| // Copyright 2010 Google Inc. |
| // |
| // 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 com.google.gwtorm.nosql.heap; |
| |
| import com.google.gwtorm.nosql.generic.GenericSchema; |
| import com.google.gwtorm.nosql.generic.Row; |
| import com.google.gwtorm.server.AtomicUpdate; |
| import com.google.gwtorm.server.ListResultSet; |
| import com.google.gwtorm.server.OrmException; |
| import com.google.gwtorm.server.ResultSet; |
| import com.google.gwtorm.server.Schema; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Map.Entry; |
| import java.util.Set; |
| |
| /** Base implementation for {@link Schema} in a {@link TreeMapDatabase}. */ |
| public abstract class TreeMapSchema extends GenericSchema { |
| private final TreeMapDatabase<?, ?, ?> db; |
| |
| protected TreeMapSchema(final TreeMapDatabase<?, ?, ?> d) { |
| super(d); |
| db = d; |
| } |
| |
| @Override |
| public void flush() { |
| // We don't buffer writes. |
| } |
| |
| @Override |
| public void close() { |
| // Nothing to do. |
| } |
| |
| @Override |
| public ResultSet<Row> scan(byte[] fromKey, byte[] toKey, int limit, boolean order) { |
| db.lock.lock(); |
| try { |
| final List<Row> res = new ArrayList<>(); |
| for (Map.Entry<byte[], byte[]> ent : entries(fromKey, toKey)) { |
| res.add(new Row(ent.getKey(), ent.getValue())); |
| |
| if (limit > 0 && res.size() == limit) { |
| break; |
| } |
| } |
| return new ListResultSet<>(res); |
| } finally { |
| db.lock.unlock(); |
| } |
| } |
| |
| private Set<Entry<byte[], byte[]>> entries(byte[] fromKey, byte[] toKey) { |
| return db.table.subMap(fromKey, toKey).entrySet(); |
| } |
| |
| @Override |
| public void upsert(byte[] key, byte[] data) throws OrmException { |
| db.lock.lock(); |
| try { |
| db.table.put(key, data); |
| } finally { |
| db.lock.unlock(); |
| } |
| } |
| |
| @Override |
| public void delete(byte[] key) throws OrmException { |
| db.lock.lock(); |
| try { |
| db.table.remove(key); |
| } finally { |
| db.lock.unlock(); |
| } |
| } |
| |
| @Override |
| public void atomicUpdate(byte[] key, AtomicUpdate<byte[]> update) throws OrmException { |
| db.lock.lock(); |
| try { |
| final byte[] oldData = fetchRow(key); |
| final byte[] newData = update.update(oldData); |
| if (newData != null) { |
| upsert(key, newData); |
| } else if (oldData != null) { |
| delete(key); |
| } |
| } finally { |
| db.lock.unlock(); |
| } |
| } |
| } |