updated to accept only .tar.zstd uploads

.gitignore

@@ -23,3 +23,6 @@ config.dtsod
 
 #backups
 .old*/
+
+# temporary files
+TEMP/

AGENTS.md

@@ -0,0 +1,256 @@
+# AGENTS.md
+
+Guidance for AI coding agents working in this repository.
+
+## Project
+
+A parser for Paradox game save files, and the backend of a save analytics
+website. Only EU4 is supported so far.
+
+- **.NET 10**, C# `latest`, nullable reference types enabled everywhere
+- **DTLib** / **DTLib.Web** for filesystem helpers, logging and the HTTP server
+- **sqlite-net-pcl** for the upload database, **ZstdSharp.Port** for zstd
+
+Projects in the solution ([ParadoxSaveParser.sln](ParadoxSaveParser.sln)):
+
+- `ParadoxSaveParser.Lib`: the parser itself (`Tokenizer`, `SaveParserEU4`,
+  `SearchExpression/`)
+- `ParadoxSaveParser.Lib.Tests`: NUnit tests for the parser
+- `ParadoxSaveParser.CLI`: command line tool, with an interactive mode
+- `ParadoxSaveParser.WebAPI`: HTTP backend for the website
+- `ParadoxSaveParser.Benchmarks`: BenchmarkDotNet comparison against regex
+  engines and jq, see [its README](ParadoxSaveParser.Benchmarks/README.md)
+
+## Architecture
+
+### Parser
+
+`SaveParserEU4` reads the plain text game state and produces nested
+`Dictionary<string, object>` values. It takes a compiled `SearchExpression`,
+a small path query such as `countries.*.technology`. **The query is what
+makes the parser fast.** `Tokenizer.SkipBlock` throws away a rejected `{...}`
+block by scanning raw bytes for brace depth, so rejected data is never turned
+into tokens or strings. Full parse: 1.2 s and 962 MB allocated; the same file
+with a query: 50 ms and 1.5 MB. Keep any parser change from bringing back
+per-byte virtual calls or eager string decoding. Check with the benchmarks
+before and after.
+
+### WebAPI
+
+The frontend is a **separate Next.js project in its own repository**. It calls
+this service through a same-origin proxy and expects it at
+`http://127.0.0.1:5226` (`BaseUrl` in `config.json`). Routes are documented
+in [ParadoxSaveParser.WebAPI/README.md](ParadoxSaveParser.WebAPI/README.md);
+keep that file in sync when a route or a response shape changes, because the
+frontend is written against it.
+
+The flow is upload, poll, fetch:
+
+```
+POST /uploadSave  ->  store blob, status "uploaded"  ->  SaveParsingOperation
+                                                          (background: parsing,
+                                                           saving_results, done)
+GET  /getSaveStatus  (polled by the frontend until status is "done" or "error")
+GET  /getSaveData    (filtered parse result as JSON)
+GET  /getSaveFile    (the uploaded blob, unchanged)
+```
+
+### Save files on the wire
+
+The server is a cheap two core machine with little disk space, so the browser
+re-compresses every save before uploading it:
+
+```
+plain text save  ->  tar { "gamestate" }               -> zstd -> upload
+archived save    ->  tar { "meta", "gamestate", ... }  -> zstd -> upload
+```
+
+- `.tar.zst` is **the only accepted format.** Zip handling was removed on
+  purpose; do not add it back. The original type and name come in as query
+  params (`originalFileType=text|zip`, `originalFileName`), and they are stored
+  so the browser can rebuild the original file from `/getSaveFile`. A
+  rebuilt EU4 zip was checked entry by entry against the original and is byte
+  identical.
+- **The blob is stored byte-for-byte.** Never re-encode it on the server.
+- The game data entry name comes from `GameSaveEntryNames.Map` in
+  [Game.cs](ParadoxSaveParser.WebAPI/Game.cs). That map mirrors the frontend's
+  `GAME_SAVE_ENTRY_NAMES`. Do not hard-code `"gamestate"`.
+- All tar and zstd handling lives in
+  [SaveArchive.cs](ParadoxSaveParser.WebAPI/SaveArchive.cs), which streams
+  through `DecompressionStream` and `TarReader`. The whole archive is never
+  loaded into memory.
+- Upload limits come from the `SaveUpload` config section.
+  `MaxSizeCompressedBytes` is checked against `Content-Length` and then again
+  while the body is copied, because chunked requests have no length.
+  `MaxSizePlainTextBytes` is checked against the tar entry size once the upload
+  has finished. Every rejected upload deletes its database row and file.
+
+### Runtime files
+
+The WebAPI creates everything relative to its **working directory**:
+`config.json` (written with defaults if missing), `database.sqlite`, `logs/`,
+`temp/` (emptied on start), and `public/data/{saves,parsed}/`. When running it
+for a test, start it with `TEMP/` as the working directory, so none of this
+lands in the project folders.
+
+### Current status
+
+- **Only EU4 works.** `Game.Stellaris` exists and has an entry name, but it has
+  no `ISaveDataFilter` and no parser, so uploads for it are rejected with 400.
+  `SaveParsingOperation` is EU4 specific.
+- **Nothing is deployed and there is no data worth keeping.** Do not write
+  database migrations or backward compatibility code for old layouts; change
+  the schema directly.
+- Open items are in [TODO.md](TODO.md): compressing parsed results,
+  re-parsing when the query changes, automatic database cleanup.
+- The WebAPI exits with code 1 after Ctrl+C even though it logs "server
+  stopped". This has not been investigated yet.
+
+## Tools and files
+
+**Prefer the editor's own tools over shell commands that do the same thing.**
+Reading, editing, writing and searching files have dedicated tools. Using
+`cat`, `sed`, `grep` or a throwaway script instead does the same work,
+spends more tokens, and may need its own approval each time. Use the shell for
+what only the shell can do: building, running tests, git, `curl`, `tar`,
+`zstd`, or running the program itself.
+
+**Work inside the project directory.** For temporary files (scratch scripts,
+intermediate output, test data, a running WebAPI's working directory), create
+a `TEMP/` directory in the project root and keep everything there. It is
+gitignored. Delete that directory once the work is done. Ask before reading or
+writing anything outside the project directory, including `/tmp` and the home
+folder. A save file the user names explicitly may be read, but never modified.
+
+## Terminal
+
+**On Windows, prefer `bash.exe`**, but only a real MSYS2, Cygwin, or
+MinGW/Git Bash installation, for example `D:\msys2\usr\bin\bash.exe`.
