2915e711f7
The glibc's generic parser is slow due to its versatility. Specialized parsers for base-10 and base-16 are much faster and we don't use other bases.
62 lines
1.1 KiB
C
62 lines
1.1 KiB
C
/*
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* BIRD Library -- Parse numbers
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*
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* (c) 2019 Maria Matejka <mq@jmq.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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#include "nest/bird.h"
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#include "lib/string.h"
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#include <errno.h>
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#define ULI_MAX_DIV10 (UINT64_MAX / 10)
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#define ULI_MAX_MOD10 (UINT64_MAX % 10)
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u64
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bstrtoul10(const char *str, char **end)
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{
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u64 out = 0;
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for (*end = (char *) str; (**end >= '0') && (**end <= '9'); (*end)++) {
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u64 digit = **end - '0';
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if ((out > ULI_MAX_DIV10) ||
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(out == ULI_MAX_DIV10) && (digit > ULI_MAX_MOD10)) {
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errno = ERANGE;
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return UINT64_MAX;
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}
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out *= 10;
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out += (**end) - '0';
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}
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return out;
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}
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u64
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bstrtoul16(const char *str, char **end)
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{
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u64 out = 0;
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for (int i=0; i<=(64/4); i++) {
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switch (str[i]) {
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case '0' ... '9':
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out *= 16;
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out += str[i] - '0';
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break;
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case 'a' ... 'f':
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out *= 16;
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out += str[i] + 10 - 'a';
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break;
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case 'A' ... 'F':
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out *= 16;
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out += str[i] + 10 - 'A';
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break;
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default:
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*end = (char *) &(str[i]);
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return out;
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}
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}
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errno = ERANGE;
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return UINT64_MAX;
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}
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