1 files changed, 61 insertions, 0 deletions
diff --git a/src/lib-fs/istream-fs-file.c b/src/lib-fs/istream-fs-file.c
new file mode 100644
index 0000000..4f61cfe
--- /dev/null
+++ b/src/lib-fs/istream-fs-file.c
@@ -0,0 +1,61 @@
+/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "istream-private.h"
+#include "fs-api-private.h"
+#include "istream-fs-file.h"
+
+struct fs_file_istream {
+	struct istream_private istream;
+	struct fs_file *file;
+};
+
+static void i_stream_fs_file_close(struct iostream_private *stream,
+				   bool close_parent ATTR_UNUSED)
+{
+	struct fs_file_istream *fstream = (struct fs_file_istream *)stream;
+
+	i_stream_destroy(&fstream->istream.parent);
+	fs_file_deinit(&fstream->file);
+}
+
+static ssize_t i_stream_fs_file_read(struct istream_private *stream)
+{
+	struct fs_file_istream *fstream = (struct fs_file_istream *)stream;
+	struct istream *input;
+
+	if (fstream->istream.parent == NULL) {
+		input = fs_read_stream(fstream->file,
+			i_stream_get_max_buffer_size(&stream->istream));
+		i_stream_init_parent(stream, input);
+		i_stream_unref(&input);
+	}
+
+	i_stream_seek(stream->parent, stream->parent_start_offset +
+		      stream->istream.v_offset);
+	return i_stream_read_copy_from_parent(&stream->istream);
+}
+
+struct istream *
+i_stream_create_fs_file(struct fs_file **file, size_t max_buffer_size)
+{
+	struct fs_file_istream *fstream;
+	struct istream *input;
+
+	fstream = i_new(struct fs_file_istream, 1);
+	fstream->file = *file;
+	fstream->istream.iostream.close = i_stream_fs_file_close;
+	fstream->istream.max_buffer_size = max_buffer_size;
+	fstream->istream.read = i_stream_fs_file_read;
+	fstream->istream.stream_size_passthrough = TRUE;
+
+	fstream->istream.istream.blocking =
+		((*file)->flags & FS_OPEN_FLAG_ASYNC) == 0;
+	fstream->istream.istream.seekable =
+		((*file)->flags & FS_OPEN_FLAG_SEEKABLE) != 0;
+
+	input = i_stream_create(&fstream->istream, NULL, -1, 0);
+	i_stream_set_name(input, fs_file_path(*file));
+	*file = NULL;
+	return input;
+}