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| -rw-r--r-- | src/contrib/time.h | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/src/contrib/time.h b/src/contrib/time.h new file mode 100644 index 0000000..20d241e --- /dev/null +++ b/src/contrib/time.h @@ -0,0 +1,211 @@ +/* Copyright (C) 2023 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + 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 <https://www.gnu.org/licenses/>. + */ + +#pragma once + +#include <inttypes.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> +#include <time.h> + +#ifdef __APPLE__ + #define st_mtim st_mtimespec +#endif + +/*! + * \brief Specify output format for knot_time_print(). + */ +typedef enum { + TIME_PRINT_UNIX, // numeric UNIX time + TIME_PRINT_ISO8601, // 2016-12-31T23:59:00 + TIME_PRINT_RELSEC, // relative +6523 + TIME_PRINT_HUMAN_MIXED, // relative with mixed-case units + TIME_PRINT_HUMAN_LOWER, // relative with lower-case units +} knot_time_print_t; + +/*! + * \brief Get current time. + */ +struct timespec time_now(void); + +/*! + * \brief Get time elapsed between two events. + */ +struct timespec time_diff(const struct timespec *begin, const struct timespec *end); + +/*! + * \brief Get time elapsed between two events in milliseconds. + */ +double time_diff_ms(const struct timespec *begin, const struct timespec *end); + +/*! + * \brief Data type for keeping UNIX timestamps. + * + * This is because time_t can be 32-bit on some systems, which is bad. + * Zero value represents infinity. + */ +typedef uint64_t knot_time_t; + +/*! + * \brief Data type for keeping time differences. + */ +typedef int64_t knot_timediff_t; + +#define KNOT_TIMEDIFF_MIN INT64_MIN +#define KNOT_TIMEDIFF_MAX INT64_MAX + +#define KNOT_TIME_PRINTF PRIu64 +#define KNOT_TIMEDIFF_PRINTF PRId64 + +/*! + * \brief Returns current time sice epoch. + */ +inline static knot_time_t knot_time(void) +{ + return (knot_time_t)time(NULL); +} + +/*! + * \brief Compare two timestamps. + * + * \return 0 if equal, -1 if the former is smaller (=earlier), 1 else. + */ +inline static int knot_time_cmp(knot_time_t a, knot_time_t b) +{ + return (a == b ? 0 : 1) * ((a && b) == 0 ? -1 : 1) * (a < b ? -1 : 1); +} + +/*! + * \brief Return the smaller (=earlier) from given two timestamps. + */ +inline static knot_time_t knot_time_min(knot_time_t a, knot_time_t b) +{ + if ((a && b) == 0) { + return a + b; + } else { + return (a < b ? a : b); + } +} + +/*! + * \brief Return the difference between two timestamps (to "minus" from). + * + * \note If both are zero (=infinity), KNOT_TIMEDIFF_MAX is returned. + */ +inline static knot_timediff_t knot_time_diff(knot_time_t to, knot_time_t from) +{ + if ((to && from) == 0) { + return (to > from ? KNOT_TIMEDIFF_MIN : KNOT_TIMEDIFF_MAX); + } else { + return (knot_timediff_t)to - (knot_timediff_t)from; + } +} + +/*! + * \brief Add a time difference to timestamp. + */ +inline static knot_time_t knot_time_add(knot_time_t since, knot_timediff_t howlong) +{ + return (since != 0 ? since + howlong : since); +} + +inline static knot_time_t knot_time_plus(knot_time_t a, knot_time_t b) +{ + return ((a && b) ? a + b : 0); +} + +/*! + * \brief Convert uint32_t-encoded timestamp to knot_time_t. + * + * In RRSIG rdata, there are inception and expiration timestamps in uint32_t format. + * One shall use 'serial arithmetics' to decode them. + * + * The result of this function is a timestamp that equals to + * given 32-bit time in lower 32 bits, and does not differ from + * now by more than 2^31. + */ +inline static knot_time_t knot_time_from_u32(uint32_t u32time, knot_time_t now) +{ + if (now == 0) { + now = knot_time(); + } + + uint32_t now_lower32 = (uint32_t)now; + uint64_t now_upper32 = now >> 32; + if (now_lower32 > u32time && now_lower32 - u32time > INT32_MAX) { + now_upper32++; + } else if (now_lower32 < u32time && u32time - now_lower32 > INT32_MAX) { + now_upper32--; + } + + return (now_upper32 << 32) + u32time; +} + +/*! + * \brief Parse a text-formatted timestamp to knot_time_t using format specification. + * + * \param format The timestamp text format specification. + * \param timespec Text-formatted timestamp. + * \param time The parsed timestamp. + * + * The format specification basics: + * <format 1>|<format 2> - The pipe sign separates two time format specifications. Leftmost + * specification matching the timespec is used. + * '<a string>' - Matches exactly <a string> (not containing apostrophes) in timespec. + * # - Hashtag matches for a number in timespec, stands for either a UNIX timestamp, + * or, within a context of an unit, as a number of such units. + * Y, M, D, h, m, s - Matches a number, stands for a number of years, months, days, hours, + * minutes and seconds, respectively. + * +, - - The + and - signs declaring that following timespec is relative to "now". + * A single sign can be used to limit the timestamp being in future or in past, + * or both +- allow the timestamp to select any (just one) of them. + * U - Matches one of Y, M, D, h, m, s in the timespec standing for a time unit. + * u - Like U, but the unit in the timestamp is from: y, mo, d, h, mi, s. + * + * \retval -1 An error occurred, out_time has no sense. + * \return 0 OK, timestamp parsed successfully. + */ +int knot_time_parse(const char *format, const char *timespec, knot_time_t *time); + +/*! + * \brief Print the timestamp in specified format into a string buffer. + * + * \param format The timestamp text format specification. + * \param time The timestamp to be printed. + * \param dst The destination buffer pointer with text-formatted timestamp. + * \param dst_len The destination buffer length. + * + * \retval -1 An error occurred, the buffer may be filled with nonsense. + * \return 0 OK, timestamp printed successfully. + */ +int knot_time_print(knot_time_print_t format, knot_time_t time, char *dst, size_t dst_len); + +/*! + * \brief Print the timestamp in a predefined human format. + * + * Condensed format (zone file compatible): 1w2d3h4m5s + * Normal format: 1 week 2 days 3 hours 4 minutes 5 seconds + * + * \param time The timestamp to be printed. + * \param dst The destination buffer pointer with text-formatted timestamp. + * \param dst_len The destination buffer length. + * \param condensed Condensed format indication. + * + * \retval -1 An error occurred, the buffer may be filled with nonsense. + * \return >0 OK, timestamp printed successfully. + */ +int knot_time_print_human(knot_time_t time, char *dst, size_t dst_len, bool condensed); |