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Added a function that generates a custom result set for SHOW DATABASES.

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Fixed SHOW TABLES not using the current database.
This commit is contained in:
Markus Makela
2014-12-15 14:12:04 +02:00
parent a91845b324
commit 3dd1f70109
1 changed files with 183 additions and 10 deletions
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193
server/modules/routing/dbshard/dbshard.c
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@ -586,12 +586,11 @@ void* dbnames_hash_init(ROUTER_INSTANCE* inst,BACKEND** backends)
* @param buffer Query to inspect
* @return Name of the backend or NULL if the query contains no known databases.
*/
char* get_shard_target_name(ROUTER_INSTANCE* router, ROUTER_CLIENT_SES* client, GWBUF* buffer){
char* get_shard_target_name(ROUTER_INSTANCE* router, ROUTER_CLIENT_SES* client, GWBUF* buffer,skygw_query_type_t qtype){
HASHTABLE* ht = router->dbnames_hash;
int sz = 0,i,j;
char** dbnms = NULL;
char* rval = NULL;
bool has_dbs = false; /**If the query targets any database other than the current one*/
if(!query_is_parsed(buffer)){
@ -618,7 +617,8 @@ char* get_shard_target_name(ROUTER_INSTANCE* router, ROUTER_CLIENT_SES* client,
* check if the session has an active database and if it is sharded.
*/
if(rval == NULL && !has_dbs && client->rses_mysql_session->db[0] != '\0'){
if(QUERY_IS_TYPE(qtype, QUERY_TYPE_SHOW_TABLES) ||
(rval == NULL && !has_dbs && client->rses_mysql_session->db[0] != '\0')){
rval = (char*)hashtable_fetch(ht,client->rses_mysql_session->db);
}
@ -1708,6 +1708,137 @@ void check_create_tmp_table(
}
}
GWBUF* gen_show_dbs_response(ROUTER_INSTANCE* router, ROUTER_CLIENT_SES* client)
{
GWBUF* rval = NULL;
HASHTABLE* ht = router->dbnames_hash;
HASHITERATOR* iter = hashtable_iterator(ht);
unsigned int coldef_len = 0;
char dbname[MYSQL_DATABASE_MAXLEN+1];
char *value;
unsigned char* ptr;
char catalog[4] = {0x03,'d','e','f'};
const char* schema = "information_schema";
const char* table = "SCHEMATA";
const char* org_table = "SCHEMATA";
const char* name = "Database";
const char* org_name = "SCHEMA_NAME";
char next_length = 0x0c;
char charset[2] = {0x21, 0x00};
char column_length[4] = { MYSQL_DATABASE_MAXLEN,
MYSQL_DATABASE_MAXLEN >> 8,
MYSQL_DATABASE_MAXLEN >> 16,
MYSQL_DATABASE_MAXLEN >> 24 };
char column_type = 0xfd;
char eof[9] = { 0x05,0x00,0x00,
0x03,0xfe,0x00,
0x00,0x22,0x00 };
char ok_packet[11] = { 0x07,0x00,0x00,0x00,
0x00,0x00,0x00,
0x00,0x00,
0x00,0x00 };
coldef_len = sizeof(catalog) + strlen(schema) + 1 +
strlen(table) + 1 +
strlen(org_table) + 1 +
strlen(name) + 1 +
strlen(org_name) + 1 +
1 + 2 + 4 + 1 + 2 + 1 + 2;
rval = gwbuf_alloc(5 + 4 + coldef_len + sizeof(eof));
ptr = rval->start;
/**First packet*/
*ptr++ = 0x01;
*ptr++ = 0x00;
*ptr++ = 0x00;
*ptr++ = 0x01;
*ptr++ = 0x01;
/**Second packet containing the column definitions*/
*ptr++ = coldef_len;
*ptr++ = coldef_len >> 8;
*ptr++ = coldef_len >> 16;
*ptr++ = 0x02;
memcpy((void*)ptr,catalog,4);
ptr += 4;
*ptr++ = strlen(schema);
memcpy((void*)ptr,schema,strlen(schema));
ptr += strlen(schema);
*ptr++ = strlen(table);
memcpy((void*)ptr,table,strlen(table));
ptr += strlen(table);
*ptr++ = strlen(org_table);
memcpy((void*)ptr,org_table,strlen(org_table));
ptr += strlen(org_table);
*ptr++ = strlen(name);
memcpy((void*)ptr,name,strlen(name));
ptr += strlen(name);
*ptr++ = strlen(org_name);
memcpy((void*)ptr,org_name,strlen(org_name));
ptr += strlen(org_name);
*ptr++ = next_length;
*ptr++ = charset[0];
*ptr++ = charset[1];
*ptr++ = column_length[0];
*ptr++ = column_length[1];
*ptr++ = column_length[2];
*ptr++ = column_length[3];
*ptr++ = column_type;
*ptr++ = 0x01;
memset(ptr,0,4);
ptr += 4;
memcpy(ptr,eof,sizeof(eof));
unsigned int packet_num = 4;
while((value = (char*)hashtable_next(iter)))
{
GWBUF* temp;
int plen = strlen(value) + 1;
sprintf(dbname,"%s",value);
temp = gwbuf_alloc(plen + 4);
ptr = temp->start;
*ptr++ = plen;
*ptr++ = plen >> 8;
*ptr++ = plen >> 16;
*ptr++ = packet_num++;
*ptr++ = plen - 1;
memcpy(ptr,dbname,plen - 1);
/** Append the row*/
rval = gwbuf_append(rval,temp);
}
eof[3] = packet_num;
GWBUF* last_packet = gwbuf_alloc(sizeof(eof));
memcpy(last_packet->start,eof,sizeof(eof));
rval = gwbuf_append(rval,last_packet);
rval = gwbuf_make_contiguous(rval);
return rval;
}
/**
* The main routing entry, this is called with every packet that is
* received and has to be forwarded to the backend database.
