// DecodeTableValue decodes a value encoded by EncodeTableValue.
func DecodeTableValue(a *DatumAlloc, valType parser.Type, b []byte) (parser.Datum, []byte, error) {
_, dataOffset, _, typ, err := encoding.DecodeValueTag(b)
if err != nil {
return nil, b, err
}
if typ == encoding.Null {
return parser.DNull, b[dataOffset:], nil
}
switch valType {
case parser.TypeBool:
var x bool
b, x, err = encoding.DecodeBoolValue(b)
// No need to chunk allocate DBool as MakeDBool returns either
// parser.DBoolTrue or parser.DBoolFalse.
return parser.MakeDBool(parser.DBool(x)), b, err
case parser.TypeInt:
var i int64
b, i, err = encoding.DecodeIntValue(b)
return a.NewDInt(parser.DInt(i)), b, err
case parser.TypeFloat:
var f float64
b, f, err = encoding.DecodeFloatValue(b)
return a.NewDFloat(parser.DFloat(f)), b, err
case parser.TypeDecimal:
var d *inf.Dec
b, d, err = encoding.DecodeDecimalValue(b)
dd := a.NewDDecimal(parser.DDecimal{})
dd.Set(d)
return dd, b, err
case parser.TypeString:
var data []byte
b, data, err = encoding.DecodeBytesValue(b)
return a.NewDString(parser.DString(data)), b, err
case parser.TypeBytes:
var data []byte
b, data, err = encoding.DecodeBytesValue(b)
return a.NewDBytes(parser.DBytes(data)), b, err
case parser.TypeDate:
var i int64
b, i, err = encoding.DecodeIntValue(b)
return a.NewDDate(parser.DDate(i)), b, err
case parser.TypeTimestamp:
var t time.Time
b, t, err = encoding.DecodeTimeValue(b)
return a.NewDTimestamp(parser.DTimestamp{Time: t}), b, err
case parser.TypeTimestampTZ:
var t time.Time
b, t, err = encoding.DecodeTimeValue(b)
return a.NewDTimestampTZ(parser.DTimestampTZ{Time: t}), b, err
case parser.TypeInterval:
var d duration.Duration
b, d, err = encoding.DecodeDurationValue(b)
return a.NewDInterval(parser.DInterval{Duration: d}), b, err
default:
return nil, nil, errors.Errorf("TODO(pmattis): decoded index value: %s", valType)
}
}
func simplifyComparisonExpr(n *parser.ComparisonExpr) (parser.TypedExpr, bool) {
// NormalizeExpr will have left comparisons in the form "<var> <op>
// <datum>" unless they could not be simplified further in which case
// simplifyExpr cannot handle them. For example, "lower(a) = 'foo'"
left, right := n.TypedLeft(), n.TypedRight()
if isVar(left) && isDatum(right) {
if right == parser.DNull {
switch n.Operator {
case parser.IsNotDistinctFrom:
switch left.(type) {
case *parser.IndexedVar:
// Transform "a IS NOT DISTINCT FROM NULL" into "a IS NULL".
return parser.NewTypedComparisonExpr(
parser.Is,
left,
right,
), true
}
case parser.IsDistinctFrom:
switch left.(type) {
case *parser.IndexedVar:
// Transform "a IS DISTINCT FROM NULL" into "a IS NOT NULL".
return parser.NewTypedComparisonExpr(
parser.IsNot,
left,
right,
), true
}
case parser.Is, parser.IsNot:
switch left.(type) {
case *parser.IndexedVar:
// "a IS {,NOT} NULL" can be used during index selection to restrict
// the range of scanned keys.
return n, true
}
default:
// All of the remaining comparison operators have the property that when
// comparing to NULL they evaluate to NULL (see evalComparisonOp). NULL is
// not the same as false, but in the context of a WHERE clause, NULL is
// considered not-true which is the same as false.
return parser.MakeDBool(false), true
}
}
switch n.Operator {
case parser.EQ:
// Translate "(a, b) = (1, 2)" to "(a, b) IN ((1, 2))".
