Rewrote free disk space checking code

Moving the portability handling into a small C library cleans up things
a lot, avoiding the pain of unpacking structs from inside haskell code.
This commit is contained in:
Joey Hess 2012-03-22 17:09:54 -04:00
parent f1398b5583
commit e38a839a80
13 changed files with 124 additions and 237 deletions

32
Utility/DiskFree.hs Normal file
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{- disk free space checking
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE ForeignFunctionInterface #-}
module Utility.DiskFree ( getDiskFree ) where
import Common
import Foreign.C.Types
import Foreign.C.String
import Foreign.C.Error
foreign import ccall unsafe "diskfree.h diskfree" c_diskfree
:: CString -> IO CULLong
getDiskFree :: String -> IO (Maybe Integer)
getDiskFree path = withFilePath path $ \c_path -> do
free <- c_diskfree c_path
ifM (safeErrno <$> getErrno)
( return $ Just $ toInteger free
, do
Errno i <- getErrno
print i
return Nothing
)
where
safeErrno (Errno v) = v == 0

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-----------------------------------------------------------------------------
-- |
--
-- (This code originally comes from xmobar)
--
-- Module : StatFS
-- Copyright : (c) Jose A Ortega Ruiz
-- License : BSD-3-clause
--
-- All rights reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions
-- are met:
--
-- 1. Redistributions of source code must retain the above copyright
-- notice, this list of conditions and the following disclaimer.
-- 2. Redistributions in binary form must reproduce the above copyright
-- notice, this list of conditions and the following disclaimer in the
-- documentation and/or other materials provided with the distribution.
-- 3. Neither the name of the author nor the names of his contributors
-- may be used to endorse or promote products derived from this software
-- without specific prior written permission.
--
-- THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-- ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-- ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
-- FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-- OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-- LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-- OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-- SUCH DAMAGE.
--
-- Maintainer : Jose A Ortega Ruiz <jao@gnu.org>
-- Stability : unstable
-- Portability : unportable
--
-- A binding to C's statvfs(2)
--
-----------------------------------------------------------------------------
{-# LANGUAGE CPP, ForeignFunctionInterface, EmptyDataDecls #-}
module Utility.StatFS ( FileSystemStats(..), getFileSystemStats ) where
import Utility.FileSystemEncoding
import Foreign
import Foreign.C.Types
import Foreign.C.String
#if defined (__FreeBSD__) || defined (__FreeBSD_kernel__) || defined (__APPLE__)
# include <sys/param.h>
# include <sys/mount.h>
#else
#if defined (__linux__)
#include <sys/vfs.h>
#else
#define UNKNOWN
#endif
#endif
data FileSystemStats = FileSystemStats {
fsStatBlockSize :: Integer
-- ^ Optimal transfer block size.
, fsStatBlockCount :: Integer
-- ^ Total data blocks in file system.
, fsStatByteCount :: Integer
-- ^ Total bytes in file system.
, fsStatBytesFree :: Integer
-- ^ Free bytes in file system.
, fsStatBytesAvailable :: Integer
-- ^ Free bytes available to non-superusers.
, fsStatBytesUsed :: Integer
-- ^ Bytes used.
} deriving (Show, Eq)
data CStatfs
#ifdef UNKNOWN
#warning free space checking code not available for this OS
#else
#if defined(__APPLE__)
foreign import ccall unsafe "sys/mount.h statfs64"
#else
#if defined(__FreeBSD__) || defined (__FreeBSD_kernel__)
foreign import ccall unsafe "sys/mount.h statfs"
#else
foreign import ccall unsafe "sys/vfs.h statfs64"
#endif
#endif
c_statfs :: CString -> Ptr CStatfs -> IO CInt
#endif
toI :: CULong -> Integer
toI = toInteger
getFileSystemStats :: String -> IO (Maybe FileSystemStats)
getFileSystemStats path =
#ifdef UNKNOWN
return Nothing
#else
allocaBytes (#size struct statfs) $ \vfs ->
withFilePath path $ \cpath -> do
res <- c_statfs cpath vfs
if res == -1 then return Nothing
else do
bsize <- (#peek struct statfs, f_bsize) vfs
bcount <- (#peek struct statfs, f_blocks) vfs
bfree <- (#peek struct statfs, f_bfree) vfs
bavail <- (#peek struct statfs, f_bavail) vfs
let bpb = toI bsize
let stats = FileSystemStats
{ fsStatBlockSize = bpb
, fsStatBlockCount = toI bcount
, fsStatByteCount = toI bcount * bpb
, fsStatBytesFree = toI bfree * bpb
, fsStatBytesAvailable = toI bavail * bpb
, fsStatBytesUsed = toI (bcount - bfree) * bpb
}
if fsStatBlockCount stats == 0 || fsStatBlockSize stats == 0
then return Nothing
else return $ Just stats
#endif

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Utility/diskfree.c Normal file
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/* disk free space checking, C mini-library
*
* Copyright 2012 Joey Hess <joey@kitenet.net>
*
* Licensed under the GNU GPL version 3 or higher.
*/
/* Include appropriate headers for the OS, and define what will be used to
* check the free space. */
#if defined(__APPLE__)
# include <sys/param.h>
# include <sys/mount.h>
# define STATSTRUCT statfs
# define STATCALL statfs64
#else
#if defined (__FreeBSD__) || defined (__FreeBSD_kernel__)
# include <sys/param.h>
# include <sys/mount.h>
# define STATSTRUCT statfs
# define STATCALL statfs
#else
#if defined (__linux__)
# include <sys/statvfs.h>
# define STATSTRUCT statvfs
# define STATCALL statvfs
#else
# warning free space checking code not available for this OS
# define UNKNOWN
#endif
#endif
#endif
#include <errno.h>
/* Checks the amount of disk that is available to regular (non-root) users.
* (If there's an error, or this is not supported,
* returns 0 and sets errno to nonzero.)
*/
unsigned long long int diskfree(const char *path) {
#ifdef UNKNOWN
errno = 1;
return 0;
#else
unsigned long long int available, blocksize;
struct STATSTRUCT buf;
errno = 0;
if (STATCALL(path, &buf) != 0)
return 0; /* errno is set */
available = buf.f_bavail;
blocksize = buf.f_bsize;
return available * blocksize;
#endif
}
/*
main () {
printf("%lli\n", diskfree("."));
}
*/

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Utility/diskfree.h Normal file
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unsigned long long int diskfree(const char *path);