380 lines
9.4 KiB
C

/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */
#include "mysys_priv.h"
#include "my_static.h"
#include <errno.h>
#include "mysys_err.h"
#include "my_thread_local.h"
static void make_ftype(char * to,int flag);
/*
Open a file as stream
SYNOPSIS
my_fopen()
FileName Path-name of file
Flags Read | write | append | trunc (like for open())
MyFlags Flags for handling errors
RETURN
0 Error
# File handler
*/
FILE *my_fopen(const char *filename, int flags, myf MyFlags)
{
FILE *fd;
char type[5];
char *dup_filename= NULL;
DBUG_ENTER("my_fopen");
DBUG_PRINT("my",("Name: '%s' flags: %d MyFlags: %d",
filename, flags, MyFlags));
make_ftype(type,flags);
#ifdef _WIN32
fd= my_win_fopen(filename, type);
#else
fd= fopen(filename, type);
#endif
if (fd != 0)
{
/*
The test works if MY_NFILE < 128. The problem is that fileno() is char
on some OS (SUNOS). Actually the filename save isn't that important
so we can ignore if this doesn't work.
*/
int filedesc= my_fileno(fd);
if ((uint)filedesc >= my_file_limit)
{
mysql_mutex_lock(&THR_LOCK_open);
my_stream_opened++;
mysql_mutex_unlock(&THR_LOCK_open);
DBUG_RETURN(fd); /* safeguard */
}
dup_filename= my_strdup(key_memory_my_file_info, filename, MyFlags);
if (dup_filename != NULL)
{
mysql_mutex_lock(&THR_LOCK_open);
my_file_info[filedesc].name= dup_filename;
my_stream_opened++;
my_file_total_opened++;
my_file_info[filedesc].type= STREAM_BY_FOPEN;
mysql_mutex_unlock(&THR_LOCK_open);
DBUG_PRINT("exit",("stream: 0x%lx", (long) fd));
DBUG_RETURN(fd);
}
(void) my_fclose(fd,MyFlags);
set_my_errno(ENOMEM);
}
else
set_my_errno(errno);
DBUG_PRINT("error",("Got error %d on open",my_errno()));
if (MyFlags & (MY_FFNF | MY_FAE | MY_WME))
{
char errbuf[MYSYS_STRERROR_SIZE];
my_error((flags & O_RDONLY) || (flags == O_RDONLY ) ? EE_FILENOTFOUND :
EE_CANTCREATEFILE,
MYF(0), filename,
my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
}
DBUG_RETURN((FILE*) 0);
} /* my_fopen */
#if defined(_WIN32)
static FILE *my_win_freopen(const char *path, const char *mode, FILE *stream)
{
int handle_fd, fd= _fileno(stream);
HANDLE osfh;
DBUG_ASSERT(path && stream);
/* Services don't have stdout/stderr on Windows, so _fileno returns -1. */
if (fd < 0)
{
if (!freopen(path, mode, stream))
return NULL;
fd= _fileno(stream);
}
if ((osfh= CreateFile(path, GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE |
FILE_SHARE_DELETE, NULL,
OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL,
NULL)) == INVALID_HANDLE_VALUE)
{
_close(fd);
return NULL;
}
if ((handle_fd= _open_osfhandle((intptr_t)osfh,
_O_APPEND | _O_TEXT)) == -1)
{
CloseHandle(osfh);
return NULL;
}
if (_dup2(handle_fd, fd) < 0)
{
CloseHandle(osfh);
return NULL;
}
_close(handle_fd);
return stream;
}
#else
/**
Replacement for freopen() which will not close the stream until the
new file has been successfully opened. This gives the ability log
the reason for reopen's failure to the stream, and also to flush any
buffered messages already written to the stream, before terminating
the process.
After a new stream to path has been opened, its file descriptor is
obtained, and dup2() is used to associate the original stream with
the new file. The newly opened stream and associated file descriptor
is then closed with fclose().
@param path file which the stream should be opened to
@param mode FILE mode to use when opening new file
@param stream stream to reopen
@retval FILE stream being passed in if successful,
@retval nullptr otherwise
*/
static FILE *my_safe_freopen(const char *path, const char *mode, FILE *stream)
{
int streamfd= -1;
FILE *pathstream= NULL;
int pathfd= -1;
int ds= -1;
DBUG_ASSERT(path != NULL && stream != NULL);
streamfd= fileno(stream);
if (streamfd == -1)
{
/* We have not done anything to the stream, but if we cannot
get its fd, it is probably in a bad state anyway... */
return NULL;
}
pathstream= fopen(path, mode);
if (pathstream == NULL)
{
/* Failed to open file for some reason. stream should still be
usable. */
return NULL;
}
pathfd= fileno(pathstream);
if (pathfd == -1)
{
fclose(pathstream);
return NULL;
}
do
{
ds= fflush(stream);
if (ds == 0)
{
ds= dup2(pathfd, streamfd);
}
}
while (ds == -1 && errno == EINTR);
fclose(pathstream);
return (ds == -1 ? NULL : stream);
}
#endif
/**
Change the file associated with a file stream.
