HDDS-271. Create a block iterator to iterate blocks in a container. Contributed by Bharat Viswanadham.

hadoop-hdds/common/src/main/java/org/apache/hadoop/utils/MetaStoreIterator.java

@@ -24,7 +24,7 @@ import java.util.Iterator;
  * Iterator for MetaDataStore DB.
  * @param <T>
  */
-interface MetaStoreIterator<T> extends Iterator<T> {
+public interface MetaStoreIterator<T> extends Iterator<T> {
 
   /**
    * seek to first entry.

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

@@ -0,0 +1,57 @@
+/**
+ * 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.hadoop.ozone.container.common.interfaces;
+
+
+import java.io.IOException;
+import java.util.NoSuchElementException;
+
+/**
+ * Block Iterator for container. Each container type need to implement this
+ * interface.
+ * @param <T>
+ */
+public interface BlockIterator<T> {
+
+  /**
+   * This checks if iterator has next element. If it has returns true,
+   * otherwise false.
+   * @return boolean
+   */
+  boolean hasNext() throws IOException;
+
+  /**
+   * Seek to first entry.
+   */
+  void seekToFirst();
+
+  /**
+   * Seek to last entry.
+   */
+  void seekToLast();
+
+  /**
+   * Get next block in the container.
+   * @return next block or null if there are no blocks
+   * @throws IOException
+   */
+  T nextBlock() throws IOException, NoSuchElementException;
+
+
+}

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

@@ -0,0 +1,148 @@
+/*
+ * 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.hadoop.ozone.container.keyvalue;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.hdds.conf.OzoneConfiguration;
+import org.apache.hadoop.ozone.OzoneConsts;
+import org.apache.hadoop.ozone.container.common.helpers.ContainerUtils;
+import org.apache.hadoop.ozone.container.common.helpers.KeyData;
+import org.apache.hadoop.ozone.container.common.impl.ContainerData;
+import org.apache.hadoop.ozone.container.common.impl.ContainerDataYaml;
+import org.apache.hadoop.ozone.container.common.interfaces.BlockIterator;
+import org.apache.hadoop.ozone.container.keyvalue.helpers.KeyUtils;
+import org.apache.hadoop.ozone.container.keyvalue.helpers.KeyValueContainerLocationUtil;
+import org.apache.hadoop.utils.MetaStoreIterator;
+import org.apache.hadoop.utils.MetadataKeyFilters;
+import org.apache.hadoop.utils.MetadataKeyFilters.KeyPrefixFilter;
+import org.apache.hadoop.utils.MetadataStore;
+import org.apache.hadoop.utils.MetadataStore.KeyValue;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.NoSuchElementException;
+
+
+/**
+ * Block Iterator for KeyValue Container. This block iterator returns blocks
+ * which match with the {@link MetadataKeyFilters.KeyPrefixFilter}. If no
+ * filter is specified, then default filter used is
+ * {@link MetadataKeyFilters#getNormalKeyFilter()}
+ */
+@InterfaceAudience.Public
+public class KeyValueBlockIterator implements BlockIterator<KeyData> {
+
+  private static final Logger LOG = LoggerFactory.getLogger(
