Freeze-Fixed

README.md

@@ -80,6 +80,20 @@ Reine Ordner mit deinen Dateien — du kannst sie auch außerhalb der App
 über den Dateimanager wirken sich beim nächsten Laden der Seite ebenfalls
 auf die App aus.
 
+## Große Dateien
+
+- Uploads laufen serverseitig in einem Hintergrund-Thread, damit auch bei
+  sehr großen Dateien (mehrere GB) der Rest der App währenddessen normal
+  bedienbar bleibt.
+- ZIP-Downloads (einzelnes Projekt oder alle Projekte) werden auf eine
+  temporäre Datei auf der Festplatte geschrieben statt komplett im
+  Arbeitsspeicher gehalten zu werden, und danach automatisch wieder
+  gelöscht.
+- Für Dateien über **150 MB** wird die 3D-Vorschau nicht automatisch
+  geladen (das würde bei sehr großen Modellen den Browser-Tab einfrieren
+  lassen), sondern zeigt einen "Vorschau laden"-Button an — du entscheidest
+  bewusst, ob der Browser versuchen soll, das Modell zu parsen.
+
 ## Bekannte Grenzen (erster Wurf)
 
 - Single-User, kein Login.

This.env.example

@@ -0,0 +1,25 @@
+# Copy this file to .env and set the absolute path to the folder on your
+# desktop where your projects (and their STL/3MF files) should live.
+#
+# Linux/macOS example:
+# PROJECTS_DIR=/home/yourname/3d-projects
+#
+# Windows (Docker Desktop) example:
+# PROJECTS_DIR=C:/Users/yourname/3d-projects
+
+PROJECTS_DIR=/home/yourname/3d-projects
+
+# SHA256 hash of the login password. Generate it with (no quotes around the
+# password, mind trailing newlines/spaces):
+#
+# Linux/macOS:
+#   echo -n "meinPasswort" | sha256sum
+#
+# Windows (PowerShell):
+#   $hash = [System.Security.Cryptography.SHA256]::Create().ComputeHash([System.Text.Encoding]::UTF8.GetBytes("meinPasswort"))
+#   ($hash | ForEach-Object { $_.ToString("x2") }) -join ""
+#
+# Paste only the resulting hex hash below, e.g.:
+# PASSWORD_SHA256=5e884898da28047151d0e56f8dc6292773603d0d6aabbdd62a11ef721d1542d
+
+PASSWORD_SHA256=changeme

backend/main.py

@@ -1,19 +1,21 @@
 import hashlib
 import hmac
-import io
 import os
 import re
 import secrets
 import shutil
+import tempfile
 import time
 import zipfile
 from pathlib import Path
 from typing import List
 
 from fastapi import APIRouter, Depends, FastAPI, HTTPException, Request, UploadFile, File
-from fastapi.responses import FileResponse, StreamingResponse
+from fastapi.responses import FileResponse
 from fastapi.staticfiles import StaticFiles
 from pydantic import BaseModel
+from starlette.background import BackgroundTask
+from starlette.concurrency import run_in_threadpool
 from starlette.middleware.sessions import SessionMiddleware
 
 PROJECTS_DIR = Path(os.environ.get("PROJECTS_DIR", "/data/projects")).resolve()
@@ -180,13 +182,19 @@ async def upload_files(name: str, files: List[UploadFile] = File(...)):
             continue
         filename = safe_filename(upload.filename)
         dest = path / filename
-        with open(dest, "wb") as out:
+        # Run the actual (blocking) disk copy in a worker thread so a large
-            shutil.copyfileobj(upload.file, out)
+        # file doesn't freeze the whole server for the duration of the copy.
+        await run_in_threadpool(_copy_upload_to_disk, upload.file, dest)
         saved.append(filename)
 
     return {"saved": saved, "skipped": skipped}
 
 
+def _copy_upload_to_disk(src_file, dest_path: Path) -> None:
+    with open(dest_path, "wb") as out:
+        shutil.copyfileobj(src_file, out, length=4 * 1024 * 1024)
+
+
 @api.get("/projects/{name}/files/{filename}")
 def get_file(name: str, filename: str):
     path = safe_project_path(name)
@@ -199,10 +207,13 @@ def get_file(name: str, filename: str):
 @api.get("/download-all")
 def download_all_projects():
     projects = [p for p in PROJECTS_DIR.iterdir() if p.is_dir()]
-    files_found = False
 
