From 1aeeb18032a3e5e45df81c44f83130bc986a424b Mon Sep 17 00:00:00 2001
From: lhchavez <lhchavez@lhchavez.com>
Date: Wed, 6 Sep 2023 02:13:14 +0000
Subject: [PATCH 1/5] [replit] The lesser of two evils

Currently the replit library has a very gross quirk: it has a global in
`replit.database.default_db.db`, and the mere action of importing this
library causes side effects to run! (connects to the database, starts a
thread to refresh the URL, and prints a warning to stdout, adding insult
to injury).

So we're trading that very gross quirk with a gross workaround to
preserve backwards compatibility: the modules that somehow end up
importing that module now have a `__getattr__` that _lazily_ calls the
code that used to be invoked as a side-effect of importing the library.
Maybe in the future we'll deploy a breaking version of the library where
we're not beholden to this backwards-compatibility quirck.
---
 src/replit/__init__.py            | 14 +++++-
 src/replit/database/__init__.py   | 16 ++++++-
 src/replit/database/default_db.py | 73 ++++++++++++++++++++-----------
 src/replit/database/server.py     | 20 +++++++--
 src/replit/web/__init__.py        | 12 ++++-
 src/replit/web/user.py            | 16 +++++--
 6 files changed, 116 insertions(+), 35 deletions(-)

diff --git a/src/replit/__init__.py b/src/replit/__init__.py
index 14f79cf9..515ffb3f 100644
--- a/src/replit/__init__.py
+++ b/src/replit/__init__.py
@@ -2,10 +2,12 @@
 
 """The Replit Python module."""
 
+from typing import Any
+
 from . import web
 from .audio import Audio
 from .database import (
-    db,
+    LazyDB,
     Database,
     AsyncDatabase,
     make_database_proxy_blueprint,
@@ -23,3 +25,13 @@ def clear() -> None:
 
 
 audio = Audio()
+
+
+# Previous versions of this library would just have side-effects and always set
+# up a database unconditionally. That is very undesirable, so instead of doing
+# that, we are using this egregious hack to get the database / database URL
+# lazily.
+def __getattr__(name: str) -> Any:
+    if name == "db":
+        return LazyDB.get_instance().db
+    raise AttributeError(name)
diff --git a/src/replit/database/__init__.py b/src/replit/database/__init__.py
index 2e94cc7a..0d44133f 100644
--- a/src/replit/database/__init__.py
+++ b/src/replit/database/__init__.py
@@ -1,6 +1,8 @@
 """Interface with the Replit Database."""
+from typing import Any
+
 from .database import AsyncDatabase, Database, DBJSONEncoder, dumps, to_primitive
-from .default_db import db, db_url
+from .default_db import LazyDB
 from .server import make_database_proxy_blueprint, start_database_proxy
 
 __all__ = [
@@ -14,3 +16,15 @@
     "start_database_proxy",
     "to_primitive",
 ]
+
+
+# Previous versions of this library would just have side-effects and always set
+# up a database unconditionally. That is very undesirable, so instead of doing
+# that, we are using this egregious hack to get the database / database URL
+# lazily.
+def __getattr__(name: str) -> Any:
+    if name == "db":
+        return LazyDB.get_instance().db
+    if name == "db_url":
+        return LazyDB.get_instance().db_url
+    raise AttributeError(name)
diff --git a/src/replit/database/default_db.py b/src/replit/database/default_db.py
index cc00c8d2..7b8c63f3 100644
--- a/src/replit/database/default_db.py
+++ b/src/replit/database/default_db.py
@@ -1,41 +1,64 @@
 """A module containing the default database."""
-from os import environ, path
+import logging
+import os
+import os.path
 import threading
-from typing import Optional
-
+from typing import Any, Optional
 
 from .database import Database
 
 
-def get_db_url() -> str:
+def get_db_url() -> Optional[str]:
     """Fetches the most up-to-date db url from the Repl environment."""
     # todo look into the security warning ignored below
     tmpdir = "/tmp/replitdb"  # noqa: S108
-    if path.exists(tmpdir):
+    if os.path.exists(tmpdir):
         with open(tmpdir, "r") as file:
-            db_url = file.read()
-    else:
-        db_url = environ.get("REPLIT_DB_URL")
+            return file.read()
+
+    return os.environ.get("REPLIT_DB_URL")
+
+
+class LazyDB:
+    """A way to lazily create a database connection."""
 
