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Use more C++ code in readconnroute

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Allocations are now done with new and casts are done using
static_cast. Removed revision history and cleaned up some assertions.
This commit is contained in:
Markus Mäkelä
2019-01-08 10:40:57 +02:00
parent b30b743455
commit 54589424f9
1 changed files with 38 additions and 79 deletions
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117
server/modules/routing/readconnroute/readconnroute.cc
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@ -32,42 +32,6 @@
* and the "slave" option will limit connections to routers that are marked * and the "slave" option will limit connections to routers that are marked
* as slaves. If neither option is specified the router will connect to either * as slaves. If neither option is specified the router will connect to either
* masters or slaves. * masters or slaves.
*
* @verbatim
* Revision History
*
* Date Who Description
* 14/06/2013 Mark Riddoch Initial implementation
* 25/06/2013 Mark Riddoch Addition of checks for current server state
* 26/06/2013 Mark Riddoch Use server with least connections since
* startup if the number of current
* connections is the same for two servers
* Addition of master and slave options
* 27/06/2013 Vilho Raatikka Added skygw_log_write command as an example
* and necessary headers.
* 17/07/2013 Massimiliano Pinto Added clientReply routine:
* called by backend server to send data to client
* Included maxscale/protocol/mysql.h
* with macros and MySQL commands with MYSQL_ prefix
* avoiding any conflict with the standard ones
* in mysql.h
* 22/07/2013 Mark Riddoch Addition of joined router option for Galera
* clusters
* 31/07/2013 Massimiliano Pinto Added a check for candidate server, if NULL return
* 12/08/2013 Mark Riddoch Log unsupported router options
* 04/09/2013 Massimiliano Pinto Added client NULL check in clientReply
* 22/10/2013 Massimiliano Pinto errorReply called from backend, for client error reply
* or take different actions such as open a new backend connection
* 20/02/2014 Massimiliano Pinto If router_options=slave, route traffic to master if no slaves available
* 06/03/2014 Massimiliano Pinto Server connection counter is now updated in closeSession
* 24/06/2014 Massimiliano Pinto New rules for selecting the Master server
* 27/06/2014 Mark Riddoch Addition of server weighting
* 11/06/2015 Martin Brampton Remove decrement n_current (moved to dcb.c)
* 09/09/2015 Martin Brampton Modify error handler
* 25/09/2015 Martin Brampton Block callback processing when no router session in the DCB
* 09/11/2015 Martin Brampton Modified routeQuery - must free "queue" regardless of outcome
*
* @endverbatim
*/ */
#include "readconnroute.hh" #include "readconnroute.hh"
@ -135,7 +99,7 @@ extern "C" MXS_MODULE* MXS_CREATE_MODULE()
clientReply, clientReply,
handleError, handleError,
getCapabilities, getCapabilities,
NULL, nullptr,
configureInstance configureInstance
}; };
@ -148,10 +112,10 @@ extern "C" MXS_MODULE* MXS_CREATE_MODULE()
"V2.0.0", "V2.0.0",
RCAP_TYPE_RUNTIME_CONFIG, RCAP_TYPE_RUNTIME_CONFIG,
&MyObject, &MyObject,
NULL, /* Process init. */ nullptr, /* Process init. */
NULL, /* Process finish. */ nullptr, /* Process finish. */
NULL, /* Thread init. */ nullptr, /* Thread init. */
NULL, /* Thread finish. */ nullptr, /* Thread finish. */
{ {
{MXS_END_MODULE_PARAMS} {MXS_END_MODULE_PARAMS}
} }
@ -162,10 +126,7 @@ extern "C" MXS_MODULE* MXS_CREATE_MODULE()
