SnkUpdateMaster.Core 1.0.1

SnkUpdateMaster.Core

Purpose: the base module with business logic, interfaces, and ready-made implementations for the update pipeline.

Typical usage

Key interfaces:

• IUpdateInfoProvider - fetches information about the available update.
• IUpdateDownloader - downloads the update file.
• IInstaller - applies the downloaded file to the application.
• IIntegrityVerifier - validates the checksum before installation.
• ICurrentVersionManager - reads and updates the current application version.

Built-in implementations:

• ZipInstaller - unpacks an update from a ZIP archive with backup.
• ShaIntegrityVerifier - SHA‑256 integrity check.
• FileVersionManager - stores the version in a text file (major.minor.build).

Use UpdateManager to orchestrate download and installation. Build it via UpdateManagerBuilder:

var updateManager = new UpdateManagerBuilder()
    .WithZipInstaller("path to app folder")
    .WithFileCurrentVersionManager()
    .WithSha256IntegrityVerifier()
    .AddDependency<IUpdateInfoProvider>(customImplementation)
    .AddDependency<IUpdateDownloader>(customImplementation)
    .Build();

Check for updates and install:

var updated = await updateManager.CheckAndInstallUpdatesAsync(progress);

💡 Besides the built-ins, you can register custom interface implementations via AddDependency and mix them with provided components.

Main subsystems

1. Application update (UpdateManager)
   Files: UpdateManager.cs, UpdateManagerBuilder.cs, UpdateInfo.cs
   Types:
   • UpdateManager - orchestrates the full update flow:
     1. get current version (ICurrentVersionManager);
     2. get available update info (IUpdateInfoProvider);
     3. download update file (IUpdateDownloader);
     4. verify checksum (IIntegrityVerifier);
     5. install update (IInstaller);
     6. update stored version (ICurrentVersionManager.UpdateCurrentVersionAsync).
        Main method:

     Task<bool> CheckAndInstallUpdatesAsync(
         IProgress<double> progress,
         CancellationToken cancellationToken = default);
     

     Returns true if an update was found and installed.
   • UpdateInfo - metadata: Id, Version (System.Version), FileName, Checksum (SHA‑256 hex), ReleaseDate (UTC), FileDir.
   • UpdateManagerBuilder (inherits DependencyBuilder<UpdateManager>) - fluent builder with shortcuts:
     • WithFileCurrentVersionManager() - stores version in version file under Environment.CurrentDirectory;
     • WithSha256IntegrityVerifier() - SHA‑256 integrity check;
     • WithZipInstaller(string appDir) - expands ZIP archive over appDir with backup.
       Sources and downloaders are added directly via AddDependency<T> or through module extensions (Ftp, SqlServer).
2. Version management (VersionManager)
   Files: VersionManager/ICurrentVersionManager.cs, VersionManager/FileVersionManager.cs
   • ICurrentVersionManager - abstraction over version storage.
   • FileVersionManager - stores version in a version text file (major.minor.build), creates the file on first update.
3. Update providers (UpdateSource)
   File: UpdateSource/IUpdateInfoProvider.cs
   • IUpdateInfoProvider - gets the latest available update from any source (FTP, DB, file system, etc.).
     Concrete implementations live in SnkUpdateMaster.Ftp and SnkUpdateMaster.SqlServer.
4. Downloaders (Downloader)
   File: Downloader/IUpdateDownloader.cs
   • IUpdateDownloader - async download of the update file (HTTP, FTP, DB, local copy, etc.), returning a local path.
     Implementations reside in SnkUpdateMaster.Ftp and SnkUpdateMaster.SqlServer.
5. Installers (Installer)
   Files: Installer/IInstaller.cs, Installer/ZipInstaller.cs
   • IInstaller - “how to apply the downloaded update.”
   • ZipInstaller:
     • makes a full backup of the application directory;
     • unpacks the ZIP over the app;
     • on failure, attempts rollback by restoring the backup.

   ⚠️ ZipInstaller performs destructive file-system operations (delete/move directories). Use only when the app is stopped.

6. Integrity and checksums (Integrity)
   Files: Integrity/IChecksumCalculator.cs, Integrity/IIntegrityProvider.cs, Integrity/IIntegrityVerifier.cs, Integrity/ShaChecksumCalculator.cs, Integrity/ShaIntegrityProvider.cs, Integrity/ShaIntegrityVerifier.cs, Integrity/IntegrityProviderType.cs
   Types:
   • IChecksumCalculator - compute file checksum;
   • IIntegrityProvider - a wrapper around the calculator, can add extra checks;
   • IIntegrityVerifier - compares calculated checksum against expected;
   • ShaChecksumCalculator / ShaIntegrityProvider / ShaIntegrityVerifier - SHA‑256 implementations.
7. Parsing update manifests (Files)
   Files: Files/IUpdateInfoFileParser.cs, Files/JsonUpdateInfoFileParser.cs
   • IUpdateInfoFileParser - parses update metadata files.
   • JsonUpdateInfoFileParser - JSON parser. Expected format (see tests/ftp-data/manifest.json):

     {
       "id": 1,
       "version": "1.0.1",
       "fileName": "release-1.0.1.zip",
       "fileDir": "/",
       "checksum": "…sha256…",
       "releaseDate": "2025-11-29"
     }