-    return db_url
+    _instance: Optional["LazyDB"] = None
 
+    def __init__(self) -> None:
+        self.db: Optional[Database] = None
+        self.db_url = get_db_url()
+        if self.db_url:
+            self.db = Database(self.db_url)
+            self.refresh_db()
+        else:
+            logging.warning(
+                "Warning: error initializing database. Replit DB is not configured."
+            )
 
-def refresh_db() -> None:
-    """Refresh the DB URL every hour."""
-    global db
-    db_url = get_db_url()
-    db.update_db_url(db_url)
-    threading.Timer(3600, refresh_db).start()
+    def refresh_db(self) -> None:
+        """Refresh the DB URL every hour."""
+        if not self.db:
+            return
+        self.db_url = get_db_url()
+        if self.db_url:
+            self.db.update_db_url(self.db_url)
+        threading.Timer(3600, self.refresh_db).start()
 
+    @classmethod
+    def get_instance(cls) -> "LazyDB":
+        """Get the lazy singleton instance."""
+        if cls._instance is None:
+            cls._instance = LazyDB()
+        return cls._instance
 
-db: Optional[Database]
-db_url = get_db_url()
-if db_url:
-    db = Database(db_url)
-else:
-    # The user will see errors if they try to use the database.
-    print("Warning: error initializing database. Replit DB is not configured.")
-    db = None
 
-if db:
-    refresh_db()
+# Previous versions of this library would just have side-effects and always set
+# up a database unconditionally. That is very undesirable, so instead of doing
+# that, we are using this egregious hack to get the database / database URL
+# lazily.
+def __getattr__(name: str) -> Any:
+    if name == "db":
+        return LazyDB.get_instance().db
+    if name == "db_url":
+        return LazyDB.get_instance().db_url
+    raise AttributeError(name)
diff --git a/src/replit/database/server.py b/src/replit/database/server.py
index 0149415f..8b8fd99c 100644
--- a/src/replit/database/server.py
+++ b/src/replit/database/server.py
@@ -4,7 +4,7 @@
 
 from flask import Blueprint, Flask, request
 
-from .default_db import db
+from .default_db import LazyDB
 
 
 def make_database_proxy_blueprint(view_only: bool, prefix: str = "") -> Blueprint:
@@ -20,10 +20,13 @@ def make_database_proxy_blueprint(view_only: bool, prefix: str = "") -> Blueprin
     app = Blueprint("database_proxy" + ("_view_only" if view_only else ""), __name__)
 
     def list_keys() -> Any:
-        user_prefix = request.args.get("prefix")
+        db = LazyDB.get_instance().db
+        if db is None:
+            return "Database is not configured", 500
+        user_prefix = request.args.get("prefix", "")
         encode = "encode" in request.args
-        keys = db.prefix(prefix=prefix + user_prefix)
-        keys = [k[len(prefix) :] for k in keys]
+        raw_keys = db.prefix(prefix=prefix + user_prefix)
+        keys = [k[len(prefix) :] for k in raw_keys]
 
         if encode:
             return "\n".join(quote(k) for k in keys)
@@ -31,6 +34,9 @@ def list_keys() -> Any:
             return "\n".join(keys)
 
     def set_key() -> Any:
+        db = LazyDB.get_instance().db
+        if db is None:
+            return "Database is not configured", 500
         if view_only:
             return "Database is view only", 401
         for k, v in request.form.items():
@@ -44,12 +50,18 @@ def index() -> Any:
         return set_key()
 
     def get_key(key: str) -> Any:
+        db = LazyDB.get_instance().db
+        if db is None:
+            return "Database is not configured", 500
         try:
             return db[prefix + key]
         except KeyError:
             return "", 404
 
     def delete_key(key: str) -> Any:
+        db = LazyDB.get_instance().db
+        if db is None:
+            return "Database is not configured", 500
         if view_only:
             return "Database is view only", 401
         try:
diff --git a/src/replit/web/__init__.py b/src/replit/web/__init__.py
index 117b02f3..9ca57814 100644
--- a/src/replit/web/__init__.py
+++ b/src/replit/web/__init__.py
@@ -9,6 +9,16 @@
 from .app import debug, ReplitAuthContext, run
 from .user import User, UserStore
 from .utils import *
-from ..database import AsyncDatabase, Database, db
+from ..database import AsyncDatabase, Database, LazyDB
 