static inline void free_readconn_instance(ReadConn* router) static inline void free_readconn_instance(ReadConn* router)
{ {
if (router) delete router;
{
MXS_FREE(router);
}
} }
static bool configureInstance(MXS_ROUTER* instance, MXS_CONFIG_PARAMETER* params) static bool configureInstance(MXS_ROUTER* instance, MXS_CONFIG_PARAMETER* params)
@ -239,7 +200,7 @@ static bool configureInstance(MXS_ROUTER* instance, MXS_CONFIG_PARAMETER* params
*/ */
static MXS_ROUTER* createInstance(SERVICE* service, MXS_CONFIG_PARAMETER* params) static MXS_ROUTER* createInstance(SERVICE* service, MXS_CONFIG_PARAMETER* params)
{ {
ReadConn* inst = static_cast<ReadConn*>(MXS_CALLOC(1, sizeof(ReadConn))); ReadConn* inst = new(std::nothrow) ReadConn;
if (inst) if (inst)
{ {
@ -247,14 +208,14 @@ static MXS_ROUTER* createInstance(SERVICE* service, MXS_CONFIG_PARAMETER* params
inst->service = service; inst->service = service;
inst->bitmask_and_bitvalue = 0; inst->bitmask_and_bitvalue = 0;
if (!configureInstance((MXS_ROUTER*)inst, params)) if (!configureInstance(static_cast<MXS_ROUTER*>(inst), params))
{ {
free_readconn_instance(inst); free_readconn_instance(inst);
inst = nullptr; inst = nullptr;
} }
} }
return (MXS_ROUTER*)inst; return static_cast<MXS_ROUTER*>(inst);
} }
/** /**
@ -266,10 +227,7 @@ static MXS_ROUTER* createInstance(SERVICE* service, MXS_CONFIG_PARAMETER* params
*/ */
static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session) static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session)
{ {
ReadConn* inst = (ReadConn*) instance; ReadConn* inst = static_cast<ReadConn*>(instance);
ReadConnSession* client_rses;
SERVER_REF* candidate = NULL;
SERVER_REF* master_host = NULL;
MXS_DEBUG("%lu [newSession] new router session with session " MXS_DEBUG("%lu [newSession] new router session with session "
"%p, and inst %p.", "%p, and inst %p.",
@ -277,11 +235,11 @@ static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session
session, session,
inst); inst);
client_rses = (ReadConnSession*) MXS_CALLOC(1, sizeof(ReadConnSession)); ReadConnSession* client_rses = new(std::nothrow) ReadConnSession;
if (client_rses == NULL) if (!client_rses)
{ {
return NULL; return nullptr;
} }
client_rses->client_dcb = session->client_dcb; client_rses->client_dcb = session->client_dcb;
@ -293,13 +251,14 @@ static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session
/** /**
* Find the Master host from available servers * Find the Master host from available servers
*/ */
master_host = get_root_master(inst->service->dbref); SERVER_REF* master_host = get_root_master(inst->service->dbref);
/** /**
* Find a backend server to connect to. This is the extent of the * Find a backend server to connect to. This is the extent of the
* load balancing algorithm we need to implement for this simple * load balancing algorithm we need to implement for this simple
* connection router. * connection router.
*/ */
SERVER_REF* candidate = nullptr;
/* /*
* Loop over all the servers and find any that have fewer connections * Loop over all the servers and find any that have fewer connections
@ -348,15 +307,15 @@ static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session
} }
else if (client_rses->bitvalue == SERVER_MASTER) else if (client_rses->bitvalue == SERVER_MASTER)
{ {
/* Master_host is NULL, no master server. If requested router_option is 'master' /* Master_host is nullptr, no master server. If requested router_option is 'master'
* candidate will be NULL. * candidate will be nullptr.
