Automatically update version to 0.6.18

Bumps [vite](https://github.com/vitejs/vite/tree/HEAD/packages/vite) from 5.1.5 to 5.1.6.
- [Release notes](https://github.com/vitejs/vite/releases)
- [Changelog](https://github.com/vitejs/vite/blob/main/packages/vite/CHANGELOG.md)
- [Commits](https://github.com/vitejs/vite/commits/v5.1.6/packages/vite)

---
updated-dependencies:
- dependency-name: vite
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

frontend/App.vue

@@ -35,15 +35,29 @@ provide('disableTap', {disableTap, setDisableTap});
 async function onModelUpdateRequest(event: NetworkUpdateEvent) {
   // Load/unload a new batch of models to optimize rendering time
   console.log("Received model update request", event.models);
+  let shutdownRequestIndex = event.models.findIndex((model) => model.isRemove == null);
+  let shutdownRequest = null;
+  if (shutdownRequestIndex !== -1) {
+    console.log("Will shut down the connection after this load, as requested by the server");
+    shutdownRequest = event.models.splice(shutdownRequestIndex, 1)[0];
+  }
   let doc = sceneDocument.value;
   for (let modelIndex in event.models) {
     let isLast = parseInt(modelIndex) === event.models.length - 1;
     let model = event.models[modelIndex];
+    try {
       if (!model.isRemove) {
         doc = await SceneMgr.loadModel(sceneUrl, doc, model.name, model.url, isLast, isLast);
       } else {
         doc = await SceneMgr.removeModel(sceneUrl, doc, model.name, isLast);
       }
+    } catch (e) {
+      console.error("Error loading model", model, e);
+    }
+  }
+  if (shutdownRequest !== null) {
+    console.log("Shutting down the connection as requested by the server");
+    event.disconnect();
   }
   sceneDocument.value = doc
   triggerRef(sceneDocument); // Why not triggered automatically?

frontend/misc/gltf.ts

@@ -12,9 +12,10 @@ export let extrasNameValueHelpers = "__helpers";
  *
  * Remember to call mergeFinalize after all models have been merged (slower required operations).
  */
-export async function mergePartial(url: string, name: string, document: Document): Promise<Document> {
+export async function mergePartial(url: string, name: string, document: Document, networkFinished: () => void = () => {}): Promise<Document> {
     // Load the new document
     let newDoc = await io.read(url);
+    networkFinished()
 
     // Remove any previous model with the same name
     await document.transform(dropByName(name));

frontend/misc/network.ts

@@ -7,22 +7,24 @@ class NetworkUpdateEventModel {
     url: string;
     // TODO: Detect and manage instances of the same object (same hash, different name)
     hash: string | null;
-    isRemove: boolean;
+    isRemove: boolean | null; // This is null for a shutdown event
 
-    constructor(name: string, url: string, hash: string | null, isDelete: boolean) {
+    constructor(name: string, url: string, hash: string | null, isRemove: boolean | null) {
         this.name = name;
         this.url = url;
         this.hash = hash;
-        this.isRemove = isDelete;
+        this.isRemove = isRemove;
     }
 }
 
 export class NetworkUpdateEvent extends Event {
     models: NetworkUpdateEventModel[];
+    disconnect: () => void;
 
-    constructor(models: NetworkUpdateEventModel[]) {
+    constructor(models: NetworkUpdateEventModel[], disconnect: () => void) {
         super("update");
         this.models = models;
+        this.disconnect = disconnect;
     }
 }
 
@@ -57,37 +59,48 @@ export class NetworkManager extends EventTarget {
         }
     }
 
-    private async monitorDevServer(url: URL) {
+    private async monitorDevServer(url: URL, stop: () => boolean = () => false) {
+        while (!stop()) {
             try {
                 // WARNING: This will spam the console logs with failed requests when the server is down
-            let response = await fetch(url.toString());
+                const controller = new AbortController();
+                let response = await fetch(url.toString(), {signal: controller.signal});
                 // console.log("Monitoring", url.toString(), response);
                 if (response.status === 200) {
                     let lines = readLinesStreamings(response.body!.getReader());
                     for await (let line of lines) {
+                        if (stop()) break;
                         if (!line || !line.startsWith("data:")) continue;
-                    let data = JSON.parse(line.slice(5));
+                        let data: { name: string, hash: string, is_remove: boolean | null } = JSON.parse(line.slice(5));
                         // console.debug("WebSocket message", data);
                         let urlObj = new URL(url);
                         urlObj.searchParams.delete("api_updates");
                         urlObj.searchParams.set("api_object", data.name);
-                    this.foundModel(data.name, data.hash, urlObj.toString(), data.is_remove);
+                        this.foundModel(data.name, data.hash, urlObj.toString(), data.is_remove, async () => {
+                            controller.abort(); // Notify the server that we are done
+                        });
                     }
                 }
+                controller.abort();
             } catch (e) { // Ignore errors (retry very soon)
             }
-        setTimeout(() => this.monitorDevServer(url), settings.monitorEveryMs);
+            await new Promise(resolve => setTimeout(resolve, settings.monitorEveryMs));
-        return;
+        }
     }
 
