Replaced the mediasrv.py SimpleHttp server by flask and waitress,

fixing HTML5 media support.
https://stackoverflow.com/questions/37044064/html-audio-cant-set-currenttime
https://stackoverflow.com/questions/21956683/enable-access-control-on-simple-http-server
https://stackoverflow.com/questions/5052635/what-is-relation-between-content-length-and-byte-ranges-in-http-1-1
https://stackoverflow.com/questions/16725907/google-app-engine-serving-mp3-for-audio-element-needs-content-range-header

qt/aqt/mediasrv.py

@@ -1,15 +1,18 @@
 # Copyright: Ankitects Pty Ltd and contributors
 # -*- coding: utf-8 -*-
 # License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
-import http.server
+import logging
+import os
 import re
-import socket
-import socketserver
+import sys
 import threading
+import traceback
 from http import HTTPStatus
-from typing import Optional
 
-from anki.collection import _Collection
+import flask
+import flask_cors  # type: ignore
+from waitress.server import create_server  # type: ignore
+
 from anki.utils import devMode
 from aqt.qt import *
 from aqt.utils import aqt_data_folder
@@ -28,146 +31,125 @@ def _getExportFolder():
 
 
 _exportFolder = _getExportFolder()
-
-# webengine on windows sometimes opens a connection and fails to send a request,
-# which will hang the server if unthreaded
-class ThreadedHTTPServer(socketserver.ThreadingMixIn, http.server.HTTPServer):
-    # allow for a flood of requests before we've started up properly
-    request_queue_size = 100
-
-    # work around python not being able to handle non-latin hostnames
-    def server_bind(self):
-        """Override server_bind to store the server name."""
-        socketserver.TCPServer.server_bind(self)
-        host, port = self.server_address[:2]
-        try:
-            self.server_name = socket.getfqdn(host)
-        except:
-            self.server_name = "server"
-        self.server_port = port
+app = flask.Flask(__name__)
+flask_cors.CORS(app)
 
 
 class MediaServer(threading.Thread):
 
-    _port: Optional[int] = None
     _ready = threading.Event()
     daemon = True
 
     def __init__(self, mw, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        self.mw = mw
+        self.is_shutdown = False
+        _redirectWebExports.mw = mw
 
     def run(self):
-        RequestHandler.mw = self.mw
-        self.server = ThreadedHTTPServer(("127.0.0.1", 0), RequestHandler)
-        self._ready.set()
-        self.server.serve_forever()
+        try:
+            if devMode:
+                # idempotent if logging has already been set up
+                logging.basicConfig()
 
-    def getPort(self):
-        self._ready.wait()
-        return self.server.server_port
+            self.server = create_server(app, host="127.0.0.1", port=0)
+            if devMode:
+                print(
+                    "Serving on http://%s:%s"
+                    % (self.server.effective_host, self.server.effective_port)
+                )
+
+            self._ready.set()
+            self.server.run()
+
+        except Exception:
+            if not self.is_shutdown:
+                raise
 
     def shutdown(self):
-        self.server.shutdown()
-
-
-class RequestHandler(http.server.SimpleHTTPRequestHandler):
-
-    timeout = 1
-    mw: Optional[_Collection] = None
-
-    def do_GET(self):
-        f = self.send_head()
-        if f:
-            try:
-                self.copyfile(f, self.wfile)
-            except Exception as e:
-                if devMode:
-                    print("http server caught exception:", e)
-                else:
-                    # swallow it - user likely surfed away from
-                    # review screen before an image had finished
-                    # downloading
-                    pass
-            finally:
-                f.close()
-
-    def send_head(self):
-        path = self.translate_path(self.path)
-        path = self._redirectWebExports(path)
-        try:
-            isdir = os.path.isdir(path)
-        except ValueError:
-            # path too long exception on Windows
-            self.send_error(HTTPStatus.NOT_FOUND, "File not found")
-            return None
+        self.is_shutdown = True
+        sockets = list(self.server._map.values())
+        for socket in sockets:
+            socket.handle_close()
+        # https://github.com/Pylons/webtest/blob/4b8a3ebf984185ff4fefb31b4d0cf82682e1fcf7/webtest/http.py#L93-L104
+        self.server.task_dispatcher.shutdown()
 
-        if isdir:
-            self.send_error(HTTPStatus.NOT_FOUND, "File not found")
-            return None
+    def getPort(self):
+        self._ready.wait()
+        return int(self.server.effective_port)
+
+
+@app.route("/", defaults={"path": ""})
+@app.route("/<path:path>")
+def allroutes(path):
+    directory, path = _redirectWebExports(path)
+    try:
+        isdir = os.path.isdir(os.path.join(directory, path))
+    except ValueError:
+        return flask.Response(
+            "Path for '%s - %s' is too long!" % (directory, path),
+            status=HTTPStatus.BAD_REQUEST,
+            mimetype="text/plain",
+        )
 
