Merge pull request #3170 from CmdrMoozy/nsec_fix

git_index_entry__init_from_stat: set nsec fields in entry stats

CMakeLists.txt

@@ -20,6 +20,7 @@ SET(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Mo
 
 INCLUDE(CheckLibraryExists)
 INCLUDE(CheckFunctionExists)
+INCLUDE(CheckStructHasMember)
 INCLUDE(AddCFlagIfSupported)
 INCLUDE(FindPkgConfig)
 
@@ -85,6 +86,12 @@ IF (NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
 	OPTION( USE_OPENSSL                     "Link with and use openssl library"             ON )
 ENDIF()
 
+CHECK_STRUCT_HAS_MEMBER("struct stat" st_mtim.tv_nsec sys/stat.h
+	HAVE_STRUCT_STAT_NSEC LANGUAGE C)
+IF(HAVE_STRUCT_STAT_NSEC OR WIN32)
+	OPTION( USE_NSEC		"Care about sub-second file mtimes and ctimes"	OFF )
+ENDIF()
+
 # This variable will contain the libraries we need to put into
 # libgit2.pc's Requires.private. That is, what we're linking to or
 # what someone who's statically linking us needs to link to.
@@ -516,6 +523,10 @@ IF (THREADSAFE)
 	ADD_DEFINITIONS(-DGIT_THREADS)
 ENDIF()
 
+IF (USE_NSEC)
+	ADD_DEFINITIONS(-DGIT_USE_NSEC)
+ENDIF()
+
 ADD_DEFINITIONS(-D_FILE_OFFSET_BITS=64)
 
 # Collect sourcefiles

include/git2/common.h

@@ -103,6 +103,7 @@ typedef enum {
 	GIT_FEATURE_THREADS	= (1 << 0),
 	GIT_FEATURE_HTTPS	= (1 << 1),
 	GIT_FEATURE_SSH		= (1 << 2),
+	GIT_FEATURE_NSEC	= (1 << 3),
 } git_feature_t;
 
 /**

src/common.h

@@ -41,6 +41,7 @@
 # include <ws2tcpip.h>
 # include "win32/msvc-compat.h"
 # include "win32/mingw-compat.h"
+# include "win32/win32-compat.h"
 # include "win32/error.h"
 # include "win32/version.h"
 # ifdef GIT_THREADS

src/diff.c

@@ -706,6 +706,31 @@ static bool diff_time_eq(
 		(!use_nanos || a->nanoseconds == b->nanoseconds);
 }
 
+/*
+ * Test if the given index time is newer than the given existing index entry.
+ * If the timestamps are exactly equivalent, then the given index time is
+ * considered "racily newer" than the existing index entry.
+ */
+static bool diff_newer_than_index(
+	const git_index_time *a, const git_index *b, bool use_nanos)
+{
+	bool is_newer = false;
+
+	if(!b)
+		return false;
+
+	is_newer = is_newer || (a->seconds > (int32_t) b->stamp.mtime.tv_sec);
+	is_newer = is_newer || (!use_nanos &&
+		(a->seconds == (int32_t) b->stamp.mtime.tv_sec));
+	if(use_nanos)
+	{
+		is_newer = is_newer || ((a->seconds == (int32_t) b->stamp.mtime.tv_sec) &&
+			(a->nanoseconds >= (uint32_t) b->stamp.mtime.tv_nsec));
+	}
+
+	return is_newer;
+}
+
 typedef struct {
 	git_repository *repo;
 	git_iterator *old_iter;
@@ -838,7 +863,11 @@ static int maybe_modified(
 	 */
 	} else if (git_oid_iszero(&nitem->id) && new_is_workdir) {
 		bool use_ctime = ((diff->diffcaps & GIT_DIFFCAPS_TRUST_CTIME) != 0);
+#ifdef GIT_USE_NSEC
 		bool use_nanos = ((diff->diffcaps & GIT_DIFFCAPS_TRUST_NANOSECS) != 0);
+#else
+		bool use_nanos = false;
+#endif
 		git_index *index;
 		git_iterator_index(&index, info->new_iter);
 
@@ -863,7 +892,7 @@ static int maybe_modified(
 			oitem->ino != nitem->ino ||
 			oitem->uid != nitem->uid ||
 			oitem->gid != nitem->gid ||
-			(index && nitem->mtime.seconds >= index->stamp.mtime))
+			diff_newer_than_index(&nitem->mtime, index, use_nanos))
 		{
 			status = GIT_DELTA_MODIFIED;
 			modified_uncertain = true;

src/fileops.c

@@ -1034,6 +1034,11 @@ int git_futils_filestamp_check(
 	git_futils_filestamp *stamp, const char *path)
 {
 	struct stat st;
+#if defined(__APPLE__)
+	const struct timespec *statmtime = &st.st_mtimespec;
+#else
+	const struct timespec *statmtime = &st.st_mtim;
+#endif
 
