AU: SplitWriter class for parsing our full update files.
Full updates now include data for two partitions (kernel + rootfs).
This CL adds a new SplitFileWriter class which takes the stream of
data, which is expected to be in our full update format (8 bytes big
endian uint64_t of the first partition size, followed by first
partition data, followed by second partition size). It parses the
size, then writes the data to each of two FileWriter classes.
BUG=None
TEST=Attached unittest
Review URL: http://codereview.chromium.org/1800009
diff --git a/split_file_writer.h b/split_file_writer.h
new file mode 100644
index 0000000..cba8161
--- /dev/null
+++ b/split_file_writer.h
@@ -0,0 +1,63 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_SPLIT_FILE_WRITER_H__
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_SPLIT_FILE_WRITER_H__
+
+#include "update_engine/file_writer.h"
+
+// SplitFileWriter is an implementation of FileWriter suited to our
+// full autoupdate format. The first 8 bytes read are assumed to be a
+// big-endian number describing how many of the next following bytes
+// go to the first FileWriter. After that, the rest of the bytes all
+// go to the second FileWriter.
+
+namespace chromeos_update_engine {
+
+class SplitFileWriter : public FileWriter {
+ public:
+ SplitFileWriter(FileWriter* first_file_writer, FileWriter* second_file_writer)
+ : first_file_writer_(first_file_writer),
+ first_length_(0),
+ first_path_(NULL),
+ first_flags_(0),
+ first_mode_(0),
+ second_file_writer_(second_file_writer),
+ bytes_received_(0) {}
+
+ void SetFirstOpenArgs(const char* path, int flags, mode_t mode) {
+ first_path_ = path;
+ first_flags_ = flags;
+ first_mode_ = mode;
+ }
+
+ // If both succeed, returns the return value from the second Open() call.
+ // On error, both files will be left closed.
+ virtual int Open(const char* path, int flags, mode_t mode);
+
+ virtual ssize_t Write(const void* bytes, size_t count);
+
+ virtual int Close();
+
+ private:
+ // Data for the first file writer.
+ FileWriter* const first_file_writer_;
+ off_t first_length_;
+ const char* first_path_;
+ int first_flags_;
+ mode_t first_mode_;
+
+ // The scond file writeer.
+ FileWriter* const second_file_writer_;
+
+ // Bytes written thus far
+ off_t bytes_received_;
+ char first_length_buf_[sizeof(uint64_t)];
+
+ DISALLOW_COPY_AND_ASSIGN(SplitFileWriter);
+};
+
+} // namespace chromeos_update_engine
+
+#endif // CHROMEOS_PLATFORM_UPDATE_ENGINE_SPLIT_FILE_WRITER_H__