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67 lines
1.4 KiB
67 lines
1.4 KiB
2 years ago
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/*
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* Copyright 2018, University Corporation for Atmospheric Research
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* See netcdf/COPYRIGHT file for copying and redistribution conditions.
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*/
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#include "config.h"
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#include "netcdf_filter_build.h"
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/*
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Common utilities related to filters.
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Taken from libdispatch/dfilters.c.
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*/
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#ifdef WORDS_BIGENDIAN
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/* Byte swap an 8-byte integer in place */
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static void
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byteswap8(unsigned char* mem)
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{
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unsigned char c;
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c = mem[0];
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mem[0] = mem[7];
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mem[7] = c;
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c = mem[1];
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mem[1] = mem[6];
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mem[6] = c;
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c = mem[2];
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mem[2] = mem[5];
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mem[5] = c;
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c = mem[3];
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mem[3] = mem[4];
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mem[4] = c;
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}
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/* Byte swap an 8-byte integer in place */
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static void
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byteswap4(unsigned char* mem)
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{
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unsigned char c;
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c = mem[0];
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mem[0] = mem[3];
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mem[3] = c;
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c = mem[1];
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mem[1] = mem[2];
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mem[2] = c;
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}
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#endif /*WORDS_BIGENDIAN*/
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void
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NC_h5filterspec_fix8(void* mem0, int decode)
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{
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#ifdef WORDS_BIGENDIAN
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unsigned char* mem = mem0;
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if(decode) { /* Apply inverse of the encode case */
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byteswap4(mem); /* step 1: byte-swap each piece */
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byteswap4(mem+4);
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byteswap8(mem); /* step 2: convert to little endian format */
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} else { /* encode */
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byteswap8(mem); /* step 1: convert to little endian format */
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byteswap4(mem); /* step 2: byte-swap each piece */
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byteswap4(mem+4);
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}
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#else /* Little endian */
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/* No action is necessary */
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#endif
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}
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