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More performance enhancements and POSIX compliance corrections.

This commit is contained in:
Keith Marshall 2012-02-01 21:26:39 +00:00
parent 89c1003e78
commit 002a1b18e6
2 changed files with 262 additions and 223 deletions
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26
winsup/mingw/ChangeLog
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@ -1,3 +1,29 @@
2012-02-01 Keith Marshall <keithmarshall@users.sourceforge.net>
More performance enhancements and POSIX compliance corrections.
* mingwex/dirent.c: Improve comments; miscellaneous format adjustments.
(direct.h): Don't include this header; it isn't, and never was, needed.
(SUFFIX, SLASH): Macros no longer required; delete them.
(_tGetFileAttributes): Function no longer required; delete it.
(DIRENT_OPEN, DIRENT_UPDATE): New macros; define them.
(_topendir): Use DIRENT_OPEN; this initialises the requisite _TDIR
struct, and populates it by calling _findfirst(), in preparation for
retrieval by the first subsequent call to _treaddir().
(_treaddir): Use DIRENT_UPDATE on all but the first call following
_topendir() or _trewinddir(); in any case, update d_namlen and d_type
fields within the associated _TDIR.dirent struct prior to return. Do
NOT automatically call _findclose() at end of "directory stream"; that
duty properly belongs exclusively to...
(_tclosedir): ...this; simplify, since we no longer need to check for
premature closure within _tclosedir().
(_trewinddir): Rewrite; it now simply invokes _findclose() in the same
manner as _tclosedir(), immediately followed by DIRENT_OPEN, resetting
the "directory stream" to the initial state as set by _topendir().
(_tseekdir): Simplify; use _trewinddir(), followed by repeated use of
DIRENT_UPDATE, as many times as necessary to advance the location
counter to the requested offset.
2011-11-30 Ozkan Sezer <sezero@users.sourceforge.net> 2011-11-30 Ozkan Sezer <sezero@users.sourceforge.net>
* include/io.h (_wfindfirst, _wfindnext, _wfindfirst32, _wfindnext32, * include/io.h (_wfindfirst, _wfindnext, _wfindfirst32, _wfindnext32,

457
winsup/mingw/mingwex/dirent.c
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@ -2,6 +2,7 @@
* dirent.c * dirent.c
* *
* This file has no copyright assigned and is placed in the Public Domain. * This file has no copyright assigned and is placed in the Public Domain.
*
* This file is a part of the mingw-runtime package. * This file is a part of the mingw-runtime package.
* No warranty is given; refer to the file DISCLAIMER within the package. * No warranty is given; refer to the file DISCLAIMER within the package.
* *
@ -12,22 +13,20 @@
* Updated by Jeremy Bettis <jeremy@hksys.com> * Updated by Jeremy Bettis <jeremy@hksys.com>
* Significantly revised and rewinddir, seekdir and telldir added * Significantly revised and rewinddir, seekdir and telldir added
* by Colin Peters <colin@fu.is.saga-u.ac.jp> * by Colin Peters <colin@fu.is.saga-u.ac.jp>
* Further significantly revised for improved memory utilisation,
* efficiency in operation, and better POSIX standards compliance
* by Keith Marshall <keithmarshall@users.sourceforge.net>
* *
*/ */
#include <stdlib.h> #include <stdlib.h>
#include <errno.h> #include <errno.h>
#include <string.h> #include <string.h>
#include <io.h> #include <io.h>
#include <direct.h>
#include <dirent.h> #include <dirent.h>
#define WIN32_LEAN_AND_MEAN #define WIN32_LEAN_AND_MEAN
#include <windows.h> /* for GetFileAttributes */ #include <windows.h>
#include <tchar.h> #include <tchar.h>
#define SUFFIX _T("*")
#define SLASH _T("\\")
#define DIRENT_RETURN_NOTHING #define DIRENT_RETURN_NOTHING
#define DIRENT_REJECT( chk, err, rtn ) \ #define DIRENT_REJECT( chk, err, rtn ) \
@ -127,119 +126,144 @@ union __wdirstream_t
*/ */
#define DT_IGNORED (_A_RDONLY | _A_HIDDEN | _A_SYSTEM | _A_ARCH) #define DT_IGNORED (_A_RDONLY | _A_HIDDEN | _A_SYSTEM | _A_ARCH)
/* Helper for opendir(). */ #define DIRENT_OPEN(D) \
static inline unsigned _tGetFileAttributes (const _TCHAR * tPath) ((D).dd_handle = _tfindfirst((D).dd_name, &((D).dd_dta)))
{
#ifdef _UNICODE
/* GetFileAttributesW does not work on W9x, so convert to ANSI */
if (_osver & 0x8000)
{
char aPath [MAX_PATH];
WideCharToMultiByte (CP_ACP, 0, tPath, -1, aPath, MAX_PATH, NULL,
NULL);
return GetFileAttributesA (aPath);
}
return GetFileAttributesW (tPath);
#else
return GetFileAttributesA (tPath);
#endif
}
/* #define DIRENT_UPDATE(D) \
* opendir _tfindnext( (D).dd_handle, &(D).dd_dta )
/*****
*
* opendir()
*
* Returns a pointer to a DIR structure appropriately filled in
* to begin searching a directory.
