Logicaler project structure, see rest of commit message

Incoming requests are handled in anonstream/routes/. Route handlers
mainly depend on files in anonstream/, which in turn depend on files in
anonstream/helpers/ and anonstream/utils/. Utils are pure functions and
helpers are almost pure functions; they don't mutate state but they
do depend on the global app config.

anonstream/__init__.py

@@ -5,7 +5,7 @@ from collections import OrderedDict
 from quart import Quart
 from werkzeug.security import generate_password_hash
 
-from anonstream.utils.users import generate_token
+from anonstream.utils.user import generate_token
 from anonstream.segments import DirectoryCache
 
 async def create_app():

anonstream/chat.py

@@ -3,8 +3,8 @@ from datetime import datetime
 
 from quart import escape
 
-from anonstream.users import users_for_websocket
-from anonstream.utils.chat import generate_nonce_hash
+from anonstream.user import users_for_websocket
+from anonstream.helpers.chat import generate_nonce_hash
 
 class Rejected(Exception):
     pass
@@ -13,9 +13,9 @@ async def broadcast(websockets, payload):
     for queue in websockets:
         await queue.put(payload)
 
-async def add_chat_message(chat, users, websockets, secret, user, nonce, comment):
+async def add_chat_message(chat, users, websockets, user, nonce, comment):
     # check message
-    nonce_hash = generate_nonce_hash(secret, nonce)
+    nonce_hash = generate_nonce_hash(nonce)
     if nonce_hash in chat['nonce_hashes']:
         raise Rejected('Discarded suspected duplicate message')
     if len(comment) == 0:

anonstream/helpers/chat.py

@@ -0,0 +1,9 @@
+import hashlib
+
+from quart import current_app
+
+CONFIG = current_app.config
+
+def generate_nonce_hash(nonce):
+    parts = CONFIG['SECRET_KEY'] + b'nonce-hash\0' + nonce.encode()
+    return hashlib.sha256(parts).digest()

anonstream/helpers/user.py

@@ -0,0 +1,54 @@
+import hashlib
+import base64
+from collections import OrderedDict
+from math import inf
+
+from quart import current_app
+
+CONFIG = current_app.config
+
+def generate_token_hash(token):
+    parts = CONFIG['SECRET_KEY'] + b'token-hash\0' + token.encode()
+    digest = hashlib.sha256(parts).digest()
+    return base64.b32encode(digest)[:26].lower().decode()
+
+def generate_user(secret, token, broadcaster, timestamp):
+    return {
+        'token': token,
+        'token_hash': generate_token_hash(token),
+        'broadcaster': broadcaster,
+        'name': None,
+        'color': '#c7007f',
+        'tripcode': None,
+        'notices': OrderedDict(),
+        'seen': {
+            'first': timestamp,
+            'last': timestamp,
+        },
+        'watching_last': -inf,
+    }
+
+def get_default_name(user):
+    return (
+        CONFIG['DEFAULT_HOST_NAME']
+        if user['broadcaster'] else
+        CONFIG['DEFAULT_ANON_NAME']
+    )
+
+def is_watching(timestamp, user):
+    return user['watching_last'] >= timestamp - CONFIG['THRESHOLD_IDLE']
+
+def is_idle(timestamp, user):
+    return is_present(timestamp, user) and not is_watching(timestamp, user)
+
+def is_present(timestamp, user):
+    return user['seen']['last'] >= timestamp - CONFIG['THRESHOLD_ABSENT']
+
+def is_absent(timestamp, user):
+    return not is_present(timestamp, user)
+
+def is_visible(timestamp, messages, user):
+    has_visible_messages = any(
+        message['token'] == user['token'] for message in messages
+    )
+    return has_visible_messages or is_present(timestamp, user)

anonstream/routes/nojs.py

@@ -1,9 +1,10 @@
 from quart import current_app, request, render_template, redirect, url_for
 
 from anonstream.stream import get_stream_title
-from anonstream.users import get_default_name, add_notice, pop_notice
+from anonstream.user import add_notice, pop_notice
 from anonstream.chat import add_chat_message, Rejected
 from anonstream.routes.wrappers import with_user_from
+from anonstream.helpers.user import get_default_name
 from anonstream.utils.chat import generate_nonce
 