-    private foundModel(name: string, hash: string | null, url: string, isRemove: boolean) {
+    private foundModel(name: string, hash: string | null, url: string, isRemove: boolean | null, disconnect: () => void = () => {
+    }) {
         let prevHash = this.knownObjectHashes[name];
         // console.debug("Found model", name, "with hash", hash, "and previous hash", prevHash);
         if (!hash || hash !== prevHash || isRemove) {
-            if (!isRemove) {
+            // Update known hashes
+            if (isRemove == false) {
                 this.knownObjectHashes[name] = hash;
-            } else {
+            } else if (isRemove == true) {
+                if (!(name in this.knownObjectHashes)) return; // Nothing to remove...
                 delete this.knownObjectHashes[name];
+                // Also update buffered updates if the model is removed
+                this.bufferedUpdates = this.bufferedUpdates.filter(m => m.name !== name);
             }
             let newModel = new NetworkUpdateEventModel(name, url, hash, isRemove);
             this.bufferedUpdates.push(newModel);
@@ -95,7 +108,7 @@ export class NetworkManager extends EventTarget {
             // Optimization: try to batch updates automatically for faster rendering
             if (this.batchTimeout !== null) clearTimeout(this.batchTimeout);
             this.batchTimeout = setTimeout(() => {
-                this.dispatchEvent(new NetworkUpdateEvent(this.bufferedUpdates));
+                this.dispatchEvent(new NetworkUpdateEvent(this.bufferedUpdates, disconnect));
                 this.bufferedUpdates = [];
             }, batchTimeout);
         }

frontend/misc/scene.ts

@@ -9,11 +9,11 @@ import {Matrix4} from "three/src/math/Matrix4.js"
 /** This class helps manage SceneManagerData. All methods are static to support reactivity... */
 export class SceneMgr {
     /** Loads a GLB model from a URL and adds it to the viewer or replaces it if the names match */
-    static async loadModel(sceneUrl: Ref<string>, document: Document, name: string, url: string, updateHelpers: boolean = true, reloadScene: boolean = true): Promise<Document> {
+    static async loadModel(sceneUrl: Ref<string>, document: Document, name: string, url: string, updateHelpers: boolean = true, reloadScene: boolean = true, networkFinished: () => void = () => {}): Promise<Document> {
         let loadStart = performance.now();
 
         // Start merging into the current document, replacing or adding as needed
-        document = await mergePartial(url, name, document);
+        document = await mergePartial(url, name, document, networkFinished);
 
         console.log("Model", name, "loaded in", performance.now() - loadStart, "ms");
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "yet-another-cad-viewer",
-  "version": "0.6.15",
+  "version": "0.6.18",
   "description": "",
   "license": "MIT",
   "private": true,
@@ -16,7 +16,7 @@
   },
   "dependencies": {
     "@gltf-transform/core": "^3.10.0",
-    "@gltf-transform/functions": "^3.10.0",
+    "@gltf-transform/functions": "^3.10.1",
     "@google/model-viewer": "^3.4.0",
     "@jamescoyle/vue-icon": "^0.1.2",
     "@mdi/js": "^7.4.47",
@@ -24,11 +24,11 @@
     "three": "^0.160.1",
     "three-orientation-gizmo": "https://github.com/jrj2211/three-orientation-gizmo",
     "vue": "^3.4.21",
-    "vuetify": "^3.5.8"
+    "vuetify": "^3.5.9"
   },
   "devDependencies": {
     "@tsconfig/node20": "^20.1.2",
-    "@types/node": "^20.11.25",
+    "@types/node": "^20.11.28",
     "@types/three": "^0.160.0",
     "@vitejs/plugin-vue": "^5.0.3",
     "@vitejs/plugin-vue-jsx": "^3.1.0",
@@ -37,9 +37,9 @@
     "commander": "^12.0.0",
     "generate-license-file": "^3.0.1",
     "npm-run-all2": "^6.1.1",
-    "terser": "^5.29.1",
+    "terser": "^5.29.2",
     "typescript": "~5.4.2",
-    "vite": "^5.1.5",
+    "vite": "^5.1.6",
     "vue-tsc": "^2.0.6"
   }
 }

poetry.lock

@@ -318,17 +318,6 @@ qtconsole = ["qtconsole"]
 test = ["pickleshare", "pytest (<7.1)", "pytest-asyncio (<0.22)", "testpath"]
 test-extra = ["curio", "matplotlib (!=3.2.0)", "nbformat", "numpy (>=1.22)", "pandas", "pickleshare", "pytest (<7.1)", "pytest-asyncio (<0.22)", "testpath", "trio"]
 
