ResourceManager will be used to match ResourceSpecs of pasted links

Author: tpietzsch

src/main/java/bdv/tools/links/DefaultResourceManager.java

@@ -0,0 +1,85 @@
+package bdv.tools.links;
+
+import java.lang.ref.WeakReference;
+import java.util.Map;
+import java.util.WeakHashMap;
+
+import bdv.tools.links.resource.UnknownResource;
+import net.imglib2.util.Cast;
+
+public class DefaultResourceManager implements ResourceManager
+{
+	private final Map< Object, ResourceSpec< ? > > resourceToSpec = new WeakHashMap<>();
+
+	private final Map< ResourceSpec< ? >, WeakReference< ? > > specToResource = new WeakHashMap<>();
+
+	private final Map< Object, Object > keepAlive = new WeakHashMap<>();
+
+	@Override
+	public synchronized < T > void put( final T resource, final ResourceSpec< T > spec )
+	{
+		resourceToSpec.put( resource, spec );
+		specToResource.put( spec, new WeakReference<>( resource ) );
+	}
+
+	@Override
+	public synchronized < T > ResourceSpec< T > getResourceSpec( final T resource )
+	{
+		final ResourceSpec< ? > spec = resourceToSpec.get( resource );
+		if ( spec == null )
+			return new UnknownResource.Spec<>();
+		else
+			return Cast.unchecked( spec );
+	}
+
+	@Override
+	public synchronized < T > T getResource( final ResourceSpec< T > spec )
+	{
+		final WeakReference< ? > ref = specToResource.get( spec );
+		return ref == null ? null : Cast.unchecked( ref.get() );
+	}
+
+	@Override
+	public synchronized < T > T getOrCreateResource( final ResourceSpec< T > spec )  throws ResourceCreationException
+	{
+		T resource = getResource( spec );
+		if ( resource == null )
+		{
+			resource = spec.create( this );
+		}
+		return resource;
+	}
+
+	@Override
+	public synchronized void keepAlive( final Object anchor, final Object object )
+	{
+		keepAlive.put( anchor, object );
+	}
+
+	@Override
+	public String toString()
+	{
+		String result = "DefaultResources{\n";
+		result += "  resourceToSpec{\n";
+		for ( Map.Entry< Object, ResourceSpec< ? > > entry : resourceToSpec.entrySet() )
+		{
+			Object key = entry.getKey();
+			ResourceSpec< ? > value = entry.getValue();
+			result += "    k = " + key + ", v = " + head( 30, value.toString() ) + "\n";
+		}
+		result += "  }, specToResource{\n";
+		for ( Map.Entry< ResourceSpec< ? >, WeakReference< ? > > entry : specToResource.entrySet() )
+		{
+			final ResourceSpec< ? > key = entry.getKey();
+			final WeakReference< ? > value = entry.getValue();
+			result += "    k = " + head( 30, key.toString() ) + ", v = " + value.get() + "\n";
+		}
+		result += "  }\n";
+		result += '}';
+		return result;
+	}
+
+	private static String head(int len, String s) {
+		return s.substring( 0, Math.min( len, s.length() ) );
+	}
+}

src/main/java/bdv/tools/links/ResourceConfig.java

@@ -0,0 +1,15 @@
+package bdv.tools.links;
+
+public interface ResourceConfig
+{
+	/**
+	 * Apply this config to the resource corresponding to the given {@code
+	 * spec}.
+	 *
+	 * @param spec
+	 * 		spec of resource that this config should be applied to
+	 * @param resources
+	 * 		maps specs to resources
+	 */
+	void apply( ResourceSpec< ? > spec, ResourceManager resources );
+}

src/main/java/bdv/tools/links/ResourceCreationException.java

@@ -0,0 +1,24 @@
+package bdv.tools.links;
+
+public class ResourceCreationException extends Exception
+{
+	public ResourceCreationException()
+	{
+		super();
+	}
+
+	public ResourceCreationException( String message )
+	{
+		super( message );
+	}
+
+	public ResourceCreationException( Throwable cause )
+	{
+		super( cause );
+	}
+
+	public ResourceCreationException( String message, Throwable cause )
+	{
+		super( message, cause );
+	}
+}

