Allow equivalent layout generation to be defined.

2 files changed, 135 insertions, 28 deletions

diff --git a/src/main/java/com/amazon/carbonado/layout/Layout.java b/src/main/java/com/amazon/carbonado/layout/Layout.java
index df20f3f..ef7f74c 100644
--- a/src/main/java/com/amazon/carbonado/layout/Layout.java
+++ b/src/main/java/com/amazon/carbonado/layout/Layout.java
@@ -43,8 +43,10 @@ import com.amazon.carbonado.PersistException;
 import com.amazon.carbonado.Query;

 import com.amazon.carbonado.RepositoryException;

 import com.amazon.carbonado.Storable;

+import com.amazon.carbonado.Storage;

 import com.amazon.carbonado.SupportException;

 import com.amazon.carbonado.UniqueConstraintException;

+import com.amazon.carbonado.cursor.FilteredCursor;

 import com.amazon.carbonado.info.StorableInfo;

 import com.amazon.carbonado.info.StorableProperty;

 import com.amazon.carbonado.synthetic.SyntheticKey;

@@ -313,49 +315,92 @@ public class Layout {
      * @throws FetchNoneException if generation not found

      */

     public Layout getGeneration(int generation) throws FetchNoneException, FetchException {

+        StoredLayout layout;

+        try {

+            layout = getStoredLayoutByGeneration(generation);

+        } catch (FetchNoneException e) {

+            try {

+                Storage<StoredLayoutEquivalence> equivStorage =

+                    mLayoutFactory.mRepository.storageFor(StoredLayoutEquivalence.class);

+                StoredLayoutEquivalence equiv = equivStorage.prepare();

+                equiv.setStorableTypeName(getStorableTypeName());

+                equiv.setGeneration(generation);

+                if (equiv.tryLoad()) {

+                    layout = getStoredLayoutByGeneration(equiv.getMatchedGeneration());

+                } else {

+                    throw e;

+                }

+            } catch (RepositoryException e2) {

+                if (e2 != e) {

+                    LogFactory.getLog(Layout.class).error("Unable to determine equivalance: ", e2);

+                }

+                throw e;

+            }

+        }

+

+        return new Layout(mLayoutFactory, layout);

+    }

+

+    private StoredLayout getStoredLayoutByGeneration(int generation)

+        throws FetchNoneException, FetchException

+    {

         final String filter = "storableTypeName = ? & generation = ?";

 

-        StoredLayout storedLayout;

+        final FetchNoneException ex;

         try {

-            storedLayout = mLayoutFactory.mLayoutStorage

+            return mLayoutFactory.mLayoutStorage

                 .query(filter)

                 .with(getStorableTypeName()).with(generation)

                 .loadOne();

         } catch (FetchNoneException e) {

-            // Try to resync with a master.

-            ResyncCapability cap =

-                mLayoutFactory.mRepository.getCapability(ResyncCapability.class);

+            ex = e;

+        }

 

-            if (cap == null) {

-                throw e;

-            }

+        // Index might be inconsistent.

+        Cursor<StoredLayout> c = 

+            FilteredCursor.applyFilter(mLayoutFactory.mLayoutStorage.query().fetch(),

+                                       StoredLayout.class, filter,

+                                       getStorableTypeName(), generation);

 

-            try {

-                cap.resync(mLayoutFactory.mLayoutStorage.getStorableType(), 1.0,

-                           filter, getStorableTypeName(), generation);

-            } catch (RepositoryException e2) {

-                // Uh oh, double trouble. Log this one and throw original exception.

-                LogFactory.getLog(Layout.class).error("Unable to resync layout", e2);

-                throw e;

+        try {

+            if (c.hasNext()) {

+                return c.next();

             }

+        } finally {

+            c.close();

+        }

 

-            storedLayout = mLayoutFactory.mLayoutStorage

-                .query(filter)

-                .with(getStorableTypeName()).with(generation)

-                .loadOne();

+        // Try to resync with a master.

