[babeltrace.git] / include / babeltrace / compat / fcntl-internal.h

#ifndef _BABELTRACE_COMPAT_FCNTL_H
#define _BABELTRACE_COMPAT_FCNTL_H

/*
 * babeltrace/compat/fcntl.h
 *
 * Copyright 2015 (c) - Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * fcntl compatibility layer.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifdef BABELTRACE_HAVE_POSIX_FALLOCATE

#include <fcntl.h>

static inline
int bt_posix_fallocate(int fd, off_t offset, off_t len)
{
	return posix_fallocate(fd, offset, len);
}

#elif defined(__MINGW32__) /* #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE */

#include <assert.h>
#include <windows.h>
#include <fcntl.h>

static inline
int bt_posix_fallocate(int fd, off_t offset, off_t len)
{
	HANDLE handle;
	LARGE_INTEGER pos, file_pos, orig_end_offset, range_end;
	int ret = 0;
	char zero = 0;
	DWORD byteswritten;

	if (offset < 0 || len <= 0) {
		ret = EINVAL;
		goto end;
	}

	range_end.QuadPart = (__int64) offset + (__int64) len;

	/* Get a handle from the fd */
	handle = (HANDLE) _get_osfhandle(fd);
	if (handle == INVALID_HANDLE_VALUE) {
		ret = EBADF;
		goto end;
	}

	/* Get the file original end offset */
	ret = GetFileSizeEx(handle, &orig_end_offset);
	if (ret == 0) {
		ret = EBADF;
		goto end;
	}

	/* Make sure we don't truncate the file */
	if (orig_end_offset.QuadPart >= range_end.QuadPart) {
		ret = 0;
		goto end;
	}

	/* Get the current file pointer position */
	pos.QuadPart = 0;
	ret = SetFilePointerEx(handle, pos, &file_pos, FILE_CURRENT);
	if (ret == 0) {
		ret = EBADF;
		goto end;
	}

	/* Move the file pointer to the new end offset */
	ret = SetFilePointerEx(handle, range_end, NULL, FILE_BEGIN);
	if (ret == 0) {
		ret = EBADF;
		goto end;
	}

	/* Sets the physical file size to the current position */
	ret = SetEndOfFile(handle);
	if (ret == 0) {
		ret = EINVAL;
		goto restore;
	}

	/*
	 * Move the file pointer back 1 byte, and write a single 0 at the
	 * last byte of the new end offset, the operating system will zero
	 * fill the file.
	 */
	pos.QuadPart = -1;
	ret = SetFilePointerEx(handle, pos, NULL, FILE_END);
	if (ret == 0) {
		ret = EBADF;
		goto end;
	}

	ret = WriteFile(handle, &zero, 1, &byteswritten, NULL);
	if (ret == 0 || byteswritten != 1) {
		ret = ENOSPC;
	} else {
		ret = 0;
	}

restore:
	/* Restore the original file pointer position */
	if (!SetFilePointerEx(handle, file_pos, NULL, FILE_BEGIN)) {
		/* We moved the file pointer but failed to restore it. */
		assert(0);
	}

end:
	return ret;
}

#else

#include <sys/types.h>
#include <unistd.h>
#include <string.h>

#define BABELTRACE_FALLOCATE_BUFLEN	256

#ifndef min_t
#define min_t(type, a, b)	\
	((type) (a) < (type) (b) ? (type) (a) : (type) (b))
#endif

static inline
int bt_posix_fallocate(int fd, off_t offset, off_t len)
{
	int ret = 0;
	ssize_t copy_len;
	char buf[BABELTRACE_FALLOCATE_BUFLEN];
	off_t i, file_pos, orig_end_offset, range_end;

	if (offset < 0 || len < 0) {
		ret = EINVAL;
		goto end;
	}

	range_end = offset + len;
	if (range_end < 0) {
		ret = EFBIG;
		goto end;
	}

	file_pos = lseek(fd, 0, SEEK_CUR);
	if (file_pos < 0) {
		ret = errno;
		goto end;
	}

	orig_end_offset = lseek(fd, 0, SEEK_END);
	if (orig_end_offset < 0) {
		ret = errno;
		goto end;
	}