* *
* Returns a pointer to a DIR structure appropriately filled in to begin
* searching a directory.
*/ */
_TDIR * _TDIR *
_topendir (const _TCHAR *szPath) _topendir( const _TCHAR *path_name )
{ {
_TDIR *nd; _TDIR *nd;
unsigned int rc; _TCHAR abs_path[MAX_PATH];
_TCHAR szFullPath[MAX_PATH];
/* Reject any request which passes a NULL or an empty path name; /* Reject any request which passes a NULL or an empty path name;
* note that POSIX doesn't specify the handling for the NULL case, * note that POSIX doesn't specify the handling for the NULL case,
* and some implementations may simply fail with a segmentation * and some implementations may simply fail with a segmentation
* fault. We will fail more gracefully; however, the choice of * fault. We will fail more gracefully. Previous versions used
* EFAULT is not specified by POSIX, for any opendir failure. * EFAULT here, but EINVAL seems more appropriate; however, POSIX
* specifies neither of these for any opendir() failure.
*/ */
DIRENT_REJECT( (!szPath), EFAULT, (_TDIR *)(0) ); DIRENT_REJECT( (path_name == NULL), EINVAL, (_TDIR *)(NULL) );
/* /*
* Conversely, POSIX *does* specify ENOENT for the empty path * Conversely, POSIX *does* specify ENOENT for the empty path
* name case, where we previously had ENOTDIR; here, we correct * name case, where we previously had ENOTDIR; here, we correct
* this previous anomaly. * this previous anomaly.
*/ */
DIRENT_REJECT( (*szPath == _T('\0')), ENOENT, (_TDIR *)(0) ); DIRENT_REJECT( (*path_name == _T('\0')), ENOENT, (_TDIR *)(NULL) );
/* Attempt to determine if the given path really is a directory. /* Identify the absolute path name corresponding to the (maybe
* On error, user may call GetLastError() for more error info * relative) path name we are to process; (this ensures that we
* may always refer back to this same path name, e.g. to rewind
* the "directory stream", even after an intervening change of
* current working directory).
*/ */
DIRENT_REJECT( ((rc = _tGetFileAttributes (szPath)) == (unsigned int)(-1)), _tfullpath( abs_path, path_name, MAX_PATH );
ENOENT, (_TDIR *)(0)
);
/* Error, entry exists but not a directory. /* Ensure that the generated absolute path name ends with a
* directory separator (backslash) character, so that we may
* correctly append a wild-card matching pattern which will
* cause _findfirst() and _findnext() to return every entry
* in the specified directory; (note that, for now we may
* simply assume that abs_path refers to a directory;
* we will verify that when we call _findfirst() on it).
