backend/src/main/java/nju/seec/helper/util/cache/GuavaCacheUtils.java

package nju.seec.helper.util.cache;

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.collect.ImmutableMap;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import java.util.Collection;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;

/**
 * @author xst
 * <p>
 * updated by cst
 */
@Component
public class GuavaCacheUtils {
    private Cache<Object, Object> cache;

    public GuavaCacheUtils(@Value("${guavaCache.maximumSize}") Long maximumSize,
                           @Value("${guavaCache.expireAfterAccessInSeconds}") Long expireAfterAccessInSeconds,
                           @Value("${guavaCache.expireAfterWriteInSeconds}") Long expireAfterWriteInSeconds) {
        cache = CacheBuilder
                .newBuilder()
                .maximumSize(maximumSize)
                .expireAfterAccess(expireAfterAccessInSeconds, TimeUnit.SECONDS)
                .expireAfterWrite(expireAfterWriteInSeconds, TimeUnit.SECONDS)
                .build();
    }

    public void set(String cacheName, String key, Object value) {
        cache.put(combineKey(cacheName, key), value);
    }

    public void setAll(String cacheName, Map<String, Object> putAll) {
        final Map<String, Object> all = putAll.entrySet().stream().collect(Collectors.toMap(entry -> combineKey(cacheName, entry.getKey()), Map.Entry::getValue));
        cache.putAll(all);
    }

    public Object get(String cacheName, String key) {
        return cache.getIfPresent(combineKey(cacheName, key));
    }

    public ImmutableMap<Object, Object> multiGet(String cacheName, Collection<String> keys) {
        Collection<String> body = keys.stream().map(s -> combineKey(cacheName, s)).collect(Collectors.toList());
        return cache.getAllPresent(body);
    }

    public void remove(String cacheName, String key) {
        cache.invalidate(combineKey(cacheName, key));
    }

    private String combineKey(String cacheName, String key) {
        return cacheName + ":" + key;
    }
}