+
+**Never use `C:\Windows\System32\bash.exe`.** Despite its name, it is not a
+POSIX bash but the launcher stub for WSL. Do not start WSL to run ordinary
+commands.
+
+If no MSYS/Cygwin/MinGW bash is installed, **use PowerShell** as the terminal.
+PowerShell is the fallback, never WSL.
+
+If bash reports `command not found` for `dotnet`, the cause is `PATH`, not a
+missing install. MSYS2 sets `MSYS2_PATH_TYPE` to `minimal` by default, which
+drops the Windows `PATH`. Setting it to `inherit` fixes it.
+
+## Commands
+
+```sh
+dotnet build ParadoxSaveParser.sln        # build everything
+dotnet test ParadoxSaveParser.Lib.Tests   # parser tests
+dotnet run --project ParadoxSaveParser.WebAPI   # run the backend (mind the working directory)
+dotnet build ParadoxSaveParser.Benchmarks -c Release   # see its README for running
+```
+
+A one-off C# check can be a .NET 10 file-based app in `TEMP/`
+(`dotnet run -c Release TEMP/check.cs`); it doesn't need a project.
+
+### Checking your work
+
+**Always build the solution and run the tests after changing code.** Do not
+report a change as finished until both pass.
+
+- `dotnet build ParadoxSaveParser.sln` must finish with zero errors and no
+  **new** warnings. Three warnings are known and come from
+  sqlite-net-pcl's `SQLitePCLRaw.lib.e_sqlite3` dependency (NU1903 twice,
+  NETSDK1206 once). Everything else is yours.
+- `dotnet test ParadoxSaveParser.Lib.Tests` must pass completely.
+- A WebAPI change is not verified until it has been run: start the server
+  from `TEMP/` and exercise the route with `curl`, including the error cases.
+  Stop the server afterwards.
+- For a parser performance change, run the relevant benchmark before and
+  after, and report both numbers.
+
+## Version control
+
+This project is managed with **git**.
+
+**Read-only git commands are fine to use without asking.**
+You can run `git status`, `git log`, `git diff`, `git show`, `git blame` and
+similar inspection commands freely.
+
+**Never run a git command that changes the repository without the user's
+explicit permission.**
+This is a strict ban. It covers every command that writes to the history, the
+index, or the working tree, including `add`, `commit`, `checkout`, `restore`,
+`reset`, `stash`, `branch`, `merge`, `rebase`, `push`, and `rm`.
+
+Ask first, and wait for a clear yes before running such a command.
+
+## Conventions
+
+Match the surrounding code exactly:
+
+- File-scoped namespaces, 4 spaces, `_camelCase` private fields, `PascalCase`
+  for everything else.
+- **`SaveFileMetadata` properties are lowercase on purpose.** They are the
+  JSON wire format that the frontend reads, and the sqlite column names too.
+  Do not rename them to PascalCase. Enums on the wire serialize in lowercase
+  through `LowerCaseEnumConverter<T>` (`SavingResults` becomes
+  `saving_results`).
+- `Program.cs` declares global usings, which make `File`, `Directory` and
+  `Path` refer to **DTLib.Filesystem**, not `System.IO`. Paths are `IOPath`.
+  When a `System.IO` member is needed, write it out in full, for example
+  `System.IO.Path.GetFileName`.
+- Errors from route handlers go through `ReturnHelper.ResponseError` with an
+  `ErrorMessage` and the right status code. Query values come from
+  `RequestHelper.GetQueryValue`. Do not write responses by hand.
+- **Line endings:** most `.cs` files are CRLF with a UTF-8 BOM. A new file
+  written with LF mixes endings once the IDE touches it. Match the files next
+  to it, or convert with `unix2dos -m`.
+
+**Comment the code you write.** Human programmers who did not write this code
+will read it, and a wall of uncommented agent-written code is expensive to
+review. Keep comments simple, preferably one line, placed above the code they
+describe, and in plain language rather than in terms of the types. Say _why_
+the code does what it does: what is non-obvious, and what would break if it
+were written the obvious way. Leave out what the code already states plainly.
+A tricky constant, a workaround for someone else's bug, or an ordering that
+matters always deserves a line.
+
+Write doc comments as XML doc comments (`///`), which the IDE shows on hover.
+Plain `//` comments do not appear in tooltips.
+
+## Dependencies
+
+**Search for an existing library before writing your own implementation.**
+Formats, protocols and codecs are full of details that only show up against
+real data, and a maintained library has already met them. Check the BCL first:
+tar (`System.Formats.Tar`), zip, JSON and vectorized span operations are all
+built in. .NET 10 has no zstd, which is why ZstdSharp.Port is here.
+
+**Read the library's source before adding it, and judge it on that.** Download
+counts say nothing about quality. Look for readable sources, comments that
+explain intent, and an API that fits the way the code here is written. Code
+that nobody can read cannot be maintained and may hide bugs nobody can find.
+Do not depend on it.
+
+If nothing of good quality exists, say so and propose writing an
+implementation here, rather than pulling in the least bad option.
+
+Do not add a second library for a job a package already referenced can do. A
+thin wrapper that shapes an installed library's API to what the code needs is
+better than a new dependency.
+
+## Things that will bite you
+
+- **Changing a route's request or response is a two-repository change.** The
+  frontend has its own copy of the protocol in `SaveParserBackendService.ts`,
+  `GAME_SAVE_ENTRY_NAMES` and its save archive code. Say what the frontend
+  needs changed; do not assume it will follow.
+- **`Config.Load` rejects any config whose `Version` differs from
+  `ActualVersion`.** New config properties with defaults don't need a version
+  bump, because a missing key keeps the default. Bump the version only for
+  changes that old files cannot express.
+- **`PathHelper.CreateTempFile` deletes the file right after opening it.** The
+  open stream keeps the data alive until it is disposed; do not reopen it by
+  path.
+- **`SaveParsingOperation.StartAsync` is `async void`.** Every exception must
+  be caught inside it, or it will crash the process. Errors are recorded on
+  the metadata row with `SetMetadataError`.
+- `Program.IsDebug` is always true for now, so debug logging is always on.

