[svn-r6400]

Purpose:
    Change feature
Description:
    Switch to Fletcher32 from Adler32 checksum
Platforms tested:
    arabica, eirene, modi4
Misc. update:
    MANIFEST and RELEASE.txt updated.

1 files changed, 161 insertions, 0 deletions

diff --git a/src/H5Zfletcher32.c b/src/H5Zfletcher32.c
new file mode 100644
index 0000000..bd4c68f
--- /dev/null
+++ b/src/H5Zfletcher32.c
@@ -0,0 +1,161 @@
+/*
+ * Copyright © 1999-2001 NCSA
+ *                       All rights reserved.
+ *
+ * Programmer:  Raymond Lu<slu@ncsa.uiuc.edu>
+ *              Jan 3, 2003
+ */
+#include "H5private.h"
+#include "H5Eprivate.h"
+#include "H5MMprivate.h"
+#include "H5Zprivate.h"
+
+#ifdef H5_HAVE_FILTER_FLETCHER32
+
+#define FLETCHER_LEN       4
+
+/* Interface initialization */
+#define PABLO_MASK	H5Z_fletcher32_mask
+#define INTERFACE_INIT	NULL
+static int interface_initialize_g = 0;
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Z_filter_fletcher32_compute
+ *
+ * Purpose:	Implement an Fletcher32 Checksum using 1's complement.
+ *
+ * Return:	Success: Fletcher32 value	
+ *
+ *		Failure: Can't fail
+ *
+ * Programmer:	Raymond Lu
+ *              Jan 3, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static unsigned int H5Z_filter_fletcher32_compute(unsigned short *buf, size_t len)
+{
+    size_t         count = len;
+    register unsigned int s1 = 0;
+    register unsigned int s2 = 0;
+    unsigned short *src = buf;
+
+    FUNC_ENTER_NOINIT(H5Z_filter_fletcher32_compute);
+
+    /* Compute checksum */
+    while(count > 1) {
+        s1 += *src++;
+        if(s1 & 0xFFFF0000) { /*Wrap around carry if occurred*/
+            s1 &= 0xFFFF;
+            s1++;
+        }
+        s2 += s1;
+        if(s2 & 0xFFFF0000) { /*Wrap around carry if occurred*/
+            s2 &= 0xFFFF;
+            s2++;
+        }
+        count -= 2;
+    }
+
+    if(count==1) {
+        s1 += *(unsigned char*)src;
+        if(s1 & 0xFFFF0000) { /*Wrap around carry if occurred*/
+            s1 &= 0xFFFF;
+            s1++;
+        }
+        s2 += s1;
+        if(s2 & 0xFFFF0000) { /*Wrap around carry if occurred*/
+            s2 &= 0xFFFF;
+            s2++;
+        }
+    }
+
+    FUNC_LEAVE_NOAPI((s2 << 16) + s1);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Z_filter_fletcher32
+ *
+ * Purpose:	Implement an I/O filter of Fletcher32 Checksum
+ *
+ * Return:	Success: size of data plus the size of Fletcher32 value	
+ *
+ *		Failure: 0	
+ *
+ * Programmer:	Raymond Lu
+ *              Jan 3, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+size_t
+H5Z_filter_fletcher32 (unsigned flags, size_t cd_nelmts, const unsigned cd_values[], 
+                     size_t nbytes, size_t *buf_size, void **buf)
+{
+    size_t	ret_value = 0;
+    void	*outbuf = NULL;
+    
+    unsigned char *src = (unsigned char*)(*buf);
+    unsigned int fletcher = 0;
+    
+    FUNC_ENTER_NOAPI(H5Z_filter_fletcher32, 0);
+
+    assert(sizeof(unsigned int)==4);
+   
+    if (flags & H5Z_FLAG_REVERSE) { /* Read */
+        size_t  src_nbytes = nbytes;
+        unsigned int origin_fletcher;
+
+        /* Do checksum if it's enabled for read; otherwise skip it
+         * to save performance. */
+        if (!(flags & H5Z_FLAG_SKIP_EDC)) { /* Read */
+            unsigned char *tmp_src;
+
+            src_nbytes -= FLETCHER_LEN;
+            tmp_src=src+src_nbytes;
+            UINT32DECODE(tmp_src, origin_fletcher);
+
+            /* Compute checksum */
+            fletcher = H5Z_filter_fletcher32_compute((unsigned short*)src,src_nbytes);
+
+            if(origin_fletcher != fletcher)
+	        HGOTO_ERROR(H5E_STORAGE, H5E_READERROR, 0, "data error detected by Fletcher32 checksum");
+        }
+        
+        *buf_size = nbytes - FLETCHER_LEN;
+        ret_value = *buf_size;
+    } else { /* Write */
+        unsigned char *dst;
+
+        /* Compute checksum */
+        fletcher = H5Z_filter_fletcher32_compute((unsigned short*)src,nbytes);
+        
+	if (NULL==(dst=outbuf=H5MM_malloc(nbytes+FLETCHER_LEN)))
+	    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "unable to allocate Fletcher32 checksum destination buffer");
+        
+        /* Copy raw data */
+        HDmemcpy((void*)dst, (void*)(*buf), nbytes);
+
+        /* Append checksum to raw data */
+        dst += nbytes;
+        UINT32ENCODE(dst, fletcher);
+
+        *buf_size = nbytes + FLETCHER_LEN;
+ 	H5MM_xfree(*buf);
+	*buf = outbuf;
+	outbuf = NULL;
+	ret_value = *buf_size;           
+    }
+
+done:
+    if(outbuf)
+        H5MM_xfree(outbuf);
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+#endif /* H5_HAVE_FILTER_FLETCHER32 */