--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/RevlogStreamFactory.java	Tue Apr 30 18:55:42 2013 +0200
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2013 TMate Software Ltd
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * For information on how to redistribute this software under
+ * the terms of a license other than GNU General Public License
+ * contact TMate Software at support@hg4j.com
+ */
+package org.tmatesoft.hg.internal;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.ref.SoftReference;
+import java.util.HashMap;
+
+import org.tmatesoft.hg.repo.HgInvalidControlFileException;
+import org.tmatesoft.hg.util.Path;
+
+/**
+ * Factory to create {@link RevlogStream RevlogStreams}, cache-capable.
+ *   
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+public final class RevlogStreamFactory {
+	
+	private final Internals repo;
+	private final HashMap<Path, SoftReference<RevlogStream>> streamsCache;
+
+
+	public RevlogStreamFactory(Internals hgRepo, boolean shallCacheRevlogs) {
+		repo = hgRepo;
+		if (shallCacheRevlogs) {
+			streamsCache = new HashMap<Path, SoftReference<RevlogStream>>();
+		} else {
+			streamsCache = null;
+		}
+	}
+	
+	/**
+	 * Creates a stream for specified file, doesn't cache stream
+	 */
+	/*package-local*/ RevlogStream create(File f) {
+		return new RevlogStream(repo.getDataAccess(), f);
+	}
+
+	/**
+	 * Perhaps, should be separate interface, like ContentLookup
+	 * @param path - normalized file name
+	 * @return <code>null</code> if path doesn't resolve to a existing file
+	 */
+	/*package-local*/ RevlogStream resolveStoreFile(Path path) {
+		final SoftReference<RevlogStream> ref = shallCacheRevlogs() ? streamsCache.get(path) : null;
+		RevlogStream cached = ref == null ? null : ref.get();
+		if (cached != null) {
+			return cached;
+		}
+		File f = repo.getFileFromDataDir(path);
+		if (f.exists()) {
+			RevlogStream s = create(f);
+			if (shallCacheRevlogs()) {
+				streamsCache.put(path, new SoftReference<RevlogStream>(s));
+			}
+			return s;
+		}
+		return null;
+	}
+	
+	/*package-local*/ RevlogStream createStoreFile(Path path) throws HgInvalidControlFileException {
+		File f = repo.getFileFromDataDir(path);
+		try {
+			if (!f.exists()) {
+				f.getParentFile().mkdirs();
+				f.createNewFile();
+			}
+			RevlogStream s = create(f);
+			if (shallCacheRevlogs()) {
+				streamsCache.put(path, new SoftReference<RevlogStream>(s));
+			}
+			return s;
+		} catch (IOException ex) {
+			throw new HgInvalidControlFileException("Can't create a file in the storage", ex, f);
+		}
+	}
+
+	private boolean shallCacheRevlogs() {
+		return streamsCache != null;
+	}
+}