ParadoxSaveParser.Lib.Tests/ParadoxSaveParser.Lib.Tests.csproj

@@ -24,7 +24,7 @@
           <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
         </PackageReference>
         <PackageReference Include="DTLib" Version="1.7.5" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.10.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.10.1" />
         <PackageReference Include="NUnit" Version="4.6.1" />
         <PackageReference Include="NUnit.Analyzers" Version="4.15.0">
           <PrivateAssets>all</PrivateAssets>

ParadoxSaveParser.WebAPI/BackgroundTasks/BackgroundJobManager.cs

@@ -6,11 +6,13 @@ namespace ParadoxSaveParser.WebAPI.BackgroundTasks;
 public class BackgroundJobManager
 {
     private readonly ILogger _parentLogger;
+    private readonly Config.SaveUploadConfig _uploadConfig;
     private long _lastJobId;
 
-    public BackgroundJobManager(ILogger logger)
+    public BackgroundJobManager(ILogger logger, Config.SaveUploadConfig uploadConfig)
     {
         _parentLogger = logger;
+        _uploadConfig = uploadConfig;
     }
     
     public SaveParsingOperation StartNewParsingOperation(
@@ -18,7 +20,8 @@ public class BackgroundJobManager
     {
         long nextId = Interlocked.Increment(ref _lastJobId);
         var contextLogger = new ContextLogger($"BackgroundJob-{nextId}", _parentLogger);
-        var op = new SaveParsingOperation(nextId, meta, filter, contextLogger, ct);
+        var op = new SaveParsingOperation(nextId, meta, filter,
+            _uploadConfig.MaxSizePlainTextBytes, contextLogger, ct);
         op.StartAsync();
         return op;
     }

