HDDS-312. Add blockIterator to Container. Contributed by Bharat Viswanadham.

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/interfaces/Container.java

@@ -29,6 +29,7 @@ import org.apache.hadoop.ozone.container.common.impl.ContainerData;
 import org.apache.hadoop.ozone.container.common.volume.VolumeSet;
 
 import java.io.File;
+import java.io.IOException;
 import java.util.Map;
 
 
@@ -103,4 +104,11 @@ public interface Container extends RwLock {
    */
   void updateDeleteTransactionId(long deleteTransactionId);
 
+  /**
+   * Returns blockIterator for the container.
+   * @return BlockIterator
+   * @throws IOException
+   */
+  BlockIterator blockIterator() throws IOException;
+
 }

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/KeyValueContainer.java

@@ -346,6 +346,12 @@ public class KeyValueContainer implements Container {
     containerData.updateDeleteTransactionId(deleteTransactionId);
   }
 
+  @Override
+  public KeyValueBlockIterator blockIterator() throws IOException{
+    return new KeyValueBlockIterator(containerData.getContainerID(), new File(
+        containerData.getContainerPath()));
+  }
+
   /**
    * Acquire read lock.
    */
@@ -420,7 +426,7 @@ public class KeyValueContainer implements Container {
   }
 
   /**
-   * Returns container DB file
+   * Returns container DB file.
    * @return
    */
   public File getContainerDBFile() {

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/keyvalue/TestKeyValueContainer.java

@@ -18,22 +18,26 @@
 
 package org.apache.hadoop.ozone.container.keyvalue;
 
+import com.google.common.primitives.Longs;
+import org.apache.hadoop.hdds.client.BlockID;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
 import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos;
 
 
 import org.apache.hadoop.hdds.scm.container.common.helpers
     .StorageContainerException;
+import org.apache.hadoop.ozone.container.common.helpers.ChunkInfo;
+import org.apache.hadoop.ozone.container.common.helpers.KeyData;
 import org.apache.hadoop.ozone.container.common.impl.ContainerDataYaml;
 import org.apache.hadoop.ozone.container.common.volume.HddsVolume;
 import org.apache.hadoop.ozone.container.common.volume
     .RoundRobinVolumeChoosingPolicy;
 import org.apache.hadoop.ozone.container.common.volume.VolumeSet;
 
-import org.apache.hadoop.ozone.container.keyvalue.helpers
-    .KeyValueContainerLocationUtil;
+import org.apache.hadoop.ozone.container.keyvalue.helpers.KeyUtils;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.util.DiskChecker;
+import org.apache.hadoop.utils.MetadataStore;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -46,6 +50,8 @@ import java.io.File;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.List;
+import java.util.LinkedList;
 import java.util.UUID;
 
 import static org.apache.ratis.util.Preconditions.assertTrue;
@@ -92,6 +98,50 @@ public class TestKeyValueContainer {
 
   }
 
+  @Test
+  public void testBlockIterator() throws Exception{
+    keyValueContainerData = new KeyValueContainerData(100L, 1);
+    keyValueContainer = new KeyValueContainer(
+        keyValueContainerData, conf);
+    keyValueContainer.create(volumeSet, volumeChoosingPolicy, scmId);
+    KeyValueBlockIterator blockIterator = keyValueContainer.blockIterator();
+    //As no blocks created, hasNext should return false.
+    assertFalse(blockIterator.hasNext());
+    int blockCount = 10;
+    addBlocks(blockCount);
+    blockIterator = keyValueContainer.blockIterator();
+    assertTrue(blockIterator.hasNext());
+    KeyData keyData;
+    int blockCounter = 0;
+    while(blockIterator.hasNext()) {
+      keyData = blockIterator.nextBlock();
+      assertEquals(blockCounter++, keyData.getBlockID().getLocalID());
+    }
+    assertEquals(blockCount, blockCounter);
+  }
+
+  private void addBlocks(int count) throws Exception {
+    long containerId = keyValueContainerData.getContainerID();
+
+    MetadataStore metadataStore = KeyUtils.getDB(keyValueContainer
+        .getContainerData(), conf);
+    for (int i=0; i < count; i++) {
+      // Creating KeyData
+      BlockID blockID = new BlockID(containerId, i);
+      KeyData keyData = new KeyData(blockID);
+      keyData.addMetadata("VOLUME", "ozone");
+      keyData.addMetadata("OWNER", "hdfs");
+      List<ContainerProtos.ChunkInfo> chunkList = new LinkedList<>();
+      ChunkInfo info = new ChunkInfo(String.format("%d.data.%d", blockID
+          .getLocalID(), 0), 0, 1024);
+      chunkList.add(info.getProtoBufMessage());
+      keyData.setChunks(chunkList);
+      metadataStore.put(Longs.toByteArray(blockID.getLocalID()), keyData
+          .getProtoBufMessage().toByteArray());
+    }
+
+  }
+
   @Test
   public void testCreateContainer() throws Exception {
 
@@ -113,8 +163,8 @@ public class TestKeyValueContainer {
     //Check whether container file and container db file exists or not.
     assertTrue(keyValueContainer.getContainerFile().exists(),
         ".Container File does not exist");
-    assertTrue(keyValueContainer.getContainerDBFile().exists(), "Container DB does " +
-        "not exist");
+    assertTrue(keyValueContainer.getContainerDBFile().exists(), "Container " +
+        "DB does not exist");
   }
 
   @Test