*/ */
DIRENT_REJECT( (!(rc & FILE_ATTRIBUTE_DIRECTORY)), ENOTDIR, (_TDIR *)(0) ); if( *abs_path != _T('\0') )
/* Make an absolute pathname. */
_tfullpath (szFullPath, szPath, MAX_PATH);
/* Allocate enough space to store DIR structure and the complete
* directory path given. */
nd = (_TDIR *)(malloc( sizeof( _TDIR )
+ (_tcslen( szFullPath ) + _tcslen( SLASH ) + _tcslen( SUFFIX ) + 1)
* sizeof( _TCHAR )
));
/* Error, out of memory.
*/
DIRENT_REJECT( (!nd), ENOMEM, (_TDIR *)(0) );
/* Create the search expression. */
_tcscpy (nd->dd_private.dd_name, szFullPath);
/* Add on a slash if the path does not end with one. */
if (nd->dd_private.dd_name[0] != _T('\0')
&& _tcsrchr (nd->dd_private.dd_name, _T('/')) != nd->dd_private.dd_name
+ _tcslen (nd->dd_private.dd_name) - 1
&& _tcsrchr (nd->dd_private.dd_name, _T('\\')) != nd->dd_private.dd_name
+ _tcslen (nd->dd_private.dd_name) - 1)
{ {
_tcscat (nd->dd_private.dd_name, SLASH); size_t offset = _tcslen( abs_path ) - 1;
if( (abs_path[offset] != _T('/')) && (abs_path[offset] != _T('\\')) )
_tcscat( abs_path, _T("\\") );
} }
/* Add on the search pattern */ /* Now append the "match everything" wild-card pattern.
_tcscat (nd->dd_private.dd_name, SUFFIX); */
_tcscat( abs_path, _T("*") );
/* Initialize handle to -1 so that a premature closedir doesn't try /* Allocate space to store DIR structure. The size MUST be
* to call _findclose on it. */ * adjusted to accommodate the complete absolute path name for
nd->dd_private.dd_handle = -1; * the specified directory, extended to include the wild-card
* matching pattern, as above; (note that we DO NOT need any
* special provision for the terminating NUL on the path name,
* since the base size of the DIR structure includes it).
*/
nd = (_TDIR *)(malloc(
sizeof( _TDIR ) + (_tcslen( abs_path ) * sizeof( _TCHAR ))
));
/* Initialize the status. */ /* Bail out, if insufficient memory.
*/
DIRENT_REJECT( (nd == NULL), ENOMEM, (_TDIR *)(NULL) );
/* Copy the extended absolute path name string into place
* within the allocated space for the DIR structure.
*/
_tcscpy( nd->dd_private.dd_name, abs_path );
/* Initialize the "directory stream", by calling _findfirst() on it;
* this leaves the data for the first directory entry in the internal
* dirent buffer, ready to be retrieved by readdir().
*/
if( DIRENT_OPEN( nd->dd_private ) == (intptr_t)(-1) )
{
/* The _findfirst() call, (implied by DIRENT_OPEN), failed;
* _findfirst() sets EINVAL where POSIX mandates ENOTDIR...
*/
if( errno == EINVAL )
errno = ENOTDIR;
/* ...otherwise, while it may not be strictly POSIX conformant,
* just accept whatever value _findfirst() assigned to errno. In
* any event, prepare to return the NULL "directory stream"; since
* this implies that we will lose our reference pointer to the
* block of memory we allocated for the stream, free that
* before we bail out.
*/
free( nd );
return (_TDIR *)(NULL);
}
/* Initialize the status, (i.e. the location index), so that
* readdir() will simply return the first directory entry, which
* has already been fetched by _findfirst(), without performing
* an intervening _findnext() call.
*/
nd->dd_private.dd_stat = 0; nd->dd_private.dd_stat = 0;
/* Initialize the dirent structure. ino and reclen are invalid under /* The d_ino and d_reclen fields have no relevance in MS-Windows;
* Win32, and name simply points at the appropriate part of the * initialize them to zero, as a one-time assignment for this DIR
* findfirst_t structure. */ * instance, and henceforth forget them; (users should simply
* ignore them).