 @current_app.route('/info.html')
@@ -52,7 +53,6 @@ async def nojs_submit_message(user):
             chat=current_app.chat,
             users=current_app.users,
             websockets=current_app.websockets,
-            secret=current_app.config['SECRET_KEY'],
             user=user,
             nonce=nonce,
             comment=comment,

anonstream/routes/websocket.py

@@ -15,8 +15,6 @@ async def live(user):
         queue=queue,
         messages=current_app.chat['messages'].values(),
         users=current_app.users,
-        default_host_name=current_app.config['DEFAULT_HOST_NAME'],
-        default_anon_name=current_app.config['DEFAULT_ANON_NAME'],
     )
     consumer = websocket_inbound(
         queue=queue,
@@ -24,7 +22,6 @@ async def live(user):
         users=current_app.users,
         connected_websockets=current_app.websockets,
         user=user,
-        secret=current_app.config['SECRET_KEY'],
     )
     try:
         await asyncio.gather(producer, consumer)

anonstream/routes/wrappers.py

@@ -4,9 +4,10 @@ from functools import wraps
 from quart import current_app, request, abort, make_response
 from werkzeug.security import check_password_hash
 
-from anonstream.users import sunset, user_for_websocket
+from anonstream.user import sunset, user_for_websocket
 from anonstream.websocket import broadcast
-from anonstream.utils.users import generate_token, generate_user
+from anonstream.helpers.user import generate_user
+from anonstream.utils.user import generate_token
 
 def check_auth(context):
     auth = context.authorization

anonstream/user.py

@@ -4,20 +4,16 @@ from math import inf
 from quart import current_app
 
 from anonstream.wrappers import with_timestamp, with_first_argument
-from anonstream.utils.users import user_for_websocket
+from anonstream.helpers.user import is_visible
+from anonstream.utils.user import user_for_websocket
 from anonstream.utils import listmap
 
-def get_default_name(user):
-    return (
-        current_app.config['DEFAULT_HOST_NAME']
-        if user['broadcaster'] else
-        current_app.config['DEFAULT_ANON_NAME']
-    )
+CONFIG = current_app.config
 
 def add_notice(user, notice):
     notice_id = time.time_ns() // 1_000_000
     user['notices'][notice_id] = notice
-    if len(user['notices']) > current_app.config['LIMIT_NOTICES']:
+    if len(user['notices']) > CONFIG['MAX_NOTICES']:
         user['notices'].popitem(last=False)
     return notice_id
 
@@ -42,31 +38,13 @@ def users_for_websocket(timestamp, messages, users):
         for user in visible_users
     }
 
-def is_watching(timestamp, user):
-    return user['watching_last'] >= timestamp - current_app.config['THRESHOLD_IDLE']
-
-def is_idle(timestamp, user):
-    return is_present(timestamp, user) and not is_watching(timestamp, user)
-
-def is_present(timestamp, user):
-    return user['seen']['last'] >= timestamp - current_app.config['THRESHOLD_ABSENT']
-
-def is_absent(timestamp, user):
-    return not is_present(timestamp, user)
-
-def is_visible(timestamp, messages, user):
-    has_visible_messages = any(
-        message['token'] == user['token'] for message in messages
-    )
-    return has_visible_messages or is_present(timestamp, user)
-
 last_checkup = -inf
 
 def sunset(messages, users):
     global last_checkup
 
     timestamp = int(time.time())
-    if timestamp - last_checkup < current_app.config['USER_CHECKUP_PERIOD']:
+    if timestamp - last_checkup < CONFIG['USER_CHECKUP_PERIOD']:
         return []
 
     to_delete = []

anonstream/utils/chat.py

@@ -8,10 +8,6 @@ class NonceReuse(Exception):
 def generate_nonce():
     return secrets.token_urlsafe(16)
 
