DecodeUvarintAscending decodes a varint encoded uint64 from the input buffer.

EncodeUvarintAscending encodes the uint64 value using a variable length (length-prefixed) representation.

FIXME consolidate.

IntMax is the maximum int tag value.

IntMin is chosen such that the range of int tags does not overlap the ascii character set that is frequently used in testing.

RowBufferSize should ideally this is sized to be the smallest size that can contain an index row key and its corresponding value.