	/* Seek back to original position. */
	ret = lseek(fd, file_pos, SEEK_SET);
	if (ret) {
		ret = errno;
		goto end;
	}

	/*
	 * The file may not need to grow, but we want to ensure the
	 * space has actually been reserved by the file system. First, copy
	 * the "existing" region of the file, then grow the file if needed.
	 */
	for (i = file_pos; i < min_t(off_t, range_end, orig_end_offset);
			i += copy_len) {
		ssize_t copy_ret;

		copy_len = min_t(size_t, BABELTRACE_FALLOCATE_BUFLEN,
				min_t(off_t, range_end - i,
					orig_end_offset - i));
		copy_ret = pread(fd, &buf, copy_len, i);
		if (copy_ret < copy_len) {
			/*
			 * The caller must handle any EINTR.
			 * POSIX_FALLOCATE(3) does not mention EINTR.
			 * However, glibc does forward to fallocate()
			 * directly on Linux, which may be interrupted.
			 */
			ret = errno;
			goto end;
		}

		copy_ret = pwrite(fd, &buf, copy_len, i);
		if (copy_ret < copy_len) {
			/* Same caveat as noted at pread() */
			ret = errno;
			goto end;
		}
	}

	/* Grow file, as necessary. */
	memset(&buf, 0, BABELTRACE_FALLOCATE_BUFLEN);
	for (i = orig_end_offset; i < range_end; i += copy_len) {
		ssize_t write_ret;

		copy_len = min_t(size_t, BABELTRACE_FALLOCATE_BUFLEN,
				range_end - i);
		write_ret = pwrite(fd, &buf, copy_len, i);
		if (write_ret < copy_len) {
			ret = errno;
			goto end;
		}
	}
end:
	return ret;
}
#endif /* #else #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE */


#ifdef BABELTRACE_HAVE_FACCESSAT

#include <fcntl.h>
#include <unistd.h>

static inline
int bt_faccessat(int dirfd, const char *dirname,
		const char *pathname, int mode, int flags)
{
	return faccessat(dirfd, pathname, mode, flags);
}

#else /* #ifdef BABELTRACE_HAVE_FACCESSAT */

#include <string.h>
#include <unistd.h>

static inline
int bt_faccessat(int dirfd, const char *dirname,
		const char *pathname, int mode, int flags)
{
	char cpath[PATH_MAX];

	if (flags != 0) {
		errno = EINVAL;
		return -1;
	}
	/* Includes middle / and final \0. */
	if (strlen(dirname) + strlen(pathname) + 2 > PATH_MAX) {
		return -1;
	}
	strcpy(cpath, dirname);
	strcat(cpath, "/");
	strcat(cpath, pathname);
	return access(cpath, mode);
}

