SEXP RS_DBI_allocResultSet(SEXP conHandle) {
RS_DBI_connection *con = RS_DBI_getConnection(conHandle);
int indx = RS_DBI_newEntry(con->resultSetIds, con->length);
if (indx < 0) {
error(
"cannot allocate a new resultSet -- maximum of %d resultSets already reached",
con->length
);
}
RS_DBI_resultSet* result = malloc(sizeof(RS_DBI_resultSet));
if (!result) {
RS_DBI_freeEntry(con->resultSetIds, indx);
error("could not malloc dbResultSet");
}
result->drvResultSet = (void *) NULL; /* driver's own resultSet (cursor)*/
result->statement = (char *) NULL;
result->connectionId = CON_ID(conHandle);
result->resultSetId = con->counter;
result->isSelect = (int) -1;
result->rowsAffected = (int) -1;
result->rowCount = (int) 0;
result->completed = (int) -1;
result->fields = NULL;
/* update connection's resultSet table */
int res_id = con->counter;
con->num_res += (int) 1;
con->counter += (int) 1;
con->resultSets[indx] = result;
con->resultSetIds[indx] = res_id;
return RS_DBI_asResHandle(MGR_ID(conHandle), CON_ID(conHandle), res_id);
}
s_object *
RS_PostgreSQL_getResult(Con_Handle * conHandle)
{
S_EVALUATOR RS_DBI_connection * con;
S_EVALUATOR RS_DBI_resultSet * result;
PGconn *my_connection;
Res_Handle *rsHandle;
Sint res_id;
PGresult *my_result;
con = RS_DBI_getConnection(conHandle);
my_connection = (PGconn *) con->drvConnection;
if (con->num_res > 0) {
res_id = (Sint) con->resultSetIds[0];
rsHandle = RS_DBI_asResHandle(MGR_ID(conHandle), CON_ID(conHandle), res_id);
result = RS_DBI_getResultSet(rsHandle);
if (result->completed == 0) {
RS_DBI_errorMessage("connection with pending rows, close resultSet before continuing", RS_DBI_ERROR);
}
else {
RS_PostgreSQL_closeResultSet(rsHandle);
}
}
my_result = PQgetResult(my_connection);
if(my_result == NULL)
return S_NULL_ENTRY;
if (strcmp(PQresultErrorMessage(my_result), "") != 0) {
char *errResultMsg;
const char *omsg;
size_t len;
omsg = PQerrorMessage(my_connection);
len = strlen(omsg);
errResultMsg = malloc(len + 80); /* 80 should be larger than the length of "could not ..."*/
snprintf(errResultMsg, len + 80, "could not Retrieve the result : %s", omsg);
RS_DBI_errorMessage(errResultMsg, RS_DBI_ERROR);
free(errResultMsg);
/* Frees the storage associated with a PGresult.
* void PQclear(PGresult *res); */
PQclear(my_result);
}
/* we now create the wrapper and copy values */
PROTECT(rsHandle = RS_DBI_allocResultSet(conHandle));
result = RS_DBI_getResultSet(rsHandle);
result->drvResultSet = (void *) my_result;
result->rowCount = (Sint) 0;
result->isSelect = 0;
result->rowsAffected = 0;
result->completed = 1;
UNPROTECT(1);
return rsHandle;
}
/* the invoking (freeing) function must provide a function for
* freeing the conParams, and by setting the (*free_drvConParams)(void *)
* pointer.
*/
void RS_DBI_freeConnection(SEXP conHandle) {
int indx;
RS_DBI_connection* con = RS_DBI_getConnection(conHandle);
MySQLDriver* mgr = rmysql_driver();
/* Are there open resultSets? If so, free them first */
if (con->num_res > 0) {
int i;
SEXP rsHandle;
for(i=0; i < con->num_res; i++){
rsHandle = RS_DBI_asResHandle(con->managerId,
con->connectionId,
(int) con->resultSetIds[i]);
RS_DBI_freeResultSet(rsHandle);
}
warning("opened resultSet(s) forcebly closed");
}
if(con->drvConnection) {
error("internal error in RS_DBI_freeConnection: driver might have left open its connection on the server");
}
if(con->conParams){
error("internal error in RS_DBI_freeConnection: non-freed con->conParams (tiny memory leaked)");
}
/* delete this connection from manager's connection table */
if(con->resultSets) free(con->resultSets);
if(con->resultSetIds) free(con->resultSetIds);
/* update the manager's connection table */
indx = RS_DBI_lookup(mgr->connectionIds, mgr->length, con->connectionId);
RS_DBI_freeEntry(mgr->connectionIds, indx);
mgr->connections[indx] = (RS_DBI_connection *) NULL;
mgr->num_con -= (int) 1;
free(con);
con = (RS_DBI_connection *) NULL;
return;
}
Res_Handle *
RS_PostgreSQL_exec(Con_Handle * conHandle, s_object * statement)
{
S_EVALUATOR RS_DBI_connection * con;
Res_Handle *rsHandle;
RS_DBI_resultSet *result;
PGconn *my_connection;
PGresult *my_result;
Sint res_id, is_select=0;
char *dyn_statement;
con = RS_DBI_getConnection(conHandle);
my_connection = (PGconn *) con->drvConnection;
dyn_statement = RS_DBI_copyString(CHR_EL(statement, 0));
/* Do we have a pending resultSet in the current connection?
* PostgreSQL only allows one resultSet per connection.
