72 lines
1.9 KiB
C
72 lines
1.9 KiB
C
/*
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* Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include "inner.h"
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/* see inner.h */
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void
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br_i32_encode(void *dst, size_t len, const uint32_t *x)
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{
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unsigned char *buf;
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size_t k;
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buf = dst;
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/*
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* Compute the announced size of x in bytes; extra bytes are
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* filled with zeros.
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*/
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k = (x[0] + 7) >> 3;
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while (len > k) {
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*buf ++ = 0;
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len --;
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}
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/*
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* Now we use k as index within x[]. That index starts at 1;
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* we initialize it to the topmost complete word, and process
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* any remaining incomplete word.
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*/
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k = (len + 3) >> 2;
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switch (len & 3) {
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case 3:
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*buf ++ = x[k] >> 16;
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/* fall through */
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case 2:
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*buf ++ = x[k] >> 8;
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/* fall through */
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case 1:
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*buf ++ = x[k];
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k --;
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}
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/*
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* Encode all complete words.
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*/
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while (k > 0) {
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br_enc32be(buf, x[k]);
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k --;
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buf += 4;
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}
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}
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