X-Git-Url: https://gerrit.simantics.org/r/gitweb?a=blobdiff_plain;f=bundles%2Forg.simantics.acorn%2Fsrc%2Forg%2Fsimantics%2Facorn%2Finternal%2FAcornDatabase.java;h=db83f1395d005babeb09dbd500f5034d2326f503;hb=refs%2Fchanges%2F95%2F495%2F1;hp=63c73dd634580e2c3f1add6c4d34b6d866ff926f;hpb=8ada31c956ee02aef38627ba4deaaae3eecb623a;p=simantics%2Fplatform.git

diff --git a/bundles/org.simantics.acorn/src/org/simantics/acorn/internal/AcornDatabase.java b/bundles/org.simantics.acorn/src/org/simantics/acorn/internal/AcornDatabase.java
index 63c73dd63..db83f1395 100644
--- a/bundles/org.simantics.acorn/src/org/simantics/acorn/internal/AcornDatabase.java
+++ b/bundles/org.simantics.acorn/src/org/simantics/acorn/internal/AcornDatabase.java
@@ -2,12 +2,16 @@ package org.simantics.acorn.internal;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.channels.FileChannel;
+import java.nio.channels.FileLock;
 import java.nio.file.DirectoryStream;
+import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.FileVisitOption;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.SimpleFileVisitor;
+import java.nio.file.StandardOpenOption;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.EnumSet;
 import java.util.Properties;
@@ -16,20 +20,36 @@ import org.simantics.acorn.GraphClientImpl2;
 import org.simantics.db.Database;
 import org.simantics.db.DatabaseUserAgent;
 import org.simantics.db.ServiceLocator;
-import org.simantics.db.common.utils.Logger;
+import org.simantics.db.server.DatabaseStartException;
 import org.simantics.db.server.ProCoreException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @author Tuukka Lehtonen
  */
 public class AcornDatabase implements Database {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(AcornDatabase.class);
+
+    private static final String LOCK_FILE_NAME = "lock";
+
     private final Path folder;
+    private final Path lockFile;
+
+    private GraphClientImpl2 currentClient;
 
     private DatabaseUserAgent userAgent;
 
+    private FileChannel lockFileChannel;
+
+    private FileLock lock;
+
+    private boolean isRunning;
+
     public AcornDatabase(Path folder) {
         this.folder = folder;
+        this.lockFile = folder.resolve(LOCK_FILE_NAME);
     }
 
     @Override
@@ -77,7 +97,7 @@ public class AcornDatabase implements Database {
         try (DirectoryStream<Path> folderStream = Files.newDirectoryStream(path)) {
             return !folderStream.iterator().hasNext();
         } catch (IOException e) {
-            Logger.defaultLogError("Failed to open folder stream. folder=" + path, e);
+            LOGGER.error("Failed to open folder stream. folder=" + path, e);
             return false;
         }
     }
@@ -93,23 +113,48 @@ public class AcornDatabase implements Database {
 
     @Override
     public void deleteFiles() throws ProCoreException {
-        // TODO: somehow check that the acorn client is not active.
         deleteTree(folder);
     }
 
     @Override
-    public void start() throws ProCoreException {
+    public synchronized void start() throws ProCoreException {
+        try {
+            lockFileChannel = lockFile.getFileSystem().provider().newFileChannel(lockFile,
+                    EnumSet.of(StandardOpenOption.CREATE, StandardOpenOption.WRITE));
+
+            lock = lockFileChannel.tryLock();
+            if (lock == null) {
+                safeLoggingClose(lockFileChannel, lockFile);
+                throw new ProCoreException("The database in folder " + folder.toAbsolutePath() + " is already in use!");
+            }
+
+            isRunning = true;
+        } catch (IOException e) {
+            LOGGER.error("Failed to start database at " + folder.toAbsolutePath(), e);
+            safeLoggingClose(lockFileChannel, lockFile);
+        }
     }
 
     @Override
     public boolean isRunning() throws ProCoreException {
-        return true;
+        return isRunning;
     }
 
     @Override
-    public boolean tryToStop() throws ProCoreException {
+    public synchronized boolean tryToStop() throws ProCoreException {
+        if (!isRunning)
+            return false;
+        try {
+            safeLoggingClose(lock, lockFile);
+            lock = null;
+            safeLoggingClose(lockFileChannel, lockFile);
+            lockFileChannel = null;
+            Files.deleteIfExists(lockFile);
+            isRunning = false;
+        } catch (IOException e) {
+            LOGGER.error("Failed to start database at " + folder.toAbsolutePath(), e);
+        }
         return true;
-//        throw new UnsupportedOperationException();
     }
 
     @Override
@@ -118,7 +163,7 @@ public class AcornDatabase implements Database {
 
     @Override
     public boolean isConnected() throws ProCoreException {
-        return true;
+        return isRunning;
     }
 
     @Override
@@ -156,22 +201,22 @@ public class AcornDatabase implements Database {
 
     @Override
     public void purgeDatabase() throws ProCoreException {
-        // TODO: implement
-        throw new UnsupportedOperationException();
+    	if(currentClient == null) throw new IllegalStateException("No current session.");
+    	currentClient.purgeDatabase();
     }
 
     @Override
     public long serverGetTailChangeSetId() throws ProCoreException {
-        // "We have it all"
-        // But after purging we don't so beware.
-        // TODO: beware for purge
-        return 1;
+    	if(currentClient == null) throw new IllegalStateException("No current session.");
+    	return currentClient.getTailChangeSetId();
     }
 
     @Override
     public Session newSession(ServiceLocator locator) throws ProCoreException {
         try {
-            return new GraphClientImpl2(this, folder, locator);
+        	if(currentClient != null) throw new DatabaseStartException(folder.toFile(), "A session is already running. Only one session is supported.");
+        	currentClient = new GraphClientImpl2(this, folder, locator); 
+            return currentClient;
         } catch (IOException e) {
             throw new ProCoreException(e);
         }
@@ -226,4 +271,13 @@ public class AcornDatabase implements Database {
 		return "LZ4";
 	}
 
+    private static void safeLoggingClose(AutoCloseable closeable, Path file) {
+        if (closeable == null)
+            return;
+        try (AutoCloseable c = closeable) {
+        } catch (Exception e) {
+            LOGGER.error("Failed to close " + closeable.getClass() + " of " + file.toAbsolutePath());
+        }
+    }
+
 }