 	/* if the stamp is NULL, then always reload */
 	if (stamp == NULL)
@@ -1042,12 +1047,18 @@ int git_futils_filestamp_check(
 	if (p_stat(path, &st) < 0)
 		return GIT_ENOTFOUND;
 
-	if (stamp->mtime == (git_time_t)st.st_mtime &&
+	if (stamp->mtime.tv_sec == statmtime->tv_sec &&
+#if defined(GIT_USE_NSEC)
+		stamp->mtime.tv_nsec == statmtime->tv_nsec &&
+#endif
 		stamp->size  == (git_off_t)st.st_size   &&
 		stamp->ino   == (unsigned int)st.st_ino)
 		return 0;
 
-	stamp->mtime = (git_time_t)st.st_mtime;
+	stamp->mtime.tv_sec = statmtime->tv_sec;
+#if defined(GIT_USE_NSEC)
+	stamp->mtime.tv_nsec = statmtime->tv_nsec;
+#endif
 	stamp->size  = (git_off_t)st.st_size;
 	stamp->ino   = (unsigned int)st.st_ino;
 
@@ -1069,8 +1080,17 @@ void git_futils_filestamp_set(
 void git_futils_filestamp_set_from_stat(
 	git_futils_filestamp *stamp, struct stat *st)
 {
+#if defined(__APPLE__)
+	const struct timespec *statmtime = &st->st_mtimespec;
+#else
+	const struct timespec *statmtime = &st->st_mtim;
+#endif
+
 	if (st) {
-		stamp->mtime = (git_time_t)st->st_mtime;
+		stamp->mtime = *statmtime;
+#if !defined(GIT_USE_NSEC)
+		stamp->mtime.tv_nsec = 0;
+#endif
 		stamp->size  = (git_off_t)st->st_size;
 		stamp->ino   = (unsigned int)st->st_ino;
 	} else {

src/fileops.h

@@ -310,7 +310,7 @@ extern int git_futils_fake_symlink(const char *new, const char *old);
  * versions could be implemented in the future.
  */
 typedef struct {
-	git_time_t mtime;
+	struct timespec mtime;
 	git_off_t  size;
 	unsigned int ino;
 } git_futils_filestamp;

src/index.c

@@ -719,18 +719,27 @@ int git_index__changed_relative_to(
 	return !!git_oid_cmp(&index->checksum, checksum);
 }
 
-static bool is_racy_timestamp(git_time_t stamp, git_index_entry *entry)
+static bool is_racy_timestamp(const struct timespec *stamp, git_index_entry *entry)
 {
 	/* Git special-cases submodules in the check */
 	if (S_ISGITLINK(entry->mode))
 		return false;
 
 	/* If we never read the index, we can't have this race either */
-	if (stamp == 0)
+	if(stamp->tv_sec == 0)
 		return false;
 
 	/* If the timestamp is the same or newer than the index, it's racy */
-	return ((int32_t) stamp) <= entry->mtime.seconds;
+#if defined(GIT_USE_NSEC)
+	if((int32_t) stamp->tv_sec < entry->mtime.seconds)
+		return true;
+	else if((int32_t) stamp->tv_sec > entry->mtime.seconds)
+		return false;
+	else
+		return (uint32_t) stamp->tv_nsec <= entry->mtime.nanoseconds;
+#else
+	return ((int32_t) stamp->tv_sec) <= entry->mtime.seconds;
+#endif
 }
 
 /*
@@ -742,7 +751,6 @@ static int truncate_racily_clean(git_index *index)
 	size_t i;
 	int error;
 	git_index_entry *entry;
-	git_time_t ts = index->stamp.mtime;
 	git_diff_options diff_opts = GIT_DIFF_OPTIONS_INIT;
 	git_diff *diff;
 
@@ -756,7 +764,7 @@ static int truncate_racily_clean(git_index *index)
 
 	diff_opts.flags |= GIT_DIFF_INCLUDE_TYPECHANGE | GIT_DIFF_IGNORE_SUBMODULES | GIT_DIFF_DISABLE_PATHSPEC_MATCH;
 	git_vector_foreach(&index->entries, i, entry) {
-		if (!is_racy_timestamp(ts, entry))
+		if (!is_racy_timestamp(&index->stamp.mtime, entry))
 			continue;
 
