/*
* Send simple query and wait for response
* send_type:
* -1: do not send this node_id
* 0: send to all nodes
* >0: send to this node_id
*/
POOL_STATUS pool_send_and_wait(POOL_QUERY_CONTEXT *query_context,
int send_type, int node_id)
{
POOL_SESSION_CONTEXT *session_context;
POOL_CONNECTION *frontend;
POOL_CONNECTION_POOL *backend;
bool is_commit;
bool is_begin_read_write;
int i;
int len;
char *string;
session_context = pool_get_session_context();
frontend = session_context->frontend;
backend = session_context->backend;
is_commit = is_commit_or_rollback_query(query_context->parse_tree);
is_begin_read_write = false;
len = 0;
string = NULL;
/*
* If the query is BEGIN READ WRITE or
* BEGIN ... SERIALIZABLE in master/slave mode,
* we send BEGIN to slaves/standbys instead.
* original_query which is BEGIN READ WRITE is sent to primary.
* rewritten_query which is BEGIN is sent to standbys.
*/
if (pool_need_to_treat_as_if_default_transaction(query_context))
{
is_begin_read_write = true;
}
else
{
if (query_context->rewritten_query)
{
len = query_context->rewritten_length;
string = query_context->rewritten_query;
}
else
{
len = query_context->original_length;
string = query_context->original_query;
}
}
/* Send query */
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
else if (send_type < 0 && i == node_id)
continue;
else if (send_type > 0 && i != node_id)
continue;
/*
* If in master/slave mode, we do not send COMMIT/ABORT to
* slaves/standbys if it's in I(idle) state.
*/
if (is_commit && MASTER_SLAVE && !IS_MASTER_NODE_ID(i) && TSTATE(backend, i) == 'I')
{
pool_unset_node_to_be_sent(query_context, i);
continue;
}
/*
* If in reset context, we send COMMIT/ABORT to nodes those
* are not in I(idle) state. This will ensure that
* transactions are closed.
*/
if (is_commit && session_context->reset_context && TSTATE(backend, i) == 'I')
{
pool_unset_node_to_be_sent(query_context, i);
continue;
}
if (is_begin_read_write)
{
if (REAL_PRIMARY_NODE_ID == i)
{
len = query_context->original_length;
string = query_context->original_query;
}
else
{
len = query_context->rewritten_length;
string = query_context->rewritten_query;
}
}
per_node_statement_log(backend, i, string);
if (send_simplequery_message(CONNECTION(backend, i), len, string, MAJOR(backend)) != POOL_CONTINUE)
{
return POOL_END;
}
}
/* Wait for response */
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
else if (send_type < 0 && i == node_id)
continue;
else if (send_type > 0 && i != node_id)
continue;
#ifdef NOT_USED
/*
* If in master/slave mode, we do not send COMMIT/ABORT to
* slaves/standbys if it's in I(idle) state.
*/
if (is_commit && MASTER_SLAVE && !IS_MASTER_NODE_ID(i) && TSTATE(backend, i) == 'I')
{
continue;
}
#endif
if (is_begin_read_write)
{
if(REAL_PRIMARY_NODE_ID == i)
string = query_context->original_query;
else
string = query_context->rewritten_query;
}
if (wait_for_query_response(frontend, CONNECTION(backend, i), MAJOR(backend)) != POOL_CONTINUE)
{
/* Cancel current transaction */
CancelPacket cancel_packet;
cancel_packet.protoVersion = htonl(PROTO_CANCEL);
cancel_packet.pid = MASTER_CONNECTION(backend)->pid;
cancel_packet.key= MASTER_CONNECTION(backend)->key;
cancel_request(&cancel_packet);
return POOL_END;
}
/*
* Check if some error detected. If so, emit
* log. This is usefull when invalid encoding error
* occurs. In this case, PostgreSQL does not report
* what statement caused that error and make users
* confused.
