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author | David Robillard <d@drobilla.net> | 2021-02-25 10:27:59 -0500 |
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committer | David Robillard <d@drobilla.net> | 2021-03-08 23:23:05 -0500 |
commit | c4821c8e6bf1f81c6ea31e11ebc0fc1666e9337b (patch) | |
tree | a62995534f5f606ac2f8bae22d525532b824cb5e /subprojects/exess/src/timezone.c | |
parent | 6bcd18ae60482790b645a345f718e7099250f261 (diff) | |
download | serd-c4821c8e6bf1f81c6ea31e11ebc0fc1666e9337b.tar.gz serd-c4821c8e6bf1f81c6ea31e11ebc0fc1666e9337b.tar.bz2 serd-c4821c8e6bf1f81c6ea31e11ebc0fc1666e9337b.zip |
Add exess from git@gitlab.com:drobilla/exess.git 4638b1f
Diffstat (limited to 'subprojects/exess/src/timezone.c')
-rw-r--r-- | subprojects/exess/src/timezone.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/subprojects/exess/src/timezone.c b/subprojects/exess/src/timezone.c new file mode 100644 index 00000000..717f0d08 --- /dev/null +++ b/subprojects/exess/src/timezone.c @@ -0,0 +1,150 @@ +/* + Copyright 2019-2021 David Robillard <d@drobilla.net> + + 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. + + THIS 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 "timezone.h" +#include "date_utils.h" +#include "read_utils.h" +#include "string_utils.h" +#include "write_utils.h" + +#include "exess/exess.h" + +#include <stdint.h> +#include <stdlib.h> + +ExessResult +exess_read_timezone(ExessTimezone* const out, const char* const str) +{ + out->quarter_hours = INT8_MAX; + + // Start at the beginning (no whitespace skipping here) + size_t i = 0; + + // Handle UTC special case + if (str[i] == 'Z') { + out->quarter_hours = 0; + return result(EXESS_SUCCESS, i + 1); + } + + // Read leading sign (required) + int sign = 1; + switch (str[i]) { + case '+': + ++i; + break; + case '-': + sign = -1; + ++i; + break; + default: + return result(EXESS_EXPECTED_SIGN, i); + } + + const char h0 = str[i]; + if (!is_digit(h0)) { + return result(EXESS_EXPECTED_DIGIT, i); + } + + const char h1 = str[++i]; + if (!is_digit(h1)) { + return result(EXESS_EXPECTED_DIGIT, i); + } + + ++i; + + const int8_t hour = (int8_t)(sign * (10 * (h0 - '0') + (h1 - '0'))); + if (hour > 14 || hour < -14) { + return result(EXESS_OUT_OF_RANGE, i); + } + + if (str[i] != ':') { + return result(EXESS_EXPECTED_COLON, i); + } + + const char m0 = str[++i]; + if (!is_digit(m0)) { + return result(EXESS_EXPECTED_DIGIT, i); + } + + const char m1 = str[++i]; + if (!is_digit(m1)) { + return result(EXESS_EXPECTED_DIGIT, i); + } + + const int8_t minute = (int8_t)(sign * (10 * (m0 - '0') + (m1 - '0'))); + + ++i; + + if (minute % 15) { + return result(EXESS_UNSUPPORTED, i); + } + + if (minute > 59 || minute < -59) { + return result(EXESS_OUT_OF_RANGE, i); + } + + const int8_t quarters = (int8_t)(4 * hour + minute / 15); + if (quarters < -56 || quarters > 56) { + return result(EXESS_OUT_OF_RANGE, i); + } + + out->quarter_hours = quarters; + + return result(EXESS_SUCCESS, i); +} + +size_t +exess_timezone_string_length(const ExessTimezone value) +{ + return value.quarter_hours != EXESS_LOCAL ? (value.quarter_hours == 0) ? 1 : 6 + : 0; +} + +ExessResult +write_timezone(const ExessTimezone value, + const size_t buf_size, + char* const buf, + size_t o) +{ + if (value.quarter_hours == EXESS_LOCAL) { + return result(EXESS_SUCCESS, 0); + } + + if (value.quarter_hours < -56 || value.quarter_hours > 56) { + return result(EXESS_BAD_VALUE, 0); + } + + if (!buf) { + return result(EXESS_SUCCESS, exess_timezone_string_length(value)); + } + + if (value.quarter_hours == 0) { + write_char('Z', buf_size, buf, o); + return result(EXESS_SUCCESS, 1); + } + + const uint8_t abs_quarters = (uint8_t)abs(value.quarter_hours); + const uint8_t abs_hour = abs_quarters / 4; + const uint8_t abs_minute = (uint8_t)(15u * (abs_quarters % 4u)); + + size_t n = 0; + n += write_char(value.quarter_hours < 0 ? '-' : '+', buf_size, buf, o + n); + n += write_two_digit_number(abs_hour, buf_size, buf, o + n); + n += write_char(':', buf_size, buf, o + n); + n += write_two_digit_number(abs_minute, buf_size, buf, o + n); + + return result(EXESS_SUCCESS, n); +} |