[svn-r6114] Purpose:

    Code Cleanup & New Feature

Description:
    H5config.h.in:
        Removed H5_HAVE_COMPRESSION & H5_HAVE_FILTER_GZIP flags.

        Added H5_HAVE_FILTER_DEFLATE flag.

    H5Z.c:
    H5Zprivate.h:
    H5Zpublic.h:
        Switched from using H5_HAVE_COMPRESSION flag in favor of
        H5_HAVE_FILTER_DEFLATE.

        Added H5Zunregister & H5Zfilter_avail API functions.

        Changed a numeric constant (256) to a symbolic constant
        (H5Z_FILTER_RESERVED).

        Automatically add the shuffling filter to the list of available filters
        (when it is enabled).

        Moved prototypes for H5Z_filter_deflate & H5Z_filter_shuffle from the
        public header into the private header.

    H5Zdeflate.c:
        Switched from using H5_HAVE_COMPRESSION & H5_HAVE_FILTER_GZIP flags in
        favor of H5_HAVE_FILTER_DEFLATE.

        Cleaned up formatting & error reporting a bit.

    H5Zshuffle.c:
        Rewrote shuffling algorithm to be more efficient.

        Added error checking & reporting.

        Added standard Pablo information.

        Added standard function header comment.

        Added FUNC_ENTER & FUNC_LEAVE macros.

Platforms tested:
    Tested h5committest {arabica (fortran), eirene (fortran, C++)
        modi4 (parallel, fortran)}
    FreeBSD 4.7 (sleipnir)

1 files changed, 93 insertions, 60 deletions

diff --git a/src/H5Zshuffle.c b/src/H5Zshuffle.c
index 61dcc4f..ffd676f 100644
--- a/src/H5Zshuffle.c
+++ b/src/H5Zshuffle.c
@@ -9,73 +9,106 @@
 #include "H5Eprivate.h"
 #include "H5MMprivate.h"
 #include "H5Zprivate.h"
-#include <stdio.h>
 
 #ifdef H5_HAVE_FILTER_SHUFFLE
 
-size_t H5Z_filter_shuffle(unsigned flags,
-			  size_t cd_nelmts,
-			  const unsigned cd_values[],
-			  size_t nbytes,
-			  size_t *buf_size,void **buf) {
-  
-  size_t i;
-  size_t j;
-  size_t k;
-  size_t ret_value = 0;
-  size_t byte_pos;
-  size_t bytesoftype;
-  void* dest = NULL;
-  char* _src;
-  char* _des;
-  char* _dest;
-  size_t numofelements;
-   
-  bytesoftype=cd_values[0];
-  numofelements=nbytes/bytesoftype;
-  _src =(char*)(*buf);
+/* Interface initialization */
+#define PABLO_MASK	H5Z_shuffle_mask
+#define INTERFACE_INIT	NULL
+static int interface_initialize_g = 0;
 
-  dest = malloc((size_t)nbytes);
-  _dest =(char*)dest;
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Z_filter_shuffle
+ *
+ * Purpose:	Implement an I/O filter which "de-interlaces" a block of data
+ *              by putting all the bytes in a byte-position for each element
+ *              together in the block.  For example, for 4-byte elements stored
+ *              as: 012301230123, shuffling will store them as: 000111222333
+ *              Usually, the bytes in each byte position are more related to
+ *              each other and putting them together will increase compression.
+ *
+ * Return:	Success:	
+ *
+ *		Failure:	
+ *
+ * Programmer:	Kent Yang
+ *              Wednesday, November 13, 2002
+ *
+ * Modifications:
+ *              Quincey Koziol, November 13, 2002
+ *              Cleaned up code.
+ *
+ *-------------------------------------------------------------------------
+ */
+size_t
+H5Z_filter_shuffle(unsigned flags, size_t cd_nelmts,
+                  const unsigned cd_values[], size_t nbytes,
+                  size_t *buf_size, void **buf)
+{
+    void *dest = NULL;          /* Buffer to deposit [un]shuffled bytes into */
+    unsigned char *_src;        /* Alias for source buffer */
+    unsigned char *_dest;       /* Alias for destination buffer */
+    unsigned bytesoftype;       /* Number of bytes per element */
+    size_t numofelements;       /* Number of elements in buffer */
+    size_t i,j;                 /* Local index variables */
+    size_t ret_value;           /* Return value */
+
+    FUNC_ENTER_NOAPI(H5Z_filter_shuffle, 0);
+
+    /* Check arguments */
+    if (cd_nelmts!=1 || cd_values[0]==0)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, 0, "invalid shuffle parameters");
+
+    /* Get the number of bytes per element from the parameter block */
+    bytesoftype=cd_values[0];
+
+    /* Don't do anything for 1-byte elements */
+    if(bytesoftype>1) {
+        /* Compute the number of elements in buffer */
+        numofelements=nbytes/bytesoftype;
+
+        /* Allocate the destination buffer */
+        if (NULL==(dest = H5MM_malloc(nbytes)))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "memory allocation failed for shuffle buffer");
+
+        if(flags & H5Z_FLAG_REVERSE) {
+            /* Get the pointer to the source buffer */
+            _src =(unsigned char *)(*buf);
+
+            /* Input; unshuffle */
+            for(i=0; i<bytesoftype; i++) {
+                _dest=((unsigned char *)dest)+i;
+                for(j=0; j<numofelements; j++) {
+                    *_dest=*_src++;
+                    _dest+=bytesoftype;
+                } /* end for */
+            } /* end for */
+        } /* end if */
+        else {
+            /* Get the pointer to the destination buffer */
+            _dest =(unsigned char *)dest;
 
-  j = 0;
-  k = 0;
-  if(flags & H5Z_FLAG_REVERSE) {
-     for(i=0;i<nbytes;i++) {
-       byte_pos = 1 +j *numofelements; 
-       if(byte_pos > nbytes) {
-	 k++;
-	 j=0;
-	 byte_pos=1;
-       }
-       *(_dest+i)=*((char*)(_src+byte_pos-1+k));
-       j++;
-     }
-     free(*buf);
-     *buf = dest;
-     dest = NULL;
-     *buf_size=nbytes;
-     ret_value = nbytes;
-  }
+            /* Output; shuffle */
+            for(i=0; i<bytesoftype; i++) {
+                _src=((unsigned char *)(*buf))+i;
+                for(j=0; j<numofelements; j++) {
+                    *_dest++=*_src;
+                    _src+=bytesoftype;
+                } /* end for */
+            } /* end for */
+        } /* end else */
 
-  else {
-    for (i=0;i<nbytes;i++){
-      byte_pos = 1+j * bytesoftype; 
-      if(byte_pos >nbytes) {
-	k++;
-	j=0;
-	byte_pos = 1;
-      }
+        /* Set the buffer information to return */
+        H5MM_xfree(*buf);
+        *buf = dest;
+        *buf_size=nbytes;
+    } /* end else */
 
-      *(_dest+i)=*(_src+byte_pos-1+k);
-      j++;
-    }
-    free(*buf);
-     *buf = dest;
-     dest = NULL;
-     *buf_size=nbytes;
-     ret_value = nbytes;
-  }
+    /* Set the return value */
+    ret_value = nbytes;
 
+done:
+    FUNC_LEAVE (ret_value);
 }
 #endif /*H5_HAVE_FILTER_SHUFFLE */