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      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.system.ErrnoException;
     20 import android.system.Os;
     21 import android.system.StructStatVfs;
     22 
     23 /**
     24  * Retrieve overall information about the space on a filesystem. This is a
     25  * wrapper for Unix statvfs().
     26  */
     27 public class StatFs {
     28     private StructStatVfs mStat;
     29 
     30     /**
     31      * Construct a new StatFs for looking at the stats of the filesystem at
     32      * {@code path}. Upon construction, the stat of the file system will be
     33      * performed, and the values retrieved available from the methods on this
     34      * class.
     35      *
     36      * @param path path in the desired file system to stat.
     37      *
     38      * @throws IllegalArgumentException if the file system access fails
     39      */
     40     public StatFs(String path) {
     41         mStat = doStat(path);
     42     }
     43 
     44     /**
     45      * @throws IllegalArgumentException if the file system access fails
     46      */
     47     private static StructStatVfs doStat(String path) {
     48         try {
     49             return Os.statvfs(path);
     50         } catch (ErrnoException e) {
     51             throw new IllegalArgumentException("Invalid path: " + path, e);
     52         }
     53     }
     54 
     55     /**
     56      * Perform a restat of the file system referenced by this object. This is
     57      * the same as re-constructing the object with the same file system path,
     58      * and the new stat values are available upon return.
     59      *
     60      * @throws IllegalArgumentException if the file system access fails
     61      */
     62     public void restat(String path) {
     63         mStat = doStat(path);
     64     }
     65 
     66     /**
     67      * @deprecated Use {@link #getBlockSizeLong()} instead.
     68      */
     69     @Deprecated
     70     public int getBlockSize() {
     71         return (int) mStat.f_frsize;
     72     }
     73 
     74     /**
     75      * The size, in bytes, of a block on the file system. This corresponds to
     76      * the Unix {@code statvfs.f_frsize} field.
     77      */
     78     public long getBlockSizeLong() {
     79         return mStat.f_frsize;
     80     }
     81 
     82     /**
     83      * @deprecated Use {@link #getBlockCountLong()} instead.
     84      */
     85     @Deprecated
     86     public int getBlockCount() {
     87         return (int) mStat.f_blocks;
     88     }
     89 
     90     /**
     91      * The total number of blocks on the file system. This corresponds to the
     92      * Unix {@code statvfs.f_blocks} field.
     93      */
     94     public long getBlockCountLong() {
     95         return mStat.f_blocks;
     96     }
     97 
     98     /**
     99      * @deprecated Use {@link #getFreeBlocksLong()} instead.
    100      */
    101     @Deprecated
    102     public int getFreeBlocks() {
    103         return (int) mStat.f_bfree;
    104     }
    105 
    106     /**
    107      * The total number of blocks that are free on the file system, including
    108      * reserved blocks (that are not available to normal applications). This
    109      * corresponds to the Unix {@code statvfs.f_bfree} field. Most applications
    110      * will want to use {@link #getAvailableBlocks()} instead.
    111      */
    112     public long getFreeBlocksLong() {
    113         return mStat.f_bfree;
    114     }
    115 
    116     /**
    117      * The number of bytes that are free on the file system, including reserved
    118      * blocks (that are not available to normal applications). Most applications
    119      * will want to use {@link #getAvailableBytes()} instead.
    120      */
    121     public long getFreeBytes() {
    122         return mStat.f_bfree * mStat.f_frsize;
    123     }
    124 
    125     /**
    126      * @deprecated Use {@link #getAvailableBlocksLong()} instead.
    127      */
    128     @Deprecated
    129     public int getAvailableBlocks() {
    130         return (int) mStat.f_bavail;
    131     }
    132 
    133     /**
    134      * The number of blocks that are free on the file system and available to
    135      * applications. This corresponds to the Unix {@code statvfs.f_bavail} field.
    136      */
    137     public long getAvailableBlocksLong() {
    138         return mStat.f_bavail;
    139     }
    140 
    141     /**
    142      * The number of bytes that are free on the file system and available to
    143      * applications.
    144      */
    145     public long getAvailableBytes() {
    146         return mStat.f_bavail * mStat.f_frsize;
    147     }
    148 
    149     /**
    150      * The total number of bytes supported by the file system.
    151      */
    152     public long getTotalBytes() {
    153         return mStat.f_blocks * mStat.f_frsize;
    154     }
    155 }
    156