/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF 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
    *
    *      https://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 org.apache.commons.pool2.impl;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  import static org.junit.jupiter.api.Assertions.fail;
  
  import java.util.LinkedList;
  import java.util.List;
  
  import org.apache.commons.lang3.ArrayFill;
  import org.apache.commons.pool2.BasePooledObjectFactory;
  import org.apache.commons.pool2.PooledObject;
  import org.junit.jupiter.api.AfterEach;
  import org.junit.jupiter.api.Test;
  
  /**
   */
  class TestSoftRefOutOfMemory {
  
      public static class LargePoolableObjectFactory extends BasePooledObjectFactory<String> {
  
          private final String buffer;
          private int counter;
  
          LargePoolableObjectFactory(final int size) {
              buffer = new StringBuffer().append(ArrayFill.fill(new char[size], '.')).toString();
          }
  
          @Override
          public String create() {
              counter++;
              return String.valueOf(counter) + buffer;
          }
  
          @Override
          public PooledObject<String> wrap(final String value) {
              return new DefaultPooledObject<>(value);
          }
      }
  
      private static final class OomeFactory extends BasePooledObjectFactory<String> {
  
          private final OomeTrigger trigger;
  
          OomeFactory(final OomeTrigger trigger) {
              this.trigger = trigger;
          }
  
          @Override
          public String create() {
              if (trigger.equals(OomeTrigger.CREATE)) {
                  throw new OutOfMemoryError();
              }
              // It seems that as of Java 1.4 String.valueOf may return an
              // intern()'ed String this may cause problems when the tests
              // depend on the returned object to be eventually garbaged
              // collected. Either way, making sure a new String instance
              // is returned eliminated false failures.
              return new StringBuffer().toString();
          }
  
          @Override
          public void destroyObject(final PooledObject<String> p) throws Exception {
              if (trigger.equals(OomeTrigger.DESTROY)) {
                  throw new OutOfMemoryError();
              }
              super.destroyObject(p);
          }
  
          @Override
          public boolean validateObject(final PooledObject<String> p) {
              if (trigger.equals(OomeTrigger.VALIDATE)) {
                  throw new OutOfMemoryError();
              }
              return !trigger.equals(OomeTrigger.DESTROY);
          }
  
          @Override
          public PooledObject<String> wrap(final String value) {
              return new DefaultPooledObject<>(value);
          }
      }
 
     private enum OomeTrigger {
         CREATE,
         VALIDATE,
         DESTROY
     }
 
     public static class SmallPoolableObjectFactory extends BasePooledObjectFactory<String> {
         private int counter;
 
         @Override
         public String create() {
             counter++;
             // It seems that as of Java 1.4 String.valueOf may return an
             // intern()'ed String this may cause problems when the tests
             // depend on the returned object to be eventually garbaged
             // collected. Either way, making sure a new String instance
             // is returned eliminated false failures.
             return new StringBuffer().append(counter).toString();
         }
         @Override
         public PooledObject<String> wrap(final String value) {
             return new DefaultPooledObject<>(value);
         }
     }
 
     private SoftReferenceObjectPool<String> pool;
 
     @AfterEach
     public void tearDown() {
         if (pool != null) {
             pool.close();
             pool = null;
         }
         System.gc();
     }
 
     @Test
     void testOutOfMemory() throws Exception {
         pool = new SoftReferenceObjectPool<>(new SmallPoolableObjectFactory());
 