-        ctype = self.guess_type(path)
-        try:
-            f = open(path, "rb")
-        except OSError:
-            self.send_error(HTTPStatus.NOT_FOUND, "File not found")
-            return None
-        try:
-            self.send_response(HTTPStatus.OK)
-            self.send_header("Content-type", ctype)
-            fs = os.fstat(f.fileno())
-            self.send_header("Content-Length", str(fs[6]))
-            self.send_header("Last-Modified", self.date_time_string(fs.st_mtime))
-            self.send_header("Access-Control-Allow-Origin", "*")
-            self.end_headers()
-            return f
-        except:
-            f.close()
-            raise
-
-    def log_message(self, format, *args):
-        if not devMode:
-            return
-        print(
-            "%s - - [%s] %s"
-            % (self.address_string(), self.log_date_time_string(), format % args)
+    if isdir:
+        return flask.Response(
+            "Path for '%s - %s' is a directory (not supported)!" % (directory, path),
+            status=HTTPStatus.FORBIDDEN,
+            mimetype="text/plain",
         )
 
-    def _redirectWebExports(self, path):
-        # catch /_anki references and rewrite them to web export folder
-        targetPath = os.path.join(os.getcwd(), "_anki", "")
-        if path.startswith(targetPath):
-            newPath = os.path.join(_exportFolder, path[len(targetPath) :])
-            return newPath
+    try:
+        if devMode:
+            print("Sending file '%s - %s'" % (directory, path))
+        return flask.send_from_directory(directory, path)
+
+    except Exception as error:
+        if devMode:
+            print(
+                "Caught HTTP server exception,\n%s"
+                % "".join(traceback.format_exception(*sys.exc_info())),
+            )
+
+        # swallow it - user likely surfed away from
+        # review screen before an image had finished
+        # downloading
+        return flask.Response(
+            "For path '%s - %s' %s!" % (directory, path, error),
+            status=HTTPStatus.INTERNAL_SERVER_ERROR,
+            mimetype="text/plain",
+        )
 
-        # catch /_addons references and rewrite them to addons folder
-        targetPath = os.path.join(os.getcwd(), "_addons", "")
-        if path.startswith(targetPath):
-            try:
-                addMgr = self.mw.addonManager
-            except AttributeError:
-                return path
 
-            addonPath = path[len(targetPath) :]
+def _redirectWebExports(path):
+    # catch /_anki references and rewrite them to web export folder
+    targetPath = "_anki/"
+    if path.startswith(targetPath):
+        return _exportFolder, path[len(targetPath) :]
 
-            try:
-                addon, subPath = addonPath.split(os.path.sep, 1)
-            except ValueError:
-                return path
-            if not addon:
-                return path
+    # catch /_addons references and rewrite them to addons folder
+    targetPath = "_addons/"
+    if path.startswith(targetPath):
+        addonPath = path[len(targetPath) :]
 
-            pattern = addMgr.getWebExports(addon)
-            if not pattern:
-                return path
+        try:
+            addMgr = _redirectWebExports.mw.addonManager
+        except AttributeError as error:
+            if devMode:
+                print("_redirectWebExports: %s" % error)
+            return _exportFolder, addonPath
 
-            subPath2 = subPath.replace(os.sep, "/")
-            if re.fullmatch(pattern, subPath) or re.fullmatch(pattern, subPath2):
-                newPath = os.path.join(addMgr.addonsFolder(), addonPath)
-                return newPath
+        try:
+            addon, subPath = addonPath.split(os.path.sep, 1)
+        except ValueError:
+            return addMgr.addonsFolder(), path
+        if not addon:
+            return addMgr.addonsFolder(), path
 
-        return path
+        pattern = addMgr.getWebExports(addon)
+        if not pattern:
+            return addMgr.addonsFolder(), path
 
+        if re.fullmatch(pattern, subPath):
+            return addMgr.addonsFolder(), addonPath
 
-# work around Windows machines with incorrect mime type
-RequestHandler.extensions_map[".css"] = "text/css"
+    return _redirectWebExports.mw.col.media.dir(), path

qt/setup.py

@@ -27,6 +27,9 @@ def package_files(directory):
     "pyaudio",
     "markdown",
     "jsonschema",
+    "flask",
+    "flask_cors",
+    "waitress",
     "pyqt5>=5.9",
     'psutil; sys.platform == "win32"',
     'pywin32; sys.platform == "win32"',