*/ */
candidate = NULL; candidate = nullptr;
break; break;
} }
/* If no candidate set, set first running server as our initial candidate server */ /* If no candidate set, set first running server as our initial candidate server */
if (candidate == NULL) if (!candidate)
{ {
candidate = ref; candidate = ref;
} }
@ -401,7 +360,7 @@ static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session
MXS_ERROR("Failed to create new routing session. Couldn't find eligible" MXS_ERROR("Failed to create new routing session. Couldn't find eligible"
" candidate server. Freeing allocated resources."); " candidate server. Freeing allocated resources.");
MXS_FREE(client_rses); MXS_FREE(client_rses);
return NULL; return nullptr;
} }
} }
@ -414,11 +373,11 @@ static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session
/** Open the backend connection */ /** Open the backend connection */
client_rses->backend_dcb = dcb_connect(candidate->server, session, candidate->server->protocol().c_str()); client_rses->backend_dcb = dcb_connect(candidate->server, session, candidate->server->protocol().c_str());
if (client_rses->backend_dcb == NULL) if (!client_rses->backend_dcb)
{ {
/** The failure is reported in dcb_connect() */ /** The failure is reported in dcb_connect() */
MXS_FREE(client_rses); delete client_rses;
return NULL; return nullptr;
} }
mxb::atomic::add(&candidate->connections, 1, mxb::atomic::RELAXED); mxb::atomic::add(&candidate->connections, 1, mxb::atomic::RELAXED);
@ -429,7 +388,7 @@ static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session
candidate->server->name(), candidate->server->name(),
candidate->connections); candidate->connections);
return reinterpret_cast<MXS_ROUTER_SESSION*>(client_rses); return static_cast<MXS_ROUTER_SESSION*>(client_rses);
} }
/** /**
@ -451,15 +410,15 @@ static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session
*/ */
static void freeSession(MXS_ROUTER* router_instance, MXS_ROUTER_SESSION* router_client_ses) static void freeSession(MXS_ROUTER* router_instance, MXS_ROUTER_SESSION* router_client_ses)
{ {
ReadConn* router = (ReadConn*) router_instance; ReadConn* router = static_cast<ReadConn*>(router_instance);
ReadConnSession* router_cli_ses = (ReadConnSession*) router_client_ses; ReadConnSession* router_cli_ses = static_cast<ReadConnSession*>(router_client_ses);
MXB_AT_DEBUG(int prev_val = ) mxb::atomic::add(&router_cli_ses->backend->connections, MXB_AT_DEBUG(int prev_val = ) mxb::atomic::add(&router_cli_ses->backend->connections,
-1, -1,
mxb::atomic::RELAXED); mxb::atomic::RELAXED);
mxb_assert(prev_val > 0); mxb_assert(prev_val > 0);
MXS_FREE(router_cli_ses); delete router_cli_ses;
} }
/** /**
@ -471,7 +430,7 @@ static void freeSession(MXS_ROUTER* router_instance, MXS_ROUTER_SESSION* router_
*/ */
static void closeSession(MXS_ROUTER* instance, MXS_ROUTER_SESSION* router_session) static void closeSession(MXS_ROUTER* instance, MXS_ROUTER_SESSION* router_session)
{ {
ReadConnSession* router_cli_ses = (ReadConnSession*) router_session; ReadConnSession* router_cli_ses = static_cast<ReadConnSession*>(router_session);
mxb_assert(router_cli_ses->backend_dcb); mxb_assert(router_cli_ses->backend_dcb);
dcb_close(router_cli_ses->backend_dcb); dcb_close(router_cli_ses->backend_dcb);
} }
@ -552,10 +511,10 @@ static inline bool connection_is_valid(ReadConn* inst, ReadConnSession* router_c
*/ */
static int routeQuery(MXS_ROUTER* instance, MXS_ROUTER_SESSION* router_session, GWBUF* queue) static int routeQuery(MXS_ROUTER* instance, MXS_ROUTER_SESSION* router_session, GWBUF* queue)
