/*
    * Copyright 2020-2022 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.driver.windows.perfmon;
   
   import static oshi.driver.windows.perfmon.PerfmonConstants.PAGING_FILE;
   import static oshi.driver.windows.perfmon.PerfmonConstants.WIN32_PERF_RAW_DATA_PERF_OS_PAGING_FILE;
   
  import java.util.Collections;
  import java.util.Map;
  
  import oshi.annotation.concurrent.ThreadSafe;
  import oshi.util.platform.windows.PerfCounterQuery;
  import oshi.util.platform.windows.PerfCounterQuery.PdhCounterProperty;
  
  /**
   * Utility to query Paging File performance counter
   */
  @ThreadSafe
  public final class PagingFile {
  
      /**
       * For swap file usage
       */
      public enum PagingPercentProperty implements PdhCounterProperty {
          PERCENTUSAGE(PerfCounterQuery.TOTAL_INSTANCE, "% Usage");
  
          private final String instance;
          private final String counter;
  
          PagingPercentProperty(String instance, String counter) {
              this.instance = instance;
              this.counter = counter;
          }
  
          @Override
          public String getInstance() {
              return instance;
          }
  
          @Override
          public String getCounter() {
              return counter;
          }
      }
  
      private PagingFile() {
      }
  
      /**
       * Returns paging file counters
       *
       * @return Paging file counters for memory.
       */
      public static Map<PagingPercentProperty, Long> querySwapUsed() {
          if (PerfmonDisabled.PERF_OS_DISABLED) {
              return Collections.emptyMap();
          }
          return PerfCounterQuery.queryValues(PagingPercentProperty.class, PAGING_FILE,
                  WIN32_PERF_RAW_DATA_PERF_OS_PAGING_FILE);
      }
  }