Issue : on a 14 GB download with 8 segments, when 7 finish there's only
1 connection left handling its assigned 1.75 GB → apparent throughput
collapses to 1/8th of the peak for the final stretch (~5 min visible
slowdown at the end).
Quick fix : double the default segment count.
- 8 segments : last has 1.75 GB to finish alone
- 16 segments : last has 875 MB → tail ~halved
Tuning surfaced in Settings → Avancés → Serveur as
« Connexions parallèles pour les téléchargements (1-32, défaut 16) ».
Power users on faster servers can push to 24-32. OVH mutualisé tolerates
up to 16-24 ; above that, soft rate-limiting kicks in.
Aligned :
- LocalConfig default : 8 → 16
- DownloadManager clamp : Math.Clamp(_, 1, 16) → 1, 32
- HttpClient handler MaxConnectionsPerServer : 16 → 32 (matches new ceiling)
Versions bumped to 0.19.0.
Existing config.json files will keep their previous value (8) untouched ;
delete config.json to pick up the new default, or just bump it in
Settings → Avancés.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
DownloadManager
- Parallel multi-segment download (default 8 connections, configurable up to 16)
with per-segment Range requests. Bypasses OVH/Apache per-connection bandwidth
throttling — typical speed-up ×4 to ×8 vs single connection.
- Reporter task on a dedicated Task with Interlocked aggregate counter (no lock
contention with workers). Reports speed/ETA every 250ms even mid-download,
fixes the "speed only shows at install transition" bug.
- Sparse file pre-allocation via FSCTL_SET_SPARSE before SetLength: no zero-fill,
no SeManageVolumePrivilege, instant on any disk type. Removes 5-30s of
preparation lag on HDD.
- HEAD probe skipped (trust manifest size, signed Ed25519). Falls back to
single-segment if first segment returns 200 instead of 206.
- Resume URL comparison fixed: ignores HMAC querystring (?exp=&sig=) which
changes per request, compares only host+path. Previously every resume started
fresh because the old URL never matched the freshly signed one.
- Auto-refresh signed URL on 403/410 mid-DL: SemaphoreSlim with 5s debounce so
8 simultaneous segment expirations trigger a single /api/download-url/ call.
Slow-connection users (1 Mbps, 30+ hours for 14 GB) keep downloading
transparently across multiple TTL cycles.
- Per-version hashAlgorithm:none in manifest skips client SHA-256 verification
(still relying on Ed25519 manifest signature + HMAC URL).
- DangerButton style (red) added to Theme.xaml for the new cancel-resume action.
IntegrityService
- 16 MiB buffer (was 1 MiB), FileOptions.SequentialScan + Asynchronous,
IncrementalHash (uses SHA-NI hardware extensions on .NET 8), double-buffering
to overlap CPU and I/O. Typical 14 GB hash verification: 60-180s → 15-40s.
HttpClient
- MaxConnectionsPerServer=16, EnableMultipleHttp2Connections, HTTP/2 preferred,
AutomaticDecompression=None (ZIPs are already compressed), 5min pooled
connection lifetime.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This is the robustness layer needed for real 14 GB builds. A 99%-complete
download that gets interrupted no longer means re-downloading 14 GB.
DownloadManager
---------------
- Range: bytes={resumeFrom}- on every (re)attempt; reads resumeFrom from
the actual size of the .partial file so retries always resume from real
on-disk state, not from a remembered counter.
- If-Range: ETag (or Last-Modified fallback). When the server returns 200
instead of 206 we know the resource changed under us, so we discard
.partial and start fresh.
- Polly resilience pipeline: 6 retries, exponential 1-32s with jitter,
on HttpRequestException / IOException / TimeoutException / 5xx / 408 /
429. Each retry re-evaluates resumeFrom from disk, so the server is
asked only for what's actually missing.
- state.json persisted every 5s OR every 100 MiB, whichever comes first,
via atomic write-then-rename. Holds url, total, downloaded, sha256,
etag, last-modified, and the .partial path.
- Disk-space check happens once at fresh-start (1.05x expected size); a
resume doesn't redo it.
- On final success: SHA-256 of the assembled .partial verified, then
atomic rename to .zip and state.json deleted.
DownloadStateStore
------------------
- New IDownloadStateStore in PSLauncher.Core/Downloads.
- Stores under %LocalAppData%/PSLauncher/downloads/.
- Save / Load / Discard / ScanResumable. Tolerates malformed state files
by ignoring them.
UI hint
-------
VersionRowViewModel now has ResumableBytes; when > 0, the install button
label switches to "↻ Reprendre (X%)" computed from
ResumableBytes / Remote.Download.SizeBytes. MainViewModel.RebuildList
queries IDownloadManager.GetResumableState(version) for each remote-only
row and populates ResumableBytes. Both the featured hero card and the
compact rows bind to InstallButtonLabel.
API change
----------
IDownloadManager gains GetResumableState(version) and
DiscardResumableState(version) so callers (and the UI) can reason about
in-progress downloads without poking at the filesystem directly.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Client (C# / .NET 8 / WPF, MVVM via CommunityToolkit.Mvvm):
- PSLauncher.App: WPF UI dark theme (Epic-style sidebar + hero + big play button)
with UpdateAvailableDialog rendering Markdown release notes via Markdig.Wpf.
- PSLauncher.Core: services for installation registry (scans Proserve v{X.Y.Z}/),
process launcher, manifest fetch, SHA-256 integrity, HTTP download with
progress, ZIP install via .tmp + atomic rename, update orchestrator.
- PSLauncher.Models: RemoteManifest, InstalledVersion, LocalConfig DTOs.
Server (PHP 8 for OVH mutualisé, deployed under www/PS_Launcher/):
- Front controller + routes /manifest and /releasenotes/{version}.
- Static signed-manifest workflow with tools/sign-manifest.php CLI to
recompute SHA-256 and sizeBytes after each ZIP upload.
- .htaccess: HTTPS redirect, rewrite, security headers.
- config.example.php template; real config.php is gitignored.
Cohabiting versions: each release lives in its own Proserve v{version}/ folder
under installRoot. Old versions are never deleted automatically.
Roadmap: v0.3 = HTTP Range resume + Polly retry + state.json,
v0.4 = MySQL license + Ed25519 signatures + DPAPI, v0.5 = settings/UX polish.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
