io.seldon.api.caching.ActionHistoryCache.java Source code

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Here is the source code for io.seldon.api.caching.ActionHistoryCache.java

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/*
 * Seldon -- open source prediction engine
 * =======================================
 *
 * Copyright 2011-2015 Seldon Technologies Ltd and Rummble Ltd (http://www.seldon.io/)
 *
 * ********************************************************************************************
 *
 * 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 io.seldon.api.caching;

import io.seldon.api.APIException;
import io.seldon.api.state.NewClientListener;
import io.seldon.api.state.options.DefaultOptions;
import io.seldon.api.state.zk.ZkClientConfigHandler;
import io.seldon.memcache.MemCacheKeys;
import io.seldon.memcache.MemCachePeer;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import javax.annotation.PostConstruct;

import net.spy.memcached.CASMutation;

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class ActionHistoryCache implements NewClientListener {

    private static Logger logger = Logger.getLogger(ActionHistoryCache.class.getName());
    public static int CACHE_TIME = 1800;

    private static ConcurrentHashMap<String, Boolean> clientsUseDb = new ConcurrentHashMap<>();

    DefaultOptions options;
    ZkClientConfigHandler clientConfigHandler;

    @Autowired
    public ActionHistoryCache(DefaultOptions options, ZkClientConfigHandler clientConfigHandler) {
        this.options = options;
        this.clientConfigHandler = clientConfigHandler;
    }

    @PostConstruct
    public void startup() {
        logger.info("Adding new client listener");
        clientConfigHandler.addNewClientListener(this, false);
    }

    @Override
    public void clientAdded(String client, Map<String, String> initialConfig) {
    }

    @Override
    public void clientDeleted(String client) {
    }

    public void removeRecentActions(String clientName, long userId) {
        String mkey = MemCacheKeys.getActionHistory(clientName, userId);
        MemCachePeer.delete(mkey);
    }

    public List<Long> getRecentActions(String clientName, long userId, int numActions) {
        String mkey = MemCacheKeys.getActionHistory(clientName, userId);
        List<Long> res = (List<Long>) MemCachePeer.get(mkey);
        if (res == null) {
            logger.debug("creating empty action history for user " + userId + " for client " + clientName);
            res = new ArrayList<>();
        } else {
            if (res.size() > numActions)
                res = res.subList(0, numActions);
            logger.debug("Got action history for user " + userId + " from memcache");
        }
        return res;
    }

    public void addAction(String clientName, long userId, final long itemId) throws APIException {
        logger.debug("Adding action to cache for " + userId + " item " + itemId);
        CASMutation<List<Long>> mutation = new CASMutation<List<Long>>() {

            // This is only invoked when a value actually exists.
            public List<Long> getNewValue(List<Long> current) {
                if (!current.contains(itemId)) {
                    current.add(0, itemId);
                }
                return current;
            }
        };
        List<Long> actions = new ArrayList<>();
        actions.add(itemId);
        String mkey = MemCacheKeys.getActionHistory(clientName, userId);
        MemCachePeer.cas(mkey, mutation, actions, CACHE_TIME);
    }

}