/*
    * Copyright 2016-2022 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.hardware.platform.unix.solaris;
   
   import static oshi.util.Memoizer.defaultExpiration;
   import static oshi.util.Memoizer.memoize;
   
  import java.util.function.Supplier;
  
  import oshi.annotation.concurrent.ThreadSafe;
  import oshi.driver.unix.solaris.kstat.SystemPages;
  import oshi.hardware.VirtualMemory;
  import oshi.hardware.common.AbstractGlobalMemory;
  import oshi.util.ExecutingCommand;
  import oshi.util.ParseUtil;
  import oshi.util.tuples.Pair;
  
  /**
   * Memory obtained by kstat
   */
  @ThreadSafe
  final class SolarisGlobalMemory extends AbstractGlobalMemory {
  
      private final Supplier<Pair<Long, Long>> availTotal = memoize(SystemPages::queryAvailableTotal,
              defaultExpiration());
  
      private final Supplier<Long> pageSize = memoize(SolarisGlobalMemory::queryPageSize);
  
      private final Supplier<VirtualMemory> vm = memoize(this::createVirtualMemory);
  
      @Override
      public long getAvailable() {
          return availTotal.get().getA() * getPageSize();
      }
  
      @Override
      public long getTotal() {
          return availTotal.get().getB() * getPageSize();
      }
  
      @Override
      public long getPageSize() {
          return pageSize.get();
      }
  
      @Override
      public VirtualMemory getVirtualMemory() {
          return vm.get();
      }
  
      private static long queryPageSize() {
          return ParseUtil.parseLongOrDefault(ExecutingCommand.getFirstAnswer("pagesize"), 4096L);
      }
  
      private VirtualMemory createVirtualMemory() {
          return new SolarisVirtualMemory(this);
      }
  }