[CAMEL-17486] camel-core - ThrottlePermit compareTo cast to int causes issues

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 3.11.6, 3.14.1, 3.15.0
• Component/s: camel-core
• Patch Info: Patch Available
• Estimated Complexity: Novice
• Assignee: Claus Ibsen
• Reporter: MARC BOULANGER
• Created: 13/Jan/22 17:54
• Updated: 14/Jan/22 06:40
• Resolved: 14/Jan/22 06:40

Description

When a Throttler has not been used for longer than Integer#MAX_VALUE, casting the result of the ThrottlePermit comparison to an int causes a bit overflow.

Using a value comparison prevents this issue.
 
Current :

private static class ThrottlePermit implements Delayed {

    @Override
    public int compareTo(final Delayed o) {
        return (int) (getDelay(TimeUnit.MILLISECONDS) - o.getDelay(TimeUnit.MILLISECONDS));
    }
}

Proposal :

private static class ThrottlePermit implements Delayed {

        @Override
        public int compareTo(final Delayed o) {
            return Long.compare(getDelay(TimeUnit.MILLISECONDS), o.getDelay(TimeUnit.MILLISECONDS));
        }
}

Unit Test :

public class ThrottlerPermitTest {

    /**
     *   When a Throttler has not been used for longer than {@link java.lang.Integer#MAX_VALUE},
     *   casting the result of the {@link ThrottlePermit} comparison to an int causes a bit overflow.
     *   Using a value comparison prevents this issue.
     **/
    @Test
    public void testThrottlerPermitWithOldScheduledTime() {
        long timeMillis = System.currentTimeMillis();
        // 30 days in the past
        ThrottlePermit throttlePermitOld = new ThrottlePermit(timeMillis -2592000000L);
        // Now
        ThrottlePermit throttlePermitNow = new ThrottlePermit(timeMillis);
        ThrottlePermit throttlePermitNow2 = new ThrottlePermit(timeMillis);
        // Future
        ThrottlePermit throttlePermitFuture = new ThrottlePermit(timeMillis + 1000);

        assertEquals(-1, throttlePermitOld.compareTo(throttlePermitNow));
        assertEquals(0, throttlePermitNow.compareTo(throttlePermitNow2));
        assertEquals(1, throttlePermitFuture.compareTo(throttlePermitNow));
    }

    private final class ThrottlePermit implements Delayed {
        private volatile long scheduledTime;

        ThrottlePermit(final long delayMs) {
            setDelayMs(delayMs);
        }

        public void setDelayMs(final long delayMs) {
            this.scheduledTime = System.currentTimeMillis() + delayMs;
        }

        @Override
        public long getDelay(final TimeUnit unit) {
            return unit.convert(scheduledTime - System.currentTimeMillis(), TimeUnit.MILLISECONDS);
        }

        @Override
        public int compareTo(final Delayed o) {
            return Long.compare(getDelay(TimeUnit.MILLISECONDS), o.getDelay(TimeUnit.MILLISECONDS));
        }
    }
}