-    buffer = io.BytesIO()
+    tmp = tempfile.NamedTemporaryFile(delete=False, suffix=".zip")
-    with zipfile.ZipFile(buffer, "w", zipfile.ZIP_DEFLATED) as zf:
+    tmp_path = Path(tmp.name)
+    tmp.close()
+
+    files_found = False
+    with zipfile.ZipFile(tmp_path, "w", zipfile.ZIP_DEFLATED) as zf:
         for project in projects:
             for f in project.iterdir():
                 if f.is_file() and f.suffix.lower() in ALLOWED_EXTENSIONS:
@@ -210,13 +221,14 @@ def download_all_projects():
                     files_found = True
 
     if not files_found:
+        tmp_path.unlink(missing_ok=True)
         raise HTTPException(404, "No files to download")
 
-    buffer.seek(0)
+    return FileResponse(
-    return StreamingResponse(
+        tmp_path,
-        buffer,
         media_type="application/zip",
-        headers={"Content-Disposition": 'attachment; filename="alle-projekte.zip"'},
+        filename="alle-projekte.zip",
+        background=BackgroundTask(lambda: tmp_path.unlink(missing_ok=True)),
     )
 
 
@@ -230,17 +242,19 @@ def download_project(name: str):
     if not files:
         raise HTTPException(404, "Project has no files to download")
 
-    buffer = io.BytesIO()
+    tmp = tempfile.NamedTemporaryFile(delete=False, suffix=".zip")
-    with zipfile.ZipFile(buffer, "w", zipfile.ZIP_DEFLATED) as zf:
+    tmp_path = Path(tmp.name)
+    tmp.close()
+
+    with zipfile.ZipFile(tmp_path, "w", zipfile.ZIP_DEFLATED) as zf:
         for f in files:
             zf.write(f, arcname=f.name)
-    buffer.seek(0)
 
-    zip_filename = f"{name}.zip"
+    return FileResponse(
-    return StreamingResponse(
+        tmp_path,
-        buffer,
         media_type="application/zip",
-        headers={"Content-Disposition": f'attachment; filename="{zip_filename}"'},
+        filename=f"{name}.zip",
+        background=BackgroundTask(lambda: tmp_path.unlink(missing_ok=True)),
     )
 
 

static/app.js

@@ -11,6 +11,11 @@ const logoutBtn = document.getElementById("logout-btn");
 const stlLoader = new STLLoader();
 const mfLoader = new ThreeMFLoader();
 
+// Files above this size are not auto-loaded into a 3D preview, since
+// parsing a huge mesh can freeze the browser tab. The user can opt in
+// via a button instead.
+const PREVIEW_SIZE_LIMIT = 150 * 1024 * 1024; // 150 MB
+
 let currentProject = null;
 const activeViewers = []; // track for cleanup / resize
 
@@ -375,9 +380,31 @@ async function loadFileGrid(projectName, container) {
 
     grid.appendChild(card);
     const canvasHost = card.querySelector(".file-card-canvas");
-    initViewer(canvasHost, `/api/projects/${encodeURIComponent(projectName)}/files/${encodeURIComponent(file.name)}`, file.type);
+    const fileUrlForViewer = `/api/projects/${encodeURIComponent(projectName)}/files/${encodeURIComponent(file.name)}`;
+
+    if (file.size > PREVIEW_SIZE_LIMIT) {
+      renderLazyPreviewPlaceholder(canvasHost, fileUrlForViewer, file.type, file.size);
+    } else {
+      initViewer(canvasHost, fileUrlForViewer, file.type);
     }
   }
+}
+
+function renderLazyPreviewPlaceholder(host, url, type, size) {
+  host.style.position = "relative";
+  const wrap = document.createElement("div");
+  wrap.className = "preview-placeholder";
+  wrap.innerHTML = `
+    <span class="preview-placeholder-text">Große Datei (${formatSize(size)})<br />keine automatische Vorschau</span>
+    <button class="btn preview-load-btn" type="button">Vorschau laden</button>
+  `;
+  host.appendChild(wrap);
+
+  wrap.querySelector(".preview-load-btn").addEventListener("click", () => {
+    wrap.remove();
+    initViewer(host, url, type);
+  });
+}
 
 // ---------- Three.js viewer ----------
 

static/style.css

@@ -348,6 +348,29 @@ button {
   height: 100%;
 }
 
+.preview-placeholder {
+  position: absolute;
+  inset: 0;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 12px;
+  padding: 16px;
+  text-align: center;
+}
+
+.preview-placeholder-text {
+  font-size: 12px;
+  color: var(--text-muted);
+  line-height: 1.5;
+}
+
+.preview-load-btn {
+  padding: 7px 14px;
+  font-size: 13px;
+}
+
 .file-card-info {
   padding: 12px 14px;
   display: flex;