Crate snss 

snss — a read-only decoder for Chromium/Brave SNSS session files.

The crate is a pure decoder: it reads bytes and returns a typed model. It has no UI, performs no clipboard or launch side effects, and exposes no write path — mutating Brave’s store is structurally impossible through this API.

Milestone 1 (this module) covers the container framing only: validate the SNSS header and split the command stream into Records. Higher layers (Pickle decode, replay) build on top of these records.

Structs

Nav

One back/forward history entry of a tab.

NavCommand

A decoded UpdateTabNavigation command: which tab, which back/forward position, and the URL + title recorded at that position.

Record

One command record from the append-only stream.

RecordStream

The result of reading a record stream: the container version, every decoded Record in stream order, and any non-fatal Warnings.

Replayed

The result of replaying one file’s command log.

SessionStore

A read-only, in-memory snapshot of a Brave profile’s Sessions directory.

Source

One decoded session file: its kind, path, and reconstructed windows.

Tab

A reconstructed tab: its history and which entry is current.

Window

A reconstructed window holding ordered tabs.

Enums

Dialect

Which command-id mapping a file uses. Session_*/Apps_* files and the recently-closed Tabs_* files number their commands differently.

PickleError

A malformed navigation payload. Surfaced as a typed error so the caller can count it as a warning rather than crash or emit a silently-wrong row.

SnssError

A fatal error that prevents producing any model at all.

SourceKind

Which on-disk file family a Source came from.

Warning

A non-fatal decode anomaly. The model is still usable; warnings record where and why something was skipped so nothing fails silently.

Constants

MAGIC

The 4-byte magic every SNSS file begins with.

SUPPORTED_VERSION

The only container version observed in the wild (and the only one supported).

Functions

decode_navigation

Decode an UpdateTabNavigation payload into a NavCommand.

read_records

Read an SNSS command stream from any byte source.

replay

Replay an append-only command RecordStream into the logical Window/Tab/Nav tree, applying last-write-wins per (tab, index) and resolving each tab’s current entry and pinned state.