codec

func CutOne ¶

func CutOne(b []byte) (data []byte, remain []byte, err error)

CutOne cuts the first encoded value from b. It will return the first encoded item and the remains as byte slice.

func DecodeAsDateTime ¶

func DecodeAsDateTime(b []byte, tp byte, loc *time.Location) (remain []byte, d types.Datum, err error)

DecodeAsDateTime decodes on datum from []byte of `KindMysqlTime`.

func DecodeBytes ¶

func DecodeBytes(b []byte, buf []byte) ([]byte, []byte, error)

DecodeBytes decodes bytes which is encoded by EncodeBytes before, returns the leftover bytes and decoded value if no error. `buf` is used to buffer data to avoid the cost of makeslice in decodeBytes when DecodeBytes is called by Decoder.DecodeOne.

func DecodeCmpUintToInt ¶

func DecodeCmpUintToInt(u uint64) int64

DecodeCmpUintToInt decodes the u that encoded by EncodeIntToCmpUint

func DecodeCompactBytes ¶

func DecodeCompactBytes(b []byte) ([]byte, []byte, error)

DecodeCompactBytes decodes bytes which is encoded by EncodeCompactBytes before.

func DecodeDecimal ¶

func DecodeDecimal(b []byte) ([]byte, *types.MyDecimal, int, int, error)

DecodeDecimal decodes bytes to decimal.

func DecodeFloat ¶

func DecodeFloat(b []byte) ([]byte, float64, error)

DecodeFloat decodes a float from a byte slice generated with EncodeFloat before.

func DecodeInt ¶

func DecodeInt(b []byte) ([]byte, int64, error)

DecodeInt decodes value encoded by EncodeInt before. It returns the leftover un-decoded slice, decoded value if no error.

func DecodeOne ¶

func DecodeOne(b []byte) (remain []byte, d types.Datum, err error)

DecodeOne decodes on datum from a byte slice generated with EncodeKey or EncodeValue.

func DecodeRange ¶

func DecodeRange(b []byte, size int, idxColumnTypes []byte, loc *time.Location) ([]types.Datum, []byte, error)

DecodeRange decodes the range values from a byte slice that generated by EncodeKey. It handles some special values like `MinNotNull` and `MaxValueDatum`. loc can be nil and only used in when the corresponding type is `mysql.TypeTimestamp`.

func DecodeUint ¶

func DecodeUint(b []byte) ([]byte, uint64, error)

DecodeUint decodes value encoded by EncodeUint before. It returns the leftover un-decoded slice, decoded value if no error.

func DecodeUvarint ¶

func DecodeUvarint(b []byte) ([]byte, uint64, error)

DecodeUvarint decodes value encoded by EncodeUvarint before. It returns the leftover un-decoded slice, decoded value if no error.

func DecodeVarint ¶

func DecodeVarint(b []byte) ([]byte, int64, error)

DecodeVarint decodes value encoded by EncodeVarint before. It returns the leftover un-decoded slice, decoded value if no error.

func EncodeBytes ¶

func EncodeBytes(b []byte, data []byte) []byte

EncodeBytes guarantees the encoded value is in ascending order for comparison, encoding with the following rule:

[group1][marker1]...[groupN][markerN]
group is 8 bytes slice which is padding with 0.
marker is `0xFF - padding 0 count`

For example:

[] -> [0, 0, 0, 0, 0, 0, 0, 0, 247]
[1, 2, 3] -> [1, 2, 3, 0, 0, 0, 0, 0, 250]
[1, 2, 3, 0] -> [1, 2, 3, 0, 0, 0, 0, 0, 251]
[1, 2, 3, 4, 5, 6, 7, 8] -> [1, 2, 3, 4, 5, 6, 7, 8, 255, 0, 0, 0, 0, 0, 0, 0, 0, 247]

Refer: https://github.com/facebook/mysql-5.6/wiki/MyRocks-record-format#memcomparable-format

func EncodeCompactBytes ¶

func EncodeCompactBytes(b []byte, data []byte) []byte

EncodeCompactBytes joins bytes with its length into a byte slice. It is more efficient in both space and time compare to EncodeBytes. Note that the encoded result is not memcomparable.

func EncodeDecimal ¶

func EncodeDecimal(b []byte, dec *types.MyDecimal, precision, frac int) ([]byte, error)

EncodeDecimal encodes a decimal into a byte slice which can be sorted lexicographically later.

func EncodeFloat ¶

func EncodeFloat(b []byte, v float64) []byte

EncodeFloat encodes a float v into a byte slice which can be sorted lexicographically later. EncodeFloat guarantees that the encoded value is in ascending order for comparison.

func EncodeInt ¶

func EncodeInt(b []byte, v int64) []byte

EncodeInt appends the encoded value to slice b and returns the appended slice. EncodeInt guarantees that the encoded value is in ascending order for comparison.

func EncodeIntToCmpUint ¶

func EncodeIntToCmpUint(v int64) uint64

EncodeIntToCmpUint make int v to comparable uint type

func EncodeKey ¶

func EncodeKey(sc *stmtctx.StatementContext, b []byte, v ...types.Datum) ([]byte, error)

EncodeKey appends the encoded values to byte slice b, returns the appended slice. It guarantees the encoded value is in ascending order for comparison. For Decimal type, datum must set datum's length and frac.

func EncodeMySQLTime ¶

func EncodeMySQLTime(sc *stmtctx.StatementContext, t types.Time, tp byte, b []byte) (_ []byte, err error)

EncodeMySQLTime encodes datum of `KindMysqlTime` to []byte.

func EncodeUint ¶

func EncodeUint(b []byte, v uint64) []byte

EncodeUint appends the encoded value to slice b and returns the appended slice. EncodeUint guarantees that the encoded value is in ascending order for comparison.

func EncodeUvarint ¶

func EncodeUvarint(b []byte, v uint64) []byte

EncodeUvarint appends the encoded value to slice b and returns the appended slice. Note that the encoded result is not memcomparable.

func EncodeValue ¶

func EncodeValue(sc *stmtctx.StatementContext, b []byte, v ...types.Datum) ([]byte, error)

EncodeValue appends the encoded values to byte slice b, returning the appended slice. It does not guarantee the order for comparison.

func EncodeVarint ¶

func EncodeVarint(b []byte, v int64) []byte

EncodeVarint appends the encoded value to slice b and returns the appended slice. Note that the encoded result is not memcomparable.