-[[package]]
-name = "iterators"
-version = "0.2.0"
-description = "Iterator utility classes and functions"
-optional = false
-python-versions = ">=3.6"
-files = [
-    {file = "iterators-0.2.0-py3-none-any.whl", hash = "sha256:1d7ff03f576c9de0e01bac66209556c066d6b1fc45583a99cfc9f4645be7900e"},
-    {file = "iterators-0.2.0.tar.gz", hash = "sha256:e9927a1ea1ef081830fd1512f3916857c36bd4b37272819a6cd29d0f44431b97"},
-]
-
 [[package]]
 name = "jedi"
 version = "0.19.1"
@@ -962,4 +951,4 @@ files = [
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.9"
-content-hash = "d9746e99dd8861758730e68d12dc72d9ec5fb0101b3c070a7d7a373439c658a0"
+content-hash = "567ef9c980c250ace7e380098b810250a36b92dd2e824b5b4f4851898a675e09"

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "yacv-server"
-version = "0.6.15"
+version = "0.6.18"
 description = "Yet Another CAD Viewer (server)"
 authors = ["Yeicor <4929005+Yeicor@users.noreply.github.com>"]
 license = "MIT"
@@ -19,7 +19,6 @@ build123d = "^0.4.0"
 # Misc
 pygltflib = "^1.16.2"
 pillow = "^10.2.0"
-iterators = "^0.2.0"
 
 [tool.poetry.build]
 generate-setup-file = false

yacv_server/myhttp.py

@@ -1,12 +1,9 @@
 import io
 import os
-import threading
 import urllib.parse
 from http import HTTPStatus
 from http.server import SimpleHTTPRequestHandler
 
-from iterators import TimeoutIterator
-
 from yacv_server.mylogger import logger
 
 # Find the frontend folder (optional, but recommended)
@@ -26,13 +23,9 @@ OBJECTS_API_PATH = '/api/object'  # /{name}
 
 class HTTPHandler(SimpleHTTPRequestHandler):
     yacv: 'yacv.YACV'
-    frontend_lock: threading.Lock  # To avoid exiting too early while frontend makes requests
-    at_least_one_client: threading.Event
 
     def __init__(self, *args, yacv: 'yacv.YACV', **kwargs):
         self.yacv = yacv
-        self.frontend_lock = threading.Lock()
-        self.at_least_one_client = threading.Event()
         super().__init__(*args, **kwargs, directory=FRONTEND_BASE_PATH)
 
     def log_message(self, fmt, *args):
@@ -77,14 +70,23 @@ class HTTPHandler(SimpleHTTPRequestHandler):
 
     def _api_updates(self):
         """Handles a publish-only websocket connection that send show_object events along with their hashes and URLs"""
+
+        # Keep a shared read lock to know if any frontend is still working before shutting down
+        with self.yacv.frontend_lock.r_locked():
+
+            # Avoid accepting new connections while shutting down
+            if self.yacv.shutting_down.is_set() and self.yacv.at_least_one_client.is_set():
+                self.send_error(HTTPStatus.SERVICE_UNAVAILABLE, 'Server is shutting down')
+                return
+            self.yacv.at_least_one_client.set()
+            logger.debug('Updates client connected')
+
             self.send_response(HTTPStatus.OK)
             self.send_header("Content-Type", "text/event-stream")
             self.send_header("Cache-Control", "no-cache")
             # Chunked transfer encoding!
             self.send_header("Transfer-Encoding", "chunked")
             self.end_headers()
-        self.at_least_one_client.set()
-        logger.debug('Updates client connected')
 
             def write_chunk(_chunk_data: str):
                 self.wfile.write(hex(len(_chunk_data))[2:].encode('utf-8'))
@@ -95,20 +97,9 @@ class HTTPHandler(SimpleHTTPRequestHandler):
 
             write_chunk('retry: 100\n\n')
 
