From 24b75b67eee393544789a71fec87a84a31c30c18 Mon Sep 17 00:00:00 2001
From: Barbagus42 <barbagus42@proton.me>
Date: Wed, 8 Nov 2023 20:59:35 +0100
Subject: [PATCH] Use async interface to database

---
 .cspell.json   | 24 ------------------------
 pyproject.toml |  1 +
 ter/config.py  |  2 ++
 ter/helpers.py | 36 ++++++++++++++++++++++++++----------
 ter/main.py    | 21 +++++++++++++++++++--
 ter/routes.py  |  8 ++++----
 6 files changed, 52 insertions(+), 40 deletions(-)
 delete mode 100644 .cspell.json

diff --git a/.cspell.json b/.cspell.json
deleted file mode 100644
index 8c48770..0000000
--- a/.cspell.json
+++ /dev/null
@@ -1,24 +0,0 @@
-// cSpell Settings
-{
-    // Version of the setting file.  Always 0.2
-    "version": "0.2",
-    // language - current active spelling language
-    "language": "en",
-    // words - list of words to be always considered correct
-    "words": [
-        "executemany",
-        "executescript",
-        "GTFS",
-        "headsign"
-    ],
-    // flagWords - list of words to be always considered incorrect
-    // This is useful for offensive words and common spelling errors.
-    // For example "hte" should be "the"
-    "flagWords": [],
-    "overrides": [
-        {
-            "language": "fr-FR",
-            "filename": "**.md"
-        }
-    ]
-}
diff --git a/pyproject.toml b/pyproject.toml
index 6f34f0e..0c76830 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -10,6 +10,7 @@ dependencies = [
     "pydantic-settings",
     "jinja2",
     "jinja2-fragments",
+    "aiosqlite",
 ]
 requires-python = ">=3.11"
 
diff --git a/ter/config.py b/ter/config.py
index 5425da8..4ff515a 100644
--- a/ter/config.py
+++ b/ter/config.py
@@ -11,6 +11,8 @@ class Settings(BaseSettings):
     TEMPLATE_DIR: str = path.join(APP_DIR, "templates")
     DATA_DIR: str = path.join(path.dirname(APP_DIR), "data")
 
+    SQLITE_URI: str = f"file:{path.join(DATA_DIR, 'db.sqlite')}?mode=ro"
+
     FASTAPI_PROPERTIES: dict = {
         "title": "TER",
         "description": "",
diff --git a/ter/helpers.py b/ter/helpers.py
index d193b53..44593c0 100644
--- a/ter/helpers.py
+++ b/ter/helpers.py
@@ -1,16 +1,32 @@
-import sqlite3
-import os.path as path
-import contextlib as ctx
+from typing import Any
+from collections.abc import Sequence, Iterable
+
+import aiosqlite
 
 from ter.config import Settings
 
 settings = Settings()
 
 
-def connect_db():
-    return ctx.closing(
-        sqlite3.connect(
-            f"file:{path.join(settings.DATA_DIR, 'db.sqlite')}?mode=ro",
-            uri=True,
-        )
-    )
+class Database:
+    Params = Sequence[Any] | dict[str, Any]
+
+    def __init__(self, uri: str) -> None:
+        self._uri: str = uri
+        self._connection: aiosqlite.Connection | None = None
+
+