summaryrefslogtreecommitdiffstats
path: root/src/port/win32stat.c
blob: e25811d290e44ba150f8fd496f40b438e95e10ab (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
/*-------------------------------------------------------------------------
 *
 * win32stat.c
 *	  Replacements for <sys/stat.h> functions using GetFileInformationByHandle
 *
 * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  src/port/win32stat.c
 *
 *-------------------------------------------------------------------------
 */

#ifdef WIN32

#include "c.h"
#include <windows.h>

/*
 * Convert a FILETIME struct into a 64 bit time_t.
 */
static __time64_t
filetime_to_time(const FILETIME *ft)
{
	ULARGE_INTEGER unified_ft = {0};
	static const uint64 EpochShift = UINT64CONST(116444736000000000);

	unified_ft.LowPart = ft->dwLowDateTime;
	unified_ft.HighPart = ft->dwHighDateTime;

	if (unified_ft.QuadPart < EpochShift)
		return -1;

	unified_ft.QuadPart -= EpochShift;
	unified_ft.QuadPart /= 10 * 1000 * 1000;

	return unified_ft.QuadPart;
}

/*
 * Convert WIN32 file attributes to a Unix-style mode.
 *
 * Only owner permissions are set.
 */
static unsigned short
fileattr_to_unixmode(int attr)
{
	unsigned short uxmode = 0;

	uxmode |= (unsigned short) ((attr & FILE_ATTRIBUTE_DIRECTORY) ?
								(_S_IFDIR) : (_S_IFREG));

	uxmode |= (unsigned short) ((attr & FILE_ATTRIBUTE_READONLY) ?
								(_S_IREAD) : (_S_IREAD | _S_IWRITE));

	/* there is no need to simulate _S_IEXEC using CMD's PATHEXT extensions */
	uxmode |= _S_IEXEC;

	return uxmode;
}

/*
 * Convert WIN32 file information (from a HANDLE) to a struct stat.
 */
static int
fileinfo_to_stat(HANDLE hFile, struct stat *buf)
{
	BY_HANDLE_FILE_INFORMATION fiData;

	memset(buf, 0, sizeof(*buf));

	/*
	 * GetFileInformationByHandle minimum supported version: Windows XP and
	 * Windows Server 2003, so it exists everywhere we care about.
	 */
	if (!GetFileInformationByHandle(hFile, &fiData))
	{
		_dosmaperr(GetLastError());
		return -1;
	}

	if (fiData.ftLastWriteTime.dwLowDateTime ||
		fiData.ftLastWriteTime.dwHighDateTime)
		buf->st_mtime = filetime_to_time(&fiData.ftLastWriteTime);

	if (fiData.ftLastAccessTime.dwLowDateTime ||
		fiData.ftLastAccessTime.dwHighDateTime)
		buf->st_atime = filetime_to_time(&fiData.ftLastAccessTime);
	else
		buf->st_atime = buf->st_mtime;

	if (fiData.ftCreationTime.dwLowDateTime ||
		fiData.ftCreationTime.dwHighDateTime)
		buf->st_ctime = filetime_to_time(&fiData.ftCreationTime);
	else
		buf->st_ctime = buf->st_mtime;

	buf->st_mode = fileattr_to_unixmode(fiData.dwFileAttributes);
	buf->st_nlink = fiData.nNumberOfLinks;

	buf->st_size = ((((uint64) fiData.nFileSizeHigh) << 32) |
					fiData.nFileSizeLow);

	return 0;
}

/*
 * Windows implementation of stat().
 *
 * This currently also implements lstat(), though perhaps that should change.
 */
int
_pgstat64(const char *name, struct stat *buf)
{
	/*
	 * Our open wrapper will report STATUS_DELETE_PENDING as ENOENT.  We
	 * request FILE_FLAG_BACKUP_SEMANTICS so that we can open directories too,
	 * for limited purposes.  We use the private handle-based version, so we
	 * don't risk running out of fds.
	 */
	HANDLE		hFile;
	int			ret;

	hFile = pgwin32_open_handle(name, O_RDONLY, true);
	if (hFile == INVALID_HANDLE_VALUE)
		return -1;

	ret = fileinfo_to_stat(hFile, buf);

	CloseHandle(hFile);
	return ret;
}

/*
 * Windows implementation of fstat().
 */
int
_pgfstat64(int fileno, struct stat *buf)
{
	HANDLE		hFile = (HANDLE) _get_osfhandle(fileno);
	DWORD		fileType = FILE_TYPE_UNKNOWN;
	unsigned short st_mode;

	if (buf == NULL)
	{
		errno = EINVAL;
		return -1;
	}

	fileType = pgwin32_get_file_type(hFile);
	if (errno != 0)
		return -1;

	switch (fileType)
	{
			/* The specified file is a disk file */
		case FILE_TYPE_DISK:
			return fileinfo_to_stat(hFile, buf);

			/*
			 * The specified file is a socket, a named pipe, or an anonymous
			 * pipe.
			 */
		case FILE_TYPE_PIPE:
			st_mode = _S_IFIFO;
			break;
			/* The specified file is a character file */
		case FILE_TYPE_CHAR:
			st_mode = _S_IFCHR;
			break;
			/* Unused flag and unknown file type */
		case FILE_TYPE_REMOTE:
		case FILE_TYPE_UNKNOWN:
		default:
			errno = EINVAL;
			return -1;
	}

	memset(buf, 0, sizeof(*buf));
	buf->st_mode = st_mode;
	buf->st_dev = fileno;
	buf->st_rdev = fileno;
	buf->st_nlink = 1;
	return 0;
}

#endif							/* WIN32 */