Home | History | Annotate | Download | only in os 
      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.os;
     18 
     19 import android.annotation.UnsupportedAppUsage;
     20 import android.system.ErrnoException;
     21 import android.system.Os;
     22 import android.system.StructStatVfs;
     23 
     24 /**
     25  * Retrieve overall information about the space on a filesystem. This is a
     26  * wrapper for Unix statvfs().
     27  */
     28 public class StatFs {
     29     @UnsupportedAppUsage
     30     private StructStatVfs mStat;
     31 
     32     /**
     33      * Construct a new StatFs for looking at the stats of the filesystem at
     34      * {@code path}. Upon construction, the stat of the file system will be
     35      * performed, and the values retrieved available from the methods on this
     36      * class.
     37      *
     38      * @param path path in the desired file system to stat.
     39      *
     40      * @throws IllegalArgumentException if the file system access fails
     41      */
     42     public StatFs(String path) {
     43         mStat = doStat(path);
     44     }
     45 
     46     /**
     47      * @throws IllegalArgumentException if the file system access fails
     48      */
     49     private static StructStatVfs doStat(String path) {
     50         try {
     51             return Os.statvfs(path);
     52         } catch (ErrnoException e) {
     53             throw new IllegalArgumentException("Invalid path: " + path, e);
     54         }
     55     }
     56 
     57     /**
     58      * Perform a restat of the file system referenced by this object. This is
     59      * the same as re-constructing the object with the same file system path,
     60      * and the new stat values are available upon return.
     61      *
     62      * @throws IllegalArgumentException if the file system access fails
     63      */
     64     public void restat(String path) {
     65         mStat = doStat(path);
     66     }
     67 
     68     /**
     69      * @deprecated Use {@link #getBlockSizeLong()} instead.
     70      */
     71     @Deprecated
     72     public int getBlockSize() {
     73         return (int) mStat.f_frsize;
     74     }
     75 
     76     /**
     77      * The size, in bytes, of a block on the file system. This corresponds to
     78      * the Unix {@code statvfs.f_frsize} field.
     79      */
     80     public long getBlockSizeLong() {
     81         return mStat.f_frsize;
     82     }
     83 
     84     /**
     85      * @deprecated Use {@link #getBlockCountLong()} instead.
     86      */
     87     @Deprecated
     88     public int getBlockCount() {
     89         return (int) mStat.f_blocks;
     90     }
     91 
     92     /**
     93      * The total number of blocks on the file system. This corresponds to the
     94      * Unix {@code statvfs.f_blocks} field.
     95      */
     96     public long getBlockCountLong() {
     97         return mStat.f_blocks;
     98     }
     99 
    100     /**
    101      * @deprecated Use {@link #getFreeBlocksLong()} instead.
    102      */
    103     @Deprecated
    104     public int getFreeBlocks() {
    105         return (int) mStat.f_bfree;
    106     }
    107 
    108     /**
    109      * The total number of blocks that are free on the file system, including
    110      * reserved blocks (that are not available to normal applications). This
    111      * corresponds to the Unix {@code statvfs.f_bfree} field. Most applications
    112      * will want to use {@link #getAvailableBlocks()} instead.
    113      */
    114     public long getFreeBlocksLong() {
    115         return mStat.f_bfree;
    116     }
    117 
    118     /**
    119      * The number of bytes that are free on the file system, including reserved
    120      * blocks (that are not available to normal applications). Most applications
    121      * will want to use {@link #getAvailableBytes()} instead.
    122      */
    123     public long getFreeBytes() {
    124         return mStat.f_bfree * mStat.f_frsize;
    125     }
    126 
    127     /**
    128      * @deprecated Use {@link #getAvailableBlocksLong()} instead.
    129      */
    130     @Deprecated
    131     public int getAvailableBlocks() {
    132         return (int) mStat.f_bavail;
    133     }
    134 
    135     /**
    136      * The number of blocks that are free on the file system and available to
    137      * applications. This corresponds to the Unix {@code statvfs.f_bavail} field.
    138      */
    139     public long getAvailableBlocksLong() {
    140         return mStat.f_bavail;
    141     }
    142 
    143     /**
    144      * The number of bytes that are free on the file system and available to
    145      * applications.
    146      */
    147     public long getAvailableBytes() {
    148         return mStat.f_bavail * mStat.f_frsize;
    149     }
    150 
    151     /**
    152      * The total number of bytes supported by the file system.
    153      */
    154     public long getTotalBytes() {
    155         return mStat.f_blocks * mStat.f_frsize;
    156     }
    157 }
    158