-        # Send buffered events first, while keeping a lock
+            subscription = self.yacv.show_events.subscribe(yield_timeout=1.0)  # Keep-alive interval
-        with self.frontend_lock:
-            for data in self.yacv.show_events.buffer():
-                logger.debug('Sending info about %s: %s', data.name, data)
-                # noinspection PyUnresolvedReferences
-                to_send = data.to_json()
-                write_chunk(f'data: {to_send}\n\n')
-
-        # Send future events over the same connection
-        # Also send keep-alive to know if the client is still connected
-        subscription = self.yacv.show_events.subscribe(include_buffered=False)
-        it = TimeoutIterator(subscription, sentinel=None, reset_on_next=True, timeout=5.0)  # Keep-alive interval
             try:
-            for data in it:
+                for data in subscription:
                     if data is None:
                         write_chunk(':keep-alive\n\n')
                     else:
@@ -119,27 +110,25 @@ class HTTPHandler(SimpleHTTPRequestHandler):
             except BrokenPipeError:  # Client disconnected normally
                 pass
             finally:
-            logger.debug('Updates client disconnected')
-            try:
-                it.interrupt()
-                next(it)  # Make sure the iterator is interrupted before trying to close the subscription
                 subscription.close()
-            except BaseException as e:
+
-                logger.debug('Ignoring error while closing subscription: %s', e)
+        logger.debug('Updates client disconnected')
 
     def _api_object(self, obj_name: str):
         """Returns the object file with the matching name, building it if necessary."""
-        with self.frontend_lock:
         # Export the object (or fail if not found)
-            exported_glb = self.yacv.export(obj_name)
+        _export = self.yacv.export(obj_name)
-            if exported_glb is None:
+        if _export is None:
             self.send_error(HTTPStatus.NOT_FOUND, f'Object {obj_name} not found')
             return io.BytesIO()
 
+        exported_glb, _hash = _export
+
         # Wrap the GLB in a response and return it
         self.send_response(HTTPStatus.OK)
         self.send_header('Content-Type', 'model/gltf-binary')
         self.send_header('Content-Length', str(len(exported_glb)))
         self.send_header('Content-Disposition', f'attachment; filename="{obj_name}.glb"')
+        self.send_header('E-Tag', f'"{_hash}"')
         self.end_headers()
         self.wfile.write(exported_glb)

yacv_server/pubsub.py

@@ -1,4 +1,4 @@
-import threading
+import queue
 import queue
 import threading
 from typing import List, TypeVar, \
@@ -8,6 +8,8 @@ from yacv_server.mylogger import logger
 
 T = TypeVar('T')
 
+_end_of_queue = object()
+
 
 class BufferedPubSub(Generic[T]):
     """A simple implementation of publish-subscribe pattern using threading and buffering all previous events"""
@@ -45,7 +47,7 @@ class BufferedPubSub(Generic[T]):
                 for event in self._buffer:
                     q.put(event)
             if not include_future:
-                q.put(None)
+                q.put(_end_of_queue)
         return q
 
     def _unsubscribe(self, q: queue.Queue[T]):
@@ -54,14 +56,18 @@ class BufferedPubSub(Generic[T]):
             self._subscribers.remove(q)
         logger.debug(f"Unsubscribed from %s (%d subscribers)", self, len(self._subscribers))
 
-    def subscribe(self, include_buffered: bool = True, include_future: bool = True) -> Generator[T, None, None]:
+    def subscribe(self, include_buffered: bool = True, include_future: bool = True, yield_timeout: float = 0.0) -> \
+            Generator[T, None, None]:
         """Subscribes to events as an generator that yields events and automatically unsubscribes"""
         q = self._subscribe(include_buffered, include_future)
         try:
             while True:
-                v = q.get()
+                try:
+                    v = q.get(timeout=yield_timeout)
+                except queue.Empty:
+                    v = None
                 # include_future is incompatible with None values as they are used to signal the end of the stream
-                if v is None and not include_future:
+                if v is _end_of_queue:
                     break
                 yield v
         finally:  # When aclose() is called

