diff options
Diffstat (limited to 'vendor/github.com/jackc/pgx/v5/extended_query_builder.go')
-rw-r--r-- | vendor/github.com/jackc/pgx/v5/extended_query_builder.go | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/vendor/github.com/jackc/pgx/v5/extended_query_builder.go b/vendor/github.com/jackc/pgx/v5/extended_query_builder.go new file mode 100644 index 0000000..526b0e9 --- /dev/null +++ b/vendor/github.com/jackc/pgx/v5/extended_query_builder.go @@ -0,0 +1,146 @@ +package pgx + +import ( + "fmt" + + "github.com/jackc/pgx/v5/pgconn" + "github.com/jackc/pgx/v5/pgtype" +) + +// ExtendedQueryBuilder is used to choose the parameter formats, to format the parameters and to choose the result +// formats for an extended query. +type ExtendedQueryBuilder struct { + ParamValues [][]byte + paramValueBytes []byte + ParamFormats []int16 + ResultFormats []int16 +} + +// Build sets ParamValues, ParamFormats, and ResultFormats for use with *PgConn.ExecParams or *PgConn.ExecPrepared. If +// sd is nil then QueryExecModeExec behavior will be used. +func (eqb *ExtendedQueryBuilder) Build(m *pgtype.Map, sd *pgconn.StatementDescription, args []any) error { + eqb.reset() + + if sd == nil { + for i := range args { + err := eqb.appendParam(m, 0, pgtype.TextFormatCode, args[i]) + if err != nil { + err = fmt.Errorf("failed to encode args[%d]: %w", i, err) + return err + } + } + return nil + } + + if len(sd.ParamOIDs) != len(args) { + return fmt.Errorf("mismatched param and argument count") + } + + for i := range args { + err := eqb.appendParam(m, sd.ParamOIDs[i], -1, args[i]) + if err != nil { + err = fmt.Errorf("failed to encode args[%d]: %w", i, err) + return err + } + } + + for i := range sd.Fields { + eqb.appendResultFormat(m.FormatCodeForOID(sd.Fields[i].DataTypeOID)) + } + + return nil +} + +// appendParam appends a parameter to the query. format may be -1 to automatically choose the format. If arg is nil it +// must be an untyped nil. +func (eqb *ExtendedQueryBuilder) appendParam(m *pgtype.Map, oid uint32, format int16, arg any) error { + if format == -1 { + preferredFormat := eqb.chooseParameterFormatCode(m, oid, arg) + preferredErr := eqb.appendParam(m, oid, preferredFormat, arg) + if preferredErr == nil { + return nil + } + + var otherFormat int16 + if preferredFormat == TextFormatCode { + otherFormat = BinaryFormatCode + } else { + otherFormat = TextFormatCode + } + + otherErr := eqb.appendParam(m, oid, otherFormat, arg) + if otherErr == nil { + return nil + } + + return preferredErr // return the error from the preferred format + } + + v, err := eqb.encodeExtendedParamValue(m, oid, format, arg) + if err != nil { + return err + } + + eqb.ParamFormats = append(eqb.ParamFormats, format) + eqb.ParamValues = append(eqb.ParamValues, v) + + return nil +} + +// appendResultFormat appends a result format to the query. +func (eqb *ExtendedQueryBuilder) appendResultFormat(format int16) { + eqb.ResultFormats = append(eqb.ResultFormats, format) +} + +// reset readies eqb to build another query. +func (eqb *ExtendedQueryBuilder) reset() { + eqb.ParamValues = eqb.ParamValues[0:0] + eqb.paramValueBytes = eqb.paramValueBytes[0:0] + eqb.ParamFormats = eqb.ParamFormats[0:0] + eqb.ResultFormats = eqb.ResultFormats[0:0] + + if cap(eqb.ParamValues) > 64 { + eqb.ParamValues = make([][]byte, 0, 64) + } + + if cap(eqb.paramValueBytes) > 256 { + eqb.paramValueBytes = make([]byte, 0, 256) + } + + if cap(eqb.ParamFormats) > 64 { + eqb.ParamFormats = make([]int16, 0, 64) + } + if cap(eqb.ResultFormats) > 64 { + eqb.ResultFormats = make([]int16, 0, 64) + } +} + +func (eqb *ExtendedQueryBuilder) encodeExtendedParamValue(m *pgtype.Map, oid uint32, formatCode int16, arg any) ([]byte, error) { + if eqb.paramValueBytes == nil { + eqb.paramValueBytes = make([]byte, 0, 128) + } + + pos := len(eqb.paramValueBytes) + + buf, err := m.Encode(oid, formatCode, arg, eqb.paramValueBytes) + if err != nil { + return nil, err + } + if buf == nil { + return nil, nil + } + eqb.paramValueBytes = buf + return eqb.paramValueBytes[pos:], nil +} + +// chooseParameterFormatCode determines the correct format code for an +// argument to a prepared statement. It defaults to TextFormatCode if no +// determination can be made. +func (eqb *ExtendedQueryBuilder) chooseParameterFormatCode(m *pgtype.Map, oid uint32, arg any) int16 { + switch arg.(type) { + case string, *string: + return TextFormatCode + } + + return m.FormatCodeForOID(oid) +} |