[svn-r80] Byte-swapping datatype conversion routine added for basic portability of

data files.  Further enhancements will need to be made to support "weird"
architectures.

src/H5Dconv.c

@@ -0,0 +1,131 @@
+/****************************************************************************
+* NCSA HDF                                                                 *
+* Software Development Group                                               *
+* National Center for Supercomputing Applications                          *
+* University of Illinois at Urbana-Champaign                               *
+* 605 E. Springfield, Champaign IL 61820                                   *
+*                                                                          *
+* For conditions of distribution and use, see the accompanying             *
+* hdf/COPYING file.                                                        *
+*                                                                          *
+****************************************************************************/
+
+#ifdef RCSID
+static char RcsId[] = "@(#)$Revision$";
+#endif
+
+/* $Id$ */
+
+/*LINTLIBRARY */
+/*+
+   FILE
+       H5Dconv.c
+   HDF5 trivial datatype converion routines
+
+   EXPORTED ROUTINES
+
+   LIBRARY-SCOPED ROUTINES
+
+   LOCAL ROUTINES
+   + */
+
+#include <H5private.h>  /* Generic Functions */
+#include <H5Dprivate.h> /* Dataset functions */
+#include <H5Eprivate.h> /* Error handling */
+
+#define PABLO_MASK	H5D_mask
+
+/*--------------------- Locally scoped variables -----------------------------*/
+
+/* Whether we've installed the library termination function yet for this interface */
+static intn interface_initialize_g = FALSE;
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5D_convert_buf
+ PURPOSE
+    Byte-Swap a buffer of data
+ USAGE
+    herr_t H5D_convert_buf(dst, src, len, size)
+        VOIDP dst;         OUT: Buffer to fill with converted data
+        VOIDP src;         IN: Buffer to converted data from
+        uintn len;         IN: Number of bytes to convert
+        uintn size;        IN: Size of quantity to byte-swap
+ RETURNS
+    SUCCEED/FAIL
+ DESCRIPTION
+        This function is a byte-swapping memcpy.
+--------------------------------------------------------------------------*/
+herr_t H5D_convert_buf(void *dst, const void *src, uintn len, uintn size)
+{
+    const char *s=(const char *)src;
+    char *d=(char *)dst;
+    herr_t        ret_value = SUCCEED;
+
+    FUNC_ENTER(H5D_convert_buf, NULL, FAIL);
+
+    /* Clear errors and check args and all the boring stuff. */
+    H5ECLEAR;
+    assert(dst);
+    assert(src);
+    assert(len>0);
+    assert(size==8 || size==4 || size==2 || size==1);
+
+    switch(size)
+      {
+          case 1:   /* straight memcpy() */
+              HDmemcpy(d,s,len);
+              break;
+
+          case 2:   /* 2-byte swapping */
+              while(len>0)
+                {
+                    *d++=*(s+1);
+                    *d++=*s;
+                    s+=2;
+                    len-=2;
+                } /* end while */
+              break;
+
+          case 4:   /* 4-byte swapping */
+              while(len>0)
+                {
+                    *d++=*(s+3);
+                    *d++=*(s+2);
+                    *d++=*(s+1);
+                    *d++=*s;
+                    s+=4;
+                    len-=4;
+                } /* end while */
+              break;
+
+          case 8:   /* 8-byte swapping */
+              while(len>0)
+                {
+                    *d++=*(s+7);
+                    *d++=*(s+6);
+                    *d++=*(s+5);
+                    *d++=*(s+4);
+                    *d++=*(s+3);
+                    *d++=*(s+2);
+                    *d++=*(s+1);
+                    *d++=*s;
+                    s+=8;
+                    len-=8;
+                } /* end while */
+              break;
+
+          default:
+              HGOTO_ERROR(H5E_INTERNAL, H5E_UNSUPPORTED, FAIL);
+      } /* end switch */
+
+done:
+  if(ret_value == FAIL)   
+    { /* Error condition cleanup */
+
+    } /* end if */
+
+    /* Normal function cleanup */
+
+    FUNC_LEAVE(ret_value);
+} /* end H5D_convert_buf() */