/*
    * Copyright 2012-2021 CodeLibs Project and the Others.
    *
    * 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 org.codelibs.fess.util;
  
  import java.time.LocalDateTime;
  import java.time.ZonedDateTime;
  import java.util.Collection;
  import java.util.Date;
  import java.util.Map;
  
  import org.apache.commons.io.FileUtils;
  import org.codelibs.core.lang.StringUtil;
  
  public final class MemoryUtil {
      private MemoryUtil() {
      }
  
      public static String getMemoryUsageLog() {
          final Runtime runtime = Runtime.getRuntime();
          final long freeBytes = runtime.freeMemory();
          final long maxBytes = runtime.maxMemory();
          final long totalBytes = runtime.totalMemory();
          final long usedBytes = totalBytes - freeBytes;
          return "Mem:{used " + byteCountToDisplaySize(usedBytes) + ", heap " + byteCountToDisplaySize(totalBytes) + ", max "
                  + byteCountToDisplaySize(maxBytes) + "}";
      }
  
      public static String byteCountToDisplaySize(final long size) {
          return FileUtils.byteCountToDisplaySize(size).replace(" ", StringUtil.EMPTY);
      }
  
      public static long getUsedMemory() {
          final Runtime runtime = Runtime.getRuntime();
          final long freeBytes = runtime.freeMemory();
          final long totalBytes = runtime.totalMemory();
          return totalBytes - freeBytes;
      }
  
      public static long sizeOf(final Object obj) {
          if (obj == null) {
              return 0L;
          }
          if (obj instanceof String) {
              return ((String) obj).length() + 56L;
          }
          if (obj instanceof Number) {
              return 24L;
          } else if (obj instanceof Date) {
              return 32L;
          } else if (obj instanceof LocalDateTime) {
              return 80L;
          } else if (obj instanceof ZonedDateTime) {
              return 2128L;
          } else if (obj instanceof Object[]) {
              long size = 0;
              for (final Object value : (Object[]) obj) {
                  size += sizeOf(value);
              }
              return size;
          } else if (obj instanceof Collection<?>) {
              long size = 0;
              for (final Object value : (Collection<?>) obj) {
                  size += sizeOf(value);
              }
              return size;
          } else if (obj instanceof Map<?, ?>) {
              long size = 0;
              for (final Map.Entry<?, ?> entry : ((Map<?, ?>) obj).entrySet()) {
                  size += sizeOf(entry.getKey());
                  size += sizeOf(entry.getValue());
              }
              return size;
          }
          return 16L;
      }
  }