Added @Authoritative annotation.

8 files changed, 111 insertions, 12 deletions

diff --git a/src/main/java/com/amazon/carbonado/Authoritative.java b/src/main/java/com/amazon/carbonado/Authoritative.java
new file mode 100644
index 0000000..70de7c2
--- /dev/null
+++ b/src/main/java/com/amazon/carbonado/Authoritative.java
@@ -0,0 +1,58 @@
+/*

+ * Copyright 2006 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;

+

+import java.lang.annotation.*;

+

+/**

+ * Indicates that all accesses to this {@link Storable} must come from an

+ * authoritative source. When reading or writing the Storable, the {@link

+ * Repository} must guarantee that it is operating on the latest, correct

+ * version of the Storable.

+ *

+ * <p>Repositories that cache potentially stale Storables are required to

+ * ensure the cache is always up-to-date or bypass the cache

+ * altogether. Replicating repositories which may have a propagation delay must

+ * always access the master repository.

+ *

+ * <p>Repositories which provide eventual consistency but don't rely on a

+ * master <i>must</i> throw {@link UnsupportedTypeException}, as there is no

+ * authoritative source.

+ *

+ * <p>Example:<pre>

+ * <b>&#64;Authoritative</b>

+ * &#64;PrimaryKey("sequenceName")

+ * public interface SequenceValue extends Storable&lt;SequenceValue&gt; {

+ *     String getSequenceName();

+ *     void setSequenceName(String name);

+ *

+ *     long getNextValue();

+ *     void setNextValue(long value);

+ *

+ *     ...

+ * }

+ * </pre>

+ *

+ * @author Brian S O'Neill

+ */

+@Documented

+@Retention(RetentionPolicy.RUNTIME)

+@Target(ElementType.TYPE)

+public @interface Authoritative {

+}

diff --git a/src/main/java/com/amazon/carbonado/UnsupportedTypeException.java b/src/main/java/com/amazon/carbonado/UnsupportedTypeException.java
index 46535a4..fcc576c 100644
--- a/src/main/java/com/amazon/carbonado/UnsupportedTypeException.java
+++ b/src/main/java/com/amazon/carbonado/UnsupportedTypeException.java
@@ -19,8 +19,8 @@
 package com.amazon.carbonado;

 

 /**

- * Thrown by a dependent {@link Repository} which cannot support an {@link

- * Independent} {@link Storable}.

+ * Thrown by a {@link Repository} which cannot support a {@link Storable} which

+ * is declared as {@link Independent} or {@link Authoritative}.

  *

  * @author Brian S O'Neill

  */

diff --git a/src/main/java/com/amazon/carbonado/info/StorableInfo.java b/src/main/java/com/amazon/carbonado/info/StorableInfo.java
index 1d6ed3e..796efb4 100644
--- a/src/main/java/com/amazon/carbonado/info/StorableInfo.java
+++ b/src/main/java/com/amazon/carbonado/info/StorableInfo.java
@@ -126,4 +126,9 @@ public interface StorableInfo<S extends Storable> {
      * @see com.amazon.carbonado.Independent

      */

     boolean isIndependent();

+

+    /**

+     * @see com.amazon.carbonado.Authoritative

+     */

+    boolean isAuthoritative();

 }

diff --git a/src/main/java/com/amazon/carbonado/info/StorableIntrospector.java b/src/main/java/com/amazon/carbonado/info/StorableIntrospector.java
index 8da9c3e..29158f1 100644
--- a/src/main/java/com/amazon/carbonado/info/StorableIntrospector.java
+++ b/src/main/java/com/amazon/carbonado/info/StorableIntrospector.java
@@ -48,6 +48,7 @@ import org.cojen.util.WeakIdentityMap;
 

 import com.amazon.carbonado.Alias;

 import com.amazon.carbonado.AlternateKeys;