 		/* TODO: use the (non-fnmatching) filelist iterator */
@@ -858,8 +866,10 @@ void git_index_entry__init_from_stat(
 {
 	entry->ctime.seconds = (git_time_t)st->st_ctime;
 	entry->mtime.seconds = (git_time_t)st->st_mtime;
-	/* entry->mtime.nanoseconds = st->st_mtimensec; */
-	/* entry->ctime.nanoseconds = st->st_ctimensec; */
+#if defined(GIT_USE_NSEC)
+	entry->mtime.nanoseconds = st->st_mtim.tv_nsec;
+	entry->ctime.nanoseconds = st->st_ctim.tv_nsec;
+#endif
 	entry->dev  = st->st_rdev;
 	entry->ino  = st->st_ino;
 	entry->mode = (!trust_mode && S_ISREG(st->st_mode)) ?

src/settings.c

@@ -34,6 +34,9 @@ int git_libgit2_features()
 #if defined(GIT_SSH)
 		| GIT_FEATURE_SSH
 #endif
+#if defined(GIT_USE_NSEC)
+		| GIT_FEATURE_NSEC
+#endif
 	;
 }
 

src/win32/mingw-compat.h

@@ -11,12 +11,6 @@
 
 #undef stat
 
-#if _WIN32_WINNT >= 0x0601
-#define stat __stat64
-#else
-#define stat _stati64
-#endif
-
 #if _WIN32_WINNT < 0x0600 && !defined(__MINGW64_VERSION_MAJOR)
 #undef MemoryBarrier
 void __mingworg_MemoryBarrier(void);

src/win32/msvc-compat.h

@@ -9,9 +9,6 @@
 
 #if defined(_MSC_VER)
 
-/* 64-bit stat information, regardless of USE_32BIT_TIME_T define */
-#define stat __stat64
-
 typedef unsigned short mode_t;
 typedef SSIZE_T ssize_t;
 

src/win32/w32_util.h

@@ -76,17 +76,23 @@ size_t git_win32__path_trim_end(wchar_t *str, size_t len);
 size_t git_win32__canonicalize_path(wchar_t *str, size_t len);
 
 /**
- * Converts a FILETIME structure to a time_t.
+ * Converts a FILETIME structure to a struct timespec.
  *
  * @param FILETIME A pointer to a FILETIME
- * @return A time_t containing the same time
+ * @param ts A pointer to the timespec structure to fill in
  */
-GIT_INLINE(time_t) git_win32__filetime_to_time_t(const FILETIME *ft)
+GIT_INLINE(void) git_win32__filetime_to_timespec(
+	const FILETIME *ft,
+	struct timespec *ts)
 {
 	long long winTime = ((long long)ft->dwHighDateTime << 32) + ft->dwLowDateTime;
 	winTime -= 116444736000000000LL; /* Windows to Unix Epoch conversion */
-	winTime /= 10000000;             /* Nano to seconds resolution */
-	return (time_t)winTime;
+	ts->tv_sec = (time_t)(winTime / 10000000);
+#ifdef GIT_USE_NSEC
+	ts->tv_nsec = (winTime % 10000000) * 100;
+#else
+	ts->tv_nsec = 0;
+#endif
 }
 
 GIT_INLINE(void) git_win32__timeval_to_filetime(
@@ -122,9 +128,9 @@ GIT_INLINE(int) git_win32__file_attribute_to_stat(
 	st->st_size = ((git_off_t)attrdata->nFileSizeHigh << 32) + attrdata->nFileSizeLow;
 	st->st_dev = _getdrive() - 1;
 	st->st_rdev = st->st_dev;
-	st->st_atime = git_win32__filetime_to_time_t(&(attrdata->ftLastAccessTime));
-	st->st_mtime = git_win32__filetime_to_time_t(&(attrdata->ftLastWriteTime));
-	st->st_ctime = git_win32__filetime_to_time_t(&(attrdata->ftCreationTime));
+	git_win32__filetime_to_timespec(&(attrdata->ftLastAccessTime), &(st->st_atim));
+	git_win32__filetime_to_timespec(&(attrdata->ftLastWriteTime), &(st->st_mtim));
+	git_win32__filetime_to_timespec(&(attrdata->ftCreationTime), &(st->st_ctim));
 
 	if (attrdata->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT && path) {
 		git_win32_path target;