switch left.(type) {
case *parser.Tuple:
return parser.NewTypedComparisonExpr(
parser.In,
left,
&parser.DTuple{right.(parser.Datum)},
), true
}
return n, true
case parser.NE, parser.GE, parser.LE:
return n, true
case parser.GT:
// This simplification is necessary so that subsequent transformation of
// > constraint to >= can use Datum.Next without concern about whether a
// next value exists. Note that if the variable (n.Left) is NULL, this
// comparison would evaluate to NULL which is equivalent to false for a
// boolean expression.
if right.(parser.Datum).IsMax() {
return parser.MakeDBool(false), true
}
return n, true
case parser.LT:
// Note that if the variable is NULL, this would evaluate to NULL which
// would equivalent to false for a boolean expression.
if right.(parser.Datum).IsMin() {
return parser.MakeDBool(false), true
}
return n, true
case parser.In, parser.NotIn:
tuple := *right.(*parser.DTuple)
if len(tuple) == 0 {
return parser.MakeDBool(false), true
}
return n, true
case parser.Like:
// a LIKE 'foo%' -> a >= "foo" AND a < "fop"
if d, ok := right.(*parser.DString); ok {
if i := strings.IndexAny(string(*d), "_%"); i >= 0 {
return makePrefixRange((*d)[:i], left, false), false
}
return makePrefixRange(*d, left, true), false
}
// TODO(pmattis): Support parser.DBytes?
case parser.SimilarTo:
// a SIMILAR TO "foo.*" -> a >= "foo" AND a < "fop"
if d, ok := right.(*parser.DString); ok {
pattern := parser.SimilarEscape(string(*d))
if re, err := regexp.Compile(pattern); err == nil {
prefix, complete := re.LiteralPrefix()
return makePrefixRange(parser.DString(prefix), left, complete), false
}
}
// TODO(pmattis): Support parser.DBytes?
}
}
return parser.MakeDBool(true), false
}
// DecodeTableKey decodes a table key/value.
func DecodeTableKey(
a *DatumAlloc, valType parser.Type, key []byte, dir encoding.Direction,
) (parser.Datum, []byte, error) {
if (dir != encoding.Ascending) && (dir != encoding.Descending) {
return nil, nil, errors.Errorf("invalid direction: %d", dir)
}
var isNull bool
if key, isNull = encoding.DecodeIfNull(key); isNull {
return parser.DNull, key, nil
}
var rkey []byte
var err error
switch valType {
case parser.TypeBool:
var i int64
if dir == encoding.Ascending {
rkey, i, err = encoding.DecodeVarintAscending(key)
} else {
rkey, i, err = encoding.DecodeVarintDescending(key)
}
// No need to chunk allocate DBool as MakeDBool returns either
// parser.DBoolTrue or parser.DBoolFalse.
