( name );
+        }
+        return value;
+    }
+
+    /**
+     * Retrieve a copy of all the properties that are "in-scope"
+     * for store.
+     *
+     * @return a copy of all the properties that are "in-scope"
+     *         for store.
+     * @throws Exception if theres an error retrieving propertys
+     */
+    public Map getProperties()
+        throws Exception
+    {
+        final Map properties = new HashMap();
+        if( m_parent != null )
+        {
+            properties.putAll( m_parent.getProperties() );
+        }
+        properties.putAll( m_contextData );
+        return properties;
+    }
+
+    /**
+     * Return a child PropertyStore with specified name.
+     * This is to allow support for scoped stores. However a
+     * store may choose to be unscoped and just return a
+     * reference to itself.
+     *
+     * @param name the name of child store
+     * @return the child store
+     * @throws Exception if theres an error creating child store
+     */
+    public PropertyStore createChildStore( final String name )
+        throws Exception
+    {
+        final DefaultPropertyStore store = new DefaultPropertyStore( this, m_validator );
+
+        final String newName = getProperty( TaskContext.NAME ) + "." + name;
+        store.setProperty( TaskContext.NAME, newName );
+
+        return store;
+    }
+
+    /**
+     * Checks that the supplied property name is valid.
+     */
+    private void checkPropertyName( final String name )
+        throws TaskException
+    {
+        try
+        {
+            m_validator.validate( name );
+        }
+        catch( Exception e )
+        {
+            String message = REZ.getString( "bad-property-name.error" );
+            throw new TaskException( message, e );
+        }
+    }
+
+    /**
+     * Make sure property is valid if it is one of the "magic" properties.
+     *
+     * @param name the name of property
+     * @param value the value of proeprty
+     * @exception TaskException if an error occurs
+     */
+    private void checkPropertyValid( final String name, final Object value )
+        throws TaskException
+    {
+        if( TaskContext.BASE_DIRECTORY.equals( name ) && !( value instanceof File ) )
+        {
+            final String message =
+                REZ.getString( "bad-property.error",
+                               TaskContext.BASE_DIRECTORY,
+                               File.class.getName() );
+            throw new TaskException( message );
+        }
+        else if( TaskContext.NAME.equals( name ) && !( value instanceof String ) )
+        {
+            final String message =
+                REZ.getString( "bad-property.error",
+                               TaskContext.NAME,
+                               String.class.getName() );
+            throw new TaskException( message );
+        }
+    }
+
+    /**
+     * Create an instance of the default the name validator.
+     *
+     * @return the default NameValidator
+     */
+    private static NameValidator createDefaultNameValidator()
+    {
+        final DefaultNameValidator defaultValidator = new DefaultNameValidator();
+        defaultValidator.setAllowInternalWhitespace( false );
+        defaultValidator.setAdditionalInternalCharacters( "_-.+" );
+        return defaultValidator;
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/store/Resources.properties

@@ -0,0 +1,5 @@
+unknown-prop.error=Unknown property {0}.
+bad-property.error=Property {0} must have a value of type {1}.
+bad-property-name.error=Invalid property name.
+null-resolved-value.error=Value "{0}" resolved to null.
+bad-resolve.error=Unable to resolve value "{0}".

proposal/myrmidon/src/java/org/apache/myrmidon/components/workspace/DefaultTaskContext.java

@@ -8,19 +8,18 @@
 package org.apache.myrmidon.components.workspace;
 
 import java.io.File;
-import java.util.Hashtable;
 import java.util.Map;
-import java.util.HashMap;
 import org.apache.avalon.excalibur.i18n.ResourceManager;
 import org.apache.avalon.excalibur.i18n.Resources;
 import org.apache.avalon.excalibur.io.FileUtil;
 import org.apache.avalon.framework.logger.Logger;
+import org.apache.avalon.framework.service.DefaultServiceManager;
 import org.apache.avalon.framework.service.ServiceException;
 import org.apache.avalon.framework.service.ServiceManager;
 import org.apache.myrmidon.api.TaskContext;
 import org.apache.myrmidon.api.TaskException;
-import org.apache.myrmidon.interfaces.model.DefaultNameValidator;
 import org.apache.myrmidon.interfaces.property.PropertyResolver;
+import org.apache.myrmidon.interfaces.store.PropertyStore;
 
 /**
  * Default implementation of TaskContext.
@@ -34,33 +33,35 @@ public class DefaultTaskContext
     private static final Resources REZ =
         ResourceManager.getPackageResources( DefaultTaskContext.class );
 
