// 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_BROWSER_FEEDBACK_SYSTEM_LOGS_SYSTEM_LOGS_FETCHER_BASE_H_
#define CHROME_BROWSER_FEEDBACK_SYSTEM_LOGS_SYSTEM_LOGS_FETCHER_BASE_H_
#include <map>
#include <string>
#include "base/callback.h"
#include "base/memory/scoped_vector.h"
#include "base/memory/weak_ptr.h"
namespace system_logs {
typedef std::map<std::string, std::string> SystemLogsResponse;
// Callback that the data sources use to return data.
typedef base::Callback<void(SystemLogsResponse* response)>
SysLogsSourceCallback;
// Callback that the SystemLogsFetcherBase uses to return data.
typedef base::Callback<void(scoped_ptr<SystemLogsResponse> response)>
SysLogsFetcherCallback;
// The SystemLogsSource provides a interface for the data sources that
// the SystemLogsFetcherBase class uses to fetch logs and other
// information.
class SystemLogsSource {
public:
// Fetches data and passes it by to the callback
virtual void Fetch(const SysLogsSourceCallback& callback) = 0;
virtual ~SystemLogsSource() {}
};
// The SystemLogsFetcherBaseBase specifies an interface for LogFetcher classes.
// Derived LogFetcher classes aggregate the logs from a list of SystemLogSource
// classes.
//
// EXAMPLE:
// class Example {
// public:
// void ProcessLogs(SystemLogsResponse* response) {
// //do something with the logs
// }
// void GetLogs() {
// SystemLogsFetcherBase* fetcher = new SystemLogsFetcherBase();
// fetcher->Fetch(base::Bind(&Example::ProcessLogs, this));
// }
class SystemLogsFetcherBase
: public base::SupportsWeakPtr<SystemLogsFetcherBase> {
public:
SystemLogsFetcherBase();
~SystemLogsFetcherBase();
void Fetch(const SysLogsFetcherCallback& callback);
protected:
// Callback passed to all the data sources. It merges the |data| it recieves
// into response_. When all the data sources have responded, it deletes their
// objects and returns the response to the callback_. After this it
// deletes this instance of the object.
void AddResponse(SystemLogsResponse* response);
ScopedVector<SystemLogsSource> data_sources_;
SysLogsFetcherCallback callback_;
scoped_ptr<SystemLogsResponse> response_; // The actual response data.
size_t num_pending_requests_; // The number of callbacks it should get.
private:
DISALLOW_COPY_AND_ASSIGN(SystemLogsFetcherBase);
};
} // namespace system_logs
#endif // CHROME_BROWSER_FEEDBACK_SYSTEM_LOGS_SYSTEM_LOGS_FETCHER_BASE_H_