*/
nd->dd_dir.d_ino = 0; nd->dd_dir.d_ino = 0;
nd->dd_dir.d_reclen = 0; nd->dd_dir.d_reclen = 0;
nd->dd_dir.d_namlen = 0;
memset (nd->dd_dir.d_name, 0, FILENAME_MAX);
/* We've now completely initialized an instance of a DIR structure,
* representing the requested "directory stream"; return a pointer
* via which the caller may access it.
*/
return nd; return nd;
} }
/* /*****
* readdir
* *
* Return a pointer to a dirent structure filled with the information on the * readdir()
* next entry in the directory. *
* Return a pointer to a dirent structure filled in with information
* on the next available entry, (if any), in the "directory stream".
*/ */
struct _tdirent * struct _tdirent *
_treaddir (_TDIR *dirp) _treaddir( _TDIR *dirp )
{ {
/* Check for a valid DIR stream reference; (we can't really /* Check for a valid DIR stream reference; (we can't really
* be certain until we try to read from it, except in the case * be certain until we try to read from it, except in the case
@ -247,34 +271,17 @@ _treaddir (_TDIR *dirp)
* POSIX mandates reporting EBADF; we previously had EFAULT, so * POSIX mandates reporting EBADF; we previously had EFAULT, so
* this version corrects the former anomaly. * this version corrects the former anomaly.
*/ */
DIRENT_REJECT( (!dirp), EBADF, (struct _tdirent *)(0) ); DIRENT_REJECT( (dirp == NULL), EBADF, (struct _tdirent *)(NULL) );
if (dirp->dd_private.dd_stat < 0) /* Okay to proceed. If this is the first readdir() request
* following an opendir(), or a rewinddir(), then we already
* have the requisite return information...
*/
if( dirp->dd_private.dd_stat++ > 0 )
{ {
/* We have already returned all files in the directory /* Otherwise...
* (or the structure has an invalid dd_stat). */ *
return (struct _tdirent *) 0; * Get the next search entry. POSIX mandates that this must
}
else if (dirp->dd_private.dd_stat == 0)
{
/* We haven't started the search yet. */
/* Start the search */
dirp->dd_private.dd_handle = _tfindfirst (dirp->dd_private.dd_name, &(dirp->dd_private.dd_dta));
if (dirp->dd_private.dd_handle == -1)
{
/* Oops! Seems there are no files in that
* directory. */
dirp->dd_private.dd_stat = -1;
}
else
{
dirp->dd_private.dd_stat = 1;
}
}
else
{
/* Get the next search entry. POSIX mandates that this must
* return NULL after the last entry has been read, but that it * return NULL after the last entry has been read, but that it
* MUST NOT change errno in this case. MS-Windows _findnext() * MUST NOT change errno in this case. MS-Windows _findnext()
* DOES change errno (to ENOENT) after the last entry has been * DOES change errno (to ENOENT) after the last entry has been
@ -282,7 +289,7 @@ _treaddir (_TDIR *dirp)
* value, when no actual error has occurred. * value, when no actual error has occurred.
*/ */
int prev_errno = errno; int prev_errno = errno;
if (_tfindnext (dirp->dd_private.dd_handle, &(dirp->dd_private.dd_dta))) if( DIRENT_UPDATE( dirp->dd_private ) != 0 )
{ {
/* May be an error, or just the case described above... /* May be an error, or just the case described above...
*/ */
@ -292,164 +299,170 @@ _treaddir (_TDIR *dirp)
*/ */
errno = prev_errno; errno = prev_errno;
/* FIXME: this is just wrong: we should NOT close the DIR /* In either case, there is no valid data to return.
* handle here; it is the responsibility of closedir().
*/ */
_findclose (dirp->dd_private.dd_handle); return (struct _tdirent *)(NULL);
dirp->dd_private.dd_handle = -1;
dirp->dd_private.dd_stat = -1;
}
else
{
/* Update the status to indicate the correct
* number. */
dirp->dd_private.dd_stat++;
} }
} }
if (dirp->dd_private.dd_stat > 0) /* Successfully got an entry. Everything about the file is
* already appropriately filled in, except for the length of
* the file name in the d_namlen field...