{ {
ReadConn* inst = (ReadConn*) instance; ReadConn* inst = static_cast<ReadConn*>(instance);
ReadConnSession* router_cli_ses = (ReadConnSession*) router_session; ReadConnSession* router_cli_ses = static_cast<ReadConnSession*>(router_session);
int rc = 0; int rc = 0;
MySQLProtocol* proto = (MySQLProtocol*)router_cli_ses->client_dcb->protocol; MySQLProtocol* proto = static_cast<MySQLProtocol*>(router_cli_ses->client_dcb->protocol);
mxs_mysql_cmd_t mysql_command = proto->current_command; mxs_mysql_cmd_t mysql_command = proto->current_command;
mxb::atomic::add(&inst->stats.n_queries, 1, mxb::atomic::RELAXED); mxb::atomic::add(&inst->stats.n_queries, 1, mxb::atomic::RELAXED);
@ -565,7 +524,7 @@ static int routeQuery(MXS_ROUTER* instance, MXS_ROUTER_SESSION* router_session,
DCB* backend_dcb = router_cli_ses->backend_dcb; DCB* backend_dcb = router_cli_ses->backend_dcb;
mxb_assert(backend_dcb); mxb_assert(backend_dcb);
char* trc = NULL; char* trc = nullptr;
if (!connection_is_valid(inst, router_cli_ses)) if (!connection_is_valid(inst, router_cli_ses))
{ {
@ -578,7 +537,7 @@ static int routeQuery(MXS_ROUTER* instance, MXS_ROUTER_SESSION* router_session,
{ {
case MXS_COM_CHANGE_USER: case MXS_COM_CHANGE_USER:
rc = backend_dcb->func.auth(backend_dcb, rc = backend_dcb->func.auth(backend_dcb,
NULL, nullptr,
backend_dcb->session, backend_dcb->session,
queue); queue);
break; break;
@ -612,7 +571,7 @@ static int routeQuery(MXS_ROUTER* instance, MXS_ROUTER_SESSION* router_session,
*/ */
static void diagnostics(MXS_ROUTER* router, DCB* dcb) static void diagnostics(MXS_ROUTER* router, DCB* dcb)
{ {
ReadConn* router_inst = (ReadConn*) router; ReadConn* router_inst = static_cast<ReadConn*>(router);
const char* weightby = serviceGetWeightingParameter(router_inst->service); const char* weightby = serviceGetWeightingParameter(router_inst->service);
dcb_printf(dcb, dcb_printf(dcb,
@ -651,7 +610,7 @@ static void diagnostics(MXS_ROUTER* router, DCB* dcb)
*/ */
static json_t* diagnostics_json(const MXS_ROUTER* router) static json_t* diagnostics_json(const MXS_ROUTER* router)
{ {
ReadConn* router_inst = (ReadConn*)router; const ReadConn* router_inst = static_cast<const ReadConn*>(router);
json_t* rval = json_object(); json_t* rval = json_object();
json_object_set_new(rval, "connections", json_integer(router_inst->stats.n_sessions)); json_object_set_new(rval, "connections", json_integer(router_inst->stats.n_sessions));
@ -683,7 +642,7 @@ static void clientReply(MXS_ROUTER* instance,
GWBUF* queue, GWBUF* queue,
DCB* backend_dcb) DCB* backend_dcb)
{ {
mxb_assert(backend_dcb->session->client_dcb != NULL); mxb_assert(backend_dcb->session->client_dcb);
MXS_SESSION_ROUTE_REPLY(backend_dcb->session, queue); MXS_SESSION_ROUTE_REPLY(backend_dcb->session, queue);
} }
@ -734,13 +693,13 @@ static uint64_t getCapabilities(MXS_ROUTER* instance)
static SERVER_REF* get_root_master(SERVER_REF* servers) static SERVER_REF* get_root_master(SERVER_REF* servers)
{ {
SERVER_REF* master_host = NULL; SERVER_REF* master_host = nullptr;
for (SERVER_REF* ref = servers; ref; ref = ref->next) for (SERVER_REF* ref = servers; ref; ref = ref->next)
{ {
if (ref->active && ref->server->is_master()) if (ref->active && ref->server->is_master())
{ {
// No master found yet or this one has better weight. // No master found yet or this one has better weight.
if (master_host == NULL || ref->server_weight > master_host->server_weight) if (!master_host || ref->server_weight > master_host->server_weight)
{ {
master_host = ref; master_host = ref;
} }