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-rw-r--r--mysql/mysys/my_fopen.c379
1 files changed, 379 insertions, 0 deletions
diff --git a/mysql/mysys/my_fopen.c b/mysql/mysys/my_fopen.c
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+/* 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 */