*/
dirp->dd_dir.d_namlen = _tcslen( dirp->dd_dir.d_name );
/*
* ...and the attributes returned in the dd_dta.attrib field;
* these require adjustment to their BSD equivalents, which are
* returned via the union with the dd_dir.d_type field:
*/
switch( dirp->dd_dir.d_type &= ~DT_IGNORED )
{ {
/* Successfully got an entry. Everything about the file is case DT_REG:
* already appropriately filled in except the length of the case DT_DIR:
* file name... /* After stripping out the modifier bits in DT_IGNORED,
*/ * (which we ALWAYS ignore), this pair require no further
dirp->dd_dir.d_namlen = _tcslen (dirp->dd_dir.d_name); * adjustment...
/* */
* ...and the attributes returned in the dd_dta.attrib field; break;
* these require adjustment to their BSD equivalents, which are
* returned via the union with the dd_dir.d_type field:
*/
switch( dirp->dd_dir.d_type &= ~DT_IGNORED )
{
case DT_REG:
case DT_DIR:
/* After stripping out the modifier bits in DT_IGNORED,
* (which we ALWAYS ignore), this pair require no further
* adjustment...
*/
break;
default: default:
/* ...while nothing else has an appropriate equivalent /* ...while nothing else has an appropriate equivalent
* in the BSD d_type identification model. * in the BSD d_type identification model.
*/ */
dirp->dd_dir.d_type = DT_UNKNOWN; dirp->dd_dir.d_type = DT_UNKNOWN;
}
return &dirp->dd_dir;
} }
return &dirp->dd_dir;
return (struct _tdirent *) 0;
} }
/* /*****
* closedir *
* closedir()
*
* Frees up resources allocated by opendir().
* *
* Frees up resources allocated by opendir.
*/ */
int int
_tclosedir (_TDIR * dirp) _tclosedir( _TDIR * dirp )
{ {
int rc = 0;
/* Attempting to reference a directory stream via a NULL pointer /* Attempting to reference a directory stream via a NULL pointer
* would cause a segmentation fault; evade this. Since NULL can * would cause a segmentation fault; evade this. Since NULL can
* never represent an open directory stream, set the EBADF errno * never represent an open directory stream, set the EBADF errno
* status, as mandated by POSIX, once again correcting previous * status, as mandated by POSIX, once again correcting previous
* anomalous use of EFAULT in this context. * anomalous use of EFAULT in this context.
*/ */
DIRENT_REJECT( (!dirp), EBADF, -1 ); DIRENT_REJECT(
((dirp == NULL) || (_findclose( dirp->dd_private.dd_handle ) != 0)),
EBADF, -1
);
if (dirp->dd_private.dd_handle != -1) /* If we didn't bail out above, we have a valid DIR structure
{ * with which we have finished; release the memory allocated
rc = _findclose (dirp->dd_private.dd_handle); * to it, before returning "success".
} */
free( dirp );
/* Delete the dir structure. */ return 0;
free (dirp);
return rc;
} }
/*
* rewinddir /*****
*
* rewinddir()
*
* Return to the beginning of the directory "stream". We simply call
* _findclose(), to clear prior context, then _findfirst() to restart
* the directory search, resetting the location index appropriately,
* as it would be left by opendir().
* *
* Return to the beginning of the directory "stream". We simply call findclose
* and then reset things like an opendir.
*/ */
void void
_trewinddir (_TDIR * dirp) _trewinddir( _TDIR * dirp )
{ {
/* Once again, evade a potential segmentation fault on passing /* This is an XSI extension to POSIX, which specifies no formal
* a NULL reference pointer, and again correct previous anomalous * error conditions; we will continue to check for and evade the
* use of EFAULT, where POSIX mandates EBADF for errno reporting. * potential segmentation fault which would result from passing a
* NULL reference pointer. For consistency with the core functions
* implemented above, we will again report this as EBADF, rather
* than the EFAULT of previous versions.
*/ */
DIRENT_REJECT( (!dirp), EBADF, DIRENT_RETURN_NOTHING ); DIRENT_REJECT(
((dirp == NULL) || (_findclose( dirp->dd_private.dd_handle ) != 0)),
EBADF, DIRENT_RETURN_NOTHING
);
if (dirp->dd_private.dd_handle != -1) /* We successfully closed the prior search context; reopen...
