func dumpTable(w io.Writer, conn *sqlConn, origDBName, origTableName string) error {
const limit = 100
// Escape names since they can't be used in placeholders.
dbname := parser.Name(origDBName).String()
tablename := parser.Name(origTableName).String()
if err := conn.Exec(fmt.Sprintf("SET DATABASE = %s", dbname), nil); err != nil {
return err
}
// Fetch all table metadata in a transaction and its time to guarantee it
// doesn't change between the various SHOW statements.
if err := conn.Exec("BEGIN", nil); err != nil {
return err
}
vals, err := conn.QueryRow("SELECT cluster_logical_timestamp()", nil)
if err != nil {
return err
}
clusterTS := string(vals[0].([]byte))
// A previous version of the code did a SELECT on system.descriptor. This
// required the SELECT privilege to the descriptor table, which only root
// has. Allowing non-root to do this would let users see other users' table
// descriptors which is a problem in multi-tenancy.
// Fetch column types.
rows, err := conn.Query(fmt.Sprintf("SHOW COLUMNS FROM %s", tablename), nil)
if err != nil {
return err
}
vals = make([]driver.Value, 2)
coltypes := make(map[string]string)
for {
if err := rows.Next(vals); err == io.EOF {
break
} else if err != nil {
return err
}
nameI, typI := vals[0], vals[1]
name, ok := nameI.(string)
if !ok {
return fmt.Errorf("unexpected value: %T", nameI)
}
typ, ok := typI.(string)
if !ok {
return fmt.Errorf("unexpected value: %T", typI)
}
coltypes[name] = typ
}
if err := rows.Close(); err != nil {
return err
}
// index holds the names, in order, of the primary key columns.
var index []string
// Primary index is always the first index returned by SHOW INDEX.
rows, err = conn.Query(fmt.Sprintf("SHOW INDEX FROM %s", tablename), nil)
if err != nil {
return err
}
vals = make([]driver.Value, 5)
var primaryIndex string
// Find the primary index columns.
for {
if err := rows.Next(vals); err == io.EOF {
break
} else if err != nil {
return err
}
b, ok := vals[1].(string)
if !ok {
return fmt.Errorf("unexpected value: %T", vals[1])
}
if primaryIndex == "" {
primaryIndex = b
} else if primaryIndex != b {
break
}
b, ok = vals[4].(string)
if !ok {
return fmt.Errorf("unexpected value: %T", vals[4])
}
index = append(index, parser.Name(b).String())
}
if err := rows.Close(); err != nil {
return err
}
if len(index) == 0 {
return fmt.Errorf("no primary key index found")
}
indexes := strings.Join(index, ", ")
// Build the SELECT query.
var sbuf bytes.Buffer
fmt.Fprintf(&sbuf, "SELECT %s, * FROM %s@%s AS OF SYSTEM TIME %s", indexes, tablename, primaryIndex, clusterTS)
var wbuf bytes.Buffer
fmt.Fprintf(&wbuf, " WHERE ROW (%s) > ROW (", indexes)
for i := range index {
if i > 0 {
wbuf.WriteString(", ")
}
fmt.Fprintf(&wbuf, "$%d", i+1)
}
wbuf.WriteString(")")
// No WHERE clause first time, so add a place to inject it.
fmt.Fprintf(&sbuf, "%%s ORDER BY %s LIMIT %d", indexes, limit)
bs := sbuf.String()
vals, err = conn.QueryRow(fmt.Sprintf("SHOW CREATE TABLE %s", tablename), nil)
if err != nil {
return err
}
create := vals[1].(string)
if _, err := w.Write([]byte(create)); err != nil {
return err
}
if _, err := w.Write([]byte(";\n")); err != nil {
return err
}
if err := conn.Exec("COMMIT", nil); err != nil {
return err
}
// pk holds the last values of the fetched primary keys
var pk []driver.Value
q := fmt.Sprintf(bs, "")
for {
rows, err := conn.Query(q, pk)
if err != nil {
return err
}
cols := rows.Columns()
pkcols := cols[:len(index)]
cols = cols[len(index):]
inserts := make([][]string, 0, limit)
i := 0
for i < limit {
vals := make([]driver.Value, len(cols)+len(pkcols))
if err := rows.Next(vals); err == io.EOF {
break
} else if err != nil {
return err
}
if pk == nil {
q = fmt.Sprintf(bs, wbuf.String())
}
pk = vals[:len(index)]
vals = vals[len(index):]
ivals := make([]string, len(vals))
// Values need to be correctly encoded for INSERT statements in a text file.