ParadoxSaveParser.WebAPI/BackgroundTasks/SaveParsingOperation.cs

@@ -1,6 +1,4 @@
 using System.IO;
-using System.IO.Compression;
-using System.Linq;
 using System.Text.Encodings.Web;
 using System.Text.Json.Serialization;
 using ParadoxSaveParser.WebAPI.Database;
@@ -14,6 +12,7 @@ public class SaveParsingOperation
     
     private readonly SaveFileMetadata _meta;
     private readonly ISaveDataFilter _filter;
+    private readonly long _maxGameDataBytes;
     private readonly ContextLogger _logger;
     private readonly CancellationToken _ct;
 
@@ -26,11 +25,12 @@ public class SaveParsingOperation
     };
 
     public SaveParsingOperation(long operationId, SaveFileMetadata meta, ISaveDataFilter filter,
-        ContextLogger logger, CancellationToken ct)
+        long maxGameDataBytes, ContextLogger logger, CancellationToken ct)
     {
         OperationId = operationId;
         _meta = meta;
         _filter = filter;
+        _maxGameDataBytes = maxGameDataBytes;
         _logger = logger;
         _ct = ct;
     }
@@ -76,16 +76,9 @@ public class SaveParsingOperation
         Dictionary<string, object> parsedData;
         await using (var gamestateStream = PathHelper.CreateTempFile())
         {
-            // TODO: ckeck if it is zip archive or plain text like in Search.cs
+            await SaveArchive.ExtractGameData(_meta.GetSaveFilePath(), _meta.game, gamestateStream,
-            using (var zipArchive = ZipFile.Open(_meta.GetSaveFilePath().Str, ZipArchiveMode.Read))
+                _maxGameDataBytes, _ct);
-            {
-                var zipEntry = zipArchive.Entries.FirstOrDefault(e => e.Name == "gamestate");
-                if (zipEntry is null)
-                    throw new Exception("Invalid save format: no 'gamestate' file found");
-
-                await zipEntry.Open().CopyToAsync(gamestateStream, _ct);
             gamestateStream.Seek(0, SeekOrigin.Begin);
-            }
 
             await Program.DB.UpdateMetadataStatus(_meta, SaveFileProcessingStatus.Parsing);
             var parser = new SaveParserEU4(gamestateStream, _filter.SearchExpression);

ParadoxSaveParser.WebAPI/Config.cs

@@ -10,6 +10,15 @@ public class Config
     public string BaseUrl { get; set; } = "http://127.0.0.1:5226/";
     public int UploadLifetimeDays { get; set; } = 30;
     public string DbPath { get; set; } = "database.sqlite";
+    public SaveUploadConfig SaveUpload { get; set; } = new();
+
+    public class SaveUploadConfig
+    {
+        /// max size of game data entry after decompression
+        public long MaxSizePlainTextBytes { get; set; } = 200 * 1024 * 1024;
+        /// max size of uploaded .tar.zst
+        public long MaxSizeCompressedBytes { get; set; } = 60 * 1024 * 1024;
+    }
 
     public static JsonSerializerOptions JsonOptions = new()
     {

ParadoxSaveParser.WebAPI/Database/DatabaseConnector.cs

@@ -28,14 +28,17 @@ public class DatabaseConnector
             .FirstOrDefault();
     }
     
-    public async Task<SaveFileMetadata> CreateMetadata(Game game)
+    public async Task<SaveFileMetadata> CreateMetadata(Game game,
+        OriginalFileType originalFileType, string originalFileName)
     {
         var meta = new SaveFileMetadata
         {
             id = Guid.NewGuid().ToString(),
             game = game,
             status = SaveFileProcessingStatus.Initialized,
-            uploadDateTime = DateTime.Now
+            uploadDateTime = DateTime.Now,
+            originalFileType = originalFileType,
+            originalFileName = originalFileName,
         };
         await _db.InsertAsync(meta);
         return meta;

ParadoxSaveParser.WebAPI/Database/SaveFileMetadata.cs

@@ -12,6 +12,14 @@ public enum SaveFileProcessingStatus
     Error,
 }
 
+public enum OriginalFileType
+{
+    Text,
+    Zip,
+}
+
+public class LowerCaseEnumConverter<T>() : JsonStringEnumConverter<T>(JsonNamingPolicy.SnakeCaseLower) where T : struct, Enum;
+
 public class SaveFileMetadata
 {
     [SQLite.PrimaryKey]
@@ -22,19 +30,26 @@ public class SaveFileMetadata
     [SQLite.NotNull]
     public Game game { get; init; }
 
-    [JsonConverter(typeof(JsonStringEnumConverter))]
+    [JsonConverter(typeof(LowerCaseEnumConverter<SaveFileProcessingStatus>))]
     [SQLite.NotNull]
     public SaveFileProcessingStatus status { get; set; }
 
