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#ifndef TARANTOOL_APPLIER_H_INCLUDED
#define TARANTOOL_APPLIER_H_INCLUDED
/*
* Copyright 2010-2016, Tarantool AUTHORS, please see AUTHORS file.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* 1. Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <netinet/in.h>
#include <sys/socket.h>
#include <tarantool_ev.h>
#include <small/ibuf.h>
#include "fiber_cond.h"
#include "trigger.h"
#include "trivia/util.h"
#include "uuid/tt_uuid.h"
#include "uri/uri.h"
#include "xrow.h"
enum { APPLIER_SOURCE_MAXLEN = 1024 }; /* enough to fit URI with passwords */
#define applier_STATE(_) \
_(APPLIER_OFF, 0) \
_(APPLIER_CONNECT, 1) \
_(APPLIER_CONNECTED, 2) \
_(APPLIER_AUTH, 3) \
_(APPLIER_READY, 4) \
_(APPLIER_INITIAL_JOIN, 5) \
_(APPLIER_FINAL_JOIN, 6) \
_(APPLIER_JOINED, 7) \
_(APPLIER_SYNC, 8) \
_(APPLIER_FOLLOW, 9) \
_(APPLIER_STOPPED, 10) \
_(APPLIER_DISCONNECTED, 11) \
_(APPLIER_LOADING, 12) \
_(APPLIER_FETCH_SNAPSHOT, 13) \
_(APPLIER_FETCHED_SNAPSHOT, 14) \
_(APPLIER_REGISTER, 15) \
_(APPLIER_REGISTERED, 16) \
/** States for the applier */
ENUM(applier_state, applier_STATE);
extern const char *applier_state_strs[];
/**
* State of a replication connection to the master
*/
struct applier {
/** Background fiber */
struct fiber *reader;
/** Background fiber to reply with vclock */
struct fiber *writer;
/** Writer cond. */
struct fiber_cond writer_cond;
/**
* True if the applier has vclocks not sent to the remote
* master. The flag is needed because during sending one
* vclock (ACK), it can be updated again. So just one
* condition variable is not enough.
*/
bool has_acks_to_send;
/** Finite-state machine */
enum applier_state state;
/** Local time of this replica when the last row has been received */
ev_tstamp last_row_time;
/** Number of seconds this replica is behind the remote master */
ev_tstamp lag;
/** The last box_error_code() logged to avoid log flooding */
uint32_t last_logged_errcode;
/** Remote instance UUID */
struct tt_uuid uuid;
/** Remote URI (string) */
char source[APPLIER_SOURCE_MAXLEN];
/** Remote URI (parsed) */
struct uri uri;
/** Remote version encoded as a number, see version_id() macro */
uint32_t version_id;
/** Remote ballot at the time of connect. */
struct ballot ballot;
/** Remote address */
union {
struct sockaddr addr;
struct sockaddr_storage addrstorage;
};
/** Length of addr */
socklen_t addr_len;
/** EV watcher for I/O */
struct ev_io io;
/** Input buffer */
struct ibuf ibuf;
/** Triggers invoked on state change */
struct rlist on_state;
/**
* Set if the applier was paused (see applier_pause()) and is now
* waiting on resume_cond to be resumed (see applier_resume()).
*/
bool is_paused;
/** Condition variable signaled to resume the applier. */
struct fiber_cond resume_cond;
/* Diag to raise an error. */
struct diag diag;
/* Master's vclock at the time of SUBSCRIBE. */
struct vclock remote_vclock_at_subscribe;
};
/**
* Start a client to a remote master using a background fiber.
*
* If recovery is finalized (i.e. r->writer != NULL) then the client
* connect to a master and follow remote updates using SUBSCRIBE command.
*
* If recovery is not finalized (i.e. r->writer == NULL) then the
* client connects to a master, downloads and processes
* a checkpoint using JOIN command and then switches to 'follow'
* mode.
*
* \sa fiber_start()
*/
void
applier_start(struct applier *applier);
/**
* Stop a client.
*/
void
applier_stop(struct applier *applier);
/**
* Allocate an instance of applier object, create applier and initialize
* remote uri (copied to struct applier).
*
* @pre the uri is a valid and checked one
* @error throws OutOfMemory exception if out of memory.
*/
struct applier *
applier_new(const char *uri);
/**
* Destroy and delete a applier.
*/
void
applier_delete(struct applier *applier);
/*
* Resume execution of applier until \a state.
*/
void
applier_resume_to_state(struct applier *applier, enum applier_state state,
double timeout);
/*
* Resume execution of applier.
*/
void
applier_resume(struct applier *applier);
/*
* Pause execution of applier.
*
* Note, in contrast to applier_resume() this function may
* only be called by the applier fiber (e.g. from on_state
* trigger).
*/
void
applier_pause(struct applier *applier);
#endif /* TARANTOOL_APPLIER_H_INCLUDED */
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