cosmopolitan/libc/str/tpencode.ncabi.c

57 lines
2.8 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/str/internal.h"
#include "libc/str/tpenc.h"
#include "libc/str/tpencode.internal.h"
/* TODO: DELETE */
/**
* Thompson-Pike Varint Encoder.
*
* Implementation Details: The header macro should ensure this function
* is only called for non-ASCII, or DCE'd entirely. In addition to that
* this function makes a promise to not clobber any registers but %rax.
*
* @param p is what ch gets encoded to
* @param size is the number of bytes available in buf
* @param ch is a 32-bit integer
* @param awesome mode enables numbers the IETF unilaterally banned
* @return number of bytes written
* @note this encoding was designed on a napkin in a new jersey diner
* @deprecated
*/
unsigned(tpencode)(char *p, size_t size, wint_t wc, bool32 awesome) {
int i, j;
unsigned long w;
if ((0 <= wc && wc < 32) && awesome && size >= 2) {
p[0] = 0xc0;
p[1] = 0x80;
p[1] |= wc;
return 2;
}
i = 0;
w = tpenc(wc);
do {
if (!size--) break;
p[i++] = w & 0xff;
} while (w >>= 8);
return i;
}