diff options
Diffstat (limited to 'vendor/github.com/jackc/pgx/v4/rows.go')
-rw-r--r-- | vendor/github.com/jackc/pgx/v4/rows.go | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/vendor/github.com/jackc/pgx/v4/rows.go b/vendor/github.com/jackc/pgx/v4/rows.go new file mode 100644 index 000000000..d57d5cbf6 --- /dev/null +++ b/vendor/github.com/jackc/pgx/v4/rows.go @@ -0,0 +1,347 @@ +package pgx + +import ( + "context" + "errors" + "fmt" + "time" + + "github.com/jackc/pgconn" + "github.com/jackc/pgproto3/v2" + "github.com/jackc/pgtype" +) + +// Rows is the result set returned from *Conn.Query. Rows must be closed before +// the *Conn can be used again. Rows are closed by explicitly calling Close(), +// calling Next() until it returns false, or when a fatal error occurs. +// +// Once a Rows is closed the only methods that may be called are Close(), Err(), and CommandTag(). +// +// Rows is an interface instead of a struct to allow tests to mock Query. However, +// adding a method to an interface is technically a breaking change. Because of this +// the Rows interface is partially excluded from semantic version requirements. +// Methods will not be removed or changed, but new methods may be added. +type Rows interface { + // Close closes the rows, making the connection ready for use again. It is safe + // to call Close after rows is already closed. + Close() + + // Err returns any error that occurred while reading. + Err() error + + // CommandTag returns the command tag from this query. It is only available after Rows is closed. + CommandTag() pgconn.CommandTag + + FieldDescriptions() []pgproto3.FieldDescription + + // Next prepares the next row for reading. It returns true if there is another + // row and false if no more rows are available. It automatically closes rows + // when all rows are read. + Next() bool + + // Scan reads the values from the current row into dest values positionally. + // dest can include pointers to core types, values implementing the Scanner + // interface, and nil. nil will skip the value entirely. + Scan(dest ...interface{}) error + + // Values returns the decoded row values. + Values() ([]interface{}, error) + + // RawValues returns the unparsed bytes of the row values. The returned [][]byte is only valid until the next Next + // call or the Rows is closed. However, the underlying byte data is safe to retain a reference to and mutate. + RawValues() [][]byte +} + +// Row is a convenience wrapper over Rows that is returned by QueryRow. +// +// Row is an interface instead of a struct to allow tests to mock QueryRow. However, +// adding a method to an interface is technically a breaking change. Because of this +// the Row interface is partially excluded from semantic version requirements. +// Methods will not be removed or changed, but new methods may be added. +type Row interface { + // Scan works the same as Rows. with the following exceptions. If no + // rows were found it returns ErrNoRows. If multiple rows are returned it + // ignores all but the first. + Scan(dest ...interface{}) error +} + +// connRow implements the Row interface for Conn.QueryRow. +type connRow connRows + +func (r *connRow) Scan(dest ...interface{}) (err error) { + rows := (*connRows)(r) + + if rows.Err() != nil { + return rows.Err() + } + + if !rows.Next() { + if rows.Err() == nil { + return ErrNoRows + } + return rows.Err() + } + + rows.Scan(dest...) + rows.Close() + return rows.Err() +} + +type rowLog interface { + shouldLog(lvl LogLevel) bool + log(ctx context.Context, lvl LogLevel, msg string, data map[string]interface{}) +} + +// connRows implements the Rows interface for Conn.Query. +type connRows struct { + ctx context.Context + logger rowLog + connInfo *pgtype.ConnInfo + values [][]byte + rowCount int + err error + commandTag pgconn.CommandTag + startTime time.Time + sql string + args []interface{} + closed bool + conn *Conn + + resultReader *pgconn.ResultReader + multiResultReader *pgconn.MultiResultReader + + scanPlans []pgtype.ScanPlan +} + +func (rows *connRows) FieldDescriptions() []pgproto3.FieldDescription { + return rows.resultReader.FieldDescriptions() +} + +func (rows *connRows) Close() { + if rows.closed { + return + } + + rows.closed = true + + if rows.resultReader != nil { + var closeErr error + rows.commandTag, closeErr = rows.resultReader.Close() + if rows.err == nil { + rows.err = closeErr + } + } + + if rows.multiResultReader != nil { + closeErr := rows.multiResultReader.Close() + if rows.err == nil { + rows.err = closeErr + } + } + + if rows.logger != nil { + if rows.err == nil { + if rows.logger.shouldLog(LogLevelInfo) { + endTime := time.Now() + rows.logger.log(rows.ctx, LogLevelInfo, "Query", map[string]interface{}{"sql": rows.sql, "args": logQueryArgs(rows.args), "time": endTime.Sub(rows.startTime), "rowCount": rows.rowCount}) + } + } else { + if rows.logger.shouldLog(LogLevelError) { + rows.logger.log(rows.ctx, LogLevelError, "Query", map[string]interface{}{"err": rows.err, "sql": rows.sql, "args": logQueryArgs(rows.args)}) + } + if