Overwrite an existing parfile unless

  - it is identical with the original parfile
  - this is a recovery run
This closes PR CactusBase/884.


git-svn-id: http://svn.cactuscode.org/arrangements/CactusBase/IOUtil/trunk@177 b32723a9-ab3a-4a60-88e2-2e5d99d7c17a

2 files changed, 104 insertions, 84 deletions

diff --git a/doc/documentation.tex b/doc/documentation.tex
index 93f7b30..39e3cb4 100644
--- a/doc/documentation.tex
+++ b/doc/documentation.tex
@@ -192,8 +192,11 @@ This is controlled by the {\tt IO::parfile\_write} parameter:
 \end{itemize}
 
 The name of the new parameter file defaults to the original filename, unless the
-parameter {\tt IO::parfile\_name} is set. Note that if a file already exists
-with the chosen name it will not be overwritten.
+parameter {\tt IO::parfile\_name} is set. Note that an already existing file
+with the chosen name will be overwritten unless it is identical with the
+original parameter file, or if Cactus was recovered from a checkpoint (in which
+case you don't want to overwrite an existing parameter file with your recovery
+parameter file).
 
 
 \section{I/O Modes}
diff --git a/src/Startup.c b/src/Startup.c
index 1359d0e..92cd526 100644
--- a/src/Startup.c
+++ b/src/Startup.c
@@ -62,8 +62,8 @@ typedef struct t_param_list
  **********************     Static Routines     *********************
  ********************************************************************/
 static void *SetupGH (tFleshConfig *config, int convergence_level, cGH *GH);
-static int CopyParFile (const char *new_parfilename, const char *out_dir);
-static int GenerateParFile (const char *new_parfilename, const char *out_dir);
+static int CopyParFile (int recovered);
+static int GenerateParFile (int recovered);
 static int DumpParameters (FILE *outfile);
 
 
@@ -669,11 +669,11 @@ static void *SetupGH (tFleshConfig *config, int convergence_level, cGH *GH)
   {
     if (CCTK_Equals (parfile_write, "copy"))
     {
-      CopyParFile (parfile_name, out_dir);
+      CopyParFile (newGH->recovered);
     }
     else if (CCTK_Equals (parfile_write, "generate"))
     {
-      GenerateParFile (parfile_name, out_dir);
+      GenerateParFile (newGH->recovered);
     }
   }
 
@@ -687,23 +687,13 @@ static void *SetupGH (tFleshConfig *config, int convergence_level, cGH *GH)
    @author     Thomas Radke
    @desc
                Copies the original parameter file to a new one in 'IO::out_dir'.
-               Note that the new parameter file is only written if no such
-               file existed before.
+               Note that the new parameter file will usually overwrite an 
+               existing file unless
+                 - the new parameter file is identical with the original one
+                 - this is a recovery run
    @enddesc
    @calls      CCTK_ParameterFilename
 
-   @var        parfile_name
-   @vdesc      name of the new parfile (or empty string if the original
-               parfile name should be used)
-   @vtype      const char *
-   @vio        in
-   @endvar
-   @var        out_dir
-   @vdesc      directory to write the new parfile to
-   @vtype      const char *
-   @vio        in
-   @endvar
-
    @returntype int
    @returndesc
                 0 for success, or<BR>
@@ -711,11 +701,12 @@ static void *SetupGH (tFleshConfig *config, int convergence_level, cGH *GH)
                -2 if new parameter file couldn't be opened for writing<BR>
    @endreturndesc
 @@*/
-static int CopyParFile (const char *parfile_name, const char *out_dir)
+static int CopyParFile (int recovered)
 {
-  int in_parfile, out_parfile, bytes;
+  int in_parfile, out_parfile, bytes, flags;
   char *out_parfilename, buffer[256];
-  struct stat stat_buf;
+  struct stat in_stat_buf, out_stat_buf;
+  DECLARE_CCTK_PARAMETERS
 