yacv_server/rwlock.py

@@ -0,0 +1,96 @@
+# -*- coding: utf-8 -*-
+""" rwlock.py
+
+    A class to implement read-write locks on top of the standard threading
+    library.
+
+    This is implemented with two mutexes (threading.Lock instances) as per this
+    wikipedia pseudocode:
+
+    https://en.wikipedia.org/wiki/Readers%E2%80%93writer_lock#Using_two_mutexes
+
+    Code written by Tyler Neylon at Unbox Research.
+
+    This file is public domain.
+"""
+
+# _______________________________________________________________________
+# Imports
+
+from contextlib import contextmanager
+from threading import Lock
+
+
+# _______________________________________________________________________
+# Class
+
+class RWLock(object):
+    """ RWLock class; this is meant to allow an object to be read from by
+        multiple threads, but only written to by a single thread at a time. See:
+        https://en.wikipedia.org/wiki/Readers%E2%80%93writer_lock
+
+        Usage:
+
+            from rwlock import RWLock
+
+            my_obj_rwlock = RWLock()
+
+            # When reading from my_obj:
+            with my_obj_rwlock.r_locked():
+                do_read_only_things_with(my_obj)
+
+            # When writing to my_obj:
+            with my_obj_rwlock.w_locked():
+                mutate(my_obj)
+    """
+
+    def __init__(self):
+
+        self.w_lock = Lock()
+        self.num_r_lock = Lock()
+        self.num_r = 0
+
+    # ___________________________________________________________________
+    # Reading methods.
+
+    def r_acquire(self, *args, **kwargs):
+        self.num_r_lock.acquire(*args, **kwargs)
+        self.num_r += 1
+        if self.num_r == 1:
+            self.w_lock.acquire(*args, **kwargs)
+        self.num_r_lock.release()
+
+    def r_release(self, *args, **kwargs):
+        assert self.num_r > 0
+        self.num_r_lock.acquire(*args, **kwargs)
+        self.num_r -= 1
+        if self.num_r == 0:
+            self.w_lock.release()
+        self.num_r_lock.release()
+
+    @contextmanager
+    def r_locked(self, *args, **kwargs):
+        """ This method is designed to be used via the `with` statement. """
+        try:
+            self.r_acquire(*args, **kwargs)
+            yield
+        finally:
+            self.r_release()
+
+    # ___________________________________________________________________
+    # Writing methods.
+
+    def w_acquire(self, *args, **kwargs):
+        self.w_lock.acquire(*args, **kwargs)
+
+    def w_release(self):
+        self.w_lock.release()
+
+    @contextmanager
+    def w_locked(self, *args, **kwargs):
+        """ This method is designed to be used via the `with` statement. """
+        try:
+            self.w_acquire(*args, **kwargs)
+            yield
+        finally:
+            self.w_release()

yacv_server/yacv.py

@@ -10,7 +10,7 @@ from dataclasses import dataclass
 from http.server import ThreadingHTTPServer
 from importlib.metadata import version
 from threading import Thread
-from typing import Optional, Dict, Union, Callable, List
+from typing import Optional, Dict, Union, Callable, List, Tuple
 
 from OCP.TopLoc import TopLoc_Location
 from OCP.TopoDS import TopoDS_Shape
@@ -18,6 +18,7 @@ from OCP.TopoDS import TopoDS_Shape
 from build123d import Shape, Axis, Location, Vector
 from dataclasses_json import dataclass_json
 
+from yacv_server.rwlock import RWLock
 from yacv_server.cad import get_shape, grab_all_cad, CADCoreLike, CADLike
 from yacv_server.myhttp import HTTPHandler
 from yacv_server.mylogger import logger
@@ -33,8 +34,8 @@ class UpdatesApiData:
     """Name of the object. Should be unique unless you want to overwrite the previous object"""
     hash: str
     """Hash of the object, to detect changes without rebuilding the object"""
-    is_remove: bool
+    is_remove: Optional[bool]
-    """Whether to remove the object from the scene"""
+    """Whether to remove the object from the scene. If None, this is a shutdown request"""
 
 
 YACVSupported = Union[bytes, CADCoreLike]
@@ -46,7 +47,7 @@ class UpdatesApiFullData(UpdatesApiData):
     kwargs: Optional[Dict[str, any]]
     """The show_object options, if any (not serialized)"""
 
-    def __init__(self, obj: YACVSupported, name: str, _hash: str, is_remove: bool = False,
+    def __init__(self, obj: YACVSupported, name: str, _hash: str, is_remove: Optional[bool] = False,
                  kwargs: Optional[Dict[str, any]] = None):
         self.name = name
         self.hash = _hash
@@ -60,22 +61,42 @@ class UpdatesApiFullData(UpdatesApiData):
 
 
 class YACV:
+    """The main yacv_server class, which manages the web server and the CAD objects."""
+
+    # Startup
     server_thread: Optional[Thread]
+    """The main thread running the server (will spawn other threads for each request)"""
     server: Optional[ThreadingHTTPServer]
+    """The server object"""
     startup_complete: threading.Event
+    """Event to signal when the server has started"""
+
+    # Running
     show_events: BufferedPubSub[UpdatesApiFullData]
+    """PubSub for show events (objects to be shown in/removed from the scene)"""
     build_events: Dict[str, BufferedPubSub[bytes]]
-    object_events_lock: threading.Lock
+    """PubSub for build events (objects that were built)"""
+    build_events_lock: threading.Lock
+    """Lock to ensure that objects are only built once"""
+
+    # Shutdown
+    at_least_one_client: threading.Event
+    """Event to signal when at least one client has connected"""
+    shutting_down: threading.Event
+    """Event to signal when the server is shutting down"""
+    frontend_lock: RWLock
+    """Lock to ensure that the frontend has finished working before we shut down"""
 