+      KeyValueBlockIterator.class);
+
+  private MetaStoreIterator<KeyValue> blockIterator;
+  private static KeyPrefixFilter defaultBlockFilter = MetadataKeyFilters
+      .getNormalKeyFilter();
+  private KeyPrefixFilter blockFilter;
+  private KeyData nextBlock;
+  private long containerId;
+
+  /**
+   * KeyValueBlockIterator to iterate blocks in a container.
+   * @param id - container id
+   * @param path -  container base path
+   * @throws IOException
+   */
+
+  public KeyValueBlockIterator(long id, File path)
+      throws IOException {
+    this(id, path, defaultBlockFilter);
+  }
+
+  /**
+   * KeyValueBlockIterator to iterate blocks in a container.
+   * @param id - container id
+   * @param path - container base path
+   * @param filter - Block filter, filter to be applied for blocks
+   * @throws IOException
+   */
+  public KeyValueBlockIterator(long id, File path, KeyPrefixFilter filter)
+      throws IOException {
+    containerId = id;
+    File metdataPath = new File(path, OzoneConsts.METADATA);
+    File containerFile = ContainerUtils.getContainerFile(metdataPath
+        .getParentFile());
+    ContainerData containerData = ContainerDataYaml.readContainerFile(
+        containerFile);
+    KeyValueContainerData keyValueContainerData = (KeyValueContainerData)
+        containerData;
+    keyValueContainerData.setDbFile(KeyValueContainerLocationUtil
+        .getContainerDBFile(metdataPath, containerId));
+    MetadataStore metadataStore = KeyUtils.getDB(keyValueContainerData, new
+        OzoneConfiguration());
+    blockIterator = metadataStore.iterator();
+    blockFilter = filter;
+  }
+
+  /**
+   * This method returns blocks matching with the filter.
+   * @return next block or null if no more blocks
+   * @throws IOException
+   */
+  @Override
+  public KeyData nextBlock() throws IOException, NoSuchElementException {
+    if (nextBlock != null) {
+      KeyData currentBlock = nextBlock;
+      nextBlock = null;
+      return currentBlock;
+    }
+    if(hasNext()) {
+      return nextBlock();
+    }
+    throw new NoSuchElementException("Block Iterator reached end for " +
+        "ContainerID " + containerId);
+  }
+
+  @Override
+  public boolean hasNext() throws IOException {
+    if (nextBlock != null) {
+      return true;
+    }
+    if (blockIterator.hasNext()) {
+      KeyValue block = blockIterator.next();
+      if (blockFilter.filterKey(null, block.getKey(), null)) {
+        nextBlock = KeyUtils.getKeyData(block.getValue());
+        LOG.trace("Block matching with filter found: blockID is : {} for " +
+            "containerID {}", nextBlock.getLocalID(), containerId);
+        return true;
+      }
+      hasNext();
+    }
+    return false;
+  }
+
+  @Override
+  public void seekToFirst() {
+    nextBlock = null;
+    blockIterator.seekToFirst();
+  }
+
+  @Override
+  public void seekToLast() {
+    nextBlock = null;
+    blockIterator.seekToLast();
+  }
+}