*/
per_node_error_log(backend, i, string, "pool_send_and_wait: Error or notice message from backend: ", true);
}
return POOL_CONTINUE;
}
/*
* Send extended query and wait for response
* send_type:
* -1: do not send this node_id
* 0: send to all nodes
* >0: send to this node_id
*/
POOL_STATUS pool_extended_send_and_wait(POOL_QUERY_CONTEXT *query_context,
char *kind, int len, char *contents,
int send_type, int node_id)
{
POOL_SESSION_CONTEXT *session_context;
POOL_CONNECTION *frontend;
POOL_CONNECTION_POOL *backend;
bool is_commit;
bool is_begin_read_write;
int i;
int str_len;
int rewritten_len;
char *str;
char *rewritten_begin;
session_context = pool_get_session_context();
frontend = session_context->frontend;
backend = session_context->backend;
is_commit = is_commit_or_rollback_query(query_context->parse_tree);
is_begin_read_write = false;
str_len = 0;
rewritten_len = 0;
str = NULL;
rewritten_begin = NULL;
/*
* If the query is BEGIN READ WRITE or
* BEGIN ... SERIALIZABLE in master/slave mode,
* we send BEGIN to slaves/standbys instead.
* original_query which is BEGIN READ WRITE is sent to primary.
* rewritten_query which is BEGIN is sent to standbys.
*/
if (pool_need_to_treat_as_if_default_transaction(query_context))
{
is_begin_read_write = true;
if (*kind == 'P')
{
rewritten_begin = remove_read_write(len, contents, &rewritten_len);
if (rewritten_begin == NULL)
return POOL_END;
}
}
if (!rewritten_begin)
{
str_len = len;
str = contents;
}
/* Send query */
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
else if (send_type < 0 && i == node_id)
continue;
else if (send_type > 0 && i != node_id)
continue;
/*
* If in reset context, we send COMMIT/ABORT to nodes those
* are not in I(idle) state. This will ensure that
* transactions are closed.
*/
if (is_commit && session_context->reset_context && TSTATE(backend, i) == 'I')
{
pool_unset_node_to_be_sent(query_context, i);
continue;
}
if (rewritten_begin)
{
if (REAL_PRIMARY_NODE_ID == i)
{
str = contents;
str_len = len;
}
else
{
str = rewritten_begin;
str_len = rewritten_len;
}
}
if (pool_config->log_per_node_statement)
{
char msgbuf[QUERY_STRING_BUFFER_LEN];
char *stmt;
if (*kind == 'P' || *kind == 'E')
{
if (query_context->rewritten_query)
{
if (is_begin_read_write)
{
if (REAL_PRIMARY_NODE_ID == i)
stmt = query_context->original_query;
else
stmt = query_context->rewritten_query;
}
else
{
stmt = query_context->rewritten_query;
}
}
else
{
stmt = query_context->original_query;
}
if (*kind == 'P')
snprintf(msgbuf, sizeof(msgbuf), "Parse: %s", stmt);
else
snprintf(msgbuf, sizeof(msgbuf), "Execute: %s", stmt);
}
else
{
snprintf(msgbuf, sizeof(msgbuf), "%c message", *kind);
}
per_node_statement_log(backend, i, msgbuf);
}
if (send_extended_protocol_message(backend, i, kind, str_len, str) != POOL_CONTINUE)
{
free(rewritten_begin);
return POOL_END;
}
}
if (!is_begin_read_write)
{
if (query_context->rewritten_query)
str = query_context->rewritten_query;
else
str = query_context->original_query;
}
/* Wait for response */
for (i=0;i<NUM_BACKENDS;i++)
{
if (!VALID_BACKEND(i))
continue;
else if (send_type < 0 && i == node_id)
continue;
else if (send_type > 0 && i != node_id)
continue;
/*
* If in master/slave mode, we do not send COMMIT/ABORT to
* slaves/standbys if it's in I(idle) state.
