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Diffstat (limited to 'src/slibc-human/machinesize.c')
| -rw-r--r-- | src/slibc-human/machinesize.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/src/slibc-human/machinesize.c b/src/slibc-human/machinesize.c new file mode 100644 index 0000000..75aa989 --- /dev/null +++ b/src/slibc-human/machinesize.c @@ -0,0 +1,158 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <slibc-human.h> +#include <slibc/internals.h> +#include <errno.h> +#include <stddef.h> +#include <stdint.h> +#include <ctype.h> + + + +/** + * Get prefix-value. + * + * @param str Pointer to the string, will be updated to point to the end of the unit. + * @param mode How to parse ambiguous units. + * @return The multiple for the value, 0 on error. + * + * @throws EINVAL The prefix is unrecognised. + * @throws ERANGE The prefix is too large. + */ +__attribute__((nonnull)) +static size_t prefix(char** restrict str, enum machinesize_mode mode) +{ +#define P(A, B) case A: case B: n++ + char* p = *str; + size_t power = 0; + size_t base = 0; + size_t rc = 1; + + switch (*p++) + { + P('Y', 'y'); + P('Z', 'z'); + P('E', 'e'); + P('P', 'p'); + P('T', 't'); + P('G', 'g'); + P('M', 'm'); + P('k', 'K'); + case 'B': case 'b': + break; + default: + return errno = EINVAL, (size_t)0; + } + if (power == 0) + goto done; + + if ((*p == 'i') || (*p == 'I')) + base = 1024, p++; + if ((*p == 'B') || (*p == 'b')) + { + p++; + if ((!base) && (mode == (MACHINESIZE_SI | MACHINESIZE_IEC))) + base = 1000; + } + if (!base) + base = (mode == MACHINESIZE_SI) ? 1000 : 1024; + + while (power--) + OVERFLOW(umull, rc, base, &rc, ERANGE, (size_t)0); + + done: + return *str = p, rc; +#undef P +} + + +/** + * Parses a human representation of storage size or file offset. + * + * If no unit is used, bytes are assumed. If you rather it be + * (for example) kilobytes, you can multiply it if + * `strpbrk(str, "qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM") == NULL`. + * + * @etymology Convert to (machine)-representation: `(size)_t`. + * + * @param size Output parameter for the value, must not be `NULL`. + * @param str The value to parse, must not `NULL`. + * @param mode How to parse ambiguous strings, 0 for default. + * @param space Characters to ignore (thousand-group delimiters). + * Supports UTF-8. `NULL` for default. Default value + * is " '". + * @param point Decimal pointer chracters. Supports UTF-8. `NULL` + * for default. Default value is ",.". + * @return Zero on success, -1 on error. + * + * @throws EINVAL If `mode` is invalid. + * @throws EINVAL If `str` is not parseable. + * @throws ERANGE If the value is too range to fit in a `size_t`. + * + * @since Always. + */ +int machinesize(size_t* restrict size, const char* restrict str, enum machinesize_mode mode, + const char* restrict space, const char* restrict point) +{ + size_t r = 0; + size_t word; + long double dword; + size_t u; + char* p; + char* q; + int started = 0; + int pluses = 0; + int have_unitless = 0; + size_t words = 0; + + if (space == NULL) space = " '"; + if (point == NULL) point = ".,"; + + if (mode == 0) mode = MACHINESIZE_SI | MACHINESIZE_IEC; + if (mode > 3) goto invalid; + + for (p = str; *p;) + if (strchr(" \t+", *p)) + { + if ((pluses += (*p++ == '+')) > 1) + goto invalid; + } + else if ((q = machinefloat(&dword, p, space, point))) + { + p = q, words++, pluses = 0, started = 1; + while (strchr(" \t-", *p)) + p++; + if (isalpha(*p) == 0) u = 1, have_unitless = 1; + else u = prefix(&p, mode); + if (u == 0) return -1; + dword *= (long double)u; + if (dword > (long double)SIZE_MAX) + return errno = ERANGE, -1; + down = (size_t)dword; + OVERFLOW(uaddl, word, r, &r, ERANGE, -1); + } + else + return -1; + + if ((!started) || (have_unitless && (words > 1))) + goto invalid; + return *save = r, 0; + invalid: + return errno = EINVAL, -1; +} + |