for si, sv := range vals {
switch t := sv.(type) {
case nil:
ivals[si] = "NULL"
case bool:
ivals[si] = parser.MakeDBool(parser.DBool(t)).String()
case int64:
ivals[si] = parser.NewDInt(parser.DInt(t)).String()
case float64:
ivals[si] = parser.NewDFloat(parser.DFloat(t)).String()
case string:
ivals[si] = parser.NewDString(t).String()
case []byte:
switch ct := coltypes[cols[si]]; ct {
case "INTERVAL":
ivals[si] = fmt.Sprintf("'%s'", t)
case "BYTES":
ivals[si] = parser.NewDBytes(parser.DBytes(t)).String()
default:
// STRING and DECIMAL types can have optional length
// suffixes, so only examine the prefix of the type.
if strings.HasPrefix(coltypes[cols[si]], "STRING") {
ivals[si] = parser.NewDString(string(t)).String()
} else if strings.HasPrefix(coltypes[cols[si]], "DECIMAL") {
ivals[si] = string(t)
} else {
panic(errors.Errorf("unknown []byte type: %s, %v: %s", t, cols[si], coltypes[cols[si]]))
}
}
case time.Time:
var d parser.Datum
ct := coltypes[cols[si]]
switch ct {
case "DATE":
d = parser.NewDDateFromTime(t, time.UTC)
case "TIMESTAMP":
d = parser.MakeDTimestamp(t, time.Nanosecond)
case "TIMESTAMP WITH TIME ZONE":
d = parser.MakeDTimestampTZ(t, time.Nanosecond)
default:
panic(errors.Errorf("unknown timestamp type: %s, %v: %s", t, cols[si], coltypes[cols[si]]))
}
ivals[si] = fmt.Sprintf("'%s'", d)
default:
panic(errors.Errorf("unknown field type: %T (%s)", t, cols[si]))
}
}
inserts = append(inserts, ivals)
i++
}
for si, sv := range pk {
b, ok := sv.([]byte)
if ok && strings.HasPrefix(coltypes[pkcols[si]], "STRING") {
// Primary key strings need to be converted to a go string, but not SQL
// encoded since they aren't being written to a text file.
pk[si] = string(b)
}
}
if err := rows.Close(); err != nil {
return err
}
if i == 0 {
break
}
fmt.Fprintf(w, "\nINSERT INTO %s VALUES", tablename)
for idx, values := range inserts {
if idx > 0 {
fmt.Fprint(w, ",")
}
fmt.Fprint(w, "\n\t(")
for vi, v := range values {
if vi > 0 {
fmt.Fprint(w, ", ")
}
fmt.Fprint(w, v)
}
fmt.Fprint(w, ")")
}
fmt.Fprintln(w, ";")
if i < limit {
break
}
}
return nil
}
// decodeOidDatum decodes bytes with specified Oid and format code into
// a datum.
