nghttp2/src/shrpx_memcached_connection.h

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/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2015 Tatsuhiro Tsujikawa
*
* 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 SHRPX_MEMCACHED_CONNECTION_H
#define SHRPX_MEMCACHED_CONNECTION_H
#include "shrpx.h"
#include <memory>
#include <deque>
#include <ev.h>
#include "shrpx_connection.h"
#include "buffer.h"
using namespace nghttp2;
namespace shrpx {
struct MemcachedRequest;
struct Address;
enum {
MEMCACHED_PARSE_HEADER24,
MEMCACHED_PARSE_EXTRA,
MEMCACHED_PARSE_VALUE,
};
// Stores state when parsing response from memcached server
struct MemcachedParseState {
// Buffer for value, dynamically allocated.
std::vector<uint8_t> value;
// cas in response
uint64_t cas;
// keylen in response
size_t keylen;
// extralen in response
size_t extralen;
// totalbody in response. The length of value is totalbody -
// extralen - keylen.
size_t totalbody;
// Number of bytes left to read variable length field.
size_t read_left;
// Parser state; see enum above
int state;
// status_code in response
int status_code;
// op in response
int op;
};
struct MemcachedSendbuf {
// Buffer for header + extra + key
Buffer<512> headbuf;
// MemcachedRequest associated to this object
MemcachedRequest *req;
// Number of bytes left when sending value
size_t send_value_left;
// Returns the number of bytes this object transmits.
size_t left() const { return headbuf.rleft() + send_value_left; }
};
constexpr uint8_t MEMCACHED_REQ_MAGIC = 0x80;
constexpr uint8_t MEMCACHED_RES_MAGIC = 0x81;
// MemcachedConnection implements part of memcached binary protocol.
// This is not full brown implementation. Just the part we need is
// implemented. We only use GET and ADD.
//
// https://github.com/memcached/memcached/blob/master/doc/protocol-binary.xml
// https://code.google.com/p/memcached/wiki/MemcacheBinaryProtocol
class MemcachedConnection {
public:
MemcachedConnection(const Address *addr, struct ev_loop *loop);
~MemcachedConnection();
void disconnect();
int add_request(std::unique_ptr<MemcachedRequest> req);
int initiate_connection();
int on_connect();
int on_write();
int on_read();
int send_request();
void make_request(MemcachedSendbuf *sendbuf, MemcachedRequest *req);
int parse_packet();
size_t serialized_size(MemcachedRequest *req);
void signal_write();
private:
Connection conn_;
std::deque<std::unique_ptr<MemcachedRequest>> recvq_;
std::deque<std::unique_ptr<MemcachedRequest>> sendq_;
std::deque<MemcachedSendbuf> sendbufv_;
MemcachedParseState parse_state_;
const Address *addr_;
// Sum of the bytes to be transmitted in sendbufv_.
size_t sendsum_;
bool connected_;
Buffer<8_k> recvbuf_;
};
} // namespace shrpx
#endif // SHRPX_MEMCACHED_CONNECTION_H