[GitHub] [samza] mynameborat commented on a change in pull request #1413: SAMZA-2578: Excessive trimming during transactional state restore

[GitBox <gi...@apache.org>]

mynameborat commented on a change in pull request #1413:
URL: https://github.com/apache/samza/pull/1413#discussion_r471583711



##########
File path: samza-api/src/main/java/org/apache/samza/system/BoundedSSPIterator.java
##########
@@ -0,0 +1,84 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.samza.system;
+
+import java.util.ArrayDeque;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Queue;
+import java.util.Set;
+import org.apache.samza.SamzaException;
+
+/**
+ * Iterates over messages in the provided changelog {@link SystemStreamPartition} using the provided

Review comment:
       s/changelog/input|topic

##########
File path: samza-api/src/test/java/org/apache/samza/system/TestBoundedSSPIterator.java
##########
@@ -0,0 +1,118 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.samza.system;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import java.util.List;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import org.apache.samza.Partition;
+import org.junit.Assert;
+import org.junit.Test;
+import org.mockito.stubbing.OngoingStubbing;
+
+import static org.mockito.Mockito.*;

Review comment:
       nit: can we change this to non-star imports?

##########
File path: samza-api/src/main/java/org/apache/samza/system/BoundedSSPIterator.java
##########
@@ -0,0 +1,84 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.samza.system;
+
+import java.util.ArrayDeque;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Queue;
+import java.util.Set;
+import org.apache.samza.SamzaException;
+
+/**
+ * Iterates over messages in the provided changelog {@link SystemStreamPartition} using the provided
+ * {@link SystemConsumer} until all messages with offsets up to and including the bound offset have been consumed.
+ */
+public class BoundedSSPIterator {
+
+  protected final SystemAdmin admin;
+
+  private final SystemConsumer systemConsumer;
+  private final String endOffset;
+  private final Set<SystemStreamPartition> fetchSet;
+  private Queue<IncomingMessageEnvelope> peeks;
+
+  public BoundedSSPIterator(SystemConsumer systemConsumer,
+      SystemStreamPartition systemStreamPartition, String endOffset, SystemAdmin admin) {
+    this.systemConsumer = systemConsumer;
+    this.endOffset = endOffset;
+    this.admin = admin;
+    this.fetchSet = new HashSet<>();
+    this.fetchSet.add(systemStreamPartition);

Review comment:
       looks like it only allows feeding one SSP. why do we need a set?

##########
File path: samza-api/src/main/java/org/apache/samza/system/BoundedSSPIterator.java
##########
@@ -0,0 +1,84 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.samza.system;
+
+import java.util.ArrayDeque;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Queue;
+import java.util.Set;
+import org.apache.samza.SamzaException;
+
+/**
+ * Iterates over messages in the provided changelog {@link SystemStreamPartition} using the provided
+ * {@link SystemConsumer} until all messages with offsets up to and including the bound offset have been consumed.
+ */
+public class BoundedSSPIterator {
+
+  protected final SystemAdmin admin;
+
+  private final SystemConsumer systemConsumer;
+  private final String endOffset;
+  private final Set<SystemStreamPartition> fetchSet;
+  private Queue<IncomingMessageEnvelope> peeks;
+
+  public BoundedSSPIterator(SystemConsumer systemConsumer,
+      SystemStreamPartition systemStreamPartition, String endOffset, SystemAdmin admin) {
+    this.systemConsumer = systemConsumer;
+    this.endOffset = endOffset;
+    this.admin = admin;
+    this.fetchSet = new HashSet<>();
+    this.fetchSet.add(systemStreamPartition);
+    this.peeks = new ArrayDeque<>();
+  }
+
+  public boolean hasNext() {
+    refresh();
+
+    return peeks.size() > 0 && (endOffset == null || admin.offsetComparator(peeks.peek().getOffset(), endOffset) <= 0);

Review comment:
       Can we add a pre-check on the `endOffset` as not `null` in the constructor? Or, do you intend have this as a `UnBoundedSSPIterator` in the event no `endOffset`? If latter, please update the java docs to reflect the contract.

##########
File path: samza-api/src/main/java/org/apache/samza/system/BoundedSSPIterator.java
##########
@@ -0,0 +1,84 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.samza.system;
+
+import java.util.ArrayDeque;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Queue;
+import java.util.Set;
+import org.apache.samza.SamzaException;
+
+/**
+ * Iterates over messages in the provided changelog {@link SystemStreamPartition} using the provided
+ * {@link SystemConsumer} until all messages with offsets up to and including the bound offset have been consumed.
+ */
+public class BoundedSSPIterator {
+
+  protected final SystemAdmin admin;
+
+  private final SystemConsumer systemConsumer;
+  private final String endOffset;
+  private final Set<SystemStreamPartition> fetchSet;

Review comment:
       nit: group final fields together.




----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
users@infra.apache.org