return parser.MakeDBool(parser.DBool(i != 0)), rkey, err
case parser.TypeInt:
var i int64
if dir == encoding.Ascending {
rkey, i, err = encoding.DecodeVarintAscending(key)
} else {
rkey, i, err = encoding.DecodeVarintDescending(key)
}
return a.NewDInt(parser.DInt(i)), rkey, err
case parser.TypeFloat:
var f float64
if dir == encoding.Ascending {
rkey, f, err = encoding.DecodeFloatAscending(key)
} else {
rkey, f, err = encoding.DecodeFloatDescending(key)
}
return a.NewDFloat(parser.DFloat(f)), rkey, err
case parser.TypeDecimal:
var d *inf.Dec
if dir == encoding.Ascending {
rkey, d, err = encoding.DecodeDecimalAscending(key, nil)
} else {
rkey, d, err = encoding.DecodeDecimalDescending(key, nil)
}
dd := a.NewDDecimal(parser.DDecimal{})
dd.Set(d)
return dd, rkey, err
case parser.TypeString:
var r string
if dir == encoding.Ascending {
rkey, r, err = encoding.DecodeUnsafeStringAscending(key, nil)
} else {
rkey, r, err = encoding.DecodeUnsafeStringDescending(key, nil)
}
return a.NewDString(parser.DString(r)), rkey, err
case parser.TypeBytes:
var r []byte
if dir == encoding.Ascending {
rkey, r, err = encoding.DecodeBytesAscending(key, nil)
} else {
rkey, r, err = encoding.DecodeBytesDescending(key, nil)
}
return a.NewDBytes(parser.DBytes(r)), rkey, err
case parser.TypeDate:
var t int64
if dir == encoding.Ascending {
rkey, t, err = encoding.DecodeVarintAscending(key)
} else {
rkey, t, err = encoding.DecodeVarintDescending(key)
}
return a.NewDDate(parser.DDate(t)), rkey, err
case parser.TypeTimestamp:
var t time.Time
if dir == encoding.Ascending {
rkey, t, err = encoding.DecodeTimeAscending(key)
} else {
rkey, t, err = encoding.DecodeTimeDescending(key)
}
return a.NewDTimestamp(parser.DTimestamp{Time: t}), rkey, err
case parser.TypeTimestampTZ:
var t time.Time
if dir == encoding.Ascending {
rkey, t, err = encoding.DecodeTimeAscending(key)
} else {
rkey, t, err = encoding.DecodeTimeDescending(key)
}
return a.NewDTimestampTZ(parser.DTimestampTZ{Time: t}), rkey, err
case parser.TypeInterval:
var d duration.Duration
if dir == encoding.Ascending {
rkey, d, err = encoding.DecodeDurationAscending(key)
} else {
rkey, d, err = encoding.DecodeDurationDescending(key)
}
return a.NewDInterval(parser.DInterval{Duration: d}), rkey, err
default:
return nil, nil, errors.Errorf("TODO(pmattis): decoded index key: %s", valType)
}
}
// UnmarshalColumnValue decodes the value from a key-value pair using the type
// expected by the column. An error is returned if the value's type does not
// match the column's type.
func UnmarshalColumnValue(
a *DatumAlloc, kind ColumnType_Kind, value *roachpb.Value,
) (parser.Datum, error) {
if value == nil {
return parser.DNull, nil
}
switch kind {
case ColumnType_BOOL:
v, err := value.GetBool()
if err != nil {
return nil, err
}
return parser.MakeDBool(parser.DBool(v)), nil
case ColumnType_INT:
v, err := value.GetInt()
if err != nil {
return nil, err
}
return a.NewDInt(parser.DInt(v)), nil
case ColumnType_FLOAT:
v, err := value.GetFloat()
if err != nil {
return nil, err
}
return a.NewDFloat(parser.DFloat(v)), nil
case ColumnType_DECIMAL:
v, err := value.GetDecimal()
if err != nil {
return nil, err
}
dd := a.NewDDecimal(parser.DDecimal{})
dd.Set(v)
return dd, nil
case ColumnType_STRING:
v, err := value.GetBytes()
if err != nil {
return nil, err
}
return a.NewDString(parser.DString(v)), nil
case ColumnType_BYTES:
v, err := value.GetBytes()
if err != nil {
return nil, err
}
return a.NewDBytes(parser.DBytes(v)), nil
case ColumnType_DATE:
v, err := value.GetInt()
if err != nil {
return nil, err
}
return a.NewDDate(parser.DDate(v)), nil
case ColumnType_TIMESTAMP:
v, err := value.GetTime()
if err != nil {
return nil, err
}
return a.NewDTimestamp(parser.DTimestamp{Time: v}), nil
case ColumnType_TIMESTAMPTZ:
v, err := value.GetTime()
if err != nil {
return nil, err
}
return a.NewDTimestampTZ(parser.DTimestampTZ{Time: v}), nil
case ColumnType_INTERVAL:
d, err := value.GetDuration()
if err != nil {
return nil, err
}
return a.NewDInterval(parser.DInterval{Duration: d}), nil
default:
return nil, errors.Errorf("unsupported column type: %s", kind)
}
}
