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d5a00cf634
"If you just want to have a good hash function, and cannot wait, djb2 is one of the best string hash functions I know."
84 lines
1.2 KiB
C
84 lines
1.2 KiB
C
/*
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* This file is part of RGBDS.
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*
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* Copyright (c) 1997-2019, Carsten Sorensen and RGBDS contributors.
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*
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* SPDX-License-Identifier: MIT
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*/
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#include <ctype.h>
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#include <stdint.h>
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#include "asm/main.h"
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#include "asm/util.h"
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#include "asm/warning.h"
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#include "extern/utf8decoder.h"
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/*
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* Calculate the hash value for a string.
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* Uses the djb2 algorithm (xor version).
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* http://www.cse.yorku.ca/~oz/hash.html
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*/
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uint32_t calchash(const char *s)
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{
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uint32_t hash = 5381;
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while (*s != 0)
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hash = (hash * 33) ^ (*s++);
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return hash;
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}
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char const *print(int c)
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{
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static char buf[5]; /* '\xNN' + '\0' */
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if (c == EOF)
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return "EOF";
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if (isprint(c)) {
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buf[0] = c;
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buf[1] = '\0';
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return buf;
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}
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buf[0] = '\\';
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switch (c) {
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case '\n':
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buf[1] = 'n';
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break;
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case '\r':
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buf[1] = 'r';
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break;
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case '\t':
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buf[1] = 't';
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break;
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default: /* Print as hex */
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buf[1] = 'x';
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sprintf(&buf[2], "%02hhx", c);
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return buf;
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}
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buf[2] = '\0';
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return buf;
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}
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size_t readUTF8Char(uint8_t *dest, char const *src)
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{
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uint32_t state = 0;
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uint32_t codep;
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size_t i = 0;
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for (;;) {
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if (decode(&state, &codep, src[i]) == 1)
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return 0;
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dest[i] = src[i];
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i++;
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if (state == 0)
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return i;
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}
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}
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