MemoryTransactionLogStorage.java

/*
 * Copyright 1999-2015 dangdang.com.
 * <p>
 * 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.
 * </p>
 */

package com.dangdang.ddframe.rdb.transaction.soft.storage.impl;

import com.dangdang.ddframe.rdb.transaction.soft.constants.SoftTransactionType;
import com.dangdang.ddframe.rdb.transaction.soft.storage.TransactionLog;
import com.dangdang.ddframe.rdb.transaction.soft.storage.TransactionLogStorage;
import lombok.RequiredArgsConstructor;

import java.sql.Connection;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 基于内存的事务日志存储器接口.
 * 
 * @author zhangliang
 */
@RequiredArgsConstructor
public final class MemoryTransactionLogStorage implements TransactionLogStorage {
    
    private static final ConcurrentHashMap<String, TransactionLog> DATA = new ConcurrentHashMap<>();
    
    @Override
    public void add(final TransactionLog transactionLog) {
        DATA.putIfAbsent(transactionLog.getId(), transactionLog);
    }
    
    @Override
    public void remove(final String id) {
        DATA.remove(id);
    }
    
    @Override
    public List<TransactionLog> findEligibleTransactionLogs(final int size, final int maxDeliveryTryTimes, final long maxDeliveryTryDelayMillis) {
        List<TransactionLog> result = new ArrayList<>();
        int count = 0;
        for (TransactionLog each : DATA.values()) {
            if (count >= size) {
                break;
            }
            if (each.getAsyncDeliveryTryTimes() < maxDeliveryTryTimes
                    && SoftTransactionType.BestEffortsDelivery == each.getTransactionType() 
                    && each.getCreationTime() < System.currentTimeMillis() - maxDeliveryTryDelayMillis) {
                result.add(each);
            }
            count++;
        }
        return result;
    }
    
    @Override
    public void increaseAsyncDeliveryTryTimes(final String id) {
        if (DATA.containsKey(id)) {
            TransactionLog transactionLog = DATA.get(id);
            transactionLog.setAsyncDeliveryTryTimes(new AtomicInteger(transactionLog.getAsyncDeliveryTryTimes()).incrementAndGet());
            DATA.put(id, transactionLog);
        }
    }
    
    @Override
    public boolean processData(final Connection connection, final TransactionLog transactionLog, final int maxDeliveryTryTimes) {
        return false;
    }
}