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

@@ -0,0 +1,275 @@
+/**
+ * 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.hadoop.ozone.container.keyvalue;
+
+import com.google.common.primitives.Longs;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileUtil;
+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.hdfs.DFSUtil;
+import org.apache.hadoop.ozone.OzoneConsts;
+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.volume.RoundRobinVolumeChoosingPolicy;
+import org.apache.hadoop.ozone.container.common.volume.VolumeSet;
+import org.apache.hadoop.ozone.container.keyvalue.helpers.KeyUtils;
+import org.apache.hadoop.test.GenericTestUtils;
+import org.apache.hadoop.utils.MetadataKeyFilters;
+import org.apache.hadoop.utils.MetadataStore;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.io.File;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.UUID;
+
+import static org.apache.hadoop.hdds.scm.ScmConfigKeys.HDDS_DATANODE_DIR_KEY;
+import static org.apache.hadoop.ozone.OzoneConfigKeys.OZONE_METADATA_STORE_IMPL;
+import static org.apache.hadoop.ozone.OzoneConfigKeys
+    .OZONE_METADATA_STORE_IMPL_LEVELDB;
+import static org.apache.hadoop.ozone.OzoneConfigKeys
+    .OZONE_METADATA_STORE_IMPL_ROCKSDB;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * This class is used to test KeyValue container block iterator.
+ */
+@RunWith(Parameterized.class)
+public class TestKeyValueBlockIterator {
+
+  private KeyValueContainer container;
+  private KeyValueContainerData containerData;
+  private VolumeSet volumeSet;
+  private Configuration conf;
+  private File testRoot;
+
+  private final String storeImpl;
+
+  public TestKeyValueBlockIterator(String metadataImpl) {
+    this.storeImpl = metadataImpl;
+  }
+
+  @Parameterized.Parameters
+  public static Collection<Object[]> data() {
+    return Arrays.asList(new Object[][] {
+        {OZONE_METADATA_STORE_IMPL_LEVELDB},
+        {OZONE_METADATA_STORE_IMPL_ROCKSDB}});
+  }
+
+  @Before
+  public void setUp() throws Exception {
+    testRoot = GenericTestUtils.getRandomizedTestDir();
+    conf = new OzoneConfiguration();
+    conf.set(HDDS_DATANODE_DIR_KEY, testRoot.getAbsolutePath());
+    conf.set(OZONE_METADATA_STORE_IMPL, storeImpl);
+    volumeSet = new VolumeSet(UUID.randomUUID().toString(), conf);
+  }
+
+
+  @After
+  public void tearDown() {
+    volumeSet.shutdown();
+    FileUtil.fullyDelete(testRoot);
+  }
+
+  @Test
+  public void testKeyValueBlockIteratorWithMixedBlocks() throws Exception {
+
+    long containerID = 100L;
+    int deletedBlocks = 5;
+    int normalBlocks = 5;
+    createContainerWithBlocks(containerID, normalBlocks, deletedBlocks);
+    String containerPath = new File(containerData.getMetadataPath())
+        .getParent();
+    KeyValueBlockIterator keyValueBlockIterator = new KeyValueBlockIterator(
+        containerID, new File(containerPath));
+
+    int counter = 0;
+    while(keyValueBlockIterator.hasNext()) {
+      KeyData keyData = keyValueBlockIterator.nextBlock();
+      assertEquals(keyData.getLocalID(), counter++);
+    }
+
+    assertFalse(keyValueBlockIterator.hasNext());
+
+    keyValueBlockIterator.seekToFirst();
+    counter = 0;
+    while(keyValueBlockIterator.hasNext()) {
+      KeyData keyData = keyValueBlockIterator.nextBlock();
+      assertEquals(keyData.getLocalID(), counter++);
+    }
+    assertFalse(keyValueBlockIterator.hasNext());
+
+    try {
+      keyValueBlockIterator.nextBlock();
+    } catch (NoSuchElementException ex) {
+      GenericTestUtils.assertExceptionContains("Block Iterator reached end " +
+          "for ContainerID " + containerID, ex);
+    }
+  }
+
+  @Test
+  public void testKeyValueBlockIteratorWithNextBlock() throws Exception {
+    long containerID = 101L;
+    createContainerWithBlocks(containerID, 2, 0);
+    String containerPath = new File(containerData.getMetadataPath())
+        .getParent();
+    KeyValueBlockIterator keyValueBlockIterator = new KeyValueBlockIterator(
+        containerID, new File(containerPath));
+    long blockID = 0L;
+    assertEquals(blockID++, keyValueBlockIterator.nextBlock().getLocalID());
+    assertEquals(blockID, keyValueBlockIterator.nextBlock().getLocalID());
+
+    try {
+      keyValueBlockIterator.nextBlock();
+    } catch (NoSuchElementException ex) {