src/win32/win32-compat.h

+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_win32_compat__
+#define INCLUDE_win32_compat__
+
+#include <stdint.h>
+#include <time.h>
+#include <wchar.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+struct p_timespec {
+	time_t tv_sec;
+	long tv_nsec;
+};
+
+#define timespec p_timespec
+
+struct p_stat {
+	_dev_t st_dev;
+	_ino_t st_ino;
+	mode_t st_mode;
+	short st_nlink;
+	short st_uid;
+	short st_gid;
+	_dev_t st_rdev;
+	uint64_t st_size;
+	struct timespec st_atim;
+	struct timespec st_mtim;
+	struct timespec st_ctim;
+#define st_atime st_atim.tv_sec
+#define st_mtime st_mtim.tv_sec
+#define st_ctime st_ctim.tv_sec
+};
+
+#define stat p_stat
+
+#endif /* INCLUDE_win32_compat__ */

tests/checkout/checkout_helpers.c

@@ -132,7 +132,7 @@ int checkout_count_callback(
 
 void tick_index(git_index *index)
 {
-	git_time_t ts;
+	struct timespec ts;
 	struct timeval times[2];
 
 	cl_assert(index->on_disk);
@@ -141,10 +141,10 @@ void tick_index(git_index *index)
 	cl_git_pass(git_index_read(index, true));
 	ts = index->stamp.mtime;
 
-	times[0].tv_sec  = ts;
-	times[0].tv_usec = 0;
-	times[1].tv_sec  = ts + 5;
-	times[1].tv_usec = 0;
+	times[0].tv_sec = ts.tv_sec;
+	times[0].tv_usec = ts.tv_nsec / 1000;
+	times[1].tv_sec = ts.tv_sec + 5;
+	times[1].tv_usec = ts.tv_nsec / 1000;
 
 	cl_git_pass(p_utimes(git_index_path(index), times));
 	cl_git_pass(git_index_read(index, true));

tests/core/features.c

@@ -28,4 +28,10 @@ void test_core_features__0(void)
 #else
 	cl_assert((caps & GIT_FEATURE_SSH) == 0);
 #endif
+
+#if defined(GIT_USE_NSEC)
+	cl_assert((caps & GIT_FEATURE_NSEC) != 0);
+#else
+	cl_assert((caps & GIT_FEATURE_NSEC) == 0);
+#endif
 }

tests/index/racy.c

@@ -63,10 +63,10 @@ void test_index_racy__write_index_just_after_file(void)
 	cl_git_pass(git_buf_joinpath(&path, git_repository_workdir(g_repo), "A"));
 	cl_git_mkfile(path.ptr, "A");
 	/* Force the file's timestamp to be a second after we wrote the index */
-	times[0].tv_sec = index->stamp.mtime + 1;
-	times[0].tv_usec = 0;
-	times[1].tv_sec = index->stamp.mtime + 1;
-	times[1].tv_usec = 0;
+	times[0].tv_sec = index->stamp.mtime.tv_sec + 1;
+	times[0].tv_usec = index->stamp.mtime.tv_nsec / 1000;
+	times[1].tv_sec = index->stamp.mtime.tv_sec + 1;
+	times[1].tv_usec = index->stamp.mtime.tv_nsec / 1000;
 	cl_git_pass(p_utimes(path.ptr, times));
 
 	/*
@@ -82,10 +82,10 @@ void test_index_racy__write_index_just_after_file(void)
 	 * Pretend this index' modification happend a second after the
 	 * file update, and rewrite the file in that same second.
 	 */
-	times[0].tv_sec = index->stamp.mtime + 2;
-	times[0].tv_usec = 0;
-	times[1].tv_sec = index->stamp.mtime + 2;
-	times[0].tv_usec = 0;
+	times[0].tv_sec = index->stamp.mtime.tv_sec + 2;
+	times[0].tv_usec = index->stamp.mtime.tv_nsec / 1000;
+	times[1].tv_sec = index->stamp.mtime.tv_sec + 2;
+	times[0].tv_usec = index->stamp.mtime.tv_nsec / 1000;
 
 	cl_git_pass(p_utimes(git_index_path(index), times));
 	cl_git_pass(p_utimes(path.ptr, times));

tests/merge/workdir/dirty.c

@@ -163,9 +163,14 @@ static void hack_index(char *files[])
 		cl_git_pass(p_stat(path.ptr, &statbuf));
 
 		entry->ctime.seconds = (git_time_t)statbuf.st_ctime;
-		entry->ctime.nanoseconds = 0;
 		entry->mtime.seconds = (git_time_t)statbuf.st_mtime;
+#if defined(GIT_USE_NSEC)
+		entry->ctime.nanoseconds = statbuf.st_ctim.tv_nsec;
+		entry->mtime.nanoseconds = statbuf.st_mtim.tv_nsec;
+#else
+		entry->ctime.nanoseconds = 0;
 		entry->mtime.nanoseconds = 0;
+#endif
 		entry->dev = statbuf.st_dev;
 		entry->ino = statbuf.st_ino;
 		entry->uid  = statbuf.st_uid;