1/* 2 * nghttp2 - HTTP/2 C Library 3 * 4 * Copyright (c) 2013 Tatsuhiro Tsujikawa 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining 7 * a copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sublicense, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be 15 * included in all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 20 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 21 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 22 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 23 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 24 */ 25#include "timegm.h" 26 27#include <inttypes.h> 28 29/* Counter the number of leap year in the range [0, y). The |y| is the 30 year, including century (e.g., 2012) */ 31static int count_leap_year(int y) { 32 y -= 1; 33 return y / 4 - y / 100 + y / 400; 34} 35 36/* Based on the algorithm of Python 2.7 calendar.timegm. */ 37time_t nghttp2_timegm(struct tm *tm) { 38 int days; 39 int num_leap_year; 40 int64_t t; 41 if (tm->tm_mon > 11) { 42 return -1; 43 } 44 num_leap_year = count_leap_year(tm->tm_year + 1900) - count_leap_year(1970); 45 days = (tm->tm_year - 70) * 365 + num_leap_year + tm->tm_yday; 46 t = ((int64_t)days * 24 + tm->tm_hour) * 3600 + tm->tm_min * 60 + tm->tm_sec; 47 48#if SIZEOF_TIME_T == 4 49 if (t < INT32_MIN || t > INT32_MAX) { 50 return -1; 51 } 52#endif /* SIZEOF_TIME_T == 4 */ 53 54 return (time_t)t; 55} 56 57/* Returns nonzero if the |y| is the leap year. The |y| is the year, 58 including century (e.g., 2012) */ 59static int is_leap_year(int y) { 60 return y % 4 == 0 && (y % 100 != 0 || y % 400 == 0); 61} 62 63/* The number of days before ith month begins */ 64static int daysum[] = {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}; 65 66time_t nghttp2_timegm_without_yday(struct tm *tm) { 67 int days; 68 int num_leap_year; 69 int64_t t; 70 if (tm->tm_mon > 11) { 71 return -1; 72 } 73 num_leap_year = count_leap_year(tm->tm_year + 1900) - count_leap_year(1970); 74 days = (tm->tm_year - 70) * 365 + num_leap_year + daysum[tm->tm_mon] + 75 tm->tm_mday - 1; 76 if (tm->tm_mon >= 2 && is_leap_year(tm->tm_year + 1900)) { 77 ++days; 78 } 79 t = ((int64_t)days * 24 + tm->tm_hour) * 3600 + tm->tm_min * 60 + tm->tm_sec; 80 81#if SIZEOF_TIME_T == 4 82 if (t < INT32_MIN || t > INT32_MAX) { 83 return -1; 84 } 85#endif /* SIZEOF_TIME_T == 4 */ 86 87 return (time_t)t; 88} 89