Module service_instance 

Which commit service instance belongs to a worktree: its name, socket and unit instances. What: Which commit service instance belongs to a worktree: a name made from the worktree’s own Git directory, and the socket, the unit instances and the journal directory that name gives. Why: One service instance runs per worktree, the way Bazel runs one server per workspace, so a wait in one worktree (a foreign holder of its index lock, a slow push) never delays another’s commits. A worktree’s own Git directory (the main worktree’s .git, or .git/worktrees/<id> of a linked one) holds its HEAD, its index and its work records, and Git allows one branch to be checked out in one worktree only, so the instances never write the same branch (doc/planning/cli-git-resident-service.md, “One service per worktree”). The name is a hash because an escaped path does not fit a unit name for an ordinary home directory, and the hash is the same in the wrapper and in the service, which are built together. A collision of two worktrees would only make one instance serve both, never land anywhere wrong.

In TS you’d write (pseudocode):

const socket = join(runtimeDir, 'cli-git', `${instanceOf(gitDir)}.sock`);

Constants

INSTANCE_LENGTH

The number of hexadecimal digits of an instance name.

LEGACY_SOCKET_RELATIVE

The socket of the one service every worktree of an account shared until the release that gave each worktree its own. A service still listening here is asked to retire and its units are removed.

SOCKET_DIRECTORY

Directory of the sockets under the user’s runtime directory.

Functions

instance_of

What: The instance name of a worktree: 32 hexadecimal digits of the FNV-1a hash of its real Git directory path. Why: The real path makes two spellings of one directory (a link, a relative part) one instance. A directory that cannot be resolved is hashed as given.

service_unit_instance

The name of the service unit instance of a worktree.

socket_for

The socket of the worktree whose own Git directory is git_dir.

socket_path

The socket of an instance under the user’s runtime directory.

socket_unit_instance

The name of the socket unit instance of a worktree.