#endif /* #else #ifdef BABELTRACE_HAVE_FACCESSAT */

#endif /* _BABELTRACE_COMPAT_FCNTL_H */
Commit	Line	Data
a323afb2 JG	1	#ifndef _BABELTRACE_COMPAT_FCNTL_H
	2	#define _BABELTRACE_COMPAT_FCNTL_H
	3
	4	/*
	5	* babeltrace/compat/fcntl.h
	6	*
	7	* Copyright 2015 (c) - Jérémie Galarneau <jeremie.galarneau@efficios.com>
	8	*
	9	* fcntl compatibility layer.
	10	*
	11	* Permission is hereby granted, free of charge, to any person obtaining a copy
	12	* of this software and associated documentation files (the "Software"), to deal
	13	* in the Software without restriction, including without limitation the rights
	14	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	15	* copies of the Software, and to permit persons to whom the Software is
	16	* furnished to do so, subject to the following conditions:
	17	*
	18	* The above copyright notice and this permission notice shall be included in
	19	* all copies or substantial portions of the Software.
	20	*
	21	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	22	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	23	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	24	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	25	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	26	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	27	* SOFTWARE.
	28	*/
	29
a323afb2 JG	30	#ifdef BABELTRACE_HAVE_POSIX_FALLOCATE
	31
	32	#include <fcntl.h>
	33
	34	static inline
	35	int bt_posix_fallocate(int fd, off_t offset, off_t len)
	36	{
	37	return posix_fallocate(fd, offset, len);
	38	}
	39
26fdbcef MJ	40	#elif defined(__MINGW32__) /* #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE */
	41
	42	#include <assert.h>
	43	#include <windows.h>
	44	#include <fcntl.h>
	45
	46	static inline
	47	int bt_posix_fallocate(int fd, off_t offset, off_t len)
	48	{
	49	HANDLE handle;
	50	LARGE_INTEGER pos, file_pos, orig_end_offset, range_end;
	51	int ret = 0;
	52	char zero = 0;
	53	DWORD byteswritten;
	54
	55	if (offset < 0 \|\| len <= 0) {
	56	ret = EINVAL;
	57	goto end;
	58	}
	59
	60	range_end.QuadPart = (__int64) offset + (__int64) len;
	61
	62	/* Get a handle from the fd */
	63	handle = (HANDLE) _get_osfhandle(fd);
	64	if (handle == INVALID_HANDLE_VALUE) {
	65	ret = EBADF;
	66	goto end;
	67	}
	68
	69	/* Get the file original end offset */
	70	ret = GetFileSizeEx(handle, &orig_end_offset);
	71	if (ret == 0) {
	72	ret = EBADF;
	73	goto end;
	74	}
	75
	76	/* Make sure we don't truncate the file */
	77	if (orig_end_offset.QuadPart >= range_end.QuadPart) {
	78	ret = 0;
	79	goto end;
	80	}
	81
	82	/* Get the current file pointer position */
	83	pos.QuadPart = 0;
	84	ret = SetFilePointerEx(handle, pos, &file_pos, FILE_CURRENT);
	85	if (ret == 0) {
	86	ret = EBADF;
	87	goto end;
	88	}
	89
	90	/* Move the file pointer to the new end offset */
	91	ret = SetFilePointerEx(handle, range_end, NULL, FILE_BEGIN);
	92	if (ret == 0) {
	93	ret = EBADF;
	94	goto end;
	95	}
	96
	97	/* Sets the physical file size to the current position */
	98	ret = SetEndOfFile(handle);
	99	if (ret == 0) {
	100	ret = EINVAL;
	101	goto restore;
	102	}
	103
104	/*
105	* Move the file pointer back 1 byte, and write a single 0 at the
106	* last byte of the new end offset, the operating system will zero
107	* fill the file.
108	*/
109	pos.QuadPart = -1;
110	ret = SetFilePointerEx(handle, pos, NULL, FILE_END);
111	if (ret == 0) {
112	ret = EBADF;
113	goto end;
114	}
115
116	ret = WriteFile(handle, &zero, 1, &byteswritten, NULL);
117	if (ret == 0 \|\| byteswritten != 1) {
118	ret = ENOSPC;
119	} else {
120	ret = 0;
121	}
122
123	restore:
124	/* Restore the original file pointer position */