 auth = LocalProxy(lambda: ReplitAuthContext.from_headers(flask.request.headers))
+
+
+# Previous versions of this library would just have side-effects and always set
+# up a database unconditionally. That is very undesirable, so instead of doing
+# that, we are using this egregious hack to get the database / database URL
+# lazily.
+def __getattr__(name: str) -> Any:
+    if name == "db":
+        return LazyDB.get_instance().db
+    raise AttributeError(name)
diff --git a/src/replit/web/user.py b/src/replit/web/user.py
index fa85ba87..c4bbe4a7 100644
--- a/src/replit/web/user.py
+++ b/src/replit/web/user.py
@@ -5,9 +5,7 @@
 import flask
 
 from .app import ReplitAuthContext
-from ..database import Database, db as real_db
-
-db: Database = real_db  # type: ignore
+from ..database import LazyDB
 
 
 class User(MutableMapping):
@@ -31,10 +29,19 @@ def set_value(self, value: str) -> None:
 
         Args:
             value (str): The value to set in the database
+
+        Raises:
+            RuntimeError: Raised if the database is not configured.
         """
+        db = LazyDB.get_instance().db
+        if db is None:
+            raise RuntimeError("database not configured")
         db[self.db_key()] = value
 
     def _ensure_value(self) -> Any:
+        db = LazyDB.get_instance().db
+        if db is None:
+            raise RuntimeError("database not configured")
         try:
             return db[self.db_key()]
         except KeyError:
@@ -103,6 +110,9 @@ def __getitem__(self, name: str) -> User:
         return User(username=name, prefix=self.prefix)
 
     def __iter__(self) -> Iterator[str]:
+        db = LazyDB.get_instance().db
+        if db is None:
+            raise RuntimeError("database not configured")
         for k in db.keys():
             if k.startswith(self.prefix):
                 yield self._strip_prefix(k)

From a34c32199dd54aefebca4bc381139e65e5bce0f6 Mon Sep 17 00:00:00 2001
From: Devon Stewart <devon.stewart@repl.it>
Date: Sat, 24 Feb 2024 07:24:01 +0000
Subject: [PATCH 2/5] Marking internal properties as private

Providing accessors, to hint that we are accessing mutable state
---
 src/replit/__init__.py            |  2 +-
 src/replit/database/__init__.py   |  4 ++--
 src/replit/database/default_db.py | 30 ++++++++++++++++++++----------
 src/replit/database/server.py     |  8 ++++----
 src/replit/web/__init__.py        |  2 +-
 src/replit/web/user.py            |  6 +++---
 6 files changed, 31 insertions(+), 21 deletions(-)

diff --git a/src/replit/__init__.py b/src/replit/__init__.py
index 515ffb3f..805e49bd 100644
--- a/src/replit/__init__.py
+++ b/src/replit/__init__.py
@@ -33,5 +33,5 @@ def clear() -> None:
 # lazily.
 def __getattr__(name: str) -> Any:
     if name == "db":
-        return LazyDB.get_instance().db
+        return LazyDB.get_db()
     raise AttributeError(name)
diff --git a/src/replit/database/__init__.py b/src/replit/database/__init__.py
index 0d44133f..802e7fe3 100644
--- a/src/replit/database/__init__.py
+++ b/src/replit/database/__init__.py
@@ -24,7 +24,7 @@
 # lazily.
 def __getattr__(name: str) -> Any:
     if name == "db":
-        return LazyDB.get_instance().db
+        return LazyDB.get_db()
     if name == "db_url":
-        return LazyDB.get_instance().db_url
+        return LazyDB.get_db_url()
     raise AttributeError(name)
diff --git a/src/replit/database/default_db.py b/src/replit/database/default_db.py
index 7b8c63f3..987004b0 100644
--- a/src/replit/database/default_db.py
+++ b/src/replit/database/default_db.py
@@ -25,10 +25,10 @@ class LazyDB:
     _instance: Optional["LazyDB"] = None
 
     def __init__(self) -> None:
-        self.db: Optional[Database] = None
-        self.db_url = get_db_url()
-        if self.db_url:
-            self.db = Database(self.db_url)
+        self._db: Optional[Database] = None
+        self._db_url = get_db_url()
+        if self._db_url:
+            self._db = Database(self._db_url)
             self.refresh_db()
         else:
             logging.warning(
@@ -37,11 +37,11 @@ def __init__(self) -> None:
 
     def refresh_db(self) -> None:
         """Refresh the DB URL every hour."""
-        if not self.db:
+        if not self._db:
             return
-        self.db_url = get_db_url()
-        if self.db_url:
-            self.db.update_db_url(self.db_url)
+        self._db_url = get_db_url()
+        if self._db_url:
+            self._db.update_db_url(self._db_url)
         threading.Timer(3600, self.refresh_db).start()
 
