enable chunk driver when chunking hint is set

Author: khou2020

src/dispatchers/file.c

@@ -290,6 +290,9 @@ ncmpi_create(MPI_Comm    comm,
 #ifdef ENABLE_BURST_BUFFER
     int enable_bb_driver=0;
 #endif
+#ifdef ENABLE_CHUNKING
+    int enable_chk_driver=0;
+#endif
 
     MPI_Comm_rank(comm, &rank);
     MPI_Comm_size(comm, &nprocs);
@@ -382,6 +385,18 @@ ncmpi_create(MPI_Comm    comm,
             enable_bb_driver = 1;
     }
 #endif
+#ifdef ENABLE_CHUNKING
+    if (combined_info != MPI_INFO_NULL) {
+        char value[MPI_MAX_INFO_VAL];
+        int flag;
+
+        /* check if nc_chunking is enabled */
+        MPI_Info_get(combined_info, "nc_chunking", MPI_MAX_INFO_VAL-1,
+                     value, &flag);
+        if (flag && strcasecmp(value, "enable") == 0)
+            enable_chk_driver = 1;
+    }
+#endif
 
     /* Use environment variable and cmode to tell the file format
      * which is later used to select the right driver.
@@ -462,6 +477,11 @@ ncmpi_create(MPI_Comm    comm,
     if (enable_bb_driver)
         driver = ncbbio_inq_driver();
     else
+#endif
+#ifdef ENABLE_CHUNKING
+    if (enable_chk_driver)
+        driver = ncchkio_inq_driver();
+    else
 #endif
         /* default is the driver built on top of MPI-IO */
         driver = ncmpio_inq_driver();
@@ -558,6 +578,9 @@ ncmpi_open(MPI_Comm    comm,
 #ifdef ENABLE_BURST_BUFFER
     int enable_bb_driver=0;
 #endif
+#ifdef ENABLE_CHUNKING
+    int enable_chk_driver=0;
+#endif
 
     MPI_Comm_rank(comm, &rank);
     MPI_Comm_size(comm, &nprocs);
@@ -688,6 +711,18 @@ ncmpi_open(MPI_Comm    comm,
             enable_bb_driver = 1;
     }
 #endif
+#ifdef ENABLE_CHUNKING
+    if (combined_info != MPI_INFO_NULL) {
+        char value[MPI_MAX_INFO_VAL];
+        int flag;
+
+        /* check if nc_chunking is enabled */
+        MPI_Info_get(combined_info, "nc_chunking", MPI_MAX_INFO_VAL-1,
+                     value, &flag);
+        if (flag && strcasecmp(value, "enable") == 0)
+            enable_chk_driver = 1;
+    }
+#endif
 
 #ifdef ENABLE_NETCDF4
     if (format == NC_FORMAT_NETCDF4_CLASSIC || format == NC_FORMAT_NETCDF4) {
@@ -716,6 +751,11 @@ ncmpi_open(MPI_Comm    comm,
     if (enable_bb_driver)
         driver = ncbbio_inq_driver();
     else
+#endif
+#ifdef ENABLE_CHUNKING
+    if (enable_chk_driver)
+        driver = ncchkio_inq_driver();
+    else
 #endif
     {
         /* ncmpio driver */

src/include/dispatch.h

@@ -153,6 +153,8 @@ extern PNC_driver* ncfoo_inq_driver(void);
 
 extern PNC_driver* ncbbio_inq_driver(void);
 
+extern PNC_driver* ncchkio_inq_driver(void);
+
 extern int PNC_check_id(int ncid, PNC **pncp);
 
 #endif /* _PNC_DISPATCH_H */

src/libs/Makefile.am

@@ -32,6 +32,9 @@ endif
 if ENABLE_BURST_BUFFER
    libpnetcdf_la_LIBADD += ../drivers/ncbbio/libncbbio.la
 endif
+if ENABLE_CHUNKING
+   libpnetcdf_la_LIBADD += ../drivers/ncchunkio/libncchkio.la
+endif
 if ENABLE_ADIOS
    libpnetcdf_la_LIBADD += ../drivers/ncadios/libncadios.la
 endif