-    // Property name validator allows digits, but no internal whitespace.
-    private static DefaultNameValidator c_propertyNameValidator =
-        new DefaultNameValidator();
-
-    static
-    {
-        c_propertyNameValidator.setAllowInternalWhitespace( false );
-        c_propertyNameValidator.setAdditionalInternalCharacters( "_-.+" );
-    }
-
-    private final Map m_contextData = new Hashtable();
-    private final TaskContext m_parent;
     private final ServiceManager m_serviceManager;
     private final Logger m_logger;
+    private final PropertyStore m_store;
     private PropertyResolver m_propertyResolver;
 
     /**
      * Constructor that takes both parent context and a service directory.
      */
-    public DefaultTaskContext( final TaskContext parent,
-                               final ServiceManager serviceManager,
-                               final Logger logger )
+    public DefaultTaskContext( final ServiceManager serviceManager,
+                               final Logger logger,
+                               final PropertyStore store )
         throws TaskException
     {
-        m_parent = parent;
         m_serviceManager = serviceManager;
         m_logger = logger;
+        m_store = store;
+
+        if( null == m_serviceManager )
+        {
+            throw new NullPointerException( "serviceManager" );
+        }
+        if( null == m_logger )
+        {
+            throw new NullPointerException( "logger" );
+        }
+        if( null == m_store )
+        {
+            throw new NullPointerException( "store" );
+        }
     }
 
     /**
@@ -96,8 +97,8 @@ public class DefaultTaskContext
     public Object getService( final Class serviceClass )
         throws TaskException
     {
-        // Try this context first
         final String name = serviceClass.getName();
+        //Note that this will chain up to parent ServiceManagers (if any)
         if( null != m_serviceManager && m_serviceManager.hasService( name ) )
         {
             try
@@ -110,12 +111,6 @@ public class DefaultTaskContext
             }
         }
 
-        // Try parent
-        if( null != m_parent )
-        {
-            return m_parent.getService( serviceClass );
-        }
-
         // Not found
         final String message = REZ.getString( "bad-find-service.error", name );
         throw new TaskException( message );
@@ -179,12 +174,14 @@ public class DefaultTaskContext
      */
     public Object getProperty( final String name )
     {
-        Object value = m_contextData.get( name );
-        if( value == null && m_parent != null )
+        try
+        {
+            return m_store.getProperty( name );
+        }
+        catch( final Exception e )
         {
-            value = m_parent.getProperty( name );
+            return null;
         }
-        return value;
     }
 
     /**
@@ -193,14 +190,16 @@ public class DefaultTaskContext
      * @return the map of all property names to values
      */
     public Map getProperties()
+        throws TaskException
     {
-        Map props = new HashMap();
-        if( m_parent != null )
+        try
+        {
+            return m_store.getProperties();
+        }
+        catch( final Exception e )
         {
-            props.putAll( m_parent.getProperties() );
+            throw new TaskException( e.getMessage(), e );
         }
-        props.putAll( m_contextData );
-        return props;
     }
 
     /**
@@ -212,16 +211,13 @@ public class DefaultTaskContext
     public void setProperty( final String name, final Object value )
         throws TaskException
     {
-        checkPropertyName( name );
-        checkPropertyValid( name, value );
-
-        if ( value == null )
+        try
         {
-            m_contextData.remove( name );
+            m_store.setProperty( name, value );
         }
-        else
+        catch( final Exception e )
         {
-            m_contextData.put( name, value );
+            throw new TaskException( e.getMessage(), e );
         }
     }
 
@@ -390,53 +386,19 @@ public class DefaultTaskContext
      */
     public TaskContext createSubContext( final String name )
         throws TaskException
-    {
-        final DefaultTaskContext context =
-            new DefaultTaskContext( this, m_serviceManager, m_logger );
-
-        context.setProperty( TaskContext.NAME, getName() + "." + name );
-        context.setProperty( TaskContext.BASE_DIRECTORY, getBaseDirectory() );
-
-        return context;
-    }
-
-    /**
-     * Checks that the supplied property name is valid.
-     */
-    private void checkPropertyName( final String name ) throws TaskException
     {
         try
         {
-            c_propertyNameValidator.validate( name );
-        }
-        catch( Exception e )
-        {
-            String message = REZ.getString( "bad-property-name.error" );
-            throw new TaskException( message, e );
-        }
-    }
+            final PropertyStore store = m_store.createChildStore( name );
+            final DefaultServiceManager serviceManager =
+                new DefaultServiceManager( m_serviceManager );
+            final Logger logger = m_logger.getChildLogger( name );
 
