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 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you 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
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package org.elasticsearch.indices.memory.breaker;

import org.elasticsearch.common.breaker.CircuitBreaker;
import org.elasticsearch.common.settings.ClusterSettings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.indices.breaker.BreakerSettings;
import org.elasticsearch.indices.breaker.CircuitBreakerService;
import org.elasticsearch.indices.breaker.HierarchyCircuitBreakerService;
import org.elasticsearch.test.ESTestCase;

import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.instanceOf;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.notNullValue;

/**
 * Unit tests for the circuit breaker
 */
public class CircuitBreakerUnitTests extends ESTestCase {
    public static long pctBytes(String percentString) {
        return Settings.EMPTY.getAsMemory("", percentString).getBytes();
    }

    public void testBreakerSettingsValidationWithValidSettings() {
        // parent: {:limit 70}, fd: {:limit 50}, request: {:limit 20}
        BreakerSettings fd = new BreakerSettings(CircuitBreaker.FIELDDATA, pctBytes("50%"), 1.0);
        BreakerSettings request = new BreakerSettings(CircuitBreaker.REQUEST, pctBytes("20%"), 1.0);
        HierarchyCircuitBreakerService.validateSettings(new BreakerSettings[]{fd, request});

        // parent: {:limit 70}, fd: {:limit 40}, request: {:limit 30}
        fd = new BreakerSettings(CircuitBreaker.FIELDDATA, pctBytes("40%"), 1.0);
        request = new BreakerSettings(CircuitBreaker.REQUEST, pctBytes("30%"), 1.0);
        HierarchyCircuitBreakerService.validateSettings(new BreakerSettings[]{fd, request});
    }

    public void testBreakerSettingsValidationNegativeOverhead() {
        // parent: {:limit 70}, fd: {:limit 50}, request: {:limit 20}
        BreakerSettings fd = new BreakerSettings(CircuitBreaker.FIELDDATA, pctBytes("50%"), -0.1);
        BreakerSettings request = new BreakerSettings(CircuitBreaker.REQUEST, pctBytes("20%"), 1.0);
        try {
            HierarchyCircuitBreakerService.validateSettings(new BreakerSettings[]{fd, request});
            fail("settings are invalid but validate settings did not throw an exception");
        } catch (Exception e) {
            assertThat("Incorrect message: " + e.getMessage(),
                    e.getMessage().contains("must be non-negative"), equalTo(true));
        }
    }

    public void testRegisterCustomBreaker() throws Exception {
        CircuitBreakerService service = new HierarchyCircuitBreakerService(Settings.EMPTY, new ClusterSettings(Settings.EMPTY, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS));
        String customName = "custom";
        BreakerSettings settings = new BreakerSettings(customName, 20, 1.0);
        service.registerBreaker(settings);

        CircuitBreaker breaker = service.getBreaker(customName);
        assertThat(breaker, notNullValue());
        assertThat(breaker, instanceOf(CircuitBreaker.class));
        assertThat(breaker.getName(), is(customName));
    }
}
