com.almende.util.tokens.TokenStore.java Source code

Introduction

Here is the source code for com.almende.util.tokens.TokenStore.java

Source

/*
 * Copyright: Almende B.V. (2014), Rotterdam, The Netherlands
 * License: The Apache Software License, Version 2.0
 */
package com.almende.util.tokens;

import java.util.logging.Level;
import java.util.logging.Logger;

import org.joda.time.DateTime;

import com.almende.eve.agent.AgentHost;
import com.almende.eve.state.State;
import com.almende.eve.state.StateFactory;
import com.almende.util.uuid.UUID;

/**
 * Simple token system: Each outbound call gets a token, which is newly
 * generated each hour. Last 5 tokens are
 * kept in memory. If remote peer wants to check if this host has actually send
 * the call, it can request a resend of the
 * token at time X.
 * 
 * 
 * @author ludo
 * 
 */
public final class TokenStore {
    private static final Logger LOG = Logger.getLogger(TokenStore.class.getCanonicalName());
    private static final int SIZE = 5;
    private static State tokens;
    private static DateTime last = DateTime.now();

    static {
        final AgentHost host = AgentHost.getInstance();

        StateFactory factory = null;
        if (host.getConfig() != null) {
            factory = host.getStateFactoryFromConfig(host.getConfig(), "tokens");
        }
        if (factory == null) {
            factory = host.getStateFactory();
        }
        if (factory.exists("_TokenStore")) {
            tokens = factory.get("_TokenStore");
        } else {
            try {
                tokens = factory.create("_TokenStore");
                tokens.setAgentType(TokenStore.class);
            } catch (final Exception e) {
                LOG.log(Level.WARNING, "", e);
            }
        }
    }

    /**
     * Instantiates a new token store.
     */
    private TokenStore() {
    };

    /**
     * Gets the.
     *
     * @param time the time
     * @return the string
     */
    public static String get(final String time) {
        try {
            return tokens.get(time, String.class);
        } catch (final Exception e) {
            LOG.log(Level.WARNING, "Exception during TokenStore get:", e);
            return null;
        }
    }

    /**
     * Creates the.
     *
     * @return the token ret
     */
    public static TokenRet create() {
        synchronized (tokens) {
            TokenRet result;
            if (tokens.size() == 0 || tokens.get(last.toString(), String.class) == null
                    || last.plus(3600000).isBeforeNow()) {
                final DateTime now = DateTime.now();
                final String token = new UUID().toString();
                result = new TokenRet(token, now);
                tokens.put(now.toString(), token);
                last = now;

                if (tokens.size() > SIZE + 2) {
                    DateTime oldest = last;
                    for (final String time : tokens.keySet()) {
                        try {
                            if (time.equals(State.KEY_AGENT_TYPE)) {
                                continue;
                            }
                            if (DateTime.parse(time).isBefore(oldest)) {
                                oldest = DateTime.parse(time);
                            }
                        } catch (final Exception e) {
                            LOG.log(Level.WARNING, "Failed in eviction of tokens:", e);
                        }
                    }
                    tokens.remove(oldest.toString());
                }
            } else {
                result = new TokenRet(tokens.get(last.toString(), String.class), last);
            }
            return result;
        }
    }
}