     @classmethod
@@ -51,6 +51,16 @@ def get_instance(cls) -> "LazyDB":
             cls._instance = LazyDB()
         return cls._instance
 
+    @classmethod
+    def get_db(cls) -> Optional[Database]:
+        """Get a reference to the singleton Database instance."""
+        return cls.get_instance()._db
+
+    @classmethod
+    def get_db_url(cls) -> Optional[str]:
+        """Get the db_url connection string."""
+        return cls.get_instance()._db_url
+
 
 # Previous versions of this library would just have side-effects and always set
 # up a database unconditionally. That is very undesirable, so instead of doing
@@ -58,7 +68,7 @@ def get_instance(cls) -> "LazyDB":
 # lazily.
 def __getattr__(name: str) -> Any:
     if name == "db":
-        return LazyDB.get_instance().db
+        return LazyDB.get_db()
     if name == "db_url":
-        return LazyDB.get_instance().db_url
+        return LazyDB.get_db_url()
     raise AttributeError(name)
diff --git a/src/replit/database/server.py b/src/replit/database/server.py
index 8b8fd99c..237f7d3c 100644
--- a/src/replit/database/server.py
+++ b/src/replit/database/server.py
@@ -20,7 +20,7 @@ def make_database_proxy_blueprint(view_only: bool, prefix: str = "") -> Blueprin
     app = Blueprint("database_proxy" + ("_view_only" if view_only else ""), __name__)
 
     def list_keys() -> Any:
-        db = LazyDB.get_instance().db
+        db = LazyDB.get_db()
         if db is None:
             return "Database is not configured", 500
         user_prefix = request.args.get("prefix", "")
@@ -34,7 +34,7 @@ def list_keys() -> Any:
             return "\n".join(keys)
 
     def set_key() -> Any:
-        db = LazyDB.get_instance().db
+        db = LazyDB.get_db()
         if db is None:
             return "Database is not configured", 500
         if view_only:
@@ -50,7 +50,7 @@ def index() -> Any:
         return set_key()
 
     def get_key(key: str) -> Any:
-        db = LazyDB.get_instance().db
+        db = LazyDB.get_db()
         if db is None:
             return "Database is not configured", 500
         try:
@@ -59,7 +59,7 @@ def get_key(key: str) -> Any:
             return "", 404
 
     def delete_key(key: str) -> Any:
-        db = LazyDB.get_instance().db
+        db = LazyDB.get_db()
         if db is None:
             return "Database is not configured", 500
         if view_only:
diff --git a/src/replit/web/__init__.py b/src/replit/web/__init__.py
index 9ca57814..ec8e6ba2 100644
--- a/src/replit/web/__init__.py
+++ b/src/replit/web/__init__.py
@@ -20,5 +20,5 @@
 # lazily.
 def __getattr__(name: str) -> Any:
     if name == "db":
-        return LazyDB.get_instance().db
+        return LazyDB.get_db()
     raise AttributeError(name)
diff --git a/src/replit/web/user.py b/src/replit/web/user.py
index c4bbe4a7..cb635369 100644
--- a/src/replit/web/user.py
+++ b/src/replit/web/user.py
@@ -33,13 +33,13 @@ def set_value(self, value: str) -> None:
         Raises:
             RuntimeError: Raised if the database is not configured.
         """
-        db = LazyDB.get_instance().db
+        db = LazyDB.get_db()
         if db is None:
             raise RuntimeError("database not configured")
         db[self.db_key()] = value
 
     def _ensure_value(self) -> Any:
-        db = LazyDB.get_instance().db
+        db = LazyDB.get_db()
         if db is None:
             raise RuntimeError("database not configured")
         try:
@@ -110,7 +110,7 @@ def __getitem__(self, name: str) -> User:
         return User(username=name, prefix=self.prefix)
 
     def __iter__(self) -> Iterator[str]:
-        db = LazyDB.get_instance().db
+        db = LazyDB.get_db()
         if db is None:
             raise RuntimeError("database not configured")
         for k in db.keys():

From e6284786bd9ded718b6c5bf10bedc12ef5d30e05 Mon Sep 17 00:00:00 2001
From: Devon Stewart <devon.stewart@repl.it>
Date: Sat, 24 Feb 2024 07:56:15 +0000
Subject: [PATCH 3/5] Reintroduce refresh_db noop to avoid errors on upgrade