func decodeOidDatum(id oid.Oid, code formatCode, b []byte) (parser.Datum, error) {
var d parser.Datum
switch id {
case oid.T_bool:
switch code {
case formatText:
v, err := strconv.ParseBool(string(b))
if err != nil {
return d, err
}
d = parser.MakeDBool(parser.DBool(v))
case formatBinary:
switch b[0] {
case 0:
d = parser.MakeDBool(false)
case 1:
d = parser.MakeDBool(true)
default:
return d, errors.Errorf("unsupported binary bool: %q", b)
}
default:
return d, errors.Errorf("unsupported bool format code: %d", code)
}
case oid.T_int2:
switch code {
case formatText:
i, err := strconv.ParseInt(string(b), 10, 64)
if err != nil {
return d, err
}
d = parser.NewDInt(parser.DInt(i))
case formatBinary:
if len(b) < 2 {
return d, errors.Errorf("int2 requires 2 bytes for binary format")
}
i := int16(binary.BigEndian.Uint16(b))
d = parser.NewDInt(parser.DInt(i))
default:
return d, errors.Errorf("unsupported int2 format code: %d", code)
}
case oid.T_int4:
switch code {
case formatText:
i, err := strconv.ParseInt(string(b), 10, 64)
if err != nil {
return d, err
}
d = parser.NewDInt(parser.DInt(i))
case formatBinary:
if len(b) < 4 {
return d, errors.Errorf("int4 requires 4 bytes for binary format")
}
i := int32(binary.BigEndian.Uint32(b))
d = parser.NewDInt(parser.DInt(i))
default:
return d, errors.Errorf("unsupported int4 format code: %d", code)
}
case oid.T_int8:
switch code {
case formatText:
i, err := strconv.ParseInt(string(b), 10, 64)
if err != nil {
return d, err
}
d = parser.NewDInt(parser.DInt(i))
case formatBinary:
if len(b) < 8 {
return d, errors.Errorf("int8 requires 8 bytes for binary format")
}
i := int64(binary.BigEndian.Uint64(b))
d = parser.NewDInt(parser.DInt(i))
default:
return d, errors.Errorf("unsupported int8 format code: %d", code)
}
case oid.T_float4:
switch code {
case formatText:
f, err := strconv.ParseFloat(string(b), 64)
if err != nil {
return d, err
}
d = parser.NewDFloat(parser.DFloat(f))
case formatBinary:
if len(b) < 4 {
return d, errors.Errorf("float4 requires 4 bytes for binary format")
}
f := math.Float32frombits(binary.BigEndian.Uint32(b))
d = parser.NewDFloat(parser.DFloat(f))
default:
return d, errors.Errorf("unsupported float4 format code: %d", code)
}
case oid.T_float8:
switch code {
case formatText:
f, err := strconv.ParseFloat(string(b), 64)
if err != nil {
return d, err
}
d = parser.NewDFloat(parser.DFloat(f))
case formatBinary:
if len(b) < 8 {
return d, errors.Errorf("float8 requires 8 bytes for binary format")
}
f := math.Float64frombits(binary.BigEndian.Uint64(b))
d = parser.NewDFloat(parser.DFloat(f))
default:
return d, errors.Errorf("unsupported float8 format code: %d", code)
}
case oid.T_numeric:
switch code {
case formatText:
dd := &parser.DDecimal{}
if _, ok := dd.SetString(string(b)); !ok {
return nil, errors.Errorf("could not parse string %q as decimal", b)
}
d = dd
case formatBinary:
r := bytes.NewReader(b)
alloc := struct {
pgNum pgNumeric
i16 int16
dd parser.DDecimal
}{}
for _, ptr := range []interface{}{
&alloc.pgNum.ndigits,
&alloc.pgNum.weight,
&alloc.pgNum.sign,
&alloc.pgNum.dscale,
} {
if err := binary.Read(r, binary.BigEndian, ptr); err != nil {
return d, err
}
}
if alloc.pgNum.ndigits > 0 {
decDigits := make([]byte, 0, alloc.pgNum.ndigits*pgDecDigits)
nextDigit := func() error {
if err := binary.Read(r, binary.BigEndian, &alloc.i16); err != nil {
return err
}
numZeroes := pgDecDigits
for i16 := alloc.i16; i16 > 0; i16 /= 10 {
numZeroes--
}
for ; numZeroes > 0; numZeroes-- {
decDigits = append(decDigits, '0')
}
return nil
}
for i := int16(0); i < alloc.pgNum.ndigits-1; i++ {
if err := nextDigit(); err != nil {
return d, err
}
if alloc.i16 > 0 {
decDigits = strconv.AppendUint(decDigits, uint64(alloc.i16), 10)
}
}
// The last digit may contain padding, which we need to deal with.