     [SQLite.NotNull]
     public DateTime uploadDateTime { get; set; }
 
+    [JsonConverter(typeof(LowerCaseEnumConverter<OriginalFileType>))]
+    [SQLite.NotNull]
+    public OriginalFileType originalFileType { get; init; }
+
+    [SQLite.NotNull]
+    public string originalFileName { get; init; } = null!;
+
     // if error occured during parsing, it's message is saved here
     // status stays the same as when error occured
     public string? errorMessage { get; set; }
 
 
-    public IOPath GetSaveFilePath() => Path.Concat(PathHelper.SAVES_DIR, id + ".eu4");
+    public IOPath GetSaveFilePath() => Path.Concat(PathHelper.SAVES_DIR, id + ".tar.zst");
 
     public IOPath GetParsedDataPath() => Path.Concat(PathHelper.PARSED_DIR, id + ".parsed.json");
 

ParadoxSaveParser.WebAPI/Game.cs

@@ -3,5 +3,16 @@
 public enum Game
 {
     Unknown,
-    EU4
+    EU4,
+    Stellaris,
+}
+
+public static class GameSaveEntryNames
+{
+    /// name of the entry in uploaded .tar.zst which contains game data
+    public static readonly IReadOnlyDictionary<Game, string> Map = new Dictionary<Game, string>
+    {
+        { Game.EU4, "gamestate" },
+        { Game.Stellaris, "gamestate" },
+    };
 }

ParadoxSaveParser.WebAPI/ParadoxSaveParser.WebAPI.csproj

@@ -14,15 +14,7 @@
 
     <ItemGroup>
         <PackageReference Include="DTLib.Web" Version="1.4.0" />
-<!--        <PackageReference Include="Google.Protobuf" Version="3.31.0" />-->
         <PackageReference Include="sqlite-net-pcl" Version="1.11.285" />
+        <PackageReference Include="ZstdSharp.Port" Version="0.8.8" />
     </ItemGroup>
-
-<!--    <ItemGroup>-->
-<!--        <Compile Include="obj\Protobuf\*.g.cs" />-->
-<!--    </ItemGroup>-->
-
-<!--    <Target Name="PreBuild" BeforeTargets="PreBuildEvent">-->
-<!--        <Exec Command="sh -c &quot;mkdir -p obj/Protobuf &amp;&amp; protoc Protobuf/*.proto &#45;&#45;csharp_out=obj/Protobuf &#45;&#45;csharp_opt=file_extension=.g.cs&quot;" />-->
-<!--    </Target>-->
 </Project>

ParadoxSaveParser.WebAPI/Program.cs

@@ -87,7 +87,7 @@ public static class Program
             await DB.InitializeAsync();
             await DB.DeleteInvalidData();
 
-            var bgJobManager = new BackgroundJobManager(loggerRoot);
+            var bgJobManager = new BackgroundJobManager(loggerRoot, config.SaveUpload);
             var saveFilters = new Dictionary<Game, ISaveDataFilter>
             {
                 { Game.EU4, new SaveDataFilterEU4() },
@@ -98,11 +98,13 @@ public static class Program
             router.DefaultRoute = new SimpleRouter.RouteWithMethod(HttpMethod.GET,
                 new ServeFilesRouteHandler(PathHelper.PUBLIC_DIR));
             router.MapRoute("/uploadSave", HttpMethod.POST,
-                new UploadSaveHandler(mainCancel.Token, bgJobManager, saveFilters));
+                new UploadSaveHandler(mainCancel.Token, bgJobManager, saveFilters, config.SaveUpload));
             router.MapRoute("/getSaveStatus", HttpMethod.GET,
                 new GetSaveStatusHandler(mainCancel.Token));
             router.MapRoute("/getSaveData", HttpMethod.GET,
                 new GetSaveDataHandler(mainCancel.Token));
+            router.MapRoute("/getSaveFile", HttpMethod.GET,
+                new GetSaveFileHandler(mainCancel.Token));
 
             var app = new WebApp(config.BaseUrl, loggerRoot, router, mainCancel.Token);
             await app.Run();

ParadoxSaveParser.WebAPI/Protobuf/ParsedData.proto

@@ -1,21 +0,0 @@
-syntax = "proto3";
-option csharp_namespace = "ParadoxSaveParser.WebAPI.MyProtobuf";
-
-message Item {
-  oneof value {
-    bool b = 1;
-    int64 i64 = 2;
-    double f64 = 3;
-    string str = 4;
-    ItemList list = 5;
-    ItemListMap map = 6;
-  }
-}
-
-message ItemList {
-  repeated Item items = 1;
-}
-
-message ItemListMap {
-  map<string, ItemList> items_map = 1;
-}

ParadoxSaveParser.WebAPI/README.md

@@ -5,30 +5,50 @@ Simple web application created using DTLib.Web.
 ## Important
 Restart web application once per day to delete outdated data and clean RAM.
 