---
 src/replit/database/default_db.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/replit/database/default_db.py b/src/replit/database/default_db.py
index 987004b0..5e080e6d 100644
--- a/src/replit/database/default_db.py
+++ b/src/replit/database/default_db.py
@@ -19,6 +19,11 @@ def get_db_url() -> Optional[str]:
     return os.environ.get("REPLIT_DB_URL")
 
 
+def refresh_db() -> None:
+    """Deprecated: refresh_db is now located inside the LazyDB singleton instance."""
+    pass
+
+
 class LazyDB:
     """A way to lazily create a database connection."""
 

From 5be6253cf442d2c97da63d80e00f3e7c8a3db196 Mon Sep 17 00:00:00 2001
From: Devon Stewart <devon.stewart@repl.it>
Date: Sat, 24 Feb 2024 09:07:54 +0000
Subject: [PATCH 4/5] Reflow LazyDB back down into default_db module

An issue with LazyDB is that the refresh_db timer would not get canceled
if the user closes the database.

Additionally, the db_url refresh logic relies on injection, whereas the Database should ideally be the thing requesting that information from the environment
---
 src/replit/__init__.py            |  5 +-
 src/replit/database/__init__.py   |  6 +-
 src/replit/database/database.py   | 96 ++++++++++++++++++++++++++++---
 src/replit/database/default_db.py | 71 ++++++++---------------
 src/replit/database/server.py     | 22 +++----
 src/replit/web/__init__.py        |  5 +-
 src/replit/web/user.py            | 21 +++----
 7 files changed, 140 insertions(+), 86 deletions(-)

diff --git a/src/replit/__init__.py b/src/replit/__init__.py
index 805e49bd..66f5ef4f 100644
--- a/src/replit/__init__.py
+++ b/src/replit/__init__.py
@@ -4,10 +4,9 @@
 
 from typing import Any
 
-from . import web
+from . import database, web
 from .audio import Audio
 from .database import (
-    LazyDB,
     Database,
     AsyncDatabase,
     make_database_proxy_blueprint,
@@ -33,5 +32,5 @@ def clear() -> None:
 # lazily.
 def __getattr__(name: str) -> Any:
     if name == "db":
-        return LazyDB.get_db()
+        return database.db
     raise AttributeError(name)
diff --git a/src/replit/database/__init__.py b/src/replit/database/__init__.py
index 802e7fe3..2fafdec0 100644
--- a/src/replit/database/__init__.py
+++ b/src/replit/database/__init__.py
@@ -1,8 +1,8 @@
 """Interface with the Replit Database."""
 from typing import Any
 
+from . import default_db
 from .database import AsyncDatabase, Database, DBJSONEncoder, dumps, to_primitive
-from .default_db import LazyDB
 from .server import make_database_proxy_blueprint, start_database_proxy
 
 __all__ = [
@@ -24,7 +24,7 @@
 # lazily.
 def __getattr__(name: str) -> Any:
     if name == "db":
-        return LazyDB.get_db()
+        return default_db.db
     if name == "db_url":
-        return LazyDB.get_db_url()
+        return default_db.db_url
     raise AttributeError(name)
diff --git a/src/replit/database/database.py b/src/replit/database/database.py
index f4e63399..025e6767 100644
--- a/src/replit/database/database.py
+++ b/src/replit/database/database.py
@@ -1,7 +1,8 @@
-"""Async and dict-like interfaces for interacting with Repl.it Database."""
+"""Async and dict-like interfaces for interacting with Replit Database."""
 
 from collections import abc
 import json
+import threading
 from typing import (
     Any,
     Callable,
@@ -61,24 +62,57 @@ def dumps(val: Any) -> str:
 
 
 class AsyncDatabase:
-    """Async interface for Repl.it Database."""
+    """Async interface for Replit Database.
 
-    __slots__ = ("db_url", "sess", "client")
+    :param str db_url: The Database URL to connect to
+    :param int retry_count: How many retry attempts we should make
+    :param get_db_url Callable: A callback that returns the current db_url
+    :param unbind Callable: Permit additional behavior after Database close
+    """
+
+    __slots__ = ("db_url", "sess", "client", "_get_db_url", "_unbind", "_refresh_timer")
+    _refresh_timer: Optional[threading.Timer]
 
-    def __init__(self, db_url: str, retry_count: int = 5) -> None:
+    def __init__(
+        self,
+        db_url: str,
+        retry_count: int = 5,
+        get_db_url: Optional[Callable[[], Optional[str]]] = None,
+        unbind: Optional[Callable[[], None]] = None,
+    ) -> None:
         """Initialize database. You shouldn't have to do this manually.
 