if err := nextDigit(); err != nil {
return d, err
}
dscale := (alloc.pgNum.ndigits - (alloc.pgNum.weight + 1)) * pgDecDigits
if overScale := dscale - alloc.pgNum.dscale; overScale > 0 {
dscale -= overScale
for i := int16(0); i < overScale; i++ {
alloc.i16 /= 10
}
}
decDigits = strconv.AppendUint(decDigits, uint64(alloc.i16), 10)
decString := string(decDigits)
if _, ok := alloc.dd.UnscaledBig().SetString(decString, 10); !ok {
return nil, errors.Errorf("could not parse string %q as decimal", decString)
}
alloc.dd.SetScale(inf.Scale(dscale))
}
switch alloc.pgNum.sign {
case pgNumericPos:
case pgNumericNeg:
alloc.dd.Neg(&alloc.dd.Dec)
default:
return d, errors.Errorf("unsupported numeric sign: %d", alloc.pgNum.sign)
}
d = &alloc.dd
default:
return d, errors.Errorf("unsupported numeric format code: %d", code)
}
case oid.T_text, oid.T_varchar:
switch code {
case formatText, formatBinary:
d = parser.NewDString(string(b))
default:
return d, errors.Errorf("unsupported text format code: %d", code)
}
case oid.T_bytea:
switch code {
case formatText:
// http://www.postgresql.org/docs/current/static/datatype-binary.html#AEN5667
// Code cribbed from github.com/lib/pq.
// We only support hex encoding.
if len(b) >= 2 && bytes.Equal(b[:2], []byte("\\x")) {
b = b[2:] // trim off leading "\\x"
result := make([]byte, hex.DecodedLen(len(b)))
_, err := hex.Decode(result, b)
if err != nil {
return d, err
}
d = parser.NewDBytes(parser.DBytes(result))
} else {
return d, errors.Errorf("unsupported bytea encoding: %q", b)
}
case formatBinary:
d = parser.NewDBytes(parser.DBytes(b))
default:
return d, errors.Errorf("unsupported bytea format code: %d", code)
}
case oid.T_timestamp:
switch code {
case formatText:
ts, err := parseTs(string(b))
if err != nil {
return d, errors.Errorf("could not parse string %q as timestamp", b)
}
d = parser.MakeDTimestamp(ts, time.Microsecond)
case formatBinary:
if len(b) < 8 {
return d, errors.Errorf("timestamp requires 8 bytes for binary format")
}
i := int64(binary.BigEndian.Uint64(b))
d = parser.MakeDTimestamp(pgBinaryToTime(i), time.Microsecond)
default:
return d, errors.Errorf("unsupported timestamp format code: %d", code)
}
case oid.T_timestamptz:
switch code {
case formatText:
ts, err := parseTs(string(b))
if err != nil {
return d, errors.Errorf("could not parse string %q as timestamp", b)
}
d = parser.MakeDTimestampTZ(ts, time.Microsecond)
case formatBinary:
if len(b) < 8 {
return d, errors.Errorf("timestamptz requires 8 bytes for binary format")
}
i := int64(binary.BigEndian.Uint64(b))
d = parser.MakeDTimestampTZ(pgBinaryToTime(i), time.Microsecond)
default:
return d, errors.Errorf("unsupported timestamptz format code: %d", code)
}
case oid.T_date:
switch code {
case formatText:
ts, err := parseTs(string(b))
if err != nil {
res, err := parser.ParseDDate(string(b), time.UTC)
if err != nil {
return d, errors.Errorf("could not parse string %q as date", b)
}
d = res
} else {
daysSinceEpoch := ts.Unix() / secondsInDay
d = parser.NewDDate(parser.DDate(daysSinceEpoch))
}
case formatBinary:
if len(b) < 4 {
return d, errors.Errorf("date requires 4 bytes for binary format")
}
i := int32(binary.BigEndian.Uint32(b))
d = pgBinaryToDate(i)
default:
return d, errors.Errorf("unsupported date format code: %d", code)
}
case oid.T_interval:
switch code {
case formatText:
d, err := parser.ParseDInterval(string(b))
if err != nil {
return d, errors.Errorf("could not parse string %q as interval", b)
}
return d, nil
default:
return d, errors.Errorf("unsupported interval format code: %d", code)
}
default:
return d, errors.Errorf("unsupported OID: %v", id)
}
return d, nil
}