RangeDB

Description

RangeDB is a database abstraction that makes it easy to map ranges, defined by a start and an end, to arbitrary values.

API

Structs

RangeEntry

interface RangeEntry {
  start: number
  end: number
  value: Buffer
}
Description

Represents a value in the database. All values are constructed with respect to some range, defined by start and end.

Fields
  1. start - number: Start of the range described by this entry.
  2. end - number: End of the range described by this entry.
  3. value - Buffer: Value at this specific range.

Methods

get

async function get(start: number, end: number): Promise<RangeEntry[]>
Description

Queries RangeEntry values that intersect with a given start and end. Ranges must be treated as start-inclusive and end-exclusive.

Parameters
  1. start - number: Start of the range to query.
  2. end - number: End of the range to query.
Returns

Promise<RangeEntry[]>: All RangeEntry objects in the database such that entry.start and entry.end intersect with the given start and end.

put

async function put(start: number, end: number, value: Buffer): Promise<void>
Description

Adds a value to the database at a given range. Overwrites all existing RangeEntry objects that overlap with the range. put MUST modify or break apart existing RangeEntry objects if the given range only partially overlaps with the object. For example, if we currently have a RangeEntry over the range (0, 100) and call put(25, 75, "some value"), this function must break the existing RangeEntry into new entries for (0, 25) and (75, 100).

Parameters
  1. start - number: Start of the range to insert into.
  2. end - number: End of the range to insert into.
  3. value - Buffer: Value to insert into the range as a Buffer.
Returns

Promise<void>: Promise that resolves once the range has been inserted.

del

async function del(start: number, end: number): Promise<void>
Description

Deletes the values for the given range. Will insert new RangeEntry objects or modify existing ones when the given range only partially overlaps with those already in the database. This method MUST delete objects under the same scheme described above for put.

Parameters
  1. start - number: Start of the range to delete.
  2. end - number: End of the range to delete.
Returns

Promise<void>: Promise which resolves once the range has been deleted.