ludic/packages/ludic.update

ludic.update

A game installed by Velopack updating itself, a frame at a time, with nothing on screen but the game's own panel. Uses ludic.base and nothing else.

import "ludic.update"

Two halves:

• Is there a newer version? <feed>/latest.json ({"version": "1.2.0", "notes": {"en": [...], "tr": [...]}}) asked once and polled a frame at a time, so a slow or absent network costs the frame nothing - it simply never says there is one.
• Installing it. Velopack's own feed (releases.win.json, releases.osx.json: every package with its version, type, size and SHA-256), then the plan - the chain of deltas when the installed full package is on disk, no delta is missing and they weigh less than the full one; the newest full package otherwise - then each package streamed into the packages folder with its bytes on the bar, its SHA-256 by a child (Get-FileHash on Windows, shasum elsewhere) so the frame keeps drawing, Update patch per delta, and Update apply --waitPid <this>. On UPDATE_APPLYING the game exits; Velopack waits for it, swaps the install and starts the new version.

What differs on macOS is where things live: the .app is the install, UpdateMac sits beside the binary in Contents/MacOS, and the packages must be OUTSIDE the bundle (mac_packages) - a bundle is read-only, and apply cannot replace a directory it is reading a package out of. A package's name always comes from the feed (Velopack puts the channel in a macOS name), and a translocated Mac app (still where it was downloaded) is "not installed".

The package never words anything: a step, an error and a pace are numbers and codes, and the game says them in its own language.

Config and ports

property UpdateConfig {
  feed, app_id, version        # the release bucket, Velopack's pack id, this build's version
  latest ("latest.json")
  root, packages               # outright (a stand-in install, for a test); "" works them out
  mac_packages                 # where packages go on macOS
  scratch                      # where a hash is written
}
port UpdateWorld { platform, exe, pid, now_ms }                   # unbound: Os and the wall clock
port UpdateNet { get, download, poll, text, received, free }      # unbound: Http
port UpdateProc { spawn, poll, free }                             # unbound: Process

Every member has the runtime as its default; a game binds only what it wants to replace (a finer clock for the pace), and a test binds fakes.

API

update_config(c)	before anything else
update_check_tick(show_current), update_ask_state(), update_shown(), update_fresh(), update_latest(), update_notes(lang)	the newest version: UPDATE_ASKING, _NONE, _NEWER, _CURRENT (the version being played, kept only with show_current); its notes in a language, else English
update_start() -> bool, update_tick()	the Update button (false, and UPDATE_ERR_NOT_INSTALLED, on a copy Velopack did not install), then once a frame
update_state(), update_busy(), update_failed(), update_working(), update_error()	UPDATE_IDLE, _FEED, _FETCH, _CHECK, _PATCH, _APPLY, _FAILED; working is a check or a patch (no fraction: sweep the bar); the error is an UPDATE_ERR_*
update_progress(), update_received(), update_file_received(), update_file_size(), update_eta_seconds(), update_step_seconds()	the bar (0..1000 over every byte of the plan), the bytes, the time left at an eased pace (-1 until known), the seconds a check or patch has run
update_index(), update_file(), update_version_at(), update_package_count(), update_target(), update_total_bytes(), update_plan_file(i), update_plan_is_delta(i), update_plan_version(i)	the plan and where in it
update_plan(feed) -> bool	the plan from a parsed feed, outright
update_facts() -> Queue<UpdateFact>	{ what, error, target, packages, bytes }: UPDATE_STARTED, UPDATE_STOPPED, UPDATE_APPLYING (exit now)
update_newer(a, b), update_is_install_hook(), update_installed(), update_translocated(), update_dir(), update_root(), update_packages(), update_open(url)	versions compared a number at a time; Velopack's --veloapp-* hooks (exit at once); the install's layout; a page in the browser
update_reset()	back to before anything (tests)

Tests

ludic build packages/ludic.update/tests/update_test.ludic --headless -o /tmp/update_test && /tmp/update_test

A fake network, fake children and a stand-in root in the temp directory: the notes, the plan both ways, the whole package and the delta chain end to end, a wrong hash, a failed download and a package already on disk.