blob: 272d521db8b7c37f9616d88bd14b044cc8dcb762 [file] [log] [blame]
// Copyright (c) 2006-2008 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.
#include <string>
#include "base/basictypes.h"
class Pickle;
// SessionCommand contains a command id and arbitrary chunk of data. The id
// and chunk of data are specific to the service creating them.
// Both TabRestoreService and SessionService use SessionCommands to represent
// state on disk.
// There are two ways to create a SessionCommand:
// . Specificy the size of the data block to create. This is useful for
// commands that have a fixed size.
// . From a pickle, this is useful for commands whose length varies.
class SessionCommand {
// These get written to disk, so we define types for them.
// Type for the identifier.
typedef uint8 id_type;
// Type for writing the size.
typedef uint16 size_type;
// Creates a session command with the specified id. This allocates a buffer
// of size |size| that must be filled via contents().
SessionCommand(id_type id, size_type size);
// Convenience constructor that creates a session command with the specified
// id whose contents is populated from the contents of pickle.
SessionCommand(id_type id, const Pickle& pickle);
// The contents of the command.
char* contents() { return const_cast<char*>(contents_.c_str()); }
const char* contents() const { return contents_.c_str(); }
// Identifier for the command.
id_type id() const { return id_; }
// Size of data.
size_type size() const { return static_cast<size_type>(contents_.size()); }
// Convenience for extracting the data to a target. Returns false if
// count is not equal to the size of data this command contains.
bool GetPayload(void* dest, size_t count) const;
// Returns the contents as a pickle. It is up to the caller to delete the
// returned Pickle. The returned Pickle references the underlying data of
// this SessionCommand. If you need it to outlive the command, copy the
// pickle.
Pickle* PayloadAsPickle() const;
const id_type id_;
std::string contents_;