src/main/java/bdv/tools/links/ResourceManager.java

@@ -0,0 +1,33 @@
+package bdv.tools.links;
+
+/**
+ * Associates resources and {@code ResourceSpec}s for copy&paste between
+ * BigDataViewer instances.
+ * <p>
+ * Resources are for example {@code SpimData} objects, {@code
+ * SourceAndConverter} for a particular setup in a {@code SpimData}, opened N5
+ * datasets, etc.
+ */
+public interface ResourceManager
+{
+	< T > void put( final T resource, final ResourceSpec< T > spec );
+
+	/**
+	 * Get ResourceSpec registered for resource.
+	 * (Return null if no spec was registered.)
+	 */
+	< T > ResourceSpec< T > getResourceSpec( T resource );
+
+	/**
+	 * If spec is registered, get the corresponding resource.
+	 */
+	< T > T getResource( ResourceSpec< T > spec );
+
+	< T > T getOrCreateResource( ResourceSpec< T > spec ) throws ResourceCreationException;
+
+	/**
+	 * Puts a mapping from {@code anchor} to {@code object} into a {@code WeakHashMap}.
+	 * This will keep {@code object} alive while {@code anchor} is strongly referenced.
+	 */
+	void keepAlive( Object anchor, Object object );
+}

src/main/java/bdv/tools/links/ResourceSpec.java

@@ -0,0 +1,28 @@
+package bdv.tools.links;
+
+public interface ResourceSpec< T >
+{
+	/**
+	 * Creates the specified resource. Resources for nested specs are
+	 * retrieved from a {@code Resources} map, or created and put into the map.
+	 *
+	 * @throws ResourceCreationException
+	 * 		if the resource could not be created
+	 */
+	T create( ResourceManager resources ) throws ResourceCreationException;
+
+	/**
+	 * Create a {@code ResourceConfig} corresponding to this {@code ResourceSpec}.
+	 * <p>
+	 * A typical implementation gets the resource corresponding to this {@code
+	 * ResourceSpec} from {@code resources}, extracts dynamic properties (such
+	 * as the current transform of a {@code TransformedSource}), and builds the
+	 * config.
+	 *
+	 * @param resources
+	 * 		maps specs to resources
+	 *
+	 * @return the current {@code ResourceConfig} of the resource corresponding to this spec
+	 */
+	ResourceConfig getConfig( ResourceManager resources );
+}

src/main/java/bdv/tools/links/resource/UnknownResource.java

@@ -0,0 +1,95 @@
+package bdv.tools.links.resource;
+
+import java.lang.reflect.Type;
+
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+
+import bdv.tools.JsonUtils;
+import bdv.tools.links.ResourceConfig;
+import bdv.tools.links.ResourceCreationException;
+import bdv.tools.links.ResourceManager;
+import bdv.tools.links.ResourceSpec;
+
+/**
+ * Used for resources that do not have associated specs.
+ * <p>
+ * Equality is Object identity. This should make sure that ResourceSpecs
+ * wrapping {@link UnknownResource} are never equal unless they are the same
+ * instance.
+ */
+public interface UnknownResource
+{
+	class Spec< T > implements ResourceSpec< T >
+	{
+		@Override
+		public T create( final ResourceManager resources ) throws ResourceCreationException
+		{
+			throw new ResourceCreationException( "UnknownResource cannot be created" );
+		}
+
+		@Override
+		public ResourceConfig getConfig( final ResourceManager resources )
+		{
+			return new Config();
+		}
+	}
+
+	class Config implements ResourceConfig
+	{
+		@Override
+		public void apply( final ResourceSpec< ? > spec, final ResourceManager resources )
+		{
+			// nothing to configure
+		}
+	}
+
+	@JsonUtils.JsonIo( jsonType = "UnknownResource.Spec", type = UnknownResource.Spec.class )
+	class SpecAdapter implements JsonDeserializer< Spec >, JsonSerializer< Spec >
+	{
+		@Override
+		public Spec deserialize(
+				final JsonElement json,
+				final Type typeOfT,
+				final JsonDeserializationContext context ) throws JsonParseException
+		{
+			return new Spec<>();
+		}
+
+		@Override
+		public JsonElement serialize(
+				final Spec src,
+				final Type typeOfSrc,
+				final JsonSerializationContext context )
+		{
+			return new JsonObject();
+		}
+	}
+
+	@JsonUtils.JsonIo( jsonType = "UnknownResource.Config", type = UnknownResource.Config.class )
+	class ConfigAdapter implements JsonDeserializer< Config >, JsonSerializer< Config >
+	{
+		@Override
+		public Config deserialize(
+				final JsonElement json,
+				final Type typeOfT,
+				final JsonDeserializationContext context ) throws JsonParseException
+		{
+			return new Config();
+		}
+
+		@Override
+		public JsonElement serialize(
+				final Config src,
+				final Type typeOfSrc,
+				final JsonSerializationContext context )
+		{
+			return new JsonObject();
+		}
+	}
+}