+## Config
+`SaveUpload` section of `config.json`:
+- `MaxSizeCompressedBytes` - max size of uploaded `.tar.zst` (default 60 MiB)
+- `MaxSizePlainTextBytes` - max size of the game data entry after decompression (default 200 MiB)
+
 ## Routes
 ### POST `/uploadSave`
 - **Query Params:**
   - `game` - short name of the game (see [../README.md](../README.md))
-- **Request Body:** `application/octet-stream` - .eu4 file
+  - `originalFileType` - `text` | `zip`
+  - `originalFileName` - name of the original save file (max 255 characters)
+- **Request Body:** `application/zstd` - single zstd frame containing a tar with files of the original save.
+  Game data is read from the entry named in [GameSaveEntryNames](./Game.cs) (`gamestate` for EU4).
+  A plain text save is a tar with just that one entry.
+  The blob is stored byte-for-byte and can be downloaded with `/getSaveFile`.
 - **Response:**
     ```json
-    { "saveId": "string" }
+    { "id": "string" }
     ```
     or `{ "errorMessage": "string" }` 
+    (status 413 if upload or uncompressed game data exceeds the limits from config)
 
 ### GET `/getSaveStatus`
 - **Query Params:**
     - `id` - id of uploaded save file
-- **Response:** [SaveFileMetadata](./SaveFileMetadata.cs)
+- **Response:** [SaveFileMetadata](./Database/SaveFileMetadata.cs)
     ```json
     {
         "id": "string",
         "game": "string",
-        "status": "string",
+        "status": "initialized | uploaded | parsing | saving_results | done | error",
+        "uploadDateTime": "string",
+        "originalFileType": "text | zip",
+        "originalFileName": "string",
         "errorMessage": "string?"
     }
     ```
 
+### GET `/getSaveFile`
+- **Query Params:**
+    - `id` - id of uploaded save file
+- **Response:** `application/zstd` - uploaded blob, unchanged
+    or `{ "errorMessage": "string" }`
+
 ### GET `/getSaveData`
 - **Query Params:**
     - `id` - id of uploaded save file

ParadoxSaveParser.WebAPI/Routes/GetSaveFileHandler.cs

@@ -0,0 +1,45 @@
+using System.Net;
+using ParadoxSaveParser.WebAPI.Database;
+using ParadoxSaveParser.WebAPI.HttpHelpers;
+
+namespace ParadoxSaveParser.WebAPI.Routes;
+
+internal class GetSaveFileHandler : RouteHandlerBase
+{
+    public GetSaveFileHandler(CancellationToken cancelAllToken)
+        : base(cancelAllToken)
+    {
+    }
+
+    public override async Task<HttpStatusCode> HandleRequest(
+        HttpListenerContext ctx, ContextLogger requestLogger)
+    {
+        var idOrError = RequestHelper.GetQueryValue(ctx, "id");
+        if (idOrError.HasError)
+            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken, idOrError.Error!);
+        string id = idOrError.Value!;
+
+        var meta = await Program.DB.GetMetadata(id);
+        if(meta is null)
+            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
+                new ErrorMessage(HttpStatusCode.NotFound,
+                    $"Save with id {id} not found"));
+        // file is being uploaded (Initialized) or was deleted (Error)
+        if(meta.status is SaveFileProcessingStatus.Initialized or SaveFileProcessingStatus.Error)
+            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
+                new ErrorMessage(HttpStatusCode.BadRequest,
+                    $"Save with id {id} has status {meta.status}"));
+
+        IOPath saveFilePath = meta.GetSaveFilePath();
+        if (!File.Exists(saveFilePath))
+            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
+                new ErrorMessage(HttpStatusCode.InternalServerError,
+                    $"Save with id {id} not found")
+            );
+
+        await using var saveFile = File.OpenRead(saveFilePath);
+
+        return await ReturnHelper.ResponseStream(ctx, requestLogger, _cancelAllToken,
+            saveFile, contentType: "application/zstd");
+    }
+}

