ratpack.session.internal.LocalMemorySessionStore.java Source code

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Here is the source code for ratpack.session.internal.LocalMemorySessionStore.java

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/*
 * Copyright 2015 the original author or authors.
 *
 * 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 ratpack.session.internal;

import com.google.common.cache.Cache;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.util.AsciiString;
import ratpack.exec.Operation;
import ratpack.exec.Promise;
import ratpack.session.SessionStore;

import java.util.concurrent.atomic.AtomicLong;

public class LocalMemorySessionStore implements SessionStore {

    private final Cache<AsciiString, ByteBuf> cache;
    private final AtomicLong lastCleanup = new AtomicLong(System.currentTimeMillis());

    public LocalMemorySessionStore(Cache<AsciiString, ByteBuf> cache) {
        this.cache = cache;
    }

    @Override
    public Operation store(AsciiString sessionId, ByteBuf sessionData) {
        return Operation.of(() -> {
            maybeCleanup();
            ByteBuf retained = sessionData.retain().asReadOnly();
            cache.put(sessionId, retained);
        });
    }

    @Override
    public Promise<ByteBuf> load(AsciiString sessionId) {
        return Promise.sync(() -> {
            maybeCleanup();
            ByteBuf value = cache.getIfPresent(sessionId);
            if (value != null) {
                return Unpooled.unreleasableBuffer(value.slice());
            } else {
                return Unpooled.EMPTY_BUFFER;
            }
        });
    }

    @Override
    public Promise<Long> size() {
        return Promise.sync(cache::size);
    }

    @Override
    public Operation remove(AsciiString sessionId) {
        return Operation.of(() -> {
            maybeCleanup();
            cache.invalidate(sessionId);
        });
    }

    @Override
    public void onStop(@SuppressWarnings("deprecation") ratpack.server.StopEvent event) throws Exception {
        cache.invalidateAll();
    }

    private void maybeCleanup() {
        long now = System.currentTimeMillis();
        long last = lastCleanup.get();
        if (now - last > 1000 * 10) {
            if (lastCleanup.compareAndSet(last, now)) {
                cache.cleanUp();
            }
        }
    }
}