+      GenericTestUtils.assertExceptionContains("Block Iterator reached end " +
+          "for ContainerID " + containerID, ex);
+    }
+  }
+
+  @Test
+  public void testKeyValueBlockIteratorWithHasNext() throws Exception {
+    long containerID = 102L;
+    createContainerWithBlocks(containerID, 2, 0);
+    String containerPath = new File(containerData.getMetadataPath())
+        .getParent();
+    KeyValueBlockIterator keyValueBlockIterator = new KeyValueBlockIterator(
+        containerID, new File(containerPath));
+    long blockID = 0L;
+
+    // Even calling multiple times hasNext() should not move entry forward.
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertEquals(blockID++, keyValueBlockIterator.nextBlock().getLocalID());
+
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertEquals(blockID, keyValueBlockIterator.nextBlock().getLocalID());
+
+    keyValueBlockIterator.seekToLast();
+    assertTrue(keyValueBlockIterator.hasNext());
+    assertEquals(blockID, keyValueBlockIterator.nextBlock().getLocalID());
+
+    keyValueBlockIterator.seekToFirst();
+    blockID = 0L;
+    assertEquals(blockID++, keyValueBlockIterator.nextBlock().getLocalID());
+    assertEquals(blockID, keyValueBlockIterator.nextBlock().getLocalID());
+
+    try {
+      keyValueBlockIterator.nextBlock();
+    } catch (NoSuchElementException ex) {
+      GenericTestUtils.assertExceptionContains("Block Iterator reached end " +
+          "for ContainerID " + containerID, ex);
+    }
+
+
+  }
+
+  @Test
+  public void testKeyValueBlockIteratorWithFilter() throws Exception {
+    long containerId = 103L;
+    int deletedBlocks = 5;
+    int normalBlocks = 5;
+    createContainerWithBlocks(containerId, normalBlocks, deletedBlocks);
+    String containerPath = new File(containerData.getMetadataPath())
+        .getParent();
+    KeyValueBlockIterator keyValueBlockIterator = new KeyValueBlockIterator(
+        containerId, new File(containerPath), MetadataKeyFilters
+        .getDeletingKeyFilter());
+
+    int counter = 5;
+    while(keyValueBlockIterator.hasNext()) {
+      KeyData keyData = keyValueBlockIterator.nextBlock();
+      assertEquals(keyData.getLocalID(), counter++);
+    }
+  }
+
+  @Test
+  public void testKeyValueBlockIteratorWithOnlyDeletedBlocks() throws
+      Exception {
+    long containerId = 104L;
+    createContainerWithBlocks(containerId, 0, 5);
+    String containerPath = new File(containerData.getMetadataPath())
+        .getParent();
+    KeyValueBlockIterator keyValueBlockIterator = new KeyValueBlockIterator(
+        containerId, new File(containerPath));
+    //As all blocks are deleted blocks, blocks does not match with normal key
+    // filter.
+    assertFalse(keyValueBlockIterator.hasNext());
+  }
+
+  /**
+   * Creates a container with specified number of normal blocks and deleted
+   * blocks. First it will insert normal blocks, and then it will insert
+   * deleted blocks.
+   * @param containerId
+   * @param normalBlocks
+   * @param deletedBlocks
+   * @throws Exception
+   */
+  private void createContainerWithBlocks(long containerId, int
+      normalBlocks, int deletedBlocks) throws
+      Exception {
+    containerData = new KeyValueContainerData(containerId, 1);
+    container = new KeyValueContainer(containerData, conf);
+    container.create(volumeSet, new RoundRobinVolumeChoosingPolicy(), UUID
+        .randomUUID().toString());
+    MetadataStore metadataStore = KeyUtils.getDB(containerData, conf);
+
+    List<ContainerProtos.ChunkInfo> chunkList = new LinkedList<>();
+    ChunkInfo info = new ChunkInfo("chunkfile", 0, 1024);
+    chunkList.add(info.getProtoBufMessage());
+
+    for (int i=0; i<normalBlocks; i++) {
+      BlockID blockID = new BlockID(containerId, i);
+      KeyData keyData = new KeyData(blockID);
+      keyData.setChunks(chunkList);
+      metadataStore.put(Longs.toByteArray(blockID.getLocalID()), keyData
+          .getProtoBufMessage().toByteArray());
+    }
+
+    for (int i=normalBlocks; i<deletedBlocks; i++) {
+      BlockID blockID = new BlockID(containerId, i);
+      KeyData keyData = new KeyData(blockID);
+      keyData.setChunks(chunkList);
+      metadataStore.put(DFSUtil.string2Bytes(OzoneConsts
+          .DELETING_KEY_PREFIX + blockID.getLocalID()), keyData
+          .getProtoBufMessage().toByteArray());
+    }
+  }
+
+}