git ssb

This is a simple Binary Radix Tree. The default encodeing used is cbor and the default hashing algorithim used is sha2-256.

Node

Each node is an variable length array containing at the most four elements "left branch", "right branch" "extension", "value"

node : = [LBRANCH, RBRANCH, EXTENSION, VALUE]

If no value exists at a given node the array is truncated to

node : = [LBRANCH, RBRANCH, EXTENSION]

If no value and no extension exists at a given node the array is truncated to

node : = [LBRANCH, RBRANCH]

All empty values in the array are encoded as "undefined". An emty tree is defined as [undefined, undefined]

Branches

Each link points to the next node in the tree.

branch : = <merkle link>

Where the link is a CID is encoded as a byte string. Using CIDs allow for the flexablity to update the hashing algorithim and encoding at a later date while being backwards compatiable.

Extensions

Extensions encode shared paths. Extensions are defined as

extension := [length, extension]

Where the length is an interger and the extension is a byte string padded with 0's

For example if the binary keys [0, 0, 1, 1] and [0, 0, 1, 0] have a shared path of [0, 0]. If they where the only two values in the tree the root node would have an extension of [0, 0]

root := [undefined, <link>, [2, 0x00]]