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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 "shrpx_tls.h"
+#include "shrpx_connect_blocker.h"
+#include "buffer.h"
+#include "network.h"
+
+using namespace nghttp2;
+
+namespace shrpx {
+
+struct MemcachedRequest;
+enum class MemcachedOp : uint8_t;
+enum class MemcachedStatusCode : uint16_t;
+
+enum class MemcachedParseState {
+ HEADER24,
+ EXTRA,
+ VALUE,
+};
+
+// Stores state when parsing response from memcached server
+struct MemcachedParseContext {
+ // 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
+ MemcachedParseState state;
+ // status_code in response
+ MemcachedStatusCode status_code;
+ // op in response
+ MemcachedOp 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,
+ SSL_CTX *ssl_ctx, const StringRef &sni_name,
+ MemchunkPool *mcpool, std::mt19937 &gen);
+ ~MemcachedConnection();
+
+ void disconnect();
+
+ int add_request(std::unique_ptr<MemcachedRequest> req);
+ int initiate_connection();
+
+ int connected();
+ int on_write();
+ int on_read();
+
+ int write_clear();
+ int read_clear();
+
+ int tls_handshake();
+ int write_tls();
+ int read_tls();
+
+ size_t fill_request_buffer(struct iovec *iov, size_t iovlen);
+ void drain_send_queue(size_t nwrite);
+
+ void make_request(MemcachedSendbuf *sendbuf, MemcachedRequest *req);
+ int parse_packet();
+ size_t serialized_size(MemcachedRequest *req);
+
+ void signal_write();
+
+ int noop();
+
+ void reconnect_or_fail();
+
+private:
+ Connection conn_;
+ std::deque<std::unique_ptr<MemcachedRequest>> recvq_;
+ std::deque<std::unique_ptr<MemcachedRequest>> sendq_;
+ std::deque<MemcachedSendbuf> sendbufv_;
+ std::function<int(MemcachedConnection &)> do_read_, do_write_;
+ StringRef sni_name_;
+ tls::TLSSessionCache tls_session_cache_;
+ ConnectBlocker connect_blocker_;
+ MemcachedParseContext parse_state_;
+ const Address *addr_;
+ SSL_CTX *ssl_ctx_;
+ // Sum of the bytes to be transmitted in sendbufv_.
+ size_t sendsum_;
+ size_t try_count_;
+ bool connected_;
+ Buffer<8_k> recvbuf_;
+};
+
+} // namespace shrpx
+
+#endif // SHRPX_MEMCACHED_CONNECTION_H