 
   /* get the name of the original parfile and open it for reading */
@@ -729,9 +720,9 @@ static int CopyParFile (const char *parfile_name, const char *out_dir)
     return (-1);
   }
   /* use the file mode of the original parfile to create the new one */
-  if (fstat (in_parfile, &stat_buf))
+  if (fstat (in_parfile, &in_stat_buf))
   {
-    stat_buf.st_mode = 0644;
+    in_stat_buf.st_mode = 0644;
   }
 
   /* build the name of the output parfile */
@@ -751,22 +742,39 @@ static int CopyParFile (const char *parfile_name, const char *out_dir)
   out_parfilename = (char *) malloc (strlen(out_dir) + strlen(parfile_name)+2);
   sprintf (out_parfilename, "%s/%s", out_dir, parfile_name);
 
-  /* binary-copy the input parfile to the output parfile */
-  out_parfile = open (out_parfilename, O_CREAT | O_WRONLY | O_EXCL,
-                      stat_buf.st_mode);
-  if (out_parfile >= 0)
+  /* check whether input and output files are identical */
+  if (! stat (out_parfilename, &out_stat_buf) &&
+      in_stat_buf.st_ino == out_stat_buf.st_ino)
   {
-    while ((bytes = read (in_parfile, buffer, sizeof (buffer))) > 0)
-    {
-      write (out_parfile, buffer, bytes);
-    }
-    close (out_parfile);
+    CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
+                "Parameter file '%s' to be written into directory '%s' is "
+                "identical with original parameter file. Parameter file will "
+                "not be copied.", parfile_name, out_dir);
+    out_parfile = 0;
   }
   else
   {
-    CCTK_VWarn (3, __LINE__, __FILE__, CCTK_THORNSTRING,
-                "Couldn't write parameter file '%s' (%s)",
-                out_parfilename, strerror (errno));
+    /* binary-copy the input parfile to the output parfile */
+    flags = O_CREAT | O_WRONLY;
+    if (recovered)
+    {
+      flags |= O_EXCL;
+    }
+    out_parfile = open (out_parfilename, flags, in_stat_buf.st_mode);
+    if (out_parfile >= 0)
+    {
+      while ((bytes = read (in_parfile, buffer, sizeof (buffer))) > 0)
+      {
+        write (out_parfile, buffer, bytes);
+      }
+      close (out_parfile);
+    }
+    else
+    {
+      CCTK_VWarn (3, __LINE__, __FILE__, CCTK_THORNSTRING,
+                  "Couldn't write parameter file '%s' (%s)",
+                  out_parfilename, strerror (errno));
+    }
   }
 
   /* clean up */
@@ -785,20 +793,16 @@ static int CopyParFile (const char *parfile_name, const char *out_dir)
                Generates a new parameter file in 'IO::out_dir' with an
                ActiveThorns list and a sorted list of all active parameters
                which have been set in the original parameter file.<BR>
-               Note that the new parameter file is only written if no such
-               file existed before.
+               Note that the new parameter file will usually overwrite an
+               existing file unless
+                 - the new parameter file is identical with the original one
+                 - this is a recovery run
    @enddesc
    @calls      CCTK_ParameterFilename
 
-   @var        parfile_name
-   @vdesc      name of the new parfile (or empty string if the original
-               parfile name should be used)
-   @vtype      const char *
-   @vio        in
-   @endvar
-   @var        out_dir
-   @vdesc      directory to write the new parfile to
-   @vtype      const char *
+   @var        recovered
+   @vdesc      flag indicating whether this is a recovery run
+   @vtype      int
    @vio        in
    @endvar
 
@@ -809,28 +813,24 @@ static int CopyParFile (const char *parfile_name, const char *out_dir)
                -2 if new parameter file couldn't be opened for writing<BR>
    @endreturndesc
 @@*/
-static int GenerateParFile (const char *parfile_name, const char *out_dir)
+static int GenerateParFile (int recovered)
 {
   FILE *outfile;
-  int out_parfile;
+  int out_parfile, flags;
   char *out_parfilename, buffer[256];
-  struct stat stat_buf;
+  struct stat in_stat_buf, out_stat_buf;
+  DECLARE_CCTK_PARAMETERS
 
