Extend open backend to create buffers only optionally.

src/cdi_int.h

@@ -355,7 +355,8 @@ streamUnpack(char * unpackBuffer, int unpackBufferSize,
 
 int
 cdiStreamOpenDefaultDelegate(const char *filename, const char *filemode,
-                             int filetype, stream_t *streamptr);
+                             int filetype, stream_t *streamptr,
+                             int recordBufIsToBeCreated);
 
 void
 cdiStreamDefVlist_(int streamID, int vlistID);

src/pio.c

@@ -143,7 +143,8 @@ int pioFileOpen(const char *filename, const char *mode)
 
 int
 cdiPioStreamOpen(const char *filename, const char *filemode,
-                 int filetype, stream_t *streamptr)
+                 int filetype, stream_t *streamptr,
+                 int recordBufIsToBeCreated)
 {
   if ( tolower ( * filemode ) == 'w' )
     {

src/pio.h

@@ -18,7 +18,8 @@ int pioFileOpen(const char *filename, const char *mode);
 int    pioFileClose    ( int );
 size_t pioFileWrite    ( int, int, const void*, size_t );
 int cdiPioStreamOpen(const char *filename, const char *filemode,
-                     int filetype, stream_t *streamptr);
+                     int filetype, stream_t *streamptr,
+                     int recordBufIsToBeCreated);
 void cdiPioStreamDefVlist_(int streamID, int vlistID);
 void cdiPioStreamWriteVar_(int streamID, int varID, int memtype,
                            const void *data, int nmiss);

src/stream.c

@@ -658,7 +658,8 @@ extern int cdiPioSerialOpenFileMap(int streamID);
 #endif
 
 int cdiStreamOpenDefaultDelegate(const char *filename, const char *filemode,
-                                 int filetype, stream_t *streamptr)
+                                 int filetype, stream_t *streamptr,
+                                 int recordBufIsToBeCreated)
 {
   int fileID;
   switch (filetype)
@@ -669,8 +670,11 @@ int cdiStreamOpenDefaultDelegate(const char *filename, const char *filemode,
       {
         fileID = gribOpen(filename, filemode);
         if ( fileID < 0 ) fileID = CDI_ESYSTEM;
-        streamptr->record = (Record *) malloc(sizeof(Record));
-        streamptr->record->buffer = NULL;
+        if (recordBufIsToBeCreated)
+          {
+            streamptr->record = (Record *) malloc(sizeof(Record));
+            streamptr->record->buffer = NULL;
+          }
         break;
       }
 #endif
@@ -679,9 +683,12 @@ int cdiStreamOpenDefaultDelegate(const char *filename, const char *filemode,
       {
         fileID = fileOpen(filename, filemode);
         if ( fileID < 0 ) fileID = CDI_ESYSTEM;
-        streamptr->record = (Record *) malloc(sizeof(Record));
-        streamptr->record->buffer = NULL;
-        streamptr->record->srvp   = srvNew();
+        if (recordBufIsToBeCreated)
+          {
+            streamptr->record = (Record *) malloc(sizeof(Record));
+            streamptr->record->buffer = NULL;
+            streamptr->record->srvp   = srvNew();
+          }
         break;
       }
 #endif
@@ -690,9 +697,12 @@ int cdiStreamOpenDefaultDelegate(const char *filename, const char *filemode,
       {
         fileID = fileOpen(filename, filemode);
         if ( fileID < 0 ) fileID = CDI_ESYSTEM;
-        streamptr->record = (Record *) malloc(sizeof(Record));
-        streamptr->record->buffer = NULL;
-        streamptr->record->extp   = extNew();
+        if (recordBufIsToBeCreated)
+          {
+            streamptr->record = (Record *) malloc(sizeof(Record));
+            streamptr->record->buffer = NULL;
+            streamptr->record->extp   = extNew();
+          }
         break;
       }
 #endif
@@ -701,9 +711,12 @@ int cdiStreamOpenDefaultDelegate(const char *filename, const char *filemode,
       {
         fileID = fileOpen(filename, filemode);
         if ( fileID < 0 ) fileID = CDI_ESYSTEM;
-        streamptr->record = (Record *) malloc(sizeof(Record));
-        streamptr->record->buffer = NULL;
-        streamptr->record->iegp   = iegNew();
+        if (recordBufIsToBeCreated)
+          {
+            streamptr->record = (Record *) malloc(sizeof(Record));
+            streamptr->record->buffer = NULL;
+            streamptr->record->iegp   = iegNew();
+          }
         break;
       }
 #endif