*/
if (con->num_res > 0) {
res_id = (Sint) con->resultSetIds[0]; /* recall, PostgreSQL has only 1 res */
rsHandle = RS_DBI_asResHandle(MGR_ID(conHandle), CON_ID(conHandle), res_id);
result = RS_DBI_getResultSet(rsHandle);
if (result->completed == 0) {
free(dyn_statement);
RS_DBI_errorMessage("connection with pending rows, close resultSet before continuing", RS_DBI_ERROR);
}
else {
RS_PostgreSQL_closeResultSet(rsHandle);
}
}
/* Here is where we actually run the query */
/* Example: PGresult *PQexec(PGconn *conn, const char *command); */
my_result = PQexec(my_connection, dyn_statement);
if (my_result == NULL) {
char *errMsg;
const char *omsg;
size_t len;
omsg = PQerrorMessage(my_connection);
len = strlen(omsg);
free(dyn_statement);
errMsg = R_alloc(len + 80, 1); /* 80 should be larger than the length of "could not ..."*/
snprintf(errMsg, len + 80, "could not run statement: %s", omsg);
RS_DBI_errorMessage(errMsg, RS_DBI_ERROR);
}
/* ExecStatusType PQresultStatus(const PGresult *res); */
if (PQresultStatus(my_result) == PGRES_TUPLES_OK) {
is_select = (Sint) TRUE;
}
if (PQresultStatus(my_result) == PGRES_COMMAND_OK) {
is_select = (Sint) FALSE;
}
/* char *PQresultErrorMessage(const PGresult *res); */
if (strcmp(PQresultErrorMessage(my_result), "") != 0) {
char *errResultMsg;
const char *omsg;
size_t len;
omsg = PQerrorMessage(my_connection);
len = strlen(omsg);
errResultMsg = R_alloc(len + 80, 1); /* 80 should be larger than the length of "could not ..."*/
snprintf(errResultMsg, len + 80, "could not Retrieve the result : %s", omsg);
/* Frees the storage associated with a PGresult.
* void PQclear(PGresult *res); */
PQclear(my_result);
free(dyn_statement);
RS_DBI_errorMessage(errResultMsg, RS_DBI_ERROR);
}
/* we now create the wrapper and copy values */
PROTECT(rsHandle = RS_DBI_allocResultSet(conHandle));
result = RS_DBI_getResultSet(rsHandle);
result->statement = RS_DBI_copyString(dyn_statement);
result->drvResultSet = (void *) my_result;
result->rowCount = (Sint) 0;
result->isSelect = is_select;
/* Returns the number of rows affected by the SQL command.
* char *PQcmdTuples(PGresult *res);
*/
if (!is_select) {
result->rowsAffected = (Sint) atoi(PQcmdTuples(my_result));
result->completed = 1;
}
else {
result->rowsAffected = (Sint) - 1;
result->completed = 0;
}
if (is_select) {
result->fields = RS_PostgreSQL_createDataMappings(rsHandle);
}
free(dyn_statement);
UNPROTECT(1);
return rsHandle;
}
/* Execute (currently) one sql statement (INSERT, DELETE, SELECT, etc.),
* set coercion type mappings between the server internal data types and
* S classes. Returns an S handle to a resultSet object.
*/
SEXP RS_MySQL_exec(SEXP conHandle, SEXP statement) {
RS_DBI_connection *con;
SEXP rsHandle;
RS_DBI_resultSet *result;
MYSQL *my_connection;
MYSQL_RES *my_result;
int num_fields, state;
int res_id, is_select;
char *dyn_statement;
con = RS_DBI_getConnection(conHandle);
my_connection = (MYSQL *) con->drvConnection;
dyn_statement = RS_DBI_copyString(CHR_EL(statement,0));
/* Do we have a pending resultSet in the current connection?
* MySQL only allows one resultSet per connection.
*/
if(con->num_res>0){
res_id = (int) con->resultSetIds[0]; /* recall, MySQL has only 1 res */
rsHandle = RS_DBI_asResHandle(MGR_ID(conHandle),
CON_ID(conHandle), res_id);
result = RS_DBI_getResultSet(rsHandle);
if(result->completed == 0){
free(dyn_statement);
error("connection with pending rows, close resultSet before continuing");
}
else
RS_MySQL_closeResultSet(rsHandle);
}
/* Here is where we actually run the query */
state = mysql_query(my_connection, dyn_statement);
if(state) {
error("could not run statement: %s", mysql_error(my_connection));
}
/* Do we need output column/field descriptors? Only for SELECT-like
* statements. The MySQL reference manual suggests invoking
* mysql_use_result() and if it succeed the statement is SELECT-like
* that can use a resultSet. Otherwise call mysql_field_count()
* and if it returns zero, the sql was not a SELECT-like statement.
* Finally a non-zero means a failed SELECT-like statement.
*/
my_result = mysql_use_result(my_connection);
if(!my_result)
my_result = (MYSQL_RES *) NULL;
num_fields = (int) mysql_field_count(my_connection);
is_select = (int) TRUE;
if(!my_result){
if(num_fields>0){
free(dyn_statement);
error("error in select/select-like");
}
else
is_select = FALSE;
}
/* we now create the wrapper and copy values */
rsHandle = RS_DBI_allocResultSet(conHandle);
result = RS_DBI_getResultSet(rsHandle);
result->statement = RS_DBI_copyString(dyn_statement);
result->drvResultSet = (void *) my_result;
result->rowCount = (int) 0;
result->isSelect = is_select;
if(!is_select){
result->rowsAffected = (int) mysql_affected_rows(my_connection);
result->completed = 1;
}
else {
result->rowsAffected = (int) -1;
result->completed = 0;
}
if(is_select)
result->fields = RS_MySQL_createDataMappings(rsHandle);
free(dyn_statement);
return rsHandle;
}
