// Copyright 2013 The Chromium 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 CHROME_INSTALLER_SETUP_ARCHIVE_PATCH_HELPER_H_
#define CHROME_INSTALLER_SETUP_ARCHIVE_PATCH_HELPER_H_
#include "base/basictypes.h"
#include "base/files/file_path.h"
namespace installer {
// A helper class that facilitates uncompressing and patching the chrome archive
// and installer.
//
// Chrome's installer is deployed along with a compressed archive containing
// either 1) an uncompressd archive of the product binaries or 2) a patch file
// to be applied to the uncompressed archive of the version being updated. To
// obtain the uncompressed archive, the contents of the compressed archive are
// uncompressed and extracted. Installation proceeds directly if the
// uncompressed archive is found after this step. Otherwise, the patch is
// applied to the previous version's uncompressed archive using either
// Courgette's ensemble patching or bspatch.
//
// Chrome's installer itself may also be deployed as a patch against the
// previous version's saved installer binary. The same process is followed to
// obtain the new installer. The compressed archive unconditionally contains a
// patch file in this case.
class ArchivePatchHelper {
public:
// Constructs an instance that can uncompress |compressed_archive| into
// |working_directory| and optionally apply the extracted patch file to
// |patch_source|, writing the result to |target|.
ArchivePatchHelper(const base::FilePath& working_directory,
const base::FilePath& compressed_archive,
const base::FilePath& patch_source,
const base::FilePath& target);
~ArchivePatchHelper();
// Uncompresses |compressed_archive| in |working_directory| then applies the
// extracted patch file to |patch_source|, writing the result to |target|.
// Ensemble patching via Courgette is attempted first. If that fails, bspatch
// is attempted. Returns false if uncompression or both patching steps fail.
static bool UncompressAndPatch(const base::FilePath& working_directory,
const base::FilePath& compressed_archive,
const base::FilePath& patch_source,
const base::FilePath& target);
// Uncompresses compressed_archive() into the working directory. On success,
// last_uncompressed_file (if not NULL) is populated with the path to the last
// file extracted from the archive.
bool Uncompress(base::FilePath* last_uncompressed_file);
// Attempts to use courgette to apply last_uncompressed_file() to
// patch_source() to generate target(). Returns false if patching fails.
bool EnsemblePatch();
// Attempts to use bspatch to apply last_uncompressed_file() to patch_source()
// to generate target(). Returns false if patching fails.
bool BinaryPatch();
const base::FilePath& compressed_archive() const {
return compressed_archive_;
}
void set_patch_source(const base::FilePath& patch_source) {
patch_source_ = patch_source;
}
const base::FilePath& patch_source() const {
return patch_source_;
}
const base::FilePath& target() const {
return target_;
}
// Returns the path of the last file extracted by Uncompress().
const base::FilePath& last_uncompressed_file() const {
return last_uncompressed_file_;
}
void set_last_uncompressed_file(
const base::FilePath& last_uncompressed_file) {
last_uncompressed_file_ = last_uncompressed_file;
}
private:
base::FilePath working_directory_;
base::FilePath compressed_archive_;
base::FilePath patch_source_;
base::FilePath target_;
base::FilePath last_uncompressed_file_;
DISALLOW_COPY_AND_ASSIGN(ArchivePatchHelper);
};
} // namespace installer
#endif // CHROME_INSTALLER_SETUP_ARCHIVE_PATCH_HELPER_H_