6ead5a4696
the log.hh under the root of the tree was created keep the backward compatibility when seastar was extracted into a separate library. so log.hh should belong to `utils` directory, as it is based solely on seastar, and can be used all subsystems. in this change, we move log.hh into utils/log.hh to that it is more modularized. and this also improves the readability, when one see `#include "utils/log.hh"`, it is obvious that this source file needs the logging system, instead of its own log facility -- please note, we do have two other `log.hh` in the tree. Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
125 lines
4.0 KiB
C++
125 lines
4.0 KiB
C++
/*
|
|
* Copyright (C) 2021-present ScyllaDB
|
|
*/
|
|
|
|
/*
|
|
* SPDX-License-Identifier: AGPL-3.0-or-later
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include "utils/log.hh"
|
|
|
|
#include "seastarx.hh"
|
|
|
|
#include <list>
|
|
|
|
#include <seastar/core/file-types.hh>
|
|
#include <seastar/core/future.hh>
|
|
#include <seastar/core/gate.hh>
|
|
#include <seastar/net/api.hh>
|
|
#include <seastar/net/tls.hh>
|
|
|
|
#include <boost/intrusive/list.hpp>
|
|
|
|
namespace generic_server {
|
|
|
|
class server;
|
|
|
|
// A generic TCP connection.
|
|
//
|
|
// This class is used in tandem with the `server`class to implement a protocol
|
|
// specific TCP connection.
|
|
//
|
|
// Protocol specific classes are expected to override the `process_request`
|
|
// member function to perform request processing. This base class provides a
|
|
// `_read_buf` and a `_write_buf` for reading requests and writing responses.
|
|
class connection : public boost::intrusive::list_base_hook<> {
|
|
protected:
|
|
server& _server;
|
|
connected_socket _fd;
|
|
input_stream<char> _read_buf;
|
|
output_stream<char> _write_buf;
|
|
future<> _ready_to_respond = make_ready_future<>();
|
|
seastar::gate _pending_requests_gate;
|
|
seastar::gate::holder _hold_server;
|
|
|
|
public:
|
|
connection(server& server, connected_socket&& fd);
|
|
virtual ~connection();
|
|
|
|
virtual future<> process();
|
|
|
|
virtual void handle_error(future<>&& f) = 0;
|
|
|
|
virtual future<> process_request() = 0;
|
|
|
|
virtual void on_connection_close();
|
|
|
|
virtual future<> shutdown();
|
|
};
|
|
|
|
// A generic TCP socket server.
|
|
//
|
|
// This class can be used as a base for a protocol specific TCP socket server
|
|
// that listens to incoming connections and processes requests coming over the
|
|
// connection.
|
|
//
|
|
// The provides a `listen` member function that creates a TCP server socket and
|
|
// registers it to the Seastar reactor. The class also provides a `stop` member
|
|
// function that can be used to safely stop the server.
|
|
//
|
|
// Protocol specific classes that inherit `server` are expected to also inherit
|
|
// a connection class from `connection` and override the `make_connection` member
|
|
// function to create a protocol specific connection upon `accept`.
|
|
class server {
|
|
friend class connection;
|
|
|
|
protected:
|
|
sstring _server_name;
|
|
logging::logger& _logger;
|
|
seastar::gate _gate;
|
|
future<> _all_connections_stopped = make_ready_future<>();
|
|
uint64_t _total_connections = 0;
|
|
future<> _listeners_stopped = make_ready_future<>();
|
|
using connections_list_t = boost::intrusive::list<connection>;
|
|
connections_list_t _connections_list;
|
|
struct gentle_iterator {
|
|
connections_list_t::iterator iter, end;
|
|
gentle_iterator(server& s) : iter(s._connections_list.begin()), end(s._connections_list.end()) {}
|
|
gentle_iterator(const gentle_iterator&) = delete;
|
|
gentle_iterator(gentle_iterator&&) = delete;
|
|
};
|
|
std::list<gentle_iterator> _gentle_iterators;
|
|
std::vector<server_socket> _listeners;
|
|
|
|
public:
|
|
server(const sstring& server_name, logging::logger& logger);
|
|
|
|
virtual ~server();
|
|
|
|
// Makes sure listening sockets no longer generate new connections and aborts the
|
|
// connected sockets, so that new requests are not served and existing requests don't
|
|
// send responses back.
|
|
//
|
|
// It does _not_ wait for any internal activity started by the established connections
|
|
// to finish. It's the .stop() method that does it
|
|
future<> shutdown();
|
|
future<> stop();
|
|
|
|
future<> listen(socket_address addr, std::shared_ptr<seastar::tls::credentials_builder> creds, bool is_shard_aware, bool keepalive, std::optional<file_permissions> unix_domain_socket_permissions);
|
|
|
|
future<> do_accepts(int which, bool keepalive, socket_address server_addr);
|
|
|
|
protected:
|
|
virtual seastar::shared_ptr<connection> make_connection(socket_address server_addr, connected_socket&& fd, socket_address addr) = 0;
|
|
|
|
virtual future<> advertise_new_connection(shared_ptr<connection> conn);
|
|
|
|
virtual future<> unadvertise_connection(shared_ptr<connection> conn);
|
|
|
|
future<> for_each_gently(noncopyable_function<future<>(connection&)>);
|
|
};
|
|
|
|
}
|