/**
* Copyright (c) 2018 Cornell University.
*
* Author: Ted Yin <tederminant@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is furnished to do
* so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef _SALTICIDAE_CONN_H
#define _SALTICIDAE_CONN_H
#include <cassert>
#include <cstdint>
#include <event2/event.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string>
#include <unordered_map>
#include <list>
#include <algorithm>
#include <exception>
#include "salticidae/type.h"
#include "salticidae/ref.h"
#include "salticidae/event.h"
#include "salticidae/util.h"
#include "salticidae/netaddr.h"
#include "salticidae/msg.h"
const int MAX_LISTEN_BACKLOG = 10;
const size_t BUFF_SEG_SIZE = 4096;
const size_t MAX_MSG_HANDLER = 64;
const double TRY_CONN_DELAY = 2;
const double CONN_SERVER_TIMEOUT = 2;
namespace salticidae {
inline double gen_rand_timeout(double base_timeout) {
return base_timeout + rand() / (double)RAND_MAX * 0.5 * base_timeout;
}
class RingBuffer {
struct buffer_entry_t {
bytearray_t data;
bytearray_t::iterator offset;
buffer_entry_t(bytearray_t &&_data): data(std::move(_data)) {
offset = data.begin();
}
buffer_entry_t(buffer_entry_t &&other) {
size_t _offset = other.offset - other.data.begin();
data = std::move(other.data);
offset = data.begin() + _offset;
}
buffer_entry_t(const buffer_entry_t &other): data(other.data) {
offset = data.begin() + (other.offset - other.data.begin());
}
size_t length() const { return data.end() - offset; }
};
std::list<buffer_entry_t> ring;
size_t _size;
public:
RingBuffer(): _size(0) {}
~RingBuffer() { clear(); }
void swap(RingBuffer &other) {
std::swap(ring, other.ring);
std::swap(_size, other._size);
}
RingBuffer(const RingBuffer &other):
ring(other.ring), _size(other._size) {}
RingBuffer(RingBuffer &&other):
ring(std::move(other.ring)), _size(other._size) {
other._size = 0;
}
RingBuffer &operator=(RingBuffer &&other) {
if (this != &other)
{
RingBuffer tmp(std::move(other));
tmp.swap(*this);
}
return *this;
}
RingBuffer &operator=(const RingBuffer &other) {
if (this != &other)
{
RingBuffer tmp(other);
tmp.swap(*this);
}
return *this;
}
void push(bytearray_t &&data) {
_size += data.size();
ring.push_back(buffer_entry_t(std::move(data)));
}
bytearray_t pop(size_t len) {
bytearray_t res;
auto i = ring.begin();
while (len && i != ring.end())
{
size_t copy_len = std::min(i->length(), len);
res.insert(res.end(), i->offset, i->offset + copy_len);
i->offset += copy_len;
len -= copy_len;
if (i->offset == i->data.end())
i++;
}
ring.erase(ring.begin(), i);
_size -= res.size();
return std::move(res);
}
size_t size() const { return _size; }
void clear() {
ring.clear();
_size = 0;
}
};
class ConnPoolError: public SalticidaeError {
using SalticidaeError::SalticidaeError;
};
/** The connection pool. */
class ConnPool {
public:
class Conn;
using conn_t = RcObj<Conn>;
/** The abstraction for a bi-directional connection. */
class Conn {
public:
enum ConnMode {
ACTIVE, /**< the connection is established by connect() */
PASSIVE, /**< the connection is established by accept() */
};
private:
conn_t self_ref;
int fd;
ConnPool *cpool;
ConnMode mode;
NetAddr addr;
RingBuffer send_buffer;
RingBuffer recv_buffer;
Event ev_read;
Event ev_write;
Event ev_connect;
/** does not need to wait if true */
bool ready_send;
void recv_data(evutil_socket_t, short);
void send_data(evutil_socket_t, short);
void conn_server(evutil_socket_t, short);
void try_conn(evutil_socket_t, short);
public:
friend ConnPool;
Conn(): self_ref(this) {}
virtual ~Conn() {
SALTICIDAE_LOG_INFO("destroyed connection %s", std::string(*this).c_str());
}
conn_t self() { return self_ref; }
operator std::string() const;
int get_fd() const { return fd; }
const NetAddr &get_addr() const { return addr; }
ConnMode get_mode() const { return mode; }
RingBuffer &read() { return recv_buffer; }
void write(bytearray_t &&data) {
send_buffer.push(std::move(data));
if (ready_send)
send_data(fd, EV_WRITE);
}
void move_send_buffer(conn_t other) {
send_buffer = std::move(other->send_buffer);
}
void terminate();
protected:
/** close the connection and free all on-going or planned events. */
virtual void close() {
ev_read.clear();
ev_write.clear();
ev_connect.clear();
::close(fd);
fd = -1;
}
virtual void on_read() = 0;
virtual void on_setup() = 0;
virtual void on_teardown() = 0;
};
private:
std::unordered_map<int, conn_t> pool;
int listen_fd;
Event ev_listen;
void accept_client(evutil_socket_t, short);
conn_t add_conn(conn_t conn);
protected:
EventContext eb;
virtual conn_t create_conn() = 0;
public:
friend Conn;
ConnPool(const EventContext &eb): eb(eb) {}
~ConnPool() {
for (auto it: pool)
{
conn_t conn = it.second;
conn->close();
}
}
/** create an active mode connection to addr */
conn_t create_conn(const NetAddr &addr);
/** setup and start listening */
void init(NetAddr listen_addr);
};
}
#endif