         Args:
             db_url (str): Database url to use.
             retry_count (int): How many times to retry connecting
                 (with exponential backoff)
+            get_db_url (callable[[], str]): A function that will be called to refresh
+                the db_url property
+            unbind (callable[[], None]): A callback to clean up after .close() is called
         """
         self.db_url = db_url
         self.sess = aiohttp.ClientSession()
+        self._get_db_url = get_db_url
+        self._unbind = unbind
 
         retry_options = ExponentialRetry(attempts=retry_count)
         self.client = RetryClient(client_session=self.sess, retry_options=retry_options)
 
+        if self._get_db_url:
+            self._refresh_timer = threading.Timer(3600, self._refresh_db)
+            self._refresh_timer.start()
+
+    def _refresh_db(self) -> None:
+        if self._refresh_timer:
+            self._refresh_timer.cancel()
+            self._refresh_timer = None
+        if self._get_db_url:
+            db_url = self._get_db_url()
+            if db_url:
+                self.update_db_url(db_url)
+            self._refresh_timer = threading.Timer(3600, self._refresh_db)
+            self._refresh_timer.start()
+
     def update_db_url(self, db_url: str) -> None:
         """Update the database url.
 
@@ -239,6 +273,16 @@ async def items(self) -> Tuple[Tuple[str, str], ...]:
         """
         return tuple((await self.to_dict()).items())
 
+    async def close(self) -> None:
+        """Closes the database client connection."""
+        await self.sess.close()
+        if self._refresh_timer:
+            self._refresh_timer.cancel()
+            self._refresh_timer = None
+        if self._unbind:
+            # Permit signaling to surrounding scopes that we have closed
+            self._unbind()
+
     def __repr__(self) -> str:
         """A representation of the database.
 
@@ -417,30 +461,62 @@ def item_to_observed(on_mutate: Callable[[Any], None], item: Any) -> Any:
 
 
 class Database(abc.MutableMapping):
-    """Dictionary-like interface for Repl.it Database.
+    """Dictionary-like interface for Replit Database.
 
     This interface will coerce all values everything to and from JSON. If you
     don't want this, use AsyncDatabase instead.
+
+    :param str db_url: The Database URL to connect to
+    :param int retry_count: How many retry attempts we should make
+    :param get_db_url Callable: A callback that returns the current db_url
+    :param unbind Callable: Permit additional behavior after Database close
     """
 
-    __slots__ = ("db_url", "sess")
+    __slots__ = ("db_url", "sess", "_get_db_url", "_unbind", "_refresh_timer")
+    _refresh_timer: Optional[threading.Timer]
 
-    def __init__(self, db_url: str, retry_count: int = 5) -> None:
+    def __init__(
+        self,
+        db_url: str,
+        retry_count: int = 5,
+        get_db_url: Optional[Callable[[], Optional[str]]] = None,
+        unbind: Optional[Callable[[], None]] = None,
+    ) -> None:
         """Initialize database. You shouldn't have to do this manually.
 
         Args:
             db_url (str): Database url to use.
             retry_count (int): How many times to retry connecting
                 (with exponential backoff)
+            get_db_url (callable[[], str]): A function that will be called to refresh
+                the db_url property
+            unbind (callable[[], None]): A callback to clean up after .close() is called
         """
         self.db_url = db_url
         self.sess = requests.Session()
+        self._get_db_url = get_db_url
+        self._unbind = unbind
         retries = Retry(
             total=retry_count, backoff_factor=0.1, status_forcelist=[500, 502, 503, 504]
         )
         self.sess.mount("http://", HTTPAdapter(max_retries=retries))
         self.sess.mount("https://", HTTPAdapter(max_retries=retries))
 
+        if self._get_db_url:
+            self._refresh_timer = threading.Timer(3600, self._refresh_db)
+            self._refresh_timer.start()
+
+    def _refresh_db(self) -> None:
+        if self._refresh_timer:
+            self._refresh_timer.cancel()
+            self._refresh_timer = None
+        if self._get_db_url:
+            db_url = self._get_db_url()
+            if db_url:
+                self.update_db_url(db_url)
+            self._refresh_timer = threading.Timer(3600, self._refresh_db)
+            self._refresh_timer.start()
+
     def update_db_url(self, db_url: str) -> None:
         """Update the database url.
 