 
   /* get the name of the original parfile and stat(2) it */
   CCTK_ParameterFilename (sizeof (buffer), buffer);
-  if (stat (buffer, &stat_buf))
+  if (stat (buffer, &in_stat_buf))
   {
     CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
                 "Couldn't stat(2) original parameter file '%s' (%s)",
                 buffer, strerror (errno));
     return (-1);
   }
-  /* use the file mode of the original parfile to create the new one */
-  if (stat (buffer, &stat_buf))
-  {
-    stat_buf.st_mode = 0644;
-  }
 
   /* build the name of the output parfile */
   if (! *parfile_name)
@@ -849,37 +849,54 @@ static int GenerateParFile (const char *parfile_name, const char *out_dir)
   out_parfilename = (char *) malloc (strlen(out_dir) + strlen(parfile_name)+2);
   sprintf (out_parfilename, "%s/%s", out_dir, parfile_name);
 
-  /* open the output parfile for writing */
-  out_parfile = open (out_parfilename, O_CREAT | O_WRONLY | O_EXCL,
-                      stat_buf.st_mode);
-  if (out_parfile >= 0)
-  {
-    outfile = fdopen (out_parfile, "w");
-  }
-  if (out_parfile >= 0 && outfile)
+  /* check whether input and output files are identical */
+  if (! stat (out_parfilename, &out_stat_buf) &&
+      in_stat_buf.st_ino == out_stat_buf.st_ino)
   {
-    fprintf (outfile, "# '%s' automatically generated by Cactus version %s\n",
-             out_parfilename, CCTK_FullVersion ());
-    fprintf (outfile, "# Original parameter file was '%s'\n", buffer);
-    Util_CurrentTime (sizeof (buffer), buffer);
-    fprintf (outfile, "# Run time/date was %s ", buffer);
-    Util_CurrentDate (sizeof (buffer), buffer);
-    fprintf (outfile, "%s ", buffer);
-    Util_GetHostName (buffer, sizeof (buffer));
-    fprintf (outfile, "on host '%s' with %d processor(s)\n\n",
-             buffer, CCTK_nProcs (NULL));
-    DumpParameters (outfile);
-    fclose (outfile);
+    CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
+                "Parameter file '%s' to be written into directory '%s' is "
+                "identical with original parameter file. Parameter file will "
+                "not be generated.", parfile_name, out_dir);
+    out_parfile = 0;
   }
   else
   {
-    CCTK_VWarn (3, __LINE__, __FILE__, CCTK_THORNSTRING,
-                "Couldn't write parameter file '%s' (%s)",
-                out_parfilename, strerror (errno));
-  }
-  if (out_parfile >= 0)
-  {
-    close (out_parfile);
+    flags = O_CREAT | O_WRONLY;
+    if (recovered)
+    {
+      flags |= O_EXCL;
+    }
+
+    out_parfile = open (out_parfilename, flags, in_stat_buf.st_mode);
+    if (out_parfile >= 0)
+    {
+      outfile = fdopen (out_parfile, "w");
+    }
+    if (out_parfile >= 0 && outfile)
+    {
+      fprintf (outfile, "# '%s' automatically generated by Cactus version %s\n",
+               out_parfilename, CCTK_FullVersion ());
+      fprintf (outfile, "# Original parameter file was '%s'\n", buffer);
+      Util_CurrentTime (sizeof (buffer), buffer);
+      fprintf (outfile, "# Run time/date was %s ", buffer);
+      Util_CurrentDate (sizeof (buffer), buffer);
+      fprintf (outfile, "%s ", buffer);
+      Util_GetHostName (buffer, sizeof (buffer));
+      fprintf (outfile, "on host '%s' with %d processor(s)\n\n",
+               buffer, CCTK_nProcs (NULL));
+      DumpParameters (outfile);
+      fclose (outfile);
+    }
+    else
+    {
+      CCTK_VWarn (3, __LINE__, __FILE__, CCTK_THORNSTRING,
+                  "Couldn't write parameter file '%s' (%s)",
+                  out_parfilename, strerror (errno));
+    }
+    if (out_parfile >= 0)
+    {
+      close (out_parfile);
+    }
   }
 
   /* clean up */