/*
    * Copyright 2020-2022 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.driver.mac.disk;
   
   import java.nio.charset.StandardCharsets;
   import java.util.HashMap;
   import java.util.Map;
  
  import com.sun.jna.Native;
  import com.sun.jna.platform.mac.SystemB;
  import com.sun.jna.platform.mac.SystemB.Statfs;
  
  import oshi.annotation.concurrent.ThreadSafe;
  
  /**
   * Utility to query fsstat
   */
  @ThreadSafe
  public final class Fsstat {
  
      private Fsstat() {
      }
  
      /**
       * Query fsstat to map partitions to mount points
       *
       * @return A map with partitions as the key and mount points as the value
       */
      public static Map<String, String> queryPartitionToMountMap() {
          Map<String, String> mountPointMap = new HashMap<>();
  
          // Use statfs to get size of mounted file systems
          int numfs = queryFsstat(null, 0, 0);
          // Get data on file system
          Statfs s = new Statfs();
          // Create array to hold results
          Statfs[] fs = (Statfs[]) s.toArray(numfs);
          // Write file system data to array
          queryFsstat(fs, numfs * fs[0].size(), SystemB.MNT_NOWAIT);
  
          // Iterate all mounted file systems
          for (Statfs f : fs) {
              String mntFrom = Native.toString(f.f_mntfromname, StandardCharsets.UTF_8);
              mountPointMap.put(mntFrom.replace("/dev/", ""), Native.toString(f.f_mntonname, StandardCharsets.UTF_8));
          }
          return mountPointMap;
      }
  
      private static int queryFsstat(Statfs[] buf, int bufsize, int flags) {
          return SystemB.INSTANCE.getfsstat64(buf, bufsize, flags);
      }
  
  }