@@ -627,3 +703,9 @@ def __repr__(self) -> str:
     def close(self) -> None:
         """Closes the database client connection."""
         self.sess.close()
+        if self._refresh_timer:
+            self._refresh_timer.cancel()
+            self._refresh_timer = None
+        if self._unbind:
+            # Permit signaling to surrounding scopes that we have closed
+            self._unbind()
diff --git a/src/replit/database/default_db.py b/src/replit/database/default_db.py
index 5e080e6d..7b6e1427 100644
--- a/src/replit/database/default_db.py
+++ b/src/replit/database/default_db.py
@@ -1,8 +1,6 @@
 """A module containing the default database."""
-import logging
 import os
 import os.path
-import threading
 from typing import Any, Optional
 
 from .database import Database
@@ -20,51 +18,32 @@ def get_db_url() -> Optional[str]:
 
 
 def refresh_db() -> None:
-    """Deprecated: refresh_db is now located inside the LazyDB singleton instance."""
+    """Deprecated: refresh_db is now the responsibility of the Database instance."""
     pass
 
 
-class LazyDB:
-    """A way to lazily create a database connection."""
-
-    _instance: Optional["LazyDB"] = None
-
-    def __init__(self) -> None:
-        self._db: Optional[Database] = None
-        self._db_url = get_db_url()
-        if self._db_url:
-            self._db = Database(self._db_url)
-            self.refresh_db()
-        else:
-            logging.warning(
-                "Warning: error initializing database. Replit DB is not configured."
-            )
-
-    def refresh_db(self) -> None:
-        """Refresh the DB URL every hour."""
-        if not self._db:
-            return
-        self._db_url = get_db_url()
-        if self._db_url:
-            self._db.update_db_url(self._db_url)
-        threading.Timer(3600, self.refresh_db).start()
-
-    @classmethod
-    def get_instance(cls) -> "LazyDB":
-        """Get the lazy singleton instance."""
-        if cls._instance is None:
-            cls._instance = LazyDB()
-        return cls._instance
-
-    @classmethod
-    def get_db(cls) -> Optional[Database]:
-        """Get a reference to the singleton Database instance."""
-        return cls.get_instance()._db
-
-    @classmethod
-    def get_db_url(cls) -> Optional[str]:
-        """Get the db_url connection string."""
-        return cls.get_instance()._db_url
+def _unbind() -> None:
+    global _db
+    _db = None
+
+
+def _get_db() -> Optional[Database]:
+    global _db
+    if _db is not None:
+        return _db
+
+    db_url = get_db_url()
+
+    if db_url:
+        _db = Database(db_url, get_db_url=get_db_url, unbind=_unbind)
+    else:
+        # The user will see errors if they try to use the database.
+        print("Warning: error initializing database. Replit DB is not configured.")
+        _db = None
+    return _db
+
+
+_db: Optional[Database] = None
 
 
 # Previous versions of this library would just have side-effects and always set
@@ -73,7 +52,7 @@ def get_db_url(cls) -> Optional[str]:
 # lazily.
 def __getattr__(name: str) -> Any:
     if name == "db":
-        return LazyDB.get_db()
+        return _get_db()
     if name == "db_url":
-        return LazyDB.get_db_url()
+        return get_db_url()
     raise AttributeError(name)
diff --git a/src/replit/database/server.py b/src/replit/database/server.py
index 237f7d3c..6b70b30d 100644
--- a/src/replit/database/server.py
+++ b/src/replit/database/server.py
@@ -4,7 +4,7 @@
 
 from flask import Blueprint, Flask, request
 
-from .default_db import LazyDB
+from . import default_db
 
 
 def make_database_proxy_blueprint(view_only: bool, prefix: str = "") -> Blueprint:
@@ -20,12 +20,11 @@ def make_database_proxy_blueprint(view_only: bool, prefix: str = "") -> Blueprin
     app = Blueprint("database_proxy" + ("_view_only" if view_only else ""), __name__)
 
     def list_keys() -> Any:
-        db = LazyDB.get_db()
-        if db is None:
+        if default_db.db is None:
             return "Database is not configured", 500
         user_prefix = request.args.get("prefix", "")
         encode = "encode" in request.args
-        raw_keys = db.prefix(prefix=prefix + user_prefix)
+        raw_keys = default_db.db.prefix(prefix=prefix + user_prefix)
         keys = [k[len(prefix) :] for k in raw_keys]
 
         if encode:
@@ -34,13 +33,12 @@ def list_keys() -> Any:
             return "\n".join(keys)
 
     def set_key() -> Any:
-        db = LazyDB.get_db()
-        if db is None:
+        if default_db.db is None:
             return "Database is not configured", 500
         if view_only:
             return "Database is view only", 401
         for k, v in request.form.items():
-            db[prefix + k] = v
+            default_db.db[prefix + k] = v
         return ""
 
