mirror of
https://github.com/HDFGroup/hdf5.git
synced 2025-02-17 16:10:24 +08:00
ed7d456e51
Tested platform: Kagiso only since it is only a comment block change. If it works in one machine, it should work in all, I hope. Still need to check the parallel build on copper.
169 lines
6.7 KiB
C
169 lines
6.7 KiB
C
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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* Copyright by The HDF Group. *
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* Copyright by the Board of Trustees of the University of Illinois. *
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* All rights reserved. *
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* *
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* This file is part of HDF5. The full HDF5 copyright notice, including *
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* terms governing use, modification, and redistribution, is contained in *
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* the files COPYING and Copyright.html. COPYING can be found at the root *
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* of the source code distribution tree; Copyright.html can be found at the *
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* root level of an installed copy of the electronic HDF5 document set and *
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* is linked from the top-level documents page. It can also be found at *
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* http://hdfgroup.org/HDF5/doc/Copyright.html. If you do not have *
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* access to either file, you may request a copy from help@hdfgroup.org. *
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* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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/*
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* Programmer: Raymond Lu<slu@ncsa.uiuc.edu>
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* Jan 3, 2003
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*/
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#define H5Z_PACKAGE /*suppress error about including H5Zpkg */
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#include "H5private.h" /* Generic Functions */
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#include "H5Eprivate.h" /* Error handling */
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#include "H5Fprivate.h" /* File access */
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#include "H5MMprivate.h" /* Memory management */
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#include "H5Zpkg.h" /* Data filters */
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#ifdef H5_HAVE_FILTER_FLETCHER32
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/* Local function prototypes */
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static size_t H5Z_filter_fletcher32 (unsigned flags, size_t cd_nelmts,
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const unsigned cd_values[], size_t nbytes, size_t *buf_size, void **buf);
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/* This message derives from H5Z */
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const H5Z_class_t H5Z_FLETCHER32[1] = {{
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H5Z_CLASS_T_VERS, /* H5Z_class_t version */
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H5Z_FILTER_FLETCHER32, /* Filter id number */
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1, /* encoder_present flag (set to true) */
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1, /* decoder_present flag (set to true) */
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"fletcher32", /* Filter name for debugging */
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NULL, /* The "can apply" callback */
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NULL, /* The "set local" callback */
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H5Z_filter_fletcher32, /* The actual filter function */
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}};
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#define FLETCHER_LEN 4
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/*-------------------------------------------------------------------------
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* Function: H5Z_filter_fletcher32
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*
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* Purpose: Implement an I/O filter of Fletcher32 Checksum
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*
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* Return: Success: Size of buffer filtered
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* Failure: 0
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*
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* Programmer: Raymond Lu
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* Jan 3, 2003
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*
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* Modifications:
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* Raymond Lu
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* July 8, 2005
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* There was a bug in the calculating code of the Fletcher32
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* checksum in the library before v1.6.3. The checksum
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* value wasn't consistent between big-endian and little-endian
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* systems. This bug was fixed in Release 1.6.3. However,
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* after fixing the bug, the checksum value is no longer the
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* same as before on little-endian system. We'll check both
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* the correct checksum and the wrong checksum to be consistent
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* with Release 1.6.2 and before.
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*-------------------------------------------------------------------------
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*/
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/* ARGSUSED */
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static size_t
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H5Z_filter_fletcher32 (unsigned flags, size_t UNUSED cd_nelmts, const unsigned UNUSED cd_values[],
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size_t nbytes, size_t *buf_size, void **buf)
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{
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void *outbuf = NULL; /* Pointer to new buffer */
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unsigned char *src = (unsigned char*)(*buf);
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uint32_t fletcher; /* Checksum value */
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uint32_t reversed_fletcher; /* Possible wrong checksum value */
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uint8_t c[4];
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uint8_t tmp;
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size_t ret_value; /* Return value */
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FUNC_ENTER_NOAPI(H5Z_filter_fletcher32, 0)
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assert(sizeof(uint32_t)>=4);
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if (flags & H5Z_FLAG_REVERSE) { /* Read */
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/* Do checksum if it's enabled for read; otherwise skip it
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* to save performance. */
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if (!(flags & H5Z_FLAG_SKIP_EDC)) {
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unsigned char *tmp_src; /* Pointer to checksum in buffer */
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size_t src_nbytes = nbytes; /* Original number of bytes */
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uint32_t stored_fletcher; /* Stored checksum value */
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/* Get the stored checksum */
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src_nbytes -= FLETCHER_LEN;
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tmp_src=src+src_nbytes;
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UINT32DECODE(tmp_src, stored_fletcher);
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/* Compute checksum (can't fail) */
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fletcher = H5_checksum_fletcher32(src, src_nbytes);
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/* The reversed checksum. There was a bug in the calculating code of
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* the Fletcher32 checksum in the library before v1.6.3. The checksum
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* value wasn't consistent between big-endian and little-endian systems.
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* This bug was fixed in Release 1.6.3. However, after fixing the bug,
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* the checksum value is no longer the same as before on little-endian
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* system. We'll check both the correct checksum and the wrong
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* checksum to be consistent with Release 1.6.2 and before.
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*/
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HDmemcpy(c, &fletcher, (size_t)4);
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tmp = c[1];
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c[1] = c[0];
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c[0] = tmp;
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tmp = c[3];
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c[3] = c[2];
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c[2] = tmp;
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HDmemcpy(&reversed_fletcher, c, (size_t)4);
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/* Verify computed checksum matches stored checksum */
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if(stored_fletcher != fletcher && stored_fletcher != reversed_fletcher)
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HGOTO_ERROR(H5E_STORAGE, H5E_READERROR, 0, "data error detected by Fletcher32 checksum")
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}
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/* Set return values */
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/* (Re-use the input buffer, just note that the size is smaller by the size of the checksum) */
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ret_value = nbytes-FLETCHER_LEN;
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} else { /* Write */
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unsigned char *dst; /* Temporary pointer to destination buffer */
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/* Compute checksum (can't fail) */
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fletcher = H5_checksum_fletcher32(src, nbytes);
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if (NULL==(dst=outbuf=H5MM_malloc(nbytes+FLETCHER_LEN)))
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HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "unable to allocate Fletcher32 checksum destination buffer")
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/* Copy raw data */
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HDmemcpy((void*)dst, (void*)(*buf), nbytes);
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/* Append checksum to raw data for storage */
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dst += nbytes;
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UINT32ENCODE(dst, fletcher);
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/* Free input buffer */
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H5MM_xfree(*buf);
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/* Set return values */
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*buf_size = nbytes + FLETCHER_LEN;
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*buf = outbuf;
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outbuf = NULL;
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ret_value = *buf_size;
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}
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done:
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if(outbuf)
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H5MM_xfree(outbuf);
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FUNC_LEAVE_NOAPI(ret_value)
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}
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#endif /* H5_HAVE_FILTER_FLETCHER32 */
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