-def generate_nonce_hash(secret, nonce):
-    parts = secret + b'nonce-hash\0' + nonce.encode()
-    return hashlib.sha256(parts).digest()
-
 def message_for_websocket(users, message):
     message_keys = ('id', 'date', 'time_minutes', 'time_seconds', 'markup')
     user_keys = ('token_hash',)

anonstream/utils/user.py

@@ -0,0 +1,14 @@
+import base64
+import hashlib
+import secrets
+from collections import OrderedDict
+from math import inf
+
+def generate_token():
+    return secrets.token_hex(16)
+
+def user_for_websocket(user, include_token_hash=True):
+    keys = ['broadcaster', 'name', 'color', 'tripcode']
+    if include_token_hash:
+        keys.append('token_hash')
+    return {key: user[key] for key in keys}

anonstream/utils/users.py

@@ -1,35 +0,0 @@
-import base64
-import hashlib
-import secrets
-from collections import OrderedDict
-from math import inf
-
-def generate_token():
-    return secrets.token_hex(16)
-
-def generate_token_hash(secret, token):
-    parts = secret + b'token-hash\0' + token.encode()
-    digest = hashlib.sha256(parts).digest()
-    return base64.b32encode(digest)[:26].lower().decode()
-
-def generate_user(secret, token, broadcaster, timestamp):
-    return {
-        'token': token,
-        'token_hash': generate_token_hash(secret, token),
-        'broadcaster': broadcaster,
-        'name': None,
-        'color': '#c7007f',
-        'tripcode': None,
-        'notices': OrderedDict(),
-        'seen': {
-            'first': timestamp,
-            'last': timestamp,
-        },
-        'watching_last': -inf,
-    }
-
-def user_for_websocket(user, include_token_hash=True):
-    keys = ['broadcaster', 'name', 'color', 'tripcode']
-    if include_token_hash:
-        keys.append('token_hash')
-    return {key: user[key] for key in keys}

anonstream/websocket.py

@@ -1,16 +1,19 @@
 import asyncio
 
-from quart import websocket
+from quart import current_app, websocket
 
 from anonstream.stream import get_stream_title, get_stream_uptime
 from anonstream.chat import broadcast, add_chat_message, Rejected
-from anonstream.users import is_present, users_for_websocket, see
+from anonstream.user import users_for_websocket, see
 from anonstream.wrappers import with_first_argument
+from anonstream.helpers.user import is_present
 from anonstream.utils import listmap
 from anonstream.utils.chat import generate_nonce, message_for_websocket
 from anonstream.utils.websocket import parse_websocket_data, Malformed
 
-async def websocket_outbound(queue, messages, users, default_host_name, default_anon_name):
+CONFIG = current_app.config
+
+async def websocket_outbound(queue, messages, users):
     payload = {
         'type': 'init',
         'nonce': generate_nonce(),
@@ -21,14 +24,17 @@ async def websocket_outbound(queue, messages, users, default_host_name, default_
             messages,
         ),
         'users': users_for_websocket(messages, users),
-        'default': {True: default_host_name, False: default_anon_name},
+        'default': {
+            True: CONFIG['DEFAULT_HOST_NAME'],
+            False: CONFIG['DEFAULT_ANON_NAME'],
+        },
     }
     await websocket.send_json(payload)
     while True:
         payload = await queue.get()
         await websocket.send_json(payload)
 
-async def websocket_inbound(queue, chat, users, connected_websockets, user, secret):
+async def websocket_inbound(queue, chat, users, connected_websockets, user):
     while True:
         receipt = await websocket.receive_json()
         see(user)
@@ -46,7 +52,6 @@ async def websocket_inbound(queue, chat, users, connected_websockets, user, secr
                     chat,
                     users,
                     connected_websockets,
-                    secret,
                     user,
                     nonce,
                     comment,