libio: add open handle functions to istream/ostream

For the backends, this simplifies the code as both paths (open file
and open stdio) use the same basic code. Even when merging them only
in the backend, it would be done in a similar way. Making the
functions public allows other uses as well.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 52 insertions, 84 deletions

diff --git a/lib/io/src/win32/ostream.c b/lib/io/src/win32/ostream.c
index 0fe04f3..d18130f 100644
--- a/lib/io/src/win32/ostream.c
+++ b/lib/io/src/win32/ostream.c
@@ -15,14 +15,14 @@ typedef struct {
 	HANDLE hnd;
 } file_ostream_t;
 
-static int w32_append(HANDLE hnd, const char *filename,
-		      const void *data, size_t size)
+static int file_append(ostream_t *strm, const void *data, size_t size)
 {
+	file_ostream_t *file = (file_ostream_t *)strm;
 	DWORD diff;
 
 	while (size > 0) {
-		if (!WriteFile(hnd, data, size, &diff, NULL)) {
-			w32_perror(filename);
+		if (!WriteFile(file->hnd, data, size, &diff, NULL)) {
+			w32_perror(file->path);
 			return -1;
 		}
 
@@ -33,25 +33,6 @@ static int w32_append(HANDLE hnd, const char *filename,
 	return 0;
 }
 
-static int w32_flush(HANDLE hnd, const char *filename)
-{
-	if (!FlushFileBuffers(hnd)) {
-		w32_perror(filename);
-		return -1;
-	}
-
-	return 0;
-}
-
-/*****************************************************************************/
-
-static int file_append(ostream_t *strm, const void *data, size_t size)
-{
-	file_ostream_t *file = (file_ostream_t *)strm;
-
-	return w32_append(file->hnd, file->path, data, size);
-}
-
 static int file_append_sparse(ostream_t *strm, size_t size)
 {
 	file_ostream_t *file = (file_ostream_t *)strm;
@@ -75,7 +56,12 @@ static int file_flush(ostream_t *strm)
 {
 	file_ostream_t *file = (file_ostream_t *)strm;
 
-	return w32_flush(file->hnd, file->path);
+	if (!FlushFileBuffers(file->hnd)) {
+		w32_perror(file->path);
+		return -1;
+	}
+
+	return 0;
 }
 
 static void file_destroy(sqfs_object_t *obj)
@@ -94,41 +80,11 @@ static const char *file_get_filename(ostream_t *strm)
 	return file->path;
 }
 
-/*****************************************************************************/
-
-static int stdout_append(ostream_t *strm, const void *data, size_t size)
-{
-	(void)strm;
-	return w32_append(GetStdHandle(STD_OUTPUT_HANDLE), "stdout",
-			  data, size);
-}
-
-static int stdout_flush(ostream_t *strm)
-{
-	(void)strm;
-	return w32_flush(GetStdHandle(STD_OUTPUT_HANDLE), "stdout");
-}
-
-static void stdout_destroy(sqfs_object_t *obj)
-{
-	free(obj);
-}
-
-static const char *stdout_get_filename(ostream_t *strm)
-{
-	(void)strm;
-	return "stdout";
-}
-
-/*****************************************************************************/
-
-ostream_t *ostream_open_file(const char *path, int flags)
+ostream_t *ostream_open_handle(const char *path, HANDLE hnd, int flags)
 {
 	file_ostream_t *file = calloc(1, sizeof(*file));
-	sqfs_object_t *obj = (sqfs_object_t *)file;
 	ostream_t *strm = (ostream_t *)file;
-	int access_flags, creation_mode;
-	WCHAR *wpath = NULL;
+	BOOL ret;
 
 	if (file == NULL) {
 		perror(path);
@@ -137,33 +93,21 @@ ostream_t *ostream_open_file(const char *path, int flags)
 
 	sqfs_object_init(file, file_destroy, NULL);
 
-	wpath = path_to_windows(path);
-	if (wpath == NULL)
-		goto fail_free;
-
 	file->path = strdup(path);
 	if (file->path == NULL) {
 		perror(path);
 		goto fail_free;
 	}
 
-	access_flags = GENERIC_WRITE;
-
-	if (flags & OSTREAM_OPEN_OVERWRITE) {
-		creation_mode = CREATE_ALWAYS;
-	} else {
-		creation_mode = CREATE_NEW;
-	}
-
-	file->hnd = CreateFileW(wpath, access_flags, 0, NULL, creation_mode,
-				FILE_ATTRIBUTE_NORMAL, NULL);
-
-	if (file->hnd == INVALID_HANDLE_VALUE) {
+	ret = DuplicateHandle(GetCurrentProcess(), hnd,
+			      GetCurrentProcess(), &file->hnd,
+			      0, FALSE, DUPLICATE_SAME_ACCESS);
+	if (!ret) {
 		w32_perror(path);
 		goto fail_path;
 	}
 
-	free(wpath);
+	CloseHandle(hnd);
 
 	if (flags & OSTREAM_OPEN_SPARSE)
 		strm->append_sparse = file_append_sparse;
@@ -176,24 +120,48 @@ fail_path:
 	free(file->path);
 fail_free:
 	free(file);
-	free(wpath);
 	return NULL;
 }
 
-ostream_t *ostream_open_stdout(void)
+ostream_t *ostream_open_file(const char *path, int flags)
 {
-	ostream_t *strm = calloc(1, sizeof(*strm));
-	sqfs_object_t *obj = (sqfs_object_t *)strm;
+	WCHAR *wpath = path_to_windows(path);
+	int access_flags, creation_mode;
+	ostream_t *out;
+	HANDLE hnd;
 
-	if (strm == NULL) {
-		perror("creating stdout file wrapper");
+	if (wpath == NULL)
 		return NULL;
+
+	access_flags = GENERIC_WRITE;
+
+	if (flags & OSTREAM_OPEN_OVERWRITE) {
+		creation_mode = CREATE_ALWAYS;
+	} else {
+		creation_mode = CREATE_NEW;
 	}
 
-	sqfs_object_init(strm, stdout_destroy, NULL);
+	hnd = CreateFileW(wpath, access_flags, 0, NULL, creation_mode,
+			  FILE_ATTRIBUTE_NORMAL, NULL);
 
-	strm->append = stdout_append;
-	strm->flush = stdout_flush;
-	strm->get_filename = stdout_get_filename;
-	return strm;
+	if (hnd == INVALID_HANDLE_VALUE) {
+		w32_perror(path);
+		free(wpath);
+		return NULL;
+	}
+
+	free(wpath);
+
+	out = ostream_open_handle(path, hnd, flags);
+	if (out == NULL)
+		CloseHandle(hnd);
+
+	return out;
+}
+
+ostream_t *ostream_open_stdout(void)
+{
+	HANDLE hnd = GetStdHandle(STD_OUTPUT_HANDLE);
+
+	return ostream_open_handle("stdout", hnd, 0);
 }