         String obj = pool.borrowObject();
         assertEquals("1", obj);
         pool.returnObject(obj);
         obj = null;
 
         assertEquals(1, pool.getNumIdle());
 
         final List<byte[]> garbage = new LinkedList<>();
         final Runtime runtime = Runtime.getRuntime();
         while (pool.getNumIdle() > 0) {
             try {
                 long freeMemory = runtime.freeMemory();
                 if (freeMemory > Integer.MAX_VALUE) {
                     freeMemory = Integer.MAX_VALUE;
                 }
                 garbage.add(new byte[Math.min(1024 * 1024, (int) freeMemory / 2)]);
             } catch (final OutOfMemoryError oome) {
                 System.gc();
                 assertEquals(0, pool.getNumIdle());
             }
             System.gc();
         }
         garbage.clear();
         System.gc();
 
         obj = pool.borrowObject();
         assertEquals("2", obj);
         pool.returnObject(obj);
         obj = null;
 
         assertEquals(1, pool.getNumIdle());
     }
 
     @Test
     void testOutOfMemory1000() throws Exception {
         pool = new SoftReferenceObjectPool<>(new SmallPoolableObjectFactory());
 
         for (int i = 0 ; i < 1000 ; i++) {
             pool.addObject();
         }
 
         String obj = pool.borrowObject();
         assertEquals("1000", obj);
         pool.returnObject(obj);
         obj = null;
 
         assertEquals(1000, pool.getNumIdle());
 
         final List<byte[]> garbage = new LinkedList<>();
         final Runtime runtime = Runtime.getRuntime();
         while (pool.getNumIdle() > 0) {
             try {
                 long freeMemory = runtime.freeMemory();
                 if (freeMemory > Integer.MAX_VALUE) {
                     freeMemory = Integer.MAX_VALUE;
                 }
                 garbage.add(new byte[Math.min(1024 * 1024, (int) freeMemory / 2)]);
             } catch (final OutOfMemoryError oome) {
                 System.gc();
                 assertEquals(0, pool.getNumIdle());
             }
             System.gc();
         }
         garbage.clear();
         System.gc();
 
         obj = pool.borrowObject();
         assertEquals("1001", obj);
         pool.returnObject(obj);
         obj = null;
 
         assertEquals(1, pool.getNumIdle());
     }
 
     /**
      * Makes sure an {@link OutOfMemoryError} isn't swallowed.
      *
      * @throws Exception May occur in some failure modes
      */
     @Test
     void testOutOfMemoryError() throws Exception {
         pool = new SoftReferenceObjectPool<>(new OomeFactory(OomeTrigger.CREATE));
         try {
             pool.borrowObject();
             fail("Expected out of memory.");
         } catch (final OutOfMemoryError ex) {
             // expected
         }
         pool.close();
         pool = new SoftReferenceObjectPool<>(new OomeFactory(OomeTrigger.VALIDATE));
         try {
             pool.borrowObject();
             fail("Expected out of memory.");
         } catch (final OutOfMemoryError ex) {
             // expected
         }
         pool.close();
         pool = new SoftReferenceObjectPool<>(new OomeFactory(OomeTrigger.DESTROY));
         try {
             pool.borrowObject();
             fail("Expected out of memory.");
         } catch (final OutOfMemoryError ex) {
             // expected
         }
         pool.close();
     }
 
     @Test
     void testOutOfMemoryLarge() throws Exception {
         pool = new SoftReferenceObjectPool<>(new LargePoolableObjectFactory(1000000));
 
         String obj = pool.borrowObject();
         assertTrue(obj.startsWith("1."));
         pool.returnObject(obj);
         obj = null;
 
         assertEquals(1, pool.getNumIdle());
 
         final List<byte[]> garbage = new LinkedList<>();
         final Runtime runtime = Runtime.getRuntime();
         while (pool.getNumIdle() > 0) {
             try {
                 long freeMemory = runtime.freeMemory();
                 if (freeMemory > Integer.MAX_VALUE) {
                     freeMemory = Integer.MAX_VALUE;
                 }
                 garbage.add(new byte[Math.min(1024 * 1024, (int) freeMemory / 2)]);
             } catch (final OutOfMemoryError oome) {
                 System.gc();
                 assertEquals(0, pool.getNumIdle());
             }
             System.gc();
         }
         garbage.clear();
         System.gc();
 
         obj = pool.borrowObject();
         assertTrue(obj.startsWith("2."));
         pool.returnObject(obj);
         obj = null;
 
         assertEquals(1, pool.getNumIdle());
     }
 }