Java tutorial
/** * Licensed 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.deephacks.confit.internal.hbase; import com.google.common.collect.ArrayListMultimap; import com.google.common.collect.Multimap; import org.apache.hadoop.hbase.KeyValue; import org.deephacks.confit.model.BeanId; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.HashMap; import java.util.List; import java.util.Map; import static org.deephacks.confit.internal.hbase.HBeanRow.PRED_COLUMN_FAMILY; public class HBeanPredecessors { private final Map<Short, byte[]> predecessors = new HashMap<>(); public HBeanPredecessors() { } public HBeanPredecessors(KeyValue kv) { if (!Arrays.equals(kv.getFamily(), HBeanRow.PRED_COLUMN_FAMILY)) { throw new IllegalArgumentException("KeyValue is not a predecessor column family"); } short sid = Bytes.getShort(kv.getQualifier()); predecessors.put(sid, kv.getValue()); } public List<KeyValue> getKeyValue(byte[] rowkey) { ArrayList<KeyValue> kvs = new ArrayList<>(); for (short sid : predecessors.keySet()) { byte[] sidBytes = Bytes.fromShort(sid); kvs.add(new KeyValue(rowkey, HBeanRow.PRED_COLUMN_FAMILY, sidBytes, predecessors.get(sid))); } return kvs; } public List<BeanId> getBeanId(byte[] rowkey, UniqueIds uids) { List<KeyValue> kvs = getKeyValue(rowkey); List<BeanId> result = new ArrayList<>(); for (int i = 0; i < kvs.size(); i++) { byte[] sid = kvs.get(i).getQualifier(); byte[][] ids = getIds(kvs.get(i)); for (byte[] id : ids) { byte[] key = new byte[6]; System.arraycopy(sid, 0, key, 0, 2); System.arraycopy(id, 0, key, 2, 4); result.add(HBeanRow.getBeanId(key, uids)); } } return result; } public static Multimap<byte[], byte[]> getPredecessors(Multimap<String, String> predecessors, final UniqueIds uids) { final Multimap<byte[], byte[]> bytes = ArrayListMultimap.create(); for (String schemaName : predecessors.keySet()) { final byte[] sid = uids.getUsid().getId(schemaName); Collection<String> ids = predecessors.get(schemaName); bytes.put(sid, HBeanReferences.getIids(new ArrayList<String>(ids), uids)); } return bytes; } /** * If this key value is of predecessor familiy type. */ public static boolean isPredecessor(KeyValue kv) { if (Bytes.equals(kv.getFamily(), PRED_COLUMN_FAMILY)) { return true; } return false; } public void addRow(HBeanRow row) { addId(row.getSid(), row.getUid()); } public void addKeyValue(KeyValue kv) { byte[][] ids = getIds(kv); for (byte[] id : ids) { addId(kv.getQualifier(), id); } } public void addId(byte[] sid, byte[] id) { validateInput(sid, id); short shortId = Bytes.getShort(sid); byte[] ids = predecessors.get(shortId); if (ids == null) { ids = new byte[0]; } ids = BytesUtils.add(ids, Bytes.getInt(id)); predecessors.put(shortId, ids); } public void removeKeyValue(KeyValue kv) { byte[][] ids = getIds(kv); for (byte[] id : ids) { removeId(kv.getQualifier(), id); } } public void removeRow(HBeanRow row) { removeId(row.getSid(), row.getUid()); } private byte[][] getIds(KeyValue kv) { byte[] bytes = kv.getValue(); int num = bytes.length / 4; byte[][] ids = new byte[num][]; for (int i = 0; i < num; i++) { int idx = i * 4; ids[i] = new byte[] { bytes[idx + 0], bytes[idx + 1], bytes[idx + 2], bytes[idx + 3] }; } return ids; } public void removeId(byte[] sid, byte[] id) { validateInput(sid, id); short shortId = Bytes.getShort(sid); byte[] ids = predecessors.get(shortId); ids = BytesUtils.remove(ids, Bytes.getInt(id)); predecessors.put(shortId, ids); } private void validateInput(byte[] sid, byte[] id) { if (sid.length != 2) { throw new IllegalArgumentException("sid must be 2 bytes."); } if (id.length != 4) { throw new IllegalArgumentException("Ids must be 4 bytes."); } } }