@param path Path to file.
@param mode Mode of the stream.
@param stream File stream.
@note
This function is used to redirect stdout and stderr to a file and
subsequently to close and reopen that file for log rotation.
@retval A FILE pointer on success. Otherwise, NULL.
*/
FILE *my_freopen(const char *path, const char *mode, FILE *stream)
{
FILE *result;
#if defined(_WIN32)
result= my_win_freopen(path, mode, stream);
#else
result= my_safe_freopen(path, mode, stream);
#endif
return result;
}
/* Close a stream */
int my_fclose(FILE *fd, myf MyFlags)
{
int err,file;
DBUG_ENTER("my_fclose");
DBUG_PRINT("my",("stream: 0x%lx MyFlags: %d", (long) fd, MyFlags));
mysql_mutex_lock(&THR_LOCK_open);
file= my_fileno(fd);
#ifndef _WIN32
err= fclose(fd);
#else
err= my_win_fclose(fd);
#endif
if(err < 0)
{
set_my_errno(errno);
if (MyFlags & (MY_FAE | MY_WME))
{
char errbuf[MYSYS_STRERROR_SIZE];
my_error(EE_BADCLOSE, MYF(0), my_filename(file),
my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
}
}
else
my_stream_opened--;
if ((uint) file < my_file_limit && my_file_info[file].type != UNOPEN)
{
my_file_info[file].type = UNOPEN;
my_free(my_file_info[file].name);
}
mysql_mutex_unlock(&THR_LOCK_open);
DBUG_RETURN(err);
} /* my_fclose */
/* Make a stream out of a file handle */
/* Name may be 0 */
FILE *my_fdopen(File Filedes, const char *name, int Flags, myf MyFlags)
{
FILE *fd;
char type[5];
DBUG_ENTER("my_fdopen");
DBUG_PRINT("my",("Fd: %d Flags: %d MyFlags: %d",
Filedes, Flags, MyFlags));
make_ftype(type,Flags);
#ifdef _WIN32
fd= my_win_fdopen(Filedes, type);
#else
fd= fdopen(Filedes, type);
#endif
if (!fd)
{
set_my_errno(errno);
if (MyFlags & (MY_FAE | MY_WME))
{
char errbuf[MYSYS_STRERROR_SIZE];
my_error(EE_CANT_OPEN_STREAM, MYF(0),
my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
}
}
else
{
mysql_mutex_lock(&THR_LOCK_open);
my_stream_opened++;
if ((uint) Filedes < (uint) my_file_limit)
{
if (my_file_info[Filedes].type != UNOPEN)
{
my_file_opened--; /* File is opened with my_open ! */
}
else
{
my_file_info[Filedes].name= my_strdup(key_memory_my_file_info,
name,MyFlags);
}
my_file_info[Filedes].type = STREAM_BY_FDOPEN;
}
mysql_mutex_unlock(&THR_LOCK_open);
}
DBUG_PRINT("exit",("stream: 0x%lx", (long) fd));
DBUG_RETURN(fd);
} /* my_fdopen */
/*
Make a fopen() typestring from a open() type bitmap
SYNOPSIS
make_ftype()
to String for fopen() is stored here
flag Flag used by open()
IMPLEMENTATION
This routine attempts to find the best possible match
between a numeric option and a string option that could be
fed to fopen. There is not a 1 to 1 mapping between the two.
NOTE
On Unix, O_RDONLY is usually 0
MAPPING
r == O_RDONLY
w == O_WRONLY|O_TRUNC|O_CREAT
a == O_WRONLY|O_APPEND|O_CREAT
r+ == O_RDWR
w+ == O_RDWR|O_TRUNC|O_CREAT
a+ == O_RDWR|O_APPEND|O_CREAT
*/
static void make_ftype(char * to, int flag)
{
/* check some possible invalid combinations */
DBUG_ASSERT((flag & (O_TRUNC | O_APPEND)) != (O_TRUNC | O_APPEND));
DBUG_ASSERT((flag & (O_WRONLY | O_RDWR)) != (O_WRONLY | O_RDWR));
if ((flag & (O_RDONLY|O_WRONLY)) == O_WRONLY)
*to++= (flag & O_APPEND) ? 'a' : 'w';
else if (flag & O_RDWR)
{
/* Add '+' after theese */
if (flag & (O_TRUNC | O_CREAT))
*to++= 'w';
else if (flag & O_APPEND)
*to++= 'a';
else
*to++= 'r';
*to++= '+';
}
else
*to++= 'r';
#if FILE_BINARY /* If we have binary-files */
if (flag & FILE_BINARY)
*to++='b';
#endif
*to='\0';
} /* make_ftype */