{ */
_findclose (dirp->dd_private.dd_handle); if( DIRENT_OPEN( dirp->dd_private ) != (intptr_t)(-1) )
} /*
* ...and, on success, reset the location index.
dirp->dd_private.dd_handle = -1; */
dirp->dd_private.dd_stat = 0; dirp->dd_private.dd_stat = 0;
} }
/*
* telldir /*****
*
* telldir()
*
* Returns the "position" in the "directory stream" which can then
* be passed to seekdir(), to return back to a previous entry. We
* simply return the current location index from the dd_stat field.
* *
* Returns the "position" in the "directory stream" which can be used with
* seekdir to go back to an old entry. We simply return the value in stat.
*/ */
long long
_ttelldir (_TDIR * dirp) _ttelldir( _TDIR * dirp )
{ {
/* Once again, evade a potential segmentation fault on passing /* This too is a POSIX-XSI extension, with no mandatory error
* a NULL reference pointer, and again correct previous anomalous * conditions. Once again, evade a potential segmentation fault
* use of EFAULT, where POSIX mandates EBADF for errno reporting. * on passing a NULL reference pointer, again reporting it as
* EBADF in preference to the EFAULT of previous versions.
*/
DIRENT_REJECT( (dirp == NULL), EBADF, -1 );
/* We didn't bail out; just assume dirp is valid, and return
* the location index from the dd_stat field.
*/ */
DIRENT_REJECT( (!dirp), EBADF, -1 );
return dirp->dd_private.dd_stat; return dirp->dd_private.dd_stat;
} }
/*
* seekdir /*****
*
* seekdir()
*
* Seek to an entry previously returned by telldir(). We rewind
* the "directory stream", then repeatedly call _findnext() while
* incrementing its internal location index until it matches the
* position requested, or we reach the end of the stream. This is
* not perfect, in that the directory may have changed while we
* weren't looking, but it is the best we can achieve, and may
* likely reproduce the behaviour of other implementations.
* *
* Seek to an entry previously returned by telldir. We rewind the directory
* and call readdir repeatedly until either dd_stat is the position number
* or -1 (off the end). This is not perfect, in that the directory may
* have changed while we weren't looking. But that is probably the case with
* any such system.
*/ */
void void
_tseekdir (_TDIR * dirp, long lPos) _tseekdir( _TDIR * dirp, long loc )
{ {
/* Once again, evade a potential segmentation fault on passing /* Another POSIX-XSI extension, with no specified mandatory
* a NULL reference pointer, and again correct previous anomalous * error conditions; we require a seek location of zero or
* use of EFAULT, where POSIX mandates EBADF for errno reporting. * greater, and will reject less than zero as EINVAL...
*/ */
DIRENT_REJECT( (!dirp), EBADF, DIRENT_RETURN_NOTHING ); DIRENT_REJECT( (loc < 0L), EINVAL, DIRENT_RETURN_NOTHING );
/* Seeking to an invalid position. /* Other than this, we simply accept any error condition
* which arises as we "rewind" the "directory stream"...
*/ */
DIRENT_REJECT( (lPos < -1), EINVAL, DIRENT_RETURN_NOTHING ); _trewinddir( dirp );
if (lPos == -1) /* ...and, if this is successful...
{ */
/* Seek past end. */ if( (loc > 0) && (dirp->dd_private.dd_handle != (intptr_t)(-1)) )
if (dirp->dd_private.dd_handle != -1) /*
{ * ...seek forward until the location index within
_findclose (dirp->dd_private.dd_handle); * the DIR structure matches the requested location.
} */
dirp->dd_private.dd_handle = -1; while( (++dirp->dd_private.dd_stat < loc)
dirp->dd_private.dd_stat = -1; && (DIRENT_UPDATE( dirp->dd_private ) == 0) )
} ;
else
{
/* Rewind and read forward to the appropriate index. */
_trewinddir (dirp);
while ((dirp->dd_private.dd_stat < lPos) && _treaddir (dirp))
;
}
} }
/* $RCSfile$: end of file */