-    /**
-     * Make sure property is valid if it is one of the "magic" properties.
-     *
-     * @param name the name of property
-     * @param value the value of proeprty
-     * @exception TaskException if an error occurs
-     */
-    private void checkPropertyValid( final String name, final Object value )
-        throws TaskException
-    {
-        if( BASE_DIRECTORY.equals( name ) && !( value instanceof File ) )
-        {
-            final String message =
-                REZ.getString( "bad-property.error", BASE_DIRECTORY, File.class.getName() );
-            throw new TaskException( message );
+            return new DefaultTaskContext( serviceManager, logger, store );
         }
-        else if( NAME.equals( name ) && !( value instanceof String ) )
+        catch( final Exception e )
         {
-            final String message =
-                REZ.getString( "bad-property.error", NAME, String.class.getName() );
-            throw new TaskException( message );
+            throw new TaskException( e.getMessage(), e );
         }
     }
 }

proposal/myrmidon/src/java/org/apache/myrmidon/components/workspace/DefaultWorkspace.java

@@ -37,7 +37,9 @@ import org.apache.myrmidon.interfaces.model.Target;
 import org.apache.myrmidon.interfaces.model.TypeLib;
 import org.apache.myrmidon.interfaces.type.TypeManager;
 import org.apache.myrmidon.interfaces.workspace.Workspace;
+import org.apache.myrmidon.interfaces.store.PropertyStore;
 import org.apache.myrmidon.listeners.ProjectListener;
+import org.apache.myrmidon.components.store.DefaultPropertyStore;
 
 /**
  * This is the default implementation of Workspace.
@@ -56,7 +58,7 @@ public class DefaultWorkspace
     private ProjectListenerSupport m_listenerSupport = new ProjectListenerSupport();
     private ServiceManager m_serviceManager;
     private Parameters m_parameters;
-    private TaskContext m_baseContext;
+    private PropertyStore m_baseStore;
     private HashMap m_entries = new HashMap();
     private TypeManager m_typeManager;
     private Deployer m_deployer;
@@ -105,7 +107,7 @@ public class DefaultWorkspace
     public void initialize()
         throws Exception
     {
-        m_baseContext = createBaseContext();
+        m_baseStore = createBaseStore();
     }
 
     /**
@@ -128,22 +130,22 @@ public class DefaultWorkspace
         m_listenerSupport.projectFinished( project.getProjectName() );
     }
 
-    private TaskContext createBaseContext()
-        throws TaskException
+    private PropertyStore createBaseStore()
+        throws Exception
     {
-        final TaskContext context = new DefaultTaskContext( null, null, null );
+        final DefaultPropertyStore store = new DefaultPropertyStore();
 
         final String[] names = m_parameters.getNames();
         for( int i = 0; i < names.length; i++ )
         {
             final String value = m_parameters.getParameter( names[ i ], null );
-            context.setProperty( names[ i ], value );
+            store.setProperty( names[ i ], value );
         }
 
         //Add system properties so that they overide user-defined properties
-        addToContext( context, System.getProperties() );
+        addToStore( store, System.getProperties() );
 
-        return context;
+        return store;
     }
 
     private File findTypeLib( final String libraryName )
@@ -250,9 +252,12 @@ public class DefaultWorkspace
         final Logger logger =
             new RoutingLogger( getLogger(), m_listenerSupport );
 
-        // Create and configure the context
+        //TODO: Put this in Execution Frame
+        final PropertyStore store = m_baseStore.createChildStore("");
+
+       // Create and configure the context
         final DefaultTaskContext context =
-            new DefaultTaskContext( m_baseContext, serviceManager, logger );
+            new DefaultTaskContext( serviceManager, logger, store );
         context.setProperty( TaskContext.BASE_DIRECTORY, project.getBaseDirectory() );
 
         final DefaultExecutionFrame frame =
@@ -467,13 +472,13 @@ public class DefaultWorkspace
     }
 
     /**
-     * Helper method to add values to a context
+     * Helper method to add values to a store.
      *
-     * @param context the context
+     * @param store the store
      * @param map the map of names->values
      */
-    private void addToContext( final TaskContext context, final Map map )
-        throws TaskException
+    private void addToStore( final PropertyStore store, final Map map )
+        throws Exception
     {
         final Iterator keys = map.keySet().iterator();
 
@@ -481,7 +486,7 @@ public class DefaultWorkspace
         {
             final String key = (String)keys.next();
             final Object value = map.get( key );
-            context.setProperty( key, value );
+            store.setProperty( key, value );
         }
     }
 }

proposal/myrmidon/src/java/org/apache/myrmidon/interfaces/model/NameValidator.java