+import com.amazon.carbonado.Authoritative;

 import com.amazon.carbonado.FetchException;

 import com.amazon.carbonado.Index;

 import com.amazon.carbonado.Indexes;

@@ -220,7 +221,8 @@ public class StorableIntrospector {
 

             info = new Info<S>(type, aliases, indexes, properties,

                                primaryKey, alternateKeys,

-                               type.getAnnotation(Independent.class) != null);

+                               type.getAnnotation(Independent.class) != null,

+                               type.getAnnotation(Authoritative.class) != null);

             cCache.put(type, new SoftReference<StorableInfo<?>>(info));

 

             // Finish resolving join properties, after properties have been

@@ -1121,6 +1123,7 @@ public class StorableIntrospector {
         private final StorableKey<S> mPrimaryKey;

         private final StorableKey<S>[] mAltKeys;

         private final boolean mIndependent;

+        private final boolean mAuthoritative;

 

         private transient String mName;

         private transient Map<String, StorableProperty<S>> mPrimaryKeyProperties;

@@ -1131,7 +1134,8 @@ public class StorableIntrospector {
              Map<String, StorableProperty<S>> properties,

              StorableKey<S> primaryKey,

              StorableKey<S>[] altKeys,

-             boolean independent)

+             boolean independent,

+             boolean authoritative)

         {

             mType = type;

             mAliases = aliases;

@@ -1140,6 +1144,7 @@ public class StorableIntrospector {
             mPrimaryKey = primaryKey;

             mAltKeys = altKeys;

             mIndependent = independent;

+            mAuthoritative = authoritative;

         }

 

         public String getName() {

@@ -1282,6 +1287,10 @@ public class StorableIntrospector {
         public final boolean isIndependent() {

             return mIndependent;

         }

+

+        public final boolean isAuthoritative() {

+            return mAuthoritative;

+        }

     }

 

     private static class SKey<S extends Storable> implements StorableKey<S> {

diff --git a/src/main/java/com/amazon/carbonado/repo/jdbc/JDBCStorableIntrospector.java b/src/main/java/com/amazon/carbonado/repo/jdbc/JDBCStorableIntrospector.java
index a12e0c9..c8ebfa8 100644
--- a/src/main/java/com/amazon/carbonado/repo/jdbc/JDBCStorableIntrospector.java
+++ b/src/main/java/com/amazon/carbonado/repo/jdbc/JDBCStorableIntrospector.java
@@ -1020,6 +1020,10 @@ public class JDBCStorableIntrospector extends StorableIntrospector {
             return mMainInfo.isIndependent();

         }

 

+        public boolean isAuthoritative() {

+            return mMainInfo.isAuthoritative();

+        }

+

         public boolean isSupported() {

             return mTableName != null;

         }

diff --git a/src/main/java/com/amazon/carbonado/repo/replicated/ReplicatedRepository.java b/src/main/java/com/amazon/carbonado/repo/replicated/ReplicatedRepository.java
index ebfd87f..11c11b6 100644
--- a/src/main/java/com/amazon/carbonado/repo/replicated/ReplicatedRepository.java
+++ b/src/main/java/com/amazon/carbonado/repo/replicated/ReplicatedRepository.java
@@ -50,6 +50,7 @@ import com.amazon.carbonado.capability.ShutdownCapability;
 import com.amazon.carbonado.capability.StorableInfoCapability;

 

 import com.amazon.carbonado.info.Direction;

+import com.amazon.carbonado.info.StorableInfo;

 import com.amazon.carbonado.info.StorableIntrospector;

 

 import com.amazon.carbonado.spi.StorageCollection;

@@ -152,13 +153,31 @@ class ReplicatedRepository
             protected <S extends Storable> Storage<S> createStorage(Class<S> type)

                 throws SupportException, RepositoryException

             {

-                Storage<S> replicaStorage = mReplicaRepository.storageFor(type);

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

 

-                try {

-                    return new ReplicatedStorage<S>(ReplicatedRepository.this, replicaStorage);

-                } catch (UnsupportedTypeException e) {

-                    // Okay, no master.

