// ObjectIDForKey returns the object ID (table or database) for 'key',
// or (_, false) if not within the structured key space.
func ObjectIDForKey(key roachpb.RKey) (uint32, bool) {
if key.Equal(roachpb.RKeyMax) {
return 0, false
}
if encoding.PeekType(key) != encoding.Int {
// TODO(marc): this should eventually return SystemDatabaseID.
return 0, false
}
// Consume first encoded int.
_, id64, err := encoding.DecodeUvarintAscending(key)
return uint32(id64), err == nil
}
// EnsureSafeSplitKey transforms an SQL table key such that it is a valid split key
// (i.e. does not occur in the middle of a row).
func EnsureSafeSplitKey(key roachpb.Key) (roachpb.Key, error) {
if encoding.PeekType(key) != encoding.Int {
// Not a table key, so already a split key.
return key, nil
}
n := len(key)
// The column ID length is encoded as a varint and we take advantage of the
// fact that the column ID itself will be encoded in 0-9 bytes and thus the
// length of the column ID data will fit in a single byte.
buf := key[n-1:]
if encoding.PeekType(buf) != encoding.Int {
// The last byte is not a valid column ID suffix.
return nil, errors.Errorf("%s: not a valid table key", key)
}
// Strip off the family ID / column ID suffix from the buf. The last byte of the buf
// contains the length of the column ID suffix (which might be 0 if the buf
// does not contain a column ID suffix).
_, colIDLen, err := encoding.DecodeUvarintAscending(buf)
if err != nil {
return nil, err
}
if int(colIDLen)+1 > n {
// The column ID length was impossible. colIDLen is the length of
// the encoded column ID suffix. We add 1 to account for the byte
// holding the length of the encoded column ID and if that total
// (colIDLen+1) is greater than the key suffix (n == len(buf))
// then we bail. Note that we don't consider this an error because
// EnsureSafeSplitKey can be called on keys that look like table
// keys but which do not have a column ID length suffix (e.g
// SystemConfig.ComputeSplitKeys).
return nil, errors.Errorf("%s: malformed table key", key)
}
return key[:len(key)-int(colIDLen)-1], nil
}
func localRangeIDKeyPrint(key roachpb.Key) string {
var buf bytes.Buffer
if encoding.PeekType(key) != encoding.Int {
return fmt.Sprintf("/err<%q>", []byte(key))
}
// Get the rangeID.
key, i, err := encoding.DecodeVarintAscending(key)
if err != nil {
return fmt.Sprintf("/err<%v:%q>", err, []byte(key))
}
fmt.Fprintf(&buf, "/%d", i)
// Print and remove the rangeID infix specifier.
if len(key) != 0 {
fmt.Fprintf(&buf, "/%s", string(key[0]))
key = key[1:]
}
// Get the suffix.
hasSuffix := false
for _, s := range rangeIDSuffixDict {
if bytes.HasPrefix(key, s.suffix) {
fmt.Fprintf(&buf, "/%s", s.name)
key = key[len(s.suffix):]
if s.ppFunc != nil && len(key) != 0 {
fmt.Fprintf(&buf, "%s", s.ppFunc(key))
return buf.String()
}
hasSuffix = true
break
}
}
// Get the encode values.
if hasSuffix {
fmt.Fprintf(&buf, "%s", decodeKeyPrint(key))
} else {
fmt.Fprintf(&buf, "%q", []byte(key))
}
return buf.String()
}
// MakeRekeyMVCCKeyValFunc takes an iterator function for MVCCKeyValues and
// returns a new iterator function where the keys are rewritten inline to the
// have the given table ID.
func MakeRekeyMVCCKeyValFunc(
newTableID sqlbase.ID, f func(kv engine.MVCCKeyValue) (bool, error),
) func(engine.MVCCKeyValue) (bool, error) {
encodedNewTableID := encoding.EncodeUvarintAscending(nil, uint64(newTableID))
return func(kv engine.MVCCKeyValue) (bool, error) {
if encoding.PeekType(kv.Key.Key) != encoding.Int {
return false, errors.Errorf("unable to decode table key: %s", kv.Key.Key)
}
existingTableIDLen, err := encoding.PeekLength(kv.Key.Key)
if err != nil {
return false, err
}
if existingTableIDLen == len(encodedNewTableID) {
copy(kv.Key.Key, encodedNewTableID)
} else {
kv.Key.Key = append(encodedNewTableID, kv.Key.Key[existingTableIDLen:]...)
}
return f(kv)
}
}
// DecodeTablePrefix validates that the given key has a table prefix, returning
// the remainder of the key (with the prefix removed) and the decoded descriptor
// ID of the table.
func DecodeTablePrefix(key roachpb.Key) ([]byte, uint64, error) {
if encoding.PeekType(key) != encoding.Int {
return key, 0, errors.Errorf("invalid key prefix: %q", key)
}
return encoding.DecodeUvarintAscending(key)
}