ParadoxSaveParser.WebAPI/Routes/UploadSaveHandler.cs

@@ -1,4 +1,4 @@
-using System.Linq;
+using System.IO;
 using System.Net;
 using ParadoxSaveParser.WebAPI.BackgroundTasks;
 using ParadoxSaveParser.WebAPI.Database;
@@ -9,24 +9,30 @@ namespace ParadoxSaveParser.WebAPI.Routes;
 
 public class UploadSaveHandler : RouteHandlerBase
 {
+    private const int MaxOriginalFileNameLength = 255;
+
     private readonly BackgroundJobManager _bgJobManager;
     private readonly Dictionary<Game, ISaveDataFilter> _saveFilters;
+    private readonly Config.SaveUploadConfig _uploadConfig;
 
     public UploadSaveHandler(
         CancellationToken cancelAllToken,
         BackgroundJobManager bgJobManager,
-        Dictionary<Game, ISaveDataFilter> saveFilters) 
+        Dictionary<Game, ISaveDataFilter> saveFilters,
+        Config.SaveUploadConfig uploadConfig)
         : base(cancelAllToken)
     {
         _bgJobManager = bgJobManager;
         _saveFilters = saveFilters;
+        _uploadConfig = uploadConfig;
     }
 
     public override async Task<HttpStatusCode> HandleRequest(
         HttpListenerContext ctx, ContextLogger requestLogger)
     {
-        string? contentType = ctx.Request.Headers.GetValues("Content-Type")?.FirstOrDefault();
+        string? contentType = ctx.Request.ContentType;
-        if (contentType != "application/octet-stream")
+        string? mediaType = contentType?.Split(';')[0].Trim();
+        if (!string.Equals(mediaType, "application/zstd", StringComparison.OrdinalIgnoreCase))
             return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
                     new ErrorMessage(HttpStatusCode.BadRequest,
                 $"Invalid request Content-Type: '{contentType}'"));
@@ -34,18 +40,82 @@ public class UploadSaveHandler : RouteHandlerBase
         var gameStrOrError = RequestHelper.GetQueryValue(ctx, "game");
         if (gameStrOrError.HasError)
             return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken, gameStrOrError.Error!);
-
         if (!Enum.TryParse(gameStrOrError.Value, ignoreCase: true, out Game game))
             return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
                 new ErrorMessage(HttpStatusCode.BadRequest,
                     $"Invalid requested game: '{gameStrOrError.Value}'"));
-        var meta = await Program.DB.CreateMetadata(game);
+        if (!_saveFilters.ContainsKey(game) || !GameSaveEntryNames.Map.ContainsKey(game))
+            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
+                new ErrorMessage(HttpStatusCode.BadRequest,
+                    $"Game {game} is not supported"));
 
-        var saveFilePath = meta.GetSaveFilePath();
+        var fileTypeStrOrError = RequestHelper.GetQueryValue(ctx, "originalFileType");
-        await using (var saveFile = File.OpenWrite(saveFilePath))
+        if (fileTypeStrOrError.HasError)
+            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken, fileTypeStrOrError.Error!);
+        OriginalFileType? originalFileType = fileTypeStrOrError.Value!.ToLowerInvariant() switch
+        {
+            "text" => OriginalFileType.Text,
+            "zip" => OriginalFileType.Zip,
+            _ => null
+        };
+        if (originalFileType is null)
+            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
+                new ErrorMessage(HttpStatusCode.BadRequest,
+                    $"Invalid originalFileType: '{fileTypeStrOrError.Value}'"));
+
+        var fileNameOrError = RequestHelper.GetQueryValue(ctx, "originalFileName");
+        if (fileNameOrError.HasError)
+            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken, fileNameOrError.Error!);
+        string originalFileName = fileNameOrError.Value!;
+        if (originalFileName.Length > MaxOriginalFileNameLength)
+            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
+                new ErrorMessage(HttpStatusCode.BadRequest,
+                    $"originalFileName is longer than {MaxOriginalFileNameLength} characters"));
+
+        // Content-Length is unknown (-1) for chunked requests, so body size is checked during copying too
+        if (ctx.Request.ContentLength64 > _uploadConfig.MaxSizeCompressedBytes)
+            return await ResponseUploadTooLarge(ctx, requestLogger);
+
+        var meta = await Program.DB.CreateMetadata(game, originalFileType.Value, originalFileName);
+        try
+        {
+            bool fitsLimit;
+            await using (var saveFile = File.OpenWrite(meta.GetSaveFilePath()))
             {
                 await using (var remoteStream = ctx.Request.InputStream)
-                await remoteStream.CopyToAsync(saveFile, _cancelAllToken);
+                    fitsLimit = await CopyWithLimit(remoteStream, saveFile, _uploadConfig.MaxSizeCompressedBytes);
+            }
+            if (!fitsLimit)
+            {
+                await Program.DB.DeleteMetadata(meta, "upload is too large");
+                return await ResponseUploadTooLarge(ctx, requestLogger);
+            }
+
+            long gameDataSize;
+            try
+            {
+                gameDataSize = await SaveArchive.GetGameDataSize(meta.GetSaveFilePath(), game, _cancelAllToken);
+            }
+            catch (Exception ex) when (ex is not OperationCanceledException)
+            {
+                await Program.DB.DeleteMetadata(meta, "invalid archive");
+                return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
+                    new ErrorMessage(HttpStatusCode.BadRequest,
+                        $"Invalid save archive: {ex.Message}"));
+            }
+            if (gameDataSize > _uploadConfig.MaxSizePlainTextBytes)
+            {
+                await Program.DB.DeleteMetadata(meta, "game data is too large");
+                return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
+                    new ErrorMessage(HttpStatusCode.RequestEntityTooLarge,
+                        $"Uncompressed game data size ({gameDataSize} bytes) exceeds limit "
+                        + $"({_uploadConfig.MaxSizePlainTextBytes} bytes)"));
+            }
+        }
+        catch
+        {
+            await Program.DB.DeleteMetadata(meta, "upload failed");
+            throw;
         }
         await Program.DB.UpdateMetadataStatus(meta, SaveFileProcessingStatus.Uploaded);
 
