1 files changed, 106 insertions, 0 deletions
diff --git a/plugins/org.eclipse.tm.tcf.dsf/src/org/eclipse/tm/internal/tcf/dsf/services/TCFDataCache.java b/plugins/org.eclipse.tm.tcf.dsf/src/org/eclipse/tm/internal/tcf/dsf/services/TCFDataCache.java
new file mode 100644
index 000000000..e95bb43d4
--- /dev/null
+++ b/plugins/org.eclipse.tm.tcf.dsf/src/org/eclipse/tm/internal/tcf/dsf/services/TCFDataCache.java
@@ -0,0 +1,106 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Wind River Systems, Inc. and others.
+ * All rights reserved. This program and the accompanying materials 
+ * are made available under the terms of the Eclipse Public License v1.0 
+ * which accompanies this distribution, and is available at 
+ * http://www.eclipse.org/legal/epl-v10.html 
+ *  
+ * Contributors:
+ *     Wind River Systems - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.tm.internal.tcf.dsf.services;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import org.eclipse.tm.tcf.protocol.IChannel;
+import org.eclipse.tm.tcf.protocol.IToken;
+import org.eclipse.tm.tcf.protocol.Protocol;
+
+
+public abstract class TCFDataCache<V> {
+
+    protected Throwable error;
+    protected IToken command;
+    protected boolean valid;
+    protected V data;
+    
+    protected final IChannel channel;
+    protected final Collection<IDataRequest> waiting_list = new ArrayList<IDataRequest>();
+    
+    public TCFDataCache(IChannel channel) {
+        assert channel != null;
+        this.channel = channel;
+    }
+    
+    public void cancel() {
+        // Cancel current data retrieval command
+        if (command != null) {
+            command.cancel();
+            command = null;
+        }
+        // Cancel waiting data requests
+        if (!waiting_list.isEmpty()) {
+            IDataRequest[] arr = waiting_list.toArray(new IDataRequest[waiting_list.size()]);
+            waiting_list.clear();
+            for (IDataRequest r : arr) r.cancel();
+        }
+    }
+    
+    public boolean validate() {
+        assert Protocol.isDispatchThread();
+        if (channel.getState() != IChannel.STATE_OPEN) {
+            error = null;
+            command = null;
+            data = null;
+            valid = true;
+            return true;
+        }
+        if (command != null) {
+            return false;
+        }
+        if (!valid && !startDataRetrieval()) return false;
+        assert command == null;
+        if (!waiting_list.isEmpty()) {
+            IDataRequest[] arr = waiting_list.toArray(new IDataRequest[waiting_list.size()]);
+            waiting_list.clear();
+            for (IDataRequest r : arr) r.done();
+        }
+        return true;
+    }
+    
+    public void addWaitingRequest(IDataRequest req) {
+        assert !valid;
+        waiting_list.add(req);
+    }
+    
+    public void reset(V data) {
+        cancel();
+        this.data = data;
+        error = null;
+        valid = true;
+    }
+    
+    public void reset() {
+        cancel();
+        error = null;
+        data = null;
+        valid = false;
+    }
+    
+    public boolean isValid() {
+        return valid;
+    }
+    
+    public Throwable getError() {
+        assert valid;
+        return error;
+    }
+    
+    public V getData() {
+        assert valid;
+        return data;
+    }
+    
+    public abstract boolean startDataRetrieval();
+}