*/
if (is_commit && MASTER_SLAVE && !IS_MASTER_NODE_ID(i) && TSTATE(backend, i) == 'I')
{
continue;
}
if (is_begin_read_write)
{
if (REAL_PRIMARY_NODE_ID == i)
str = query_context->original_query;
else
str = query_context->rewritten_query;
}
if (wait_for_query_response(frontend, CONNECTION(backend, i), MAJOR(backend)) != POOL_CONTINUE)
{
/* Cancel current transaction */
CancelPacket cancel_packet;
cancel_packet.protoVersion = htonl(PROTO_CANCEL);
cancel_packet.pid = MASTER_CONNECTION(backend)->pid;
cancel_packet.key= MASTER_CONNECTION(backend)->key;
cancel_request(&cancel_packet);
free(rewritten_begin);
return POOL_END;
}
/*
* Check if some error detected. If so, emit
* log. This is usefull when invalid encoding error
* occurs. In this case, PostgreSQL does not report
* what statement caused that error and make users
* confused.
*/
per_node_error_log(backend, i, str, "pool_send_and_wait: Error or notice message from backend: ", true);
}
free(rewritten_begin);
return POOL_CONTINUE;
}
/*
* Search relcache. If found, return user data. Otherwise return 0.
* If not found in cache, do the query and store the result into cache and return it.
*/
void *pool_search_relcache(POOL_RELCACHE *relcache, POOL_CONNECTION_POOL *backend, char *table)
{
char *rel;
char *dbname;
int i;
int maxrefcnt = INT_MAX;
char query[1024];
POOL_SELECT_RESULT *res = NULL;
int index = 0;
/* Eliminate double quotes */
rel = malloc(strlen(table)+1);
if (!rel)
{
pool_error("pool_search_relcache: malloc failed");
return NULL;
}
for(i=0;*table;table++)
{
if (*table != '"')
rel[i++] = *table;
}
rel[i] = '\0';
/* Obtain database name */
dbname = MASTER_CONNECTION(backend)->sp->database;
/* Look for cache first */
for (i=0;i<relcache->num;i++)
{
/*
* If cache is session local, we need to check session id
*/
if (relcache->cache_is_session_local)
{
if (relcache->cache[i].session_id != LocalSessionId)
continue;
}
if (strcasecmp(relcache->cache[i].dbname, dbname) == 0 &&
strcasecmp(relcache->cache[i].relname, rel) == 0)
{
/* Found */
if (relcache->cache[i].refcnt < INT_MAX)
relcache->cache[i].refcnt++;
free(rel);
return relcache->cache[i].data;
}
}
/* Not in cache. Check the system catalog */
snprintf(query, sizeof(query), relcache->sql, rel);
per_node_statement_log(backend, MASTER_NODE_ID, query);
if (do_query(MASTER(backend), query, &res) != POOL_CONTINUE)
{
pool_error("pool_search_relcache: do_query failed");
if (res)
free_select_result(res);
free(rel);
return NULL;
}
/*
* Look for replacement in cache
*/
for (i=0;i<relcache->num;i++)
{
/*
* If cache is session local, we can discard old cache immediately
*/
if (relcache->cache_is_session_local)
{
if (relcache->cache[i].session_id != LocalSessionId)
{
index = i;
break;
}
}
if (relcache->cache[i].refcnt == 0)
{
/* Found empty slot */
index = i;
break;
}
else if (relcache->cache[i].refcnt < maxrefcnt)
{
maxrefcnt = relcache->cache[i].refcnt;
index = i;
}
}
/* Register cache */
strncpy(relcache->cache[index].dbname, dbname, MAX_ITEM_LENGTH);
strncpy(relcache->cache[index].relname, rel, MAX_ITEM_LENGTH);
relcache->cache[index].refcnt = 1;
relcache->cache[index].session_id = LocalSessionId;
free(rel);
/*
* Call user defined unregister/register fuction.
*/
(*relcache->unregister_func)(relcache->cache[index].data);
relcache->cache[index].data = (*relcache->register_func)(res);
free_select_result(res);
return relcache->cache[index].data;
}