+        ResyncCapability cap =

+            mLayoutFactory.mRepository.getCapability(ResyncCapability.class);

+

+        if (cap == null) {

+            throw ex;

+        }

 

+        try {

+            cap.resync(mLayoutFactory.mLayoutStorage.getStorableType(), 1.0,

+                       filter, getStorableTypeName(), generation);

+        } catch (RepositoryException e) {

+            LogFactory.getLog(Layout.class).info("Unable to resync layout: ", e);

+            throw ex;

+        }

+

+        StoredLayout storedLayout = mLayoutFactory.mLayoutStorage

+            .query(filter)

+            .with(getStorableTypeName()).with(generation)

+            .loadOne();

+

+        try {

             // Make sure all the properties are re-sync'd too.

-            try {

-                cap.resync(mLayoutFactory.mPropertyStorage.getStorableType(), 1.0,

-                           "layoutID = ?", storedLayout.getLayoutID());

-            } catch (RepositoryException e2) {

-                // Uh oh, double trouble. Log this one and throw original exception.

-                LogFactory.getLog(Layout.class).error("Unable to resync layout", e2);

-                throw e;

-            }

+            cap.resync(mLayoutFactory.mPropertyStorage.getStorableType(), 1.0,

+                       "layoutID = ?", storedLayout.getLayoutID());

+        } catch (RepositoryException e) {

+            LogFactory.getLog(Layout.class).error("Unable to resync layout properties", e);

+            throw ex;

         }

 

-        return new Layout(mLayoutFactory, storedLayout);

+        return storedLayout;

     }

 

     /**

diff --git a/src/main/java/com/amazon/carbonado/layout/StoredLayoutEquivalence.java b/src/main/java/com/amazon/carbonado/layout/StoredLayoutEquivalence.java
new file mode 100644
index 0000000..9a86761
--- /dev/null
+++ b/src/main/java/com/amazon/carbonado/layout/StoredLayoutEquivalence.java
@@ -0,0 +1,62 @@
+/*

+ * Copyright 2012 Amazon Technologies, Inc. or its affiliates.

+ * Amazon, Amazon.com and Carbonado are trademarks or registered trademarks

+ * of Amazon Technologies, Inc. or its affiliates.  All rights reserved.

+ *

+ * Licensed under the Apache License, Version 2.0 (the "License");

+ * you may not use this file except in compliance with the License.

+ * You may obtain a copy of the License at

+ *

+ *     http://www.apache.org/licenses/LICENSE-2.0

+ *

+ * Unless required by applicable law or agreed to in writing, software

+ * distributed under the License is distributed on an "AS IS" BASIS,

+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

+ * See the License for the specific language governing permissions and

+ * limitations under the License.

+ */

+

+package com.amazon.carbonado.layout;

+

+import com.amazon.carbonado.Alias;

+import com.amazon.carbonado.Independent;

+import com.amazon.carbonado.Nullable;

+import com.amazon.carbonado.PrimaryKey;

+import com.amazon.carbonado.Storable;

+import com.amazon.carbonado.Version;

+

+/**

+ * Maps layout generations which are equivalent.

+ *

+ * @author Brian S O'Neill

+ */

+@PrimaryKey({"storableTypeName", "generation"})

+@Independent

+@Alias("CARBONADO_LAYOUT_EQUIV")

+public interface StoredLayoutEquivalence extends Storable<StoredLayoutEquivalence>, Unevolvable {

+    /**

+     * Storable type name is a fully qualified Java class name.

+     */

+    String getStorableTypeName();

+    void setStorableTypeName(String typeName);

+

+    /**

+     * Generation of storable, where 0 represents the first generation.

+     */

+    int getGeneration();

+    void setGeneration(int generation);

+

+    /**

+     * Generation of matched layout.

+     */

+    int getMatchedGeneration();

+    void setMatchedGeneration(int generation);

+

+    @Version

+    int getVersionNumber();

+    void setVersionNumber(int version);

+

+    @Nullable

+    byte[] getExtraData();

+    void setExtraData(byte[] data);

+}