Some Acorn improvements

[simantics/platform.git] / bundles / org.simantics.acorn / src / org / simantics / acorn / internal / AcornDatabase.java

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 63c73dd634580e2c3f1add6c4d34b6d866ff926f..be505c6039712e322ce80ffa653c1b4c6babac13 100644 (file)
--- a/bundles/org.simantics.acorn/src/org/simantics/acorn/internal/AcornDatabase.java
+++ b/bundles/org.simantics.acorn/src/org/simantics/acorn/internal/AcornDatabase.java
@@ -2,6 +2,8 @@ package org.simantics.acorn.internal;
 
 import java.io.File;
 import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.channels.FileLock;
 import java.nio.file.DirectoryStream;
 import java.nio.file.FileVisitOption;
 import java.nio.file.FileVisitResult;
@@ -28,6 +30,12 @@ public class AcornDatabase implements Database {
 
     private DatabaseUserAgent userAgent;
 
+    private RandomAccessFile raLockFile;
+
+    private FileLock lock;
+
+    private boolean isRunning;
+
     public AcornDatabase(Path folder) {
         this.folder = folder;
     }
@@ -93,23 +101,49 @@ 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 {
+        Path lockFile = folder.resolve("lock");
+        try {
+            if (!Files.exists(lockFile))
+                Files.createFile(lockFile);
+            
+            raLockFile = new RandomAccessFile(lockFile.toFile(), "rw");
+            lock = raLockFile.getChannel().tryLock();
+            if (lock == null) {
+                throw new ProCoreException("The database in folder " + folder.toAbsolutePath() + " is already in use!");
+            }
+            
+            isRunning = true;
+            
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
     }
 
     @Override
     public boolean isRunning() throws ProCoreException {
-        return true;
+        return isRunning;
     }
 
     @Override
     public boolean tryToStop() throws ProCoreException {
+        try {
+            lock.release();
+            raLockFile.close();
+            
+            Files.deleteIfExists(folder.resolve("lock"));
+            
+            isRunning = false;
+            
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        
         return true;
-//        throw new UnsupportedOperationException();
     }
 
     @Override
@@ -118,7 +152,7 @@ public class AcornDatabase implements Database {
 
     @Override
     public boolean isConnected() throws ProCoreException {
-        return true;
+        return isRunning;
     }
 
     @Override