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Diffstat (limited to 'lib/stat-time.h')
| -rw-r--r-- | lib/stat-time.h | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/lib/stat-time.h b/lib/stat-time.h new file mode 100644 index 0000000..884ffd8 --- /dev/null +++ b/lib/stat-time.h @@ -0,0 +1,252 @@ +/* stat-related time functions. + + Copyright (C) 2005, 2007, 2009-2020 Free Software Foundation, Inc. + + 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/>. */ + +/* Written by Paul Eggert. */ + +#ifndef STAT_TIME_H +#define STAT_TIME_H 1 + +#include "intprops.h" + +#include <errno.h> +#include <stddef.h> +#include <sys/stat.h> +#include <time.h> + +#ifndef _GL_INLINE_HEADER_BEGIN + #error "Please include config.h first." +#endif +_GL_INLINE_HEADER_BEGIN +#ifndef _GL_STAT_TIME_INLINE +# define _GL_STAT_TIME_INLINE _GL_INLINE +#endif + +#ifdef __cplusplus +extern "C" { +#endif + +/* STAT_TIMESPEC (ST, ST_XTIM) is the ST_XTIM member for *ST of type + struct timespec, if available. If not, then STAT_TIMESPEC_NS (ST, + ST_XTIM) is the nanosecond component of the ST_XTIM member for *ST, + if available. ST_XTIM can be st_atim, st_ctim, st_mtim, or st_birthtim + for access, status change, data modification, or birth (creation) + time respectively. + + These macros are private to stat-time.h. */ +#if _GL_WINDOWS_STAT_TIMESPEC || defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC +# if _GL_WINDOWS_STAT_TIMESPEC || defined TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC +# define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim) +# else +# define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.tv_nsec) +# endif +#elif defined HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC +# define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim##espec) +#elif defined HAVE_STRUCT_STAT_ST_ATIMENSEC +# define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim##ensec) +#elif defined HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC +# define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.st__tim.tv_nsec) +#endif + +/* Return the nanosecond component of *ST's access time. */ +_GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE +get_stat_atime_ns (struct stat const *st) +{ +# if defined STAT_TIMESPEC + return STAT_TIMESPEC (st, st_atim).tv_nsec; +# elif defined STAT_TIMESPEC_NS + return STAT_TIMESPEC_NS (st, st_atim); +# else + return 0; +# endif +} + +/* Return the nanosecond component of *ST's status change time. */ +_GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE +get_stat_ctime_ns (struct stat const *st) +{ +# if defined STAT_TIMESPEC + return STAT_TIMESPEC (st, st_ctim).tv_nsec; +# elif defined STAT_TIMESPEC_NS + return STAT_TIMESPEC_NS (st, st_ctim); +# else + return 0; +# endif +} + +/* Return the nanosecond component of *ST's data modification time. */ +_GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE +get_stat_mtime_ns (struct stat const *st) +{ +# if defined STAT_TIMESPEC + return STAT_TIMESPEC (st, st_mtim).tv_nsec; +# elif defined STAT_TIMESPEC_NS + return STAT_TIMESPEC_NS (st, st_mtim); +# else + return 0; +# endif +} + +/* Return the nanosecond component of *ST's birth time. */ +_GL_STAT_TIME_INLINE long int _GL_ATTRIBUTE_PURE +get_stat_birthtime_ns (struct stat const *st _GL_UNUSED) +{ +# if defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC + return STAT_TIMESPEC (st, st_birthtim).tv_nsec; +# elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC + return STAT_TIMESPEC_NS (st, st_birthtim); +# else + return 0; +# endif +} + +/* Return *ST's access time. */ +_GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE +get_stat_atime (struct stat const *st) +{ +#ifdef STAT_TIMESPEC + return STAT_TIMESPEC (st, st_atim); +#else + struct timespec t; + t.tv_sec = st->st_atime; + t.tv_nsec = get_stat_atime_ns (st); + return t; +#endif +} + +/* Return *ST's status change time. */ +_GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE +get_stat_ctime (struct stat const *st) +{ +#ifdef STAT_TIMESPEC + return STAT_TIMESPEC (st, st_ctim); +#else + struct timespec t; + t.tv_sec = st->st_ctime; + t.tv_nsec = get_stat_ctime_ns (st); + return t; +#endif +} + +/* Return *ST's data modification time. */ +_GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE +get_stat_mtime (struct stat const *st) +{ +#ifdef STAT_TIMESPEC + return STAT_TIMESPEC (st, st_mtim); +#else + struct timespec t; + t.tv_sec = st->st_mtime; + t.tv_nsec = get_stat_mtime_ns (st); + return t; +#endif +} + +/* Return *ST's birth time, if available; otherwise return a value + with tv_sec and tv_nsec both equal to -1. */ +_GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE +get_stat_birthtime (struct stat const *st _GL_UNUSED) +{ + struct timespec t; + +#if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \ + || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC) + t = STAT_TIMESPEC (st, st_birthtim); +#elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC + t.tv_sec = st->st_birthtime; + t.tv_nsec = st->st_birthtimensec; +#elif defined _WIN32 && ! defined __CYGWIN__ + /* Native Windows platforms (but not Cygwin) put the "file creation + time" in st_ctime (!). See + <https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/stat-functions>. */ +# if _GL_WINDOWS_STAT_TIMESPEC + t = st->st_ctim; +# else + t.tv_sec = st->st_ctime; + t.tv_nsec = 0; +# endif +#else + /* Birth time is not supported. */ + t.tv_sec = -1; + t.tv_nsec = -1; +#endif + +#if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \ + || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC \ + || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC) + /* FreeBSD and NetBSD sometimes signal the absence of knowledge by + using zero. Attempt to work around this problem. Alas, this can + report failure even for valid timestamps. Also, NetBSD + sometimes returns junk in the birth time fields; work around this + bug if it is detected. */ + if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000)) + { + t.tv_sec = -1; + t.tv_nsec = -1; + } +#endif + + return t; +} + +/* If a stat-like function returned RESULT, normalize the timestamps + in *ST, in case this platform suffers from the Solaris 11 bug where + tv_nsec might be negative. Return the adjusted RESULT, setting + errno to EOVERFLOW if normalization overflowed. This function + is intended to be private to this .h file. */ +_GL_STAT_TIME_INLINE int +stat_time_normalize (int result, struct stat *st _GL_UNUSED) +{ +#if defined __sun && defined STAT_TIMESPEC + if (result == 0) + { + long int timespec_hz = 1000000000; + short int const ts_off[] = { offsetof (struct stat, st_atim), + offsetof (struct stat, st_mtim), + offsetof (struct stat, st_ctim) }; + int i; + for (i = 0; i < sizeof ts_off / sizeof *ts_off; i++) + { + struct timespec *ts = (struct timespec *) ((char *) st + ts_off[i]); + long int q = ts->tv_nsec / timespec_hz; + long int r = ts->tv_nsec % timespec_hz; + if (r < 0) + { + r += timespec_hz; + q--; + } + ts->tv_nsec = r; + /* Overflow is possible, as Solaris 11 stat can yield + tv_sec == TYPE_MINIMUM (time_t) && tv_nsec == -1000000000. + INT_ADD_WRAPV is OK, since time_t is signed on Solaris. */ + if (INT_ADD_WRAPV (q, ts->tv_sec, &ts->tv_sec)) + { + errno = EOVERFLOW; + return -1; + } + } + } +#endif + return result; +} + +#ifdef __cplusplus +} +#endif + +_GL_INLINE_HEADER_END + +#endif |