rows.err != nil && rows.conn.stmtcache != nil { + rows.conn.stmtcache.StatementErrored(rows.sql, rows.err) + } + } + } +} + +func (rows *connRows) CommandTag() pgconn.CommandTag { + return rows.commandTag +} + +func (rows *connRows) Err() error { + return rows.err +} + +// fatal signals an error occurred after the query was sent to the server. It +// closes the rows automatically. +func (rows *connRows) fatal(err error) { + if rows.err != nil { + return + } + + rows.err = err + rows.Close() +} + +func (rows *connRows) Next() bool { + if rows.closed { + return false + } + + if rows.resultReader.NextRow() { + rows.rowCount++ + rows.values = rows.resultReader.Values() + return true + } else { + rows.Close() + return false + } +} + +func (rows *connRows) Scan(dest ...interface{}) error { + ci := rows.connInfo + fieldDescriptions := rows.FieldDescriptions() + values := rows.values + + if len(fieldDescriptions) != len(values) { + err := fmt.Errorf("number of field descriptions must equal number of values, got %d and %d", len(fieldDescriptions), len(values)) + rows.fatal(err) + return err + } + if len(fieldDescriptions) != len(dest) { + err := fmt.Errorf("number of field descriptions must equal number of destinations, got %d and %d", len(fieldDescriptions), len(dest)) + rows.fatal(err) + return err + } + + if rows.scanPlans == nil { + rows.scanPlans = make([]pgtype.ScanPlan, len(values)) + for i := range dest { + rows.scanPlans[i] = ci.PlanScan(fieldDescriptions[i].DataTypeOID, fieldDescriptions[i].Format, dest[i]) + } + } + + for i, dst := range dest { + if dst == nil { + continue + } + + err := rows.scanPlans[i].Scan(ci, fieldDescriptions[i].DataTypeOID, fieldDescriptions[i].Format, values[i], dst) + if err != nil { + err = ScanArgError{ColumnIndex: i, Err: err} + rows.fatal(err) + return err + } + } + + return nil +} + +func (rows *connRows) Values() ([]interface{}, error) { + if rows.closed { + return nil, errors.New("rows is closed") + } + + values := make([]interface{}, 0, len(rows.FieldDescriptions())) + + for i := range rows.FieldDescriptions() { + buf := rows.values[i] + fd := &rows.FieldDescriptions()[i] + + if buf == nil { + values = append(values, nil) + continue + } + + if dt, ok := rows.connInfo.DataTypeForOID(fd.DataTypeOID); ok { + value := dt.Value + + switch fd.Format { + case TextFormatCode: + decoder, ok := value.(pgtype.TextDecoder) + if !ok { + decoder = &pgtype.GenericText{} + } + err := decoder.DecodeText(rows.connInfo, buf) + if err != nil { + rows.fatal(err) + } + values = append(values, decoder.(pgtype.Value).Get()) + case BinaryFormatCode: + decoder, ok := value.(pgtype.BinaryDecoder) + if !ok { + decoder = &pgtype.GenericBinary{} + } + err := decoder.DecodeBinary(rows.connInfo, buf) + if err != nil { + rows.fatal(err) + } + values = append(values, value.Get()) + default: + rows.fatal(errors.New("Unknown format code")) + } + } else { + switch fd.Format { + case TextFormatCode: + decoder := &pgtype.GenericText{} + err := decoder.DecodeText(rows.connInfo, buf) + if err != nil { + rows.fatal(err) + } + values = append(values, decoder.Get()) + case BinaryFormatCode: + decoder := &pgtype.GenericBinary{} + err := decoder.DecodeBinary(rows.connInfo, buf) + if err != nil { + rows.fatal(err) + } + values = append(values, decoder.Get()) + default: + rows.fatal(errors.New("Unknown format code")) + } + } + + if rows.Err() != nil { + return nil, rows.Err() + } + } + + return values, rows.Err() +} + +func (rows *connRows) RawValues() [][]byte { + return rows.values +} + +type ScanArgError struct { + ColumnIndex int + Err error +} + +func (e ScanArgError) Error() string { + return fmt.Sprintf("can't scan into dest[%d]: %v", e.ColumnIndex, e.Err) +} + +func (e ScanArgError) Unwrap() error { + return e.Err +} + +// ScanRow decodes raw row data into dest. It can be used to scan rows read from the lower level pgconn interface. +// +// connInfo - OID to Go type mapping. +// fieldDescriptions - OID and format of values +// values - the raw data as returned from the PostgreSQL server +// dest - the destination that values will be decoded into +func ScanRow(connInfo *pgtype.ConnInfo, fieldDescriptions []pgproto3.FieldDescription, values [][]byte, dest ...interface{}) error { + if len(fieldDescriptions) != len(values) { + return fmt.Errorf("number of field descriptions must equal number of values, got %d and %d", len(fieldDescriptions), len(values)) + } + if len(fieldDescriptions) != len(dest) { + return fmt.Errorf("number of field descriptions must equal number of destinations, got %d and %d", len(fieldDescriptions), len(dest)) + } + + for i, d := range dest { + if d == nil { + continue + } + + err := connInfo.Scan(fieldDescriptions[i].DataTypeOID, fieldDescriptions[i].Format, values[i], d) + if err != nil { + return ScanArgError{ColumnIndex: i, Err: err} + } + } + + return nil +} |