From 100231bba8f19b4deb3c9e73911bc7bcaca8fbd8 Mon Sep 17 00:00:00 2001
From: Lars Pastewka <lars.pastewka@imtek.uni-freiburg.de>
Date: Sun, 1 Oct 2017 14:21:09 +0200
Subject: [PATCH] ENH: Enable multi file writes.

---
 src/USER-NETCDF/dump_netcdf.cpp       | 35 ++++++++++++++++++++-----
 src/USER-NETCDF/dump_netcdf_mpiio.cpp | 37 +++++++++++++++++++++------
 2 files changed, 57 insertions(+), 15 deletions(-)

diff --git a/src/USER-NETCDF/dump_netcdf.cpp b/src/USER-NETCDF/dump_netcdf.cpp
index aa2a4700a3..85a2d40935 100644
--- a/src/USER-NETCDF/dump_netcdf.cpp
+++ b/src/USER-NETCDF/dump_netcdf.cpp
@@ -88,8 +88,8 @@ DumpNetCDF::DumpNetCDF(LAMMPS *lmp, int narg, char **arg) :
 
   if (multiproc)
     error->all(FLERR,"Multi-processor writes are not supported.");
-  if (multifile)
-    error->all(FLERR,"Multiple files are not supported.");
+  if (append_flag && multifile)
+    error->all(FLERR,"Cannot append when writing to multiple files.");
 
   perat = new nc_perat_t[nfield];
 
@@ -224,6 +224,24 @@ DumpNetCDF::~DumpNetCDF()
 
 void DumpNetCDF::openfile()
 {
+  char *filecurrent = filename;
+  if (multifile && !singlefile_opened) {
+    char *filestar = filecurrent;
+    filecurrent = new char[strlen(filestar) + 16];
+    char *ptr = strchr(filestar,'*');
+    *ptr = '\0';
+    if (padflag == 0)
+      sprintf(filecurrent,"%s" BIGINT_FORMAT "%s",
+              filestar,update->ntimestep,ptr+1);
+    else {
+      char bif[8],pad[16];
+      strcpy(bif,BIGINT_FORMAT);
+      sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
+      sprintf(filecurrent,pad,filestar,update->ntimestep,ptr+1);
+    }
+    *ptr = '*';
+  }
+
   if (thermo && !singlefile_opened) {
     if (thermovar)  delete [] thermovar;
     thermovar = new int[output->thermo->nfield];
@@ -268,14 +286,14 @@ void DumpNetCDF::openfile()
   ntotalgr = group->count(igroup);
 
   if (filewriter) {
-    if (append_flag && access(filename, F_OK) != -1) {
+    if (append_flag && !multifile && access(filecurrent, F_OK) != -1) {
       // Fixme! Perform checks if dimensions and variables conform with
       // data structure standard.
 
       if (singlefile_opened) return;
       singlefile_opened = 1;
 
-      NCERRX( nc_open(filename, NC_WRITE, &ncid), filename );
+      NCERRX( nc_open(filecurrent, NC_WRITE, &ncid), filecurrent );
 
       // dimensions
       NCERRX( nc_inq_dimid(ncid, NC_FRAME_STR, &frame_dim), NC_FRAME_STR );
@@ -348,8 +366,8 @@ void DumpNetCDF::openfile()
       if (singlefile_opened) return;
       singlefile_opened = 1;
 
-      NCERRX( nc_create(filename, NC_64BIT_DATA, &ncid),
-          filename );
+      NCERRX( nc_create(filecurrent, NC_64BIT_DATA, &ncid),
+              filecurrent );
 
