com.google.cloud.trace.sdk.RateLimiterTraceEnablingPolicy.java Source code

Introduction

Here is the source code for com.google.cloud.trace.sdk.RateLimiterTraceEnablingPolicy.java

Source

// Copyright 2014 Google Inc. All rights reserved.
//
// 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 com.google.cloud.trace.sdk;

import com.google.common.util.concurrent.RateLimiter;

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

/**
 * Trace-enabling policy that uses a rate limiter to decide whether or not to enable.
 */
public class RateLimiterTraceEnablingPolicy implements TraceEnablingPolicy, CanInitFromProperties {

    private static final Logger logger = Logger.getLogger(RateLimiterTraceEnablingPolicy.class.getName());

    /**
     * The rate limiter, defaults to 1 trace enabled per second.
     */
    private RateLimiter limiter;

    /**
     * Creates a rate limiting policy with the default rate of 1 per second.
     */
    public RateLimiterTraceEnablingPolicy() {
        this(1.0);
    }

    /**
     * Creates a rate limiting policy with the given rate.
     * @param rate
     */
    public RateLimiterTraceEnablingPolicy(double rate) {
        this.limiter = RateLimiter.create(1.0);
    }

    @Override
    public boolean isTracingEnabled(boolean alreadyEnabled) {
        return limiter.tryAcquire();
    }

    @Override
    public void initFromProperties(Properties props) {
        String rateStr = props.getProperty(getClass().getName() + ".ratePerSecond");
        if (rateStr != null) {
            try {
                double rate = Double.parseDouble(rateStr);
                this.limiter = RateLimiter.create(rate);
            } catch (NumberFormatException nfe) {
                logger.log(Level.WARNING, "Found non-numeric rate in the properties (" + rateStr + ")");
            }
        }
    }

    public RateLimiter getLimiter() {
        return limiter;
    }

    public void setLimiter(RateLimiter limiter) {
        this.limiter = limiter;
    }
}