     def __init__(self):
         self.server_thread = None
         self.server = None
         self.startup_complete = threading.Event()
-        self.at_least_one_client = threading.Event()
         self.show_events = BufferedPubSub()
         self.build_events = {}
-        self.object_events_lock = threading.Lock()
+        self.build_events_lock = threading.Lock()
-        self.frontend_lock = threading.Lock()
+        self.at_least_one_client = threading.Event()
+        self.shutting_down = threading.Event()
+        self.frontend_lock = RWLock()
         logger.info('Using yacv-server v%s', version('yacv-server'))
 
     def start(self):
@@ -100,36 +121,34 @@ class YACV:
             logger.error('Cannot stop server because it is not running')
             return
 
+        # Inform the server that we are shutting down
+        self.shutting_down.set()
+        # noinspection PyTypeChecker
+        self.show_events.publish(UpdatesApiFullData(name='__shutdown', _hash='', is_remove=None, obj=None))
+
+        # If we were too fast, ensure that at least one client has connected
         graceful_secs_connect = float(os.getenv('YACV_GRACEFUL_SECS_CONNECT', 12.0))
-        graceful_secs_request = float(os.getenv('YACV_GRACEFUL_SECS_REQUEST', 5.0))
+        if graceful_secs_connect > 0:
-        # Make sure we can hold the lock for more than 100ms (to avoid exiting too early)
-        logger.info('Stopping server (waiting for at least one frontend request first, cancel with CTRL+C)...')
             start = time.time()
             try:
-            while not self.at_least_one_client.wait(
+                if not self.at_least_one_client.is_set():
-                    graceful_secs_connect / 10) and time.time() - start < graceful_secs_connect:
+                    logger.warning(
+                        'Waiting for at least one frontend request before stopping server, cancel with CTRL+C...')
+                while (not self.at_least_one_client.wait(graceful_secs_connect / 10) and
+                       time.time() - start < graceful_secs_connect):
                     time.sleep(0.01)
             except KeyboardInterrupt:
                 pass
 
-        logger.info('Stopping server (waiting for no more frontend requests)...')
+        # Wait for the server to stop gracefully (all frontends to stop working)
-        start = time.time()
+        graceful_secs_request = float(os.getenv('YACV_GRACEFUL_SECS_WORK', 1000000))
-        try:
+        with self.frontend_lock.w_locked(timeout=graceful_secs_request):
-            while time.time() - start < graceful_secs_request:
+            # Stop the server
-                if self.frontend_lock.locked():
-                    start = time.time()
-                time.sleep(0.01)
-        except KeyboardInterrupt:
-            pass
-
-        # Stop the server in the background
             self.server.shutdown()
-        logger.info('Stopping server (sent)...')
 
-        # Wait for the server to stop gracefully
+            # Wait for the server thread to stop
             self.server_thread.join(timeout=30)
             self.server_thread = None
-        logger.info('Stopping server (confirmed)...')
             if len(args) >= 1 and args[0] in (signal.SIGINT, signal.SIGTERM):
                 sys.exit(0)  # Exit with success
 
@@ -187,7 +206,7 @@ class YACV:
                 self.show_events.delete(old_show_event)
 
             # Delete any cached object builds
-            with self.object_events_lock:
+            with self.build_events_lock:
                 if name in self.build_events:
                     del self.build_events[name]
 
@@ -228,8 +247,8 @@ class YACV:
                             res.remove(old_event)
         return res
 
-    def export(self, name: str) -> Optional[bytes]:
+    def export(self, name: str) -> Optional[Tuple[bytes, str]]:
-        """Export the given previously-shown object to a single GLB file, building it if necessary."""
+        """Export the given previously-shown object to a single GLB blob, building it if necessary."""
         start = time.time()
 
         # Check that the object to build exists and grab it if it does
@@ -240,7 +259,7 @@ class YACV:
         event = events[-1]
 
         # Use the lock to ensure that we don't build the object twice
-        with self.object_events_lock:
+        with self.build_events_lock:
             # If there are no object events for this name, we need to build the object
             if name not in self.build_events:
                 logger.debug('Building object %s with hash %s', name, event.hash)
@@ -266,7 +285,7 @@ class YACV:
             # In either case return the elements of a subscription to the async generator
             subscription = self.build_events[name].subscribe()
             try:
-                return next(subscription)
+                return next(subscription), event.hash
             finally:
                 subscription.close()
 
