package com yfrog http import ie ucd murmur MurmurHash import net sf e

package com.yfrog.http;


import ie.ucd.murmur.MurmurHash;
import net.sf.ehcache.Cache;
import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Element;
import net.sf.ehcache.config.Configuration;
import net.sf.ehcache.config.DiskStoreConfiguration;
import net.sf.ehcache.config.CacheConfiguration;

import java.util.Vector;

public class MultiCacheManager {

    Vector<CacheManager> cacheManagers = new Vector<CacheManager>();

    static final public String DEFAULT_SCHEME = "/disk%d";

    public MultiCacheManager(int count) {
        for (int i = 0; i< count;++i) {
            createCache(i, DEFAULT_SCHEME);
        }
    }

    public MultiCacheManager(int count, String scheme) {
        for (int i = 0; i< count;++i) {
            createCache(i, scheme);
        }
    }

    private void createCache(int number, String scheme) {
        Configuration config = new Configuration();
        config.setName("Cache " + String.valueOf(number));

        DiskStoreConfiguration diskConfig = new DiskStoreConfiguration();
        diskConfig.setPath(String.format(scheme, number));

        config.diskStore(diskConfig);

        CacheConfiguration cacheConfig = new CacheConfiguration();
        cacheConfig.setEternal(false);
        cacheConfig.setTimeToIdleSeconds(120);
        cacheConfig.setTimeToLiveSeconds(120);
        cacheConfig.setDiskSpoolBufferSizeMB(30);
        cacheConfig.setDiskExpiryThreadIntervalSeconds(120);
        cacheConfig.setMaxBytesLocalHeap("100M");
        cacheConfig.setMemoryStoreEvictionPolicy("LRU");
        cacheConfig.setName("Cache " + String.valueOf(number));

        config.addCache(cacheConfig);

        CacheManager cacheManager = CacheManager.newInstance(config);
        cacheManagers.add(cacheManager);
    }

    private CacheManager getCacheManager(String key) {
        return cacheManagers.get(getCacheId(key));
    }

    private Cache getCache(String key) {
        CacheManager manager = getCacheManager(key);
        return manager.getCache(manager.getCacheNames()[0]);
    }

    public HttpObject getCachedValue(String key) {
        Element value = getCache(key).get(key);
        if (value == null) {
            return null;
        }
        return (HttpObject)value.getObjectValue();
    }

    private int getCacheId(String key) {
        final long integerCount = (long)Integer.MAX_VALUE - (long)Integer.MIN_VALUE; // Java int is 32 bit
        final long interval = integerCount / cacheManagers.size();

        int hash = MurmurHash.hash32(key);

        int id = (int)(((long)hash - (long)Integer.MIN_VALUE) / interval);

        return id;
    }

    public void putValue(String key, HttpObject value) {
        getCache(key).put(new Element(key, value));
    }
}