[HUDI-1191] Add incremental meta client API to query partitions modified in a time window

hudi-common/src/main/java/org/apache/hudi/common/table/timeline/TimelineUtils.java

@@ -0,0 +1,101 @@
+/*
+ * 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.hudi.common.table.timeline;
+
+import org.apache.hudi.avro.model.HoodieCleanMetadata;
+import org.apache.hudi.avro.model.HoodieRestoreMetadata;
+import org.apache.hudi.common.model.HoodieCommitMetadata;
+import org.apache.hudi.exception.HoodieIOException;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * TimelineUtils provides a common way to query incremental meta-data changes for a hoodie table.
+ *
+ * This is useful in multiple places including:
+ * 1) HiveSync - this can be used to query partitions that changed since previous sync.
+ * 2) Incremental reads - InputFormats can use this API to query
+ */
+public class TimelineUtils {
+
+  /**
+   * Returns partitions that have new data strictly after commitTime.
+   * Does not include internal operations such as clean in the timeline.
+   */
+  public static List<String> getPartitionsWritten(HoodieTimeline timeline) {
+    HoodieTimeline timelineToSync = timeline.getCommitsAndCompactionTimeline();
+    return getAffectedPartitions(timelineToSync);
+  }
+
+  /**
+   * Returns partitions that have been modified including internal operations such as clean in the passed timeline.
+   */
+  public static List<String> getAffectedPartitions(HoodieTimeline timeline) {
+    return timeline.filterCompletedInstants().getInstants().flatMap(s -> {
+      switch (s.getAction()) {
+        case HoodieTimeline.COMMIT_ACTION:
+        case HoodieTimeline.DELTA_COMMIT_ACTION:
+          try {
+            HoodieCommitMetadata commitMetadata = HoodieCommitMetadata.fromBytes(timeline.getInstantDetails(s).get(), HoodieCommitMetadata.class);
+            return commitMetadata.getPartitionToWriteStats().keySet().stream();
+          } catch (IOException e) {
+            throw new HoodieIOException("Failed to get partitions written at " + s, e);
+          }
+        case HoodieTimeline.CLEAN_ACTION:
+          try {
+            HoodieCleanMetadata cleanMetadata = TimelineMetadataUtils.deserializeHoodieCleanMetadata(timeline.getInstantDetails(s).get());
+            return cleanMetadata.getPartitionMetadata().keySet().stream();
+          } catch (IOException e) {
+            throw new HoodieIOException("Failed to get partitions cleaned at " + s, e);
+          }
+        case HoodieTimeline.ROLLBACK_ACTION:
+          try {
+            return TimelineMetadataUtils.deserializeHoodieRollbackMetadata(timeline.getInstantDetails(s).get()).getPartitionMetadata().keySet().stream();
+          } catch (IOException e) {
+            throw new HoodieIOException("Failed to get partitions rolledback at " + s, e);
+          }
+        case HoodieTimeline.RESTORE_ACTION:
+          try {
+            HoodieRestoreMetadata restoreMetadata = TimelineMetadataUtils.deserializeAvroMetadata(timeline.getInstantDetails(s).get(), HoodieRestoreMetadata.class);
+            return restoreMetadata.getHoodieRestoreMetadata().values().stream()
+                .flatMap(Collection::stream)
+                .flatMap(rollbackMetadata -> rollbackMetadata.getPartitionMetadata().keySet().stream());
+          } catch (IOException e) {
+            throw new HoodieIOException("Failed to get partitions restored at " + s, e);
+          }
+        case HoodieTimeline.SAVEPOINT_ACTION:
+          try {
+            return TimelineMetadataUtils.deserializeHoodieSavepointMetadata(timeline.getInstantDetails(s).get()).getPartitionMetadata().keySet().stream();
+          } catch (IOException e) {
+            throw new HoodieIOException("Failed to get partitions savepoint at " + s, e);
+          }
+        case HoodieTimeline.COMPACTION_ACTION:
+          // compaction is not a completed instant.  So no need to consider this action.
+          return Stream.empty();
+        default:
+          throw new HoodieIOException("unknown action in timeline " + s.getAction());
+      }
+
+    }).distinct().filter(s -> !s.isEmpty()).collect(Collectors.toList());
+  }
+}