-                    return replicaStorage;

+                if (info.isAuthoritative()) {

+                    // Cannot rely on replica to be up-to-date, so always go to master.

+                    try {

+                        return mMasterRepository.storageFor(type);

+                    } catch (UnsupportedTypeException e) {

+                        if (info.isIndependent()) {

+                            // Okay, no master. A standalone replica is

+                            // considered to be authoritative.

+                            return mReplicaRepository.storageFor(type);

+                        }

+                        throw e;

+                    }

+                } else {

+                    Storage<S> replicaStorage = mReplicaRepository.storageFor(type);

+                    try {

+                        return new ReplicatedStorage<S>(ReplicatedRepository.this, replicaStorage);

+                    } catch (UnsupportedTypeException e) {

+                        if (info.isIndependent()) {

+                            // Okay, no master.

+                            return replicaStorage;

+                        }

+                        throw e;

+                    }

                 }

             }

         };

diff --git a/src/main/java/com/amazon/carbonado/repo/replicated/ReplicatedStorage.java b/src/main/java/com/amazon/carbonado/repo/replicated/ReplicatedStorage.java
index 38c57c4..34b6880 100644
--- a/src/main/java/com/amazon/carbonado/repo/replicated/ReplicatedStorage.java
+++ b/src/main/java/com/amazon/carbonado/repo/replicated/ReplicatedStorage.java
@@ -64,7 +64,7 @@ class ReplicatedStorage<S extends Storable> implements Storage<S> {
         Storage<S> masterStorage =

             creator.get(ReplicatedRepositoryBuilder.DEFAULT_MASTER_TIMEOUT_MILLIS);

         mTrigger = new ReplicationTrigger<S>(aRepository, mReplicaStorage, masterStorage);

-        addTrigger(mTrigger);

+        mReplicaStorage.addTrigger(mTrigger);

     }

 

     /**

@@ -76,7 +76,7 @@ class ReplicatedStorage<S extends Storable> implements Storage<S> {
     {

         mReplicaStorage = replicaStorage;

         mTrigger = new ReplicationTrigger<S>(aRepository, mReplicaStorage, masterStorage);

-        addTrigger(mTrigger);

+        mReplicaStorage.addTrigger(mTrigger);

     }

 

     public Class<S> getStorableType() {

@@ -100,10 +100,12 @@ class ReplicatedStorage<S extends Storable> implements Storage<S> {
     }

 

     public boolean addTrigger(Trigger<? super S> trigger) {

+        // FIXME: Should trigger be added to master?

         return mReplicaStorage.addTrigger(trigger);

     }

 

     public boolean removeTrigger(Trigger<? super S> trigger) {

+        // FIXME: Should trigger be added to master?

         return mReplicaStorage.removeTrigger(trigger);

     }

 

diff --git a/src/main/java/com/amazon/carbonado/spi/StoredSequence.java b/src/main/java/com/amazon/carbonado/spi/StoredSequence.java
index 0a5a19e..97f18ab 100644
--- a/src/main/java/com/amazon/carbonado/spi/StoredSequence.java
+++ b/src/main/java/com/amazon/carbonado/spi/StoredSequence.java
@@ -19,6 +19,7 @@
 package com.amazon.carbonado.spi;

 

 import com.amazon.carbonado.Alias;

+import com.amazon.carbonado.Authoritative;

 import com.amazon.carbonado.Independent;

 import com.amazon.carbonado.PrimaryKey;

 import com.amazon.carbonado.Storable;

@@ -29,6 +30,7 @@ import com.amazon.carbonado.Storable;
  * @author Brian S O'Neill

  */

 @PrimaryKey("name")

+@Authoritative

 @Independent

 @Alias("CARBONADO_SEQUENCE")

 public interface StoredSequence extends Storable<StoredSequence> {