@@ -53,4 +123,27 @@ public class UploadSaveHandler : RouteHandlerBase
         dynamic responseData = new { meta.id };
         return await ReturnHelper.ResponseJson(ctx, requestLogger, _cancelAllToken, responseData);
     }
+
+    private Task<HttpStatusCode> ResponseUploadTooLarge(HttpListenerContext ctx, ContextLogger requestLogger)
+    {
+        return ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
+            new ErrorMessage(HttpStatusCode.RequestEntityTooLarge,
+                $"Upload size exceeds limit ({_uploadConfig.MaxSizeCompressedBytes} bytes)"));
+    }
+
+    /// <returns>false if source is longer than maxBytes</returns>
+    private async Task<bool> CopyWithLimit(Stream source, Stream dest, long maxBytes)
+    {
+        byte[] buffer = new byte[81920];
+        long totalBytes = 0;
+        int readBytes;
+        while ((readBytes = await source.ReadAsync(buffer, _cancelAllToken)) > 0)
+        {
+            totalBytes += readBytes;
+            if (totalBytes > maxBytes)
+                return false;
+            await dest.WriteAsync(buffer.AsMemory(0, readBytes), _cancelAllToken);
+        }
+        return true;
+    }
 }

ParadoxSaveParser.WebAPI/SaveArchive.cs

@@ -0,0 +1,52 @@
+using System.Formats.Tar;
+using System.IO;
+using ZstdSharp;
+
+namespace ParadoxSaveParser.WebAPI;
+
+/// <summary>
+/// Uploaded save is a zstd-compressed tar with files of the original save inside.
+/// Game data is stored in entry with name from <see cref="GameSaveEntryNames"/>.
+/// </summary>
+public static class SaveArchive
+{
+    public static Task<long> GetGameDataSize(IOPath archivePath, Game game, CancellationToken ct)
+    {
+        return WithGameDataEntry(archivePath, game, ct,
+            entry => Task.FromResult(entry.Length));
+    }
+
+    public static Task ExtractGameData(IOPath archivePath, Game game, Stream dest, long maxBytes,
+        CancellationToken ct)
+    {
+        return WithGameDataEntry(archivePath, game, ct, async entry =>
+        {
+            if (entry.Length > maxBytes)
+                throw new InvalidDataException(
+                    $"Game data size ({entry.Length} bytes) exceeds limit ({maxBytes} bytes)");
+            if (entry.DataStream is not null)
+                await entry.DataStream.CopyToAsync(dest, ct);
+            return true;
+        });
+    }
+
+    private static async Task<T> WithGameDataEntry<T>(IOPath archivePath, Game game, CancellationToken ct,
+        Func<TarEntry, Task<T>> action)
+    {
+        if (!GameSaveEntryNames.Map.TryGetValue(game, out string? entryName))
+            throw new ArgumentOutOfRangeException(nameof(game), game, "No game data entry name for game");
+
+        await using var file = File.OpenRead(archivePath);
+        await using var zstd = new DecompressionStream(file);
+        await using var tar = new TarReader(zstd);
+        while (await tar.GetNextEntryAsync(copyData: false, ct) is { } entry)
+        {
+            if (entry.EntryType is not (TarEntryType.RegularFile or TarEntryType.V7RegularFile))
+                continue;
+            if (System.IO.Path.GetFileName(entry.Name) == entryName)
+                return await action(entry);
+        }
+
+        throw new InvalidDataException($"Invalid save format: no '{entryName}' entry found");
+    }
+}

README.md

@@ -17,4 +17,7 @@ Yet another save files parser.
     Performance comparison of the search expression engine against regex engines and jq
 
 ## Building
-1. Install protobuf compiler https://protobuf.dev/installation/
+```sh
+cd ParadoxSaveParser.WebAPI
+dotnet build
+```

TODO.md

@@ -1,4 +1,4 @@
 ## WebAPI.SaveParsingOperation:
-	Save parsed data in protobuf
+	Save parsed data in zstd archive
 	Re-parse if saved data was parsed with another query
     Implement automatic database cleanup