Changed the API for an explicit side-effect free get and explicit mut…

…ation.

enterprise/core-edge/src/main/java/org/neo4j/coreedge/raft/replication/tx/ExpontentialBackoffStrategy.java

@@ -24,24 +24,21 @@
 public class ExpontentialBackoffStrategy implements RetryStrategy
 {
     private long timeout;
-    private long previous;
 
     public ExpontentialBackoffStrategy( long initialTimeout, TimeUnit timeUnit )
     {
         this.timeout = timeUnit.toMillis( initialTimeout );
     }
 
     @Override
-    public long nextTimeout()
+    public long get()
     {
-        previous = timeout;
-        timeout = 2 * timeout;
         return timeout;
     }
 
     @Override
-    public long previousTimeout()
+    public void increaseTimeout()
     {
-        return previous;
+        timeout = 2 * timeout;
     }
 }

enterprise/core-edge/src/main/java/org/neo4j/coreedge/raft/replication/tx/ReplicatedTransactionCommitProcess.java

@@ -104,7 +104,8 @@ public long commit( final TransactionToApply tx,
 
                 try
                 {
-                    Long txId = futureTxId.waitUntilCommitted( retryStrategy.nextTimeout(), TimeUnit.MILLISECONDS );
+                    Long txId = futureTxId.waitUntilCommitted( retryStrategy.get(), TimeUnit.MILLISECONDS );
+                    retryStrategy.increaseTimeout();
                     sessionPool.releaseSession( operationContext );
 
                     return txId;
@@ -118,7 +119,7 @@ public long commit( final TransactionToApply tx,
                 catch ( TimeoutException e )
                 {
                     log.info( "Replication of %s timed out after %d %s; retrying.",
-                            operationContext, retryStrategy.previousTimeout(), TimeUnit.MILLISECONDS );
+                            operationContext, retryStrategy.get(), TimeUnit.MILLISECONDS );
                     txRetryMonitor.retry();
                 }
             }

enterprise/core-edge/src/main/java/org/neo4j/coreedge/raft/replication/tx/RetryStrategy.java

@@ -21,6 +21,6 @@
 
 public interface RetryStrategy
 {
-    long nextTimeout();
-    long previousTimeout();
+    long get();
+    void increaseTimeout();
 }

enterprise/core-edge/src/test/java/org/neo4j/coreedge/raft/replication/tx/ConstantTimeRetryStrategy.java

@@ -23,22 +23,21 @@
 
 public class ConstantTimeRetryStrategy implements RetryStrategy
 {
-    private final long timeout;
+    private long timeout;
 
     public ConstantTimeRetryStrategy( long backoffTime, TimeUnit timeUnit )
     {
         this.timeout = timeUnit.toMillis( backoffTime );
     }
 
     @Override
-    public long nextTimeout()
+    public long get()
     {
         return timeout;
     }
 
     @Override
-    public long previousTimeout()
+    public void increaseTimeout()
     {
-        return timeout;
     }
 }

enterprise/core-edge/src/test/java/org/neo4j/coreedge/raft/replication/tx/ExpontentialBackoffStrategyTest.java

@@ -38,11 +38,11 @@ public void shouldDoubleEachTime() throws Exception
         // when
         for ( int i = 0; i < NUMBER_OF_ACCESSES; i++ )
         {
-            strategy.nextTimeout();
+            strategy.increaseTimeout();
         }
 
         // then
-        assertEquals( 2 << NUMBER_OF_ACCESSES, strategy.nextTimeout() );
+        assertEquals( 2 << NUMBER_OF_ACCESSES - 1, strategy.get() );
     }
 
     @Test
@@ -54,10 +54,10 @@ public void shouldProvidePreviousTimeout() throws Exception
         // when
         for ( int i = 0; i <= NUMBER_OF_ACCESSES; i++ )
         {
-            strategy.nextTimeout();
+            strategy.increaseTimeout();
         }
 
         // then
-        assertEquals( 2 << NUMBER_OF_ACCESSES - 1, strategy.previousTimeout() );
+        assertEquals( 2 << NUMBER_OF_ACCESSES, strategy.get() );
     }
 }