@@ -17,8 +17,10 @@ public interface NameValidator
 {
     /**
      * Validates the supplied name, failing if it is not.
+     *
      * @param name The name to be validated.
      * @throws Exception is the supplied name is not valid.
      */
-    void validate( String name ) throws Exception;
+    void validate( String name )
+        throws Exception;
 }

proposal/myrmidon/src/java/org/apache/myrmidon/interfaces/store/PropertyStore.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.interfaces.store;
+
+import java.util.Map;
+
+/**
+ * This component stores and manages properties. It is also
+ * responsible for instituting the various policies regarding
+ * propertys. ie It will enforce rules regarding
+ *
+ * <ul>
+ *   <li>Valid property names?</li>
+ *   <li>Are propertys mutable?</li>
+ *   <li>Are propertys scoped?</li>
+ *   <li>Is mapping between name and value correct?</li>
+ * </ul>
+ *
+ * @author <a href="mailto:peter@apache.org">Peter Donald</a>
+ * @version $Revision$ $Date$
+ */
+public interface PropertyStore
+{
+    /** Role name for this interface. */
+    String ROLE = PropertyStore.class.getName();
+
+    /**
+     * Set the property with specified name to specified value.
+     * The specific implementation will apply various rules
+     * before setting the property.
+     *
+     * @param name the name of property
+     * @param value the value of property
+     * @throws Exception if property can not be set
+     */
+    void setProperty( String name, Object value )
+        throws Exception;
+
+    /**
+     * Return <code>true</code> if the specified property is set.
+     *
+     * @param name the name of property
+     */
+    boolean isPropertySet( String name );
+
+    /**
+     * Retrieve the value of specified property.
+     * Will return null if no such property exists.
+     *
+     * @param name the name of the property
+     * @return the value of the property, or null if no such property
+     * @throws Exception if theres an error retrieving property, such
+     *         as an invalid property name
+     */
+    Object getProperty( String name )
+        throws Exception;
+
+    /**
+     * Retrieve a copy of all the properties that are "in-scope"
+     * for store.
+     *
+     * @return a copy of all the properties that are "in-scope"
+     *         for store.
+     * @throws Exception if theres an error retrieving propertys
+     */
+    Map getProperties()
+        throws Exception;
+
+    /**
+     * Return a child PropertyStore with specified name.
+     * This is to allow support for scoped stores. However a
+     * store may choose to be unscoped and just return a
+     * reference to itself.
+     *
+     * @param name the name of child store
+     * @return the child store
+     * @throws Exception if theres an error creating child store
+     */
+    PropertyStore createChildStore( String name )
+        throws Exception;
+}

proposal/myrmidon/src/test/org/apache/myrmidon/components/configurer/test/DefaultConfigurerTestCase.java

@@ -15,6 +15,7 @@ import org.apache.avalon.framework.configuration.ConfigurationException;
 import org.apache.avalon.framework.configuration.DefaultConfiguration;
 import org.apache.myrmidon.api.TaskContext;
 import org.apache.myrmidon.components.AbstractComponentTest;
+import org.apache.myrmidon.components.store.DefaultPropertyStore;
 import org.apache.myrmidon.components.configurer.DefaultConfigurer;
 import org.apache.myrmidon.components.configurer.test.data.ConfigTestAttributeConvert;
 import org.apache.myrmidon.components.configurer.test.data.ConfigTestConfigAdder;
@@ -76,7 +77,9 @@ public class DefaultConfigurerTestCase
         m_configurer = (Configurer)getServiceManager().lookup( Configurer.ROLE );
 
         // Setup a context
-        m_context = new DefaultTaskContext( null, getServiceManager(), getLogger() );
+        final DefaultPropertyStore store = new DefaultPropertyStore();
+        m_context =
+            new DefaultTaskContext( getServiceManager(), getLogger(), store );
         final File baseDir = new File( "." ).getAbsoluteFile();
         m_context.setProperty( TaskContext.BASE_DIRECTORY, baseDir );
     }

proposal/myrmidon/src/test/org/apache/myrmidon/components/property/test/AbstractPropertyResolverTestCase.java

@@ -11,9 +11,11 @@ import java.io.File;
 import java.util.Date;
 import org.apache.aut.converter.lib.ObjectToStringConverter;
 import org.apache.avalon.excalibur.i18n.Resources;
+import org.apache.avalon.framework.service.DefaultServiceManager;
 import org.apache.myrmidon.api.TaskContext;
 import org.apache.myrmidon.api.TaskException;
 import org.apache.myrmidon.components.AbstractComponentTest;
+import org.apache.myrmidon.components.store.DefaultPropertyStore;
 import org.apache.myrmidon.components.workspace.DefaultTaskContext;
 import org.apache.myrmidon.interfaces.property.PropertyResolver;
 
@@ -40,7 +42,9 @@ public abstract class AbstractPropertyResolverTestCase
     {
         m_resolver = (PropertyResolver)getServiceManager().lookup( PropertyResolver.ROLE );
 
-        m_context = new DefaultTaskContext( null, null, getLogger() );
+        final DefaultPropertyStore store = new DefaultPropertyStore();
+        final DefaultServiceManager serviceManager = new DefaultServiceManager();
+        m_context = new DefaultTaskContext( serviceManager, getLogger(), store );
         m_context.setProperty( "intProp", new Integer( 333 ) );
         m_context.setProperty( "stringProp", "String property" );