@ -1847,7 +1978,7 @@ static int routeQuery(
/* goto retblock; */
}
/**
/**
* !!! Temporary tablen tutkiminen voi olla turhaa. Poista tarvittaessa.
*/
/**
@ -1945,6 +2076,42 @@ static int routeQuery(
* eventually to master
*/
if(QUERY_IS_TYPE(qtype, QUERY_TYPE_SHOW_DATABASES))
{
/**
* Generate custom response that contains all the databases
* after updating the hashtable
*/
backend_ref_t* backend = NULL;
DCB* backend_dcb = NULL;
int i;
update_dbnames_hash(inst,inst->servers,inst->dbnames_hash);
for(i = 0;i < router_cli_ses->rses_nbackends;i++)
{
if(SERVER_IS_RUNNING(router_cli_ses->rses_backend_ref[i].bref_backend->backend_server))
{
backend = &router_cli_ses->rses_backend_ref[i];
backend_dcb = backend->bref_dcb;
break;
}
}
if(backend)
{
GWBUF* fake = gen_show_dbs_response(inst,router_cli_ses);
poll_add_epollin_event_to_dcb(backend_dcb,fake);
ret = 1;
}
else
{
ret = 0;
}
goto retblock;
}
if (packet_type == MYSQL_COM_INIT_DB)
{
char dbname[MYSQL_DATABASE_MAXLEN+1];
@ -1957,7 +2124,7 @@ static int routeQuery(
route_target = TARGET_NAMED_SERVER;
}
}
else if((tname = get_shard_target_name(inst,router_cli_ses,querybuf)) != NULL)
else if((tname = get_shard_target_name(inst,router_cli_ses,querybuf,qtype)) != NULL)
{
bool shard_ok = check_shard_status(inst,tname);
@ -1976,7 +2143,7 @@ static int routeQuery(
update_dbnames_hash(inst,inst->servers,inst->dbnames_hash);
if((tname = get_shard_target_name(inst,router_cli_ses,querybuf)) != NULL &&
if((tname = get_shard_target_name(inst,router_cli_ses,querybuf,qtype)) != NULL &&
check_shard_status(inst,tname))
{
route_target = TARGET_NAMED_SERVER;
@ -2007,7 +2174,7 @@ static int routeQuery(
GWBUF *errbuff;
update_dbnames_hash(inst,inst->servers,inst->dbnames_hash);
tname = get_shard_target_name(inst,router_cli_ses,querybuf);
tname = get_shard_target_name(inst,router_cli_ses,querybuf,qtype);
if((tname == NULL &&
router_cli_ses->rses_mysql_session->db[0] == '\0') ||
@ -4363,16 +4530,22 @@ static bool change_current_db(
{
bool succp;
uint8_t* packet;
unsigned int plen;
int message_len,i;
char* fail_str;
if(GWBUF_LENGTH(buf) <= MYSQL_DATABASE_MAXLEN - 5)
{
packet = GWBUF_DATA(buf);
plen = gw_mysql_get_byte3(packet) - 1;
/** Copy database name from MySQL packet to session */
strncpy(rses->rses_mysql_session->db,
(char*)(packet + 5),
(int)(GWBUF_LENGTH(buf) - 5));
memcpy(rses->rses_mysql_session->db,
packet + 5,
plen);
memset(rses->rses_mysql_session->db + plen,0,1);
/**
* Update the session's active database only if it's in the hashtable.
* If it isn't found, send a custom error packet to the client.