Module snapshot 

Workspace snapshots — pre/post-turn safety net.

Each turn the engine takes a pre-turn:<seq> snapshot of the user’s workspace into a side git repo at ~/.deepseek/snapshots/<project_hash>/<worktree_hash>/.git, then a matching post-turn:<seq> snapshot when the turn finishes. Users can roll back via /restore N (slash command) or, when the model recognises an “undo my last edit” intent, the revert_turn tool.

Why a side repo?

• The user’s own .git is never touched. --git-dir and --work-tree are always set together when we shell out to git; that single invariant is what keeps snapshots and the user’s repo completely independent.
• Workspaces without git still get snapshots.
• git’s own deduplication (object packfiles) keeps the disk footprint tractable — typical 100 MB workspace × 12 turns ≈ 1.2 GB uncompressed but git’s content-addressed storage usually brings that down 10-30×. We mitigate further with:
  • 7-day default retention (session_manager prunes at session start via prune::prune_older_than).
  • gc.auto = 0 on the side repo (we don’t want background gcs firing mid-turn) plus an explicit git gc --prune=now after prune.

Failure model

Pre/post-turn snapshot calls are non-fatal. If git is missing, the disk is full, or the workspace is on a read-only filesystem, the turn proceeds and the engine logs a warning. The snapshot is a safety net, not a correctness gate.

Modules

paths

Path resolution for the per-workspace snapshot side-repos.

prune

Boot-time snapshot pruning.

repo

Side-git repository wrapper for workspace snapshots.

size

Workspace byte-size estimation before side-git snapshot init.

Structs

Snapshot

A single snapshot record (one row in git log).

SnapshotId

Identifier for a snapshot — currently the underlying git commit SHA.

SnapshotRepo

Wrapper around the per-workspace side-git repo.

Constants

DEFAULT_MAX_AGE

Default snapshot retention window: 7 days.

DEFAULT_SNAPSHOT_MAX_WORKSPACE_GB

Default cap when [snapshots] max_workspace_gb is unset (matches upstream v0.8.32).

Functions

estimate_workspace_bytes

Sum file sizes under workspace, honoring gitignore + skip-dir rules. Stops early once limit_bytes would be exceeded (pass None for full scan).

prune_older_than

Prune snapshots older than max_age for the given workspace.

snapshot_dir_for

Compute the snapshot directory for a given workspace path.

snapshot_git_dir

Resolve the .git directory inside the snapshot dir.

workspace_exceeds_size_limit

Returns true when the workspace tree exceeds max_gb ( gibibyte-style GB: max_gb * 1024^3 bytes).