     @app.route("/", methods=["GET", "POST"])
@@ -50,22 +48,20 @@ def index() -> Any:
         return set_key()
 
     def get_key(key: str) -> Any:
-        db = LazyDB.get_db()
-        if db is None:
+        if default_db.db is None:
             return "Database is not configured", 500
         try:
-            return db[prefix + key]
+            return default_db.db[prefix + key]
         except KeyError:
             return "", 404
 
     def delete_key(key: str) -> Any:
-        db = LazyDB.get_db()
-        if db is None:
+        if default_db.db is None:
             return "Database is not configured", 500
         if view_only:
             return "Database is view only", 401
         try:
-            del db[prefix + key]
+            del default_db.db[prefix + key]
         except KeyError:
             return "", 404
         return ""
diff --git a/src/replit/web/__init__.py b/src/replit/web/__init__.py
index ec8e6ba2..03c86f1b 100644
--- a/src/replit/web/__init__.py
+++ b/src/replit/web/__init__.py
@@ -9,7 +9,8 @@
 from .app import debug, ReplitAuthContext, run
 from .user import User, UserStore
 from .utils import *
-from ..database import AsyncDatabase, Database, LazyDB
+from .. import database
+from ..database import AsyncDatabase, Database
 
 auth = LocalProxy(lambda: ReplitAuthContext.from_headers(flask.request.headers))
 
@@ -20,5 +21,5 @@
 # lazily.
 def __getattr__(name: str) -> Any:
     if name == "db":
-        return LazyDB.get_db()
+        return database.db
     raise AttributeError(name)
diff --git a/src/replit/web/user.py b/src/replit/web/user.py
index cb635369..133e6c37 100644
--- a/src/replit/web/user.py
+++ b/src/replit/web/user.py
@@ -5,7 +5,7 @@
 import flask
 
 from .app import ReplitAuthContext
-from ..database import LazyDB
+from .. import database
 
 
 class User(MutableMapping):
@@ -33,20 +33,18 @@ def set_value(self, value: str) -> None:
         Raises:
             RuntimeError: Raised if the database is not configured.
         """
-        db = LazyDB.get_db()
-        if db is None:
+        if database.db is None:
             raise RuntimeError("database not configured")
-        db[self.db_key()] = value
+        database.db[self.db_key()] = value
 
     def _ensure_value(self) -> Any:
-        db = LazyDB.get_db()
-        if db is None:
+        if database.db is None:
             raise RuntimeError("database not configured")
         try:
-            return db[self.db_key()]
+            return database.db[self.db_key()]
         except KeyError:
-            db[self.db_key()] = {}
-            return db[self.db_key()]
+            database.db[self.db_key()] = {}
+            return database.db[self.db_key()]
 
     def set(self, key: str, val: Any) -> None:
         """Sets a key to a value for this user's entry in the database.
@@ -110,10 +108,9 @@ def __getitem__(self, name: str) -> User:
         return User(username=name, prefix=self.prefix)
 
     def __iter__(self) -> Iterator[str]:
-        db = LazyDB.get_db()
-        if db is None:
+        if database.db is None:
             raise RuntimeError("database not configured")
-        for k in db.keys():
+        for k in database.db.keys():
             if k.startswith(self.prefix):
                 yield self._strip_prefix(k)
 

From e4d5a025c262ef39c77cf967afabf421923b2b4a Mon Sep 17 00:00:00 2001
From: Devon Stewart <devon.stewart@repl.it>
Date: Mon, 26 Feb 2024 22:07:51 +0000
Subject: [PATCH 5/5] Removing stale main.sh

---
 main.sh | 1 -
 1 file changed, 1 deletion(-)
 delete mode 100644 main.sh

diff --git a/main.sh b/main.sh
deleted file mode 100644
index 975cd92a..00000000
--- a/main.sh
+++ /dev/null
@@ -1 +0,0 @@
-python testapp.py
\ No newline at end of file