       // dimensions
       NCERRX( nc_def_dim(ncid, NC_FRAME_STR, NC_UNLIMITED, &frame_dim),
@@ -601,7 +619,10 @@ void DumpNetCDF::closefile()
     // append next time DumpNetCDF::openfile is called
     append_flag = 1;
     // write to next frame upon next open
-    framei++;
+    if (multifile)
+      framei = 1;
+    else
+      framei++;
   }
 }
 
diff --git a/src/USER-NETCDF/dump_netcdf_mpiio.cpp b/src/USER-NETCDF/dump_netcdf_mpiio.cpp
index e054772c41..271f963a4e 100644
--- a/src/USER-NETCDF/dump_netcdf_mpiio.cpp
+++ b/src/USER-NETCDF/dump_netcdf_mpiio.cpp
@@ -88,8 +88,8 @@ DumpNetCDFMPIIO::DumpNetCDFMPIIO(LAMMPS *lmp, int narg, char **arg) :
 
   if (multiproc)
     error->all(FLERR,"Multi-processor writes are not supported.");
-  if (multifile)
-    error->all(FLERR,"Multiple files are not supported.");
+  if (append_flag && multifile)
+    error->all(FLERR,"Cannot append when writing to multiple files.");
 
   perat = new nc_perat_t[nfield];
 
@@ -217,6 +217,24 @@ DumpNetCDFMPIIO::~DumpNetCDFMPIIO()
 
 void DumpNetCDFMPIIO::openfile()
 {
+  char *filecurrent = filename;
+  if (multifile && !singlefile_opened) {
+    char *filestar = filecurrent;
+    filecurrent = new char[strlen(filestar) + 16];
+    char *ptr = strchr(filestar,'*');
+    *ptr = '\0';
+    if (padflag == 0)
+      sprintf(filecurrent,"%s" BIGINT_FORMAT "%s",
+              filestar,update->ntimestep,ptr+1);
+    else {
+      char bif[8],pad[16];
+      strcpy(bif,BIGINT_FORMAT);
+      sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
+      sprintf(filecurrent,pad,filestar,update->ntimestep,ptr+1);
+    }
+    *ptr = '*';
+  }
+
   if (thermo && !singlefile_opened) {
     if (thermovar)  delete [] thermovar;
     thermovar = new int[output->thermo->nfield];
@@ -260,7 +278,7 @@ void DumpNetCDFMPIIO::openfile()
   // get total number of atoms
   ntotalgr = group->count(igroup);
 
-  if (append_flag && access(filename, F_OK) != -1) {
+  if (append_flag && !multifile && access(filecurrent, F_OK) != -1) {
     // Fixme! Perform checks if dimensions and variables conform with
     // data structure standard.
 
@@ -270,8 +288,8 @@ void DumpNetCDFMPIIO::openfile()
     if (singlefile_opened) return;
     singlefile_opened = 1;
 
-    NCERRX( ncmpi_open(MPI_COMM_WORLD, filename, NC_WRITE, MPI_INFO_NULL,
-                       &ncid), filename );
+    NCERRX( ncmpi_open(MPI_COMM_WORLD, filecurrent, NC_WRITE, MPI_INFO_NULL,
+                       &ncid), filecurrent );
 
     // dimensions
     NCERRX( ncmpi_inq_dimid(ncid, NC_FRAME_STR, &frame_dim), NC_FRAME_STR );
@@ -344,8 +362,8 @@ void DumpNetCDFMPIIO::openfile()
     if (singlefile_opened) return;
     singlefile_opened = 1;
 
-    NCERRX( ncmpi_create(MPI_COMM_WORLD, filename, NC_64BIT_DATA,
-                         MPI_INFO_NULL, &ncid), filename );
+    NCERRX( ncmpi_create(MPI_COMM_WORLD, filecurrent, NC_64BIT_DATA,
+                         MPI_INFO_NULL, &ncid), filecurrent );
 
     // dimensions
     NCERRX( ncmpi_def_dim(ncid, NC_FRAME_STR, NC_UNLIMITED, &frame_dim),
@@ -577,7 +595,10 @@ void DumpNetCDFMPIIO::closefile()
     // append next time DumpNetCDFMPIIO::openfile is called
     append_flag = 1;
     // write to next frame upon next open
-    framei++;
+    if (multifile)
+      framei = 1;
+    else
+      framei++;
   }
 }