// Copyright 2014 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.
// Component updates can be either differential updates or full updates.
// Full updates come in CRX format; differential updates come in CRX-style
// archives, but have a different magic number. They contain "commands.json", a
// list of commands for the patcher to follow. The patcher uses these commands,
// the other files in the archive, and the files from the existing installation
// of the component to create the contents of a full update, which is then
// installed normally.
// Component updates are specified by the 'codebasediff' attribute of an
// updatecheck response:
//
// The component updater will attempt a differential update if it is available
// and allowed to, and fall back to a full update if it fails.
//
// After installation (diff or full), the component updater records "fp", the
// fingerprint of the installed files, to later identify the existing files to
// the server so that a proper differential update can be provided next cycle.
#ifndef COMPONENTS_UPDATE_CLIENT_COMPONENT_PATCHER_H_
#define COMPONENTS_UPDATE_CLIENT_COMPONENT_PATCHER_H_
#include "base/callback_forward.h"
#include "base/memory/ref_counted.h"
#include "base/values.h"
#include "components/update_client/component_unpacker.h"
#include "third_party/abseil-cpp/absl/types/optional.h"
// TODO(crbug.com/1349158): Remove this class once Puffin patches are fully
// implemented.
namespace base {
class FilePath;
}
namespace update_client {
class CrxInstaller;
class DeltaUpdateOp;
class Patcher;
enum class UnpackerError;
// The type of a patch file.
enum PatchType {
kPatchTypeUnknown,
kPatchTypeCourgette,
kPatchTypeBsdiff,
};
// Encapsulates a task for applying a differential update to a component.
class ComponentPatcher : public base::RefCountedThreadSafe {
public:
using Callback = base::OnceCallback;
// Takes an unpacked differential CRX (|input_dir|) and a component installer,
// and sets up the class to create a new (non-differential) unpacked CRX.
// If |in_process| is true, patching will be done completely within the
// existing process. Otherwise, some steps of patching may be done
// out-of-process.
ComponentPatcher(const base::FilePath& input_dir,
const base::FilePath& unpack_dir,
scoped_refptr installer,
scoped_refptr patcher);
ComponentPatcher(const ComponentPatcher&) = delete;
ComponentPatcher& operator=(const ComponentPatcher&) = delete;
// Starts patching files. This member function returns immediately, after
// posting a task to do the patching. When patching has been completed,
// |callback| will be called with the error codes if any error codes were
// encountered.
void Start(Callback callback);
private:
friend class base::RefCountedThreadSafe;
virtual ~ComponentPatcher();
void StartPatching();
void PatchNextFile();
void DonePatchingFile(UnpackerError error, int extended_error);
void DonePatching(UnpackerError error, int extended_error);
const base::FilePath input_dir_;
const base::FilePath unpack_dir_;
scoped_refptr installer_;
scoped_refptr patcher_;
Callback callback_;
absl::optional commands_;
base::Value::List::const_iterator next_command_;
scoped_refptr current_operation_;
};
} // namespace update_client
#endif // COMPONENTS_UPDATE_CLIENT_COMPONENT_PATCHER_H_