Filename generates a filename based on the given index.

Index extracts an index from a filename.

NewDB creates a new log database.

LogDB is a simple key-value store that persists data to a log file.

Record represents a key-value pair in our database.

RecordWithOffset holds a record and its offset in the log file.

Segment represents a segment in our log database.

HashIndex is a map of keys to offsets in the segment file.