125	if (!SetFilePointerEx(handle, file_pos, NULL, FILE_BEGIN)) {
126	/* We moved the file pointer but failed to restore it. */
127	assert(0);
128	}
129
130	end:
131	return ret;
132	}
133
134	#else
a323afb2 JG	135
	136	#include <sys/types.h>
	137	#include <unistd.h>
	138	#include <string.h>
	139
	140	#define BABELTRACE_FALLOCATE_BUFLEN 256
	141
	142	#ifndef min_t
	143	#define min_t(type, a, b) \
	144	((type) (a) < (type) (b) ? (type) (a) : (type) (b))
	145	#endif
	146
	147	static inline
	148	int bt_posix_fallocate(int fd, off_t offset, off_t len)
	149	{
	150	int ret = 0;
	151	ssize_t copy_len;
	152	char buf[BABELTRACE_FALLOCATE_BUFLEN];
	153	off_t i, file_pos, orig_end_offset, range_end;
	154
	155	if (offset < 0 \|\| len < 0) {
	156	ret = EINVAL;
	157	goto end;
	158	}
	159
	160	range_end = offset + len;
	161	if (range_end < 0) {
	162	ret = EFBIG;
	163	goto end;
	164	}
	165
	166	file_pos = lseek(fd, 0, SEEK_CUR);
	167	if (file_pos < 0) {
	168	ret = errno;
	169	goto end;
	170	}
	171
	172	orig_end_offset = lseek(fd, 0, SEEK_END);
	173	if (orig_end_offset < 0) {
	174	ret = errno;
	175	goto end;
	176	}
	177
	178	/* Seek back to original position. */
	179	ret = lseek(fd, file_pos, SEEK_SET);
	180	if (ret) {
	181	ret = errno;
	182	goto end;
	183	}
	184
	185	/*
	186	* The file may not need to grow, but we want to ensure the
	187	* space has actually been reserved by the file system. First, copy
	188	* the "existing" region of the file, then grow the file if needed.
	189	*/
	190	for (i = file_pos; i < min_t(off_t, range_end, orig_end_offset);
	191	i += copy_len) {
	192	ssize_t copy_ret;
	193
	194	copy_len = min_t(size_t, BABELTRACE_FALLOCATE_BUFLEN,
	195	min_t(off_t, range_end - i,
	196	orig_end_offset - i));
	197	copy_ret = pread(fd, &buf, copy_len, i);
	198	if (copy_ret < copy_len) {
199	/*
200	* The caller must handle any EINTR.
201	* POSIX_FALLOCATE(3) does not mention EINTR.
202	* However, glibc does forward to fallocate()
203	* directly on Linux, which may be interrupted.
204	*/
205	ret = errno;
206	goto end;
207	}
208
209	copy_ret = pwrite(fd, &buf, copy_len, i);
210	if (copy_ret < copy_len) {
211	/* Same caveat as noted at pread() */
212	ret = errno;
213	goto end;
214	}
215	}
216
217	/* Grow file, as necessary. */
218	memset(&buf, 0, BABELTRACE_FALLOCATE_BUFLEN);
219	for (i = orig_end_offset; i < range_end; i += copy_len) {
220	ssize_t write_ret;
221
222	copy_len = min_t(size_t, BABELTRACE_FALLOCATE_BUFLEN,
223	range_end - i);
224	write_ret = pwrite(fd, &buf, copy_len, i);
225	if (write_ret < copy_len) {
226	ret = errno;
227	goto end;
228	}
229	}
230	end:
231	return ret;
232	}
233	#endif /* #else #ifdef BABELTRACE_HAVE_POSIX_FALLOCATE */
234
0bb657dc MD	235
	236	#ifdef BABELTRACE_HAVE_FACCESSAT
	237
	238	#include <fcntl.h>
	239	#include <unistd.h>
	240
	241	static inline
	242	int bt_faccessat(int dirfd, const char *dirname,
	243	const char *pathname, int mode, int flags)
	244	{
	245	return faccessat(dirfd, pathname, mode, flags);
	246	}
	247
	248	#else /* #ifdef BABELTRACE_HAVE_FACCESSAT */
	249
	250	#include <string.h>
	251	#include <unistd.h>
	252
	253	static inline
	254	int bt_faccessat(int dirfd, const char *dirname,
	255	const char *pathname, int mode, int flags)
	256	{
	257	char cpath[PATH_MAX];
	258
	259	if (flags != 0) {
	260	errno = EINVAL;
	261	return -1;
	262	}
	263	/* Includes middle / and final \0. */
	264	if (strlen(dirname) + strlen(pathname) + 2 > PATH_MAX) {
	265	return -1;
	266	}
	267	strcpy(cpath, dirname);
	268	strcat(cpath, "/");
	269	strcat(cpath, pathname);
	270	return access(cpath, mode);
	271	}
	272
	273	#endif /* #else #ifdef BABELTRACE_HAVE_FACCESSAT */
	274
a323afb2	275	#endif /* _BABELTRACE_COMPAT_FCNTL_H */