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-rw-r--r--mysys/mf_tempfile.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/mysys/mf_tempfile.c b/mysys/mf_tempfile.c
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+++ b/mysys/mf_tempfile.c
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+/* Copyright (c) 2000, 2013, 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 St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+#include "mysys_priv.h"
+#include <m_string.h>
+#include "my_static.h"
+#include "mysys_err.h"
+#include <errno.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+
+#ifdef HAVE_MKOSTEMP
+#define mkstemp(A) mkostemp(A, O_CLOEXEC)
+#endif
+
+/*
+ @brief
+ Create a temporary file with unique name in a given directory
+
+ @details
+ create_temp_file
+ to pointer to buffer where temporary filename will be stored
+ dir directory where to create the file
+ prefix prefix the filename with this
+ mode Flags to use for my_create/my_open
+ MyFlags Magic flags
+
+ @return
+ File descriptor of opened file if success
+ -1 and sets errno if fails.
+
+ @note
+ The behaviour of this function differs a lot between
+ implementation, it's main use is to generate a file with
+ a name that does not already exist.
+
+ When passing MY_TEMPORARY flag in MyFlags the file is automatically deleted
+
+ "mode" bits that always must be used for newly created files with
+ unique file names (O_EXCL | O_TRUNC | O_CREAT | O_RDWR) are added
+ automatically, and shouldn't be specified by the caller.
+
+ The implementation using mkstemp should be considered the
+ reference implementation when adding a new or modifying an
+ existing one
+
+*/
+
+File create_temp_file(char *to, const char *dir, const char *prefix,
+ int mode, myf MyFlags)
+{
+ File file= -1;
+
+ DBUG_ENTER("create_temp_file");
+ DBUG_PRINT("enter", ("dir: %s, prefix: %s", dir ? dir : "(null)", prefix));
+ DBUG_ASSERT((mode & (O_EXCL | O_TRUNC | O_CREAT | O_RDWR)) == 0);
+
+ mode|= O_TRUNC | O_CREAT | O_RDWR; /* not O_EXCL, see Windows code below */
+
+#ifdef _WIN32
+ {
+ TCHAR path_buf[MAX_PATH-14];
+ /*
+ Use GetTempPath to determine path for temporary files.
+ This is because the documentation for GetTempFileName
+ has the following to say about this parameter:
+ "If this parameter is NULL, the function fails."
+ */
+ if (!dir)
+ {
+ if(GetTempPath(sizeof(path_buf), path_buf) > 0)
+ dir = path_buf;
+ }
+ /*
+ Use GetTempFileName to generate a unique filename, create
+ the file and release it's handle
+ - uses up to the first three letters from prefix
+ */
+ if (GetTempFileName(dir, prefix, 0, to) == 0)
+ DBUG_RETURN(-1);
+
+ DBUG_PRINT("info", ("name: %s", to));
+
+ if (MyFlags & MY_TEMPORARY)
+ mode|= O_SHORT_LIVED | O_TEMPORARY;
+
+ /*
+ Open the file without O_EXCL flag
+ since the file has already been created by GetTempFileName
+ */
+ if ((file= my_open(to, mode, MyFlags)) < 0)
+ {
+ /* Open failed, remove the file created by GetTempFileName */
+ int tmp= my_errno;
+ (void) my_delete(to, MYF(0));
+ my_errno= tmp;
+ }
+ }
+#elif defined(HAVE_MKSTEMP)
+ if (!dir && ! (dir =getenv("TMPDIR")))
+ dir= DEFAULT_TMPDIR;
+#ifdef O_TMPFILE
+ {
+ static int O_TMPFILE_works= 1;
+
+ if ((MyFlags & MY_TEMPORARY) && O_TMPFILE_works)
+ {
+ /* explictly don't use O_EXCL here has it has a different
+ meaning with O_TMPFILE
+ */
+ if ((file= open(dir, (mode & ~O_CREAT) | O_TMPFILE | O_CLOEXEC,
+ S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP)) >= 0)
+ {
+ my_snprintf(to, FN_REFLEN, "%s/#sql/fd=%d", dir, file);
+ file=my_register_filename(file, to, FILE_BY_O_TMPFILE,
+ EE_CANTCREATEFILE, MyFlags);
+ }
+ else if (errno == EOPNOTSUPP || errno == EINVAL)
+ {
+ my_printf_error(EE_CANTCREATEFILE, "O_TMPFILE is not supported on %s "
+ "(disabling future attempts)",
+ MYF(ME_NOTE | ME_ERROR_LOG_ONLY), dir);
+ O_TMPFILE_works= 0;
+ }
+ }
+ }
+ if (file == -1)
+#endif /* O_TMPFILE */
+ {
+ char prefix_buff[30];
+ uint pfx_len;
+ File org_file;
+
+ pfx_len= (uint) (strmov(strnmov(prefix_buff,
+ prefix ? prefix : "tmp.",
+ sizeof(prefix_buff)-7),"XXXXXX") -
+ prefix_buff);
+ if (strlen(dir)+ pfx_len > FN_REFLEN-2)
+ {
+ errno=my_errno= ENAMETOOLONG;
+ DBUG_RETURN(file);
+ }
+ strmov(convert_dirname(to,dir,NullS),prefix_buff);
+ org_file=mkstemp(to);
+ if (org_file >= 0 && (MyFlags & MY_TEMPORARY))
+ (void) my_delete(to, MYF(MY_WME));
+ file=my_register_filename(org_file, to, FILE_BY_MKSTEMP,
+ EE_CANTCREATEFILE, MyFlags);
+ /* If we didn't manage to register the name, remove the temp file */
+ if (org_file >= 0 && file < 0)
+ {
+ int tmp=my_errno;
+ close(org_file);
+ (void) my_delete(to, MYF(MY_WME));
+ my_errno=tmp;
+ }
+ }
+#else
+#error No implementation found for create_temp_file
+#endif
+ if (file >= 0)
+ statistic_increment(my_tmp_file_created,&THR_LOCK_open);
+ DBUG_RETURN(file);
+}