Merge pull request #4874 from tiennou/test/4615

Test that largefiles can be read through the tree API

3 files changed, 91 insertions, 0 deletions

diff --git a/src/posix.c b/src/posix.c
index bffe02e05..b5dfac56d 100644
--- a/src/posix.c
+++ b/src/posix.c
@@ -155,6 +155,44 @@ int p_rename(const char *from, const char *to)
 	return -1;
 }
 
+int p_fallocate(int fd, off_t offset, off_t len)
+{
+#ifdef __APPLE__
+	fstore_t prealloc;
+	struct stat st;
+	size_t newsize;
+	int error;
+
+	if ((error = p_fstat(fd, &st)) < 0)
+		return error;
+
+	if (git__add_sizet_overflow(&newsize, offset, len)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (newsize < (unsigned long long)st.st_size)
+		return 0;
+
+	memset(&prealloc, 0, sizeof(prealloc));
+	prealloc.fst_flags  = F_ALLOCATEALL;
+	prealloc.fst_posmode = F_PEOFPOSMODE;
+	prealloc.fst_offset = offset;
+	prealloc.fst_length = len;
+
+	/*
+	 * fcntl will often error when the file already exists; ignore
+	 * this error since ftruncate will also resize the file (although
+	 * likely slower).
+	 */
+	fcntl(fd, F_PREALLOCATE, &prealloc);
+
+	return ftruncate(fd, (offset + len));
+#else
+	return posix_fallocate(fd, offset, len);
+#endif
+}
+
 #endif /* GIT_WIN32 */
 
 ssize_t p_read(git_file fd, void *buf, size_t cnt)
diff --git a/src/posix.h b/src/posix.h
index 2934f2479..0119b6bb7 100644
--- a/src/posix.h
+++ b/src/posix.h
@@ -115,6 +115,7 @@ extern int p_open(const char *path, int flags, ...);
 extern int p_creat(const char *path, mode_t mode);
 extern int p_getcwd(char *buffer_out, size_t size);
 extern int p_rename(const char *from, const char *to);
+extern int p_fallocate(int fd, off_t offset, off_t len);
 
 extern int git__page_size(size_t *page_size);
 extern int git__mmap_alignment(size_t *page_size);
diff --git a/src/win32/posix_w32.c b/src/win32/posix_w32.c
index d8bbebb5d..fcaf77e89 100644
--- a/src/win32/posix_w32.c
+++ b/src/win32/posix_w32.c
@@ -516,6 +516,58 @@ int p_creat(const char *path, mode_t mode)
 	return p_open(path, O_WRONLY | O_CREAT | O_TRUNC, mode);
 }
 
+int p_fallocate(int fd, off_t offset, off_t len)
+{
+	HANDLE fh = (HANDLE)_get_osfhandle(fd);
+	LARGE_INTEGER zero, position, oldsize, newsize;
+	size_t size;
+
+	if (fh == INVALID_HANDLE_VALUE) {
+		errno = EBADF;
+		return -1;
+	}
+
+	if (offset < 0 || len <= 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (git__add_sizet_overflow(&size, offset, len)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	zero.u.LowPart = 0;
+	zero.u.HighPart = 0;
+
+	newsize.u.LowPart = (size & 0xffffffff);
+
+#if (SIZE_MAX > UINT32_MAX)
+	newsize.u.HighPart = size >> 32;
+#else
+	newsize.u.HighPart = 0;
+#endif
+
+	if (!GetFileSizeEx(fh, &oldsize)) {
+		set_errno();
+		return -1;
+	}
+
+	/* POSIX emulation: attempting to shrink the file is ignored */
+	if (oldsize.QuadPart >= newsize.QuadPart)
+		return 0;
+
+	if (!SetFilePointerEx(fh, zero, &position, FILE_CURRENT) ||
+	    !SetFilePointerEx(fh, newsize, NULL, FILE_BEGIN) ||
+	    !SetEndOfFile(fh) ||
+	    !SetFilePointerEx(fh, position, 0, FILE_BEGIN)) {
+		set_errno();
+		return -1;
+	}
+
+	return 0;
+}
+
 int p_utimes(const char *path, const struct p_timeval times[2])
 {
 	git_win32_path wpath;