@@ -277,7 +296,7 @@ class YACV:
         for name in self.shown_object_names():
             if export_filter(name, self._show_events(name)[-1].obj):
                 with open(os.path.join(folder, f'{name}.glb'), 'wb') as f:
-                    f.write(self.export(name))
+                    f.write(self.export(name)[0])
 
 
 # noinspection PyUnusedLocal

yarn.lock

@@ -390,28 +390,28 @@
   resolved "https://registry.yarnpkg.com/@esbuild/win32-x64/-/win32-x64-0.19.12.tgz#c57c8afbb4054a3ab8317591a0b7320360b444ae"
   integrity sha512-T1QyPSDCyMXaO3pzBkF96E8xMkiRYbUEZADd29SyPGabqxMViNoii+NcK7eWJAEoU6RZyEm5lVSIjTmcdoB9HA==
 
-"@gltf-transform/core@^3.10.0":
+"@gltf-transform/core@^3.10.0", "@gltf-transform/core@^3.10.1":
-  version "3.10.0"
+  version "3.10.1"
-  resolved "https://registry.yarnpkg.com/@gltf-transform/core/-/core-3.10.0.tgz#854e7345f23971e4e7367a29183a2d1b62d45e46"
+  resolved "https://registry.yarnpkg.com/@gltf-transform/core/-/core-3.10.1.tgz#d99c060b499482ed2c3304466405bf4c10939831"
-  integrity sha512-NxVKhSWvH0j1tjZE8Yl461HUMyZLmYmqcbqHw0TOcQd5Q1SV7Y5w6W68XMt9/amRfMAiJLLNREE7kbr+Z0Ydbw==
+  integrity sha512-50OYemknGNxjBmiOM6iJp04JAu0bl9jvXJfN/gFt9QdJO02cPDcoXlTfSPJG6TVWDcfl0xPlsx1vybcbPVGFcQ==
   dependencies:
     property-graph "^1.3.1"
 
-"@gltf-transform/extensions@^3.10.0":
+"@gltf-transform/extensions@^3.10.1":
-  version "3.10.0"
+  version "3.10.1"
-  resolved "https://registry.yarnpkg.com/@gltf-transform/extensions/-/extensions-3.10.0.tgz#4ae11c3fe8e2a77e6e9dd04ebf0931c7b0cd3690"
+  resolved "https://registry.yarnpkg.com/@gltf-transform/extensions/-/extensions-3.10.1.tgz#71664389cae46fb12eb97dc71eb96d86a0d7801f"
-  integrity sha512-dz/cf2toBzP+w3ES2VgMiINCN6q86MVGu1lHkT0El4No77Bje9fnHVEPrKwaDCsXi5YXUiG/u6686vK6jePwDA==
+  integrity sha512-xUS9K5fMvW2dkYN4VzxHg2aBPG54M2WqgIjQ7RoSyybMoD7DsPUyMyVgRja+aiTVt/Bxza2ve7zJBD3+tN+aTA==
   dependencies:
-    "@gltf-transform/core" "^3.10.0"
+    "@gltf-transform/core" "^3.10.1"
     ktx-parse "^0.6.0"
 
-"@gltf-transform/functions@^3.10.0":
+"@gltf-transform/functions@^3.10.1":
-  version "3.10.0"
+  version "3.10.1"
-  resolved "https://registry.yarnpkg.com/@gltf-transform/functions/-/functions-3.10.0.tgz#bf0331c109ac948d19be7394d3afcfae84215cfd"
+  resolved "https://registry.yarnpkg.com/@gltf-transform/functions/-/functions-3.10.1.tgz#c40817740241c0ee770f4d1210ccc766e46d8ab2"
-  integrity sha512-FStbDaH7t2z74RyEeUQn3aBcybULbDkt72ZasC0s7DwQ2DFKKKOth4Zksi4g9+8URNM6vNa2JSfuO851dkJHEg==
+  integrity sha512-Zs6+1qvTD9w40R5qv70E4wJXXacNQ46ZxjKKW6dmfGIyjT8bsSJmV3Tdj+WJ8R6lWXXZ8e2p3ZvAUfPDEG73bQ==
   dependencies:
-    "@gltf-transform/core" "^3.10.0"
+    "@gltf-transform/core" "^3.10.1"
-    "@gltf-transform/extensions" "^3.10.0"
+    "@gltf-transform/extensions" "^3.10.1"
     ktx-parse "^0.6.0"
     ndarray "^1.0.19"
     ndarray-lanczos "^0.3.0"
@@ -805,10 +805,10 @@
   resolved "https://registry.yarnpkg.com/@types/ndarray/-/ndarray-1.0.14.tgz#96b28c09a3587a76de380243f87bb7a2d63b4b23"
   integrity sha512-oANmFZMnFQvb219SSBIhI1Ih/r4CvHDOzkWyJS/XRqkMrGH5/kaPSA1hQhdIBzouaE+5KpE/f5ylI9cujmckQg==
 
