tikhomirov@295: /*
tikhomirov@571:  * Copyright (c) 2011-2013 TMate Software Ltd
tikhomirov@295:  *  
tikhomirov@295:  * This program is free software; you can redistribute it and/or modify
tikhomirov@295:  * it under the terms of the GNU General Public License as published by
tikhomirov@295:  * the Free Software Foundation; version 2 of the License.
tikhomirov@295:  *
tikhomirov@295:  * This program is distributed in the hope that it will be useful,
tikhomirov@295:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@295:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@295:  * GNU General Public License for more details.
tikhomirov@295:  *
tikhomirov@295:  * For information on how to redistribute this software under
tikhomirov@295:  * the terms of a license other than GNU General Public License
tikhomirov@295:  * contact TMate Software at support@hg4j.com
tikhomirov@295:  */
tikhomirov@295: package org.tmatesoft.hg.core;
tikhomirov@295: 
tikhomirov@295: import org.tmatesoft.hg.util.LogFacility;
tikhomirov@571: import org.tmatesoft.hg.util.Path;
tikhomirov@295: 
tikhomirov@295: /**
tikhomirov@456:  * Access to objects that might need to be shared between various distinct operations ran during the same working session 
tikhomirov@456:  * (i.e. caches, log, etc.). It's unspecified whether session context is per repository or can span multiple repositories
tikhomirov@295:  * 
tikhomirov@456:  * <p>Note, API is likely to be extended in future versions, adding more object to share. 
tikhomirov@295:  * 
tikhomirov@295:  * @author Artem Tikhomirov
tikhomirov@295:  * @author TMate Software Ltd.
tikhomirov@295:  */
tikhomirov@456: public abstract class SessionContext {
tikhomirov@456: 	// abstract class to facilitate adding more functionality without API break
tikhomirov@338: 	
tikhomirov@338: 	/**
tikhomirov@456: 	 * Access wrapper for a system log facility.
tikhomirov@456: 	 * @return facility to direct dumps to, never <code>null</code>
tikhomirov@338: 	 */
tikhomirov@456: 	public abstract LogFacility getLog();
tikhomirov@456: 	
tikhomirov@456: 	/**
tikhomirov@456: 	 * Access configuration parameters of the session.
tikhomirov@456: 	 * @param name name of the session configuration parameter
tikhomirov@456: 	 * @param defaultValue value to return if parameter is not configured
tikhomirov@456: 	 * @return value of the session parameter, defaultValue if none found
tikhomirov@456: 	 */
tikhomirov@456: 	public abstract Object getConfigurationProperty(String name, Object defaultValue);
tikhomirov@456: 	// perhaps, later may add Configuration object, with PropertyMarshal's helpers
tikhomirov@456: 	// e.g. when there's standalone Caches and WritableSessionProperties objects
tikhomirov@490: 
tikhomirov@490: 	/**
tikhomirov@571: 	 * Provide a factory to create {@link Path} objects.
tikhomirov@571: 	 * 
tikhomirov@571: 	 * Occasionally, there's a need to construct a {@link Path} object from a string/byte data 
tikhomirov@571: 	 * kept in mercurial control files. Generally, default implementation (with {@link Path#create(CharSequence)} 
tikhomirov@571: 	 * is enough, however, if there's a need to control number of string objects in memory (i.e. prevent duplicates),
tikhomirov@571: 	 * default implementation might need to be replaced with more sophisticated (e.g. using weak references or
tikhomirov@571: 	 * just a huge hash set).
tikhomirov@571: 	 * 
tikhomirov@571: 	 * @return factory to construct Path objects, never <code>null</code>
tikhomirov@571: 	 */
tikhomirov@571: 	public Path.Source getPathFactory() {
tikhomirov@571: 		return new Path.Source() {
tikhomirov@571: 			public Path path(CharSequence p) {
tikhomirov@571: 				return Path.create(p);
tikhomirov@571: 			}
tikhomirov@571: 		};
tikhomirov@571: 	}
tikhomirov@571: 
tikhomirov@571: 	/**
tikhomirov@490: 	 * Providers of the context may implement
tikhomirov@490: 	 */
tikhomirov@490: 	public interface Source {
tikhomirov@490: 		SessionContext getSessionContext();
tikhomirov@490: 	}
tikhomirov@295: }