Request and persist layout metadata in separate thread.

1 files changed, 59 insertions, 4 deletions

diff --git a/src/main/java/com/amazon/carbonado/layout/LayoutFactory.java b/src/main/java/com/amazon/carbonado/layout/LayoutFactory.java
index 836ee54..4457ee0 100644
--- a/src/main/java/com/amazon/carbonado/layout/LayoutFactory.java
+++ b/src/main/java/com/amazon/carbonado/layout/LayoutFactory.java
@@ -32,6 +32,7 @@ import java.util.Map;
 import com.amazon.carbonado.Cursor;

 import com.amazon.carbonado.FetchDeadlockException;

 import com.amazon.carbonado.FetchException;

+import com.amazon.carbonado.FetchInterruptedException;

 import com.amazon.carbonado.FetchNoneException;

 import com.amazon.carbonado.FetchTimeoutException;

 import com.amazon.carbonado.IsolationLevel;

@@ -113,8 +114,8 @@ public class LayoutFactory implements LayoutCapability {
      * @throws PersistException if type represents a new generation, but

      * persisting this information failed

      */

-    public Layout layoutFor(boolean readOnly,

-                            Class<? extends Storable> type, LayoutOptions options)

+    public Layout layoutFor(final boolean readOnly,

+                            final Class<? extends Storable> type, final LayoutOptions options)

         throws FetchException, PersistException

     {

         if (options != null) {

@@ -131,8 +132,62 @@ public class LayoutFactory implements LayoutCapability {
             }

         }

 

-        StorableInfo<?> info = StorableIntrospector.examine(type);

+        final StorableInfo<?> info = StorableIntrospector.examine(type);

 

+        // Launch layout request in a new separate thread to ensure that

+        // transaction is top-level.

+

+        class LayoutRequest extends Thread {

+            private boolean done;

+            private Layout layout;

+            private FetchException fetchEx;

+            private PersistException persistEx;

+

+            public synchronized void run() {

+                try {

+                    try {

+                        layout = layoutFor(readOnly, info, options);

+                    } catch (FetchException e) {

+                        fetchEx = e;

+                    } catch (PersistException e) {

+                        persistEx = e;

+                    }

+                } finally {

+                    done = true;

+                    notifyAll();

+                }

+            }

+

+            synchronized Layout getLayout()

+                throws FetchException, PersistException, InterruptedException

+            {

+                while (!done) {

+                    wait();

+                }

+                if (fetchEx != null) {

+                    throw fetchEx;

+                }

+                if (persistEx != null) {

+                    throw persistEx;

+                }

+                return layout;

+            }

+        }

+

+        LayoutRequest request = new LayoutRequest();

+        request.setDaemon(true);

+        request.start();

+

+        try {

+            return request.getLayout();

+        } catch (InterruptedException e) {

+            throw new FetchInterruptedException();

+        }

+    }

+

+    private Layout layoutFor(boolean readOnly, StorableInfo<?> info, LayoutOptions options)

+        throws FetchException, PersistException

+    {

         Layout layout;

         ResyncCapability resyncCap = null;

 

@@ -192,7 +247,7 @@ public class LayoutFactory implements LayoutCapability {
                             // extremely rare, unless there is a bug somewhere.

                             throw new FetchException

                                 ("Unable to generate unique layout identifier for " +

-                                 type.getName());

+                                 info.getName());

                         }

                     }