-"@types/node@^20.11.25":
+"@types/node@^20.11.28":
-  version "20.11.25"
+  version "20.11.28"
-  resolved "https://registry.yarnpkg.com/@types/node/-/node-20.11.25.tgz#0f50d62f274e54dd7a49f7704cc16bfbcccaf49f"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-20.11.28.tgz#4fd5b2daff2e580c12316e457473d68f15ee6f66"
-  integrity sha512-TBHyJxk2b7HceLVGFcpAUjsa5zIdsPWlR6XHfyGzd0SFu+/NFgQgMAl96MSDZgQDvJAvV6BKsFOrt6zIL09JDw==
+  integrity sha512-M/GPWVS2wLkSkNHVeLkrF2fD5Lx5UC4PxA0uZcKc6QqbIQUJyW1jVjueJYi1z8n0I5PxYrtpnPnWglE+y9A0KA==
   dependencies:
     undici-types "~5.26.4"
 
@@ -2878,10 +2878,10 @@ tar@^6.1.11, tar@^6.1.2:
     mkdirp "^1.0.3"
     yallist "^4.0.0"
 
-terser@^5.29.1:
+terser@^5.29.2:
-  version "5.29.1"
+  version "5.29.2"
-  resolved "https://registry.yarnpkg.com/terser/-/terser-5.29.1.tgz#44e58045b70c09792ba14bfb7b4e14ca8755b9fa"
+  resolved "https://registry.yarnpkg.com/terser/-/terser-5.29.2.tgz#c17d573ce1da1b30f21a877bffd5655dd86fdb35"
-  integrity sha512-lZQ/fyaIGxsbGxApKmoPTODIzELy3++mXhS5hOqaAWZjQtpq/hFHAc+rm29NND1rYRxRWKcjuARNwULNXa5RtQ==
+  integrity sha512-ZiGkhUBIM+7LwkNjXYJq8svgkd+QK3UUr0wJqY4MieaezBSAIPgbSPZyIx0idM6XWK5CMzSWa8MJIzmRcB8Caw==
   dependencies:
     "@jridgewell/source-map" "^0.3.3"
     acorn "^8.8.2"
@@ -2992,10 +2992,10 @@ validate-npm-package-name@^5.0.0:
   dependencies:
     builtins "^5.0.0"
 
-vite@^5.1.5:
+vite@^5.1.6:
-  version "5.1.5"
+  version "5.1.6"
-  resolved "https://registry.yarnpkg.com/vite/-/vite-5.1.5.tgz#bdbc2b15e8000d9cc5172f059201178f9c9de5fb"
+  resolved "https://registry.yarnpkg.com/vite/-/vite-5.1.6.tgz#706dae5fab9e97f57578469eef1405fc483943e4"
-  integrity sha512-BdN1xh0Of/oQafhU+FvopafUp6WaYenLU/NFoL5WyJL++GxkNfieKzBhM24H3HVsPQrlAqB7iJYTHabzaRed5Q==
+  integrity sha512-yYIAZs9nVfRJ/AiOLCA91zzhjsHUgMjB+EigzFb6W2XTLO8JixBCKCjvhKZaye+NKYHCrkv3Oh50dH9EdLU2RA==
   dependencies:
     esbuild "^0.19.3"
     postcss "^8.4.35"
@@ -3031,10 +3031,10 @@ vue@^3.4.21:
     "@vue/server-renderer" "3.4.21"
     "@vue/shared" "3.4.21"
 
-vuetify@^3.5.8:
+vuetify@^3.5.9:
-  version "3.5.8"
+  version "3.5.9"
-  resolved "https://registry.yarnpkg.com/vuetify/-/vuetify-3.5.8.tgz#bc8f08dfd3314640e7b5d43b50138a26d650cbbf"
+  resolved "https://registry.yarnpkg.com/vuetify/-/vuetify-3.5.9.tgz#9cb3554f4b9bb7f3c277a10b99ab5944e6d04b03"
-  integrity sha512-8nGS+lKejZkev55HFwIfsRt+9fOqbeDQNmXxfmLKAlnUT8FtynVwbjAwHMtX/OQAQ3ZwRaR1ptqQQmx3OgxzbQ==
+  integrity sha512-tA3N2uWZFNSZRFNnXN841x4rWozYXKC0fGW/mJIwcKkQiI0+gmVCETtjF8bnOS7L1s0buWzw94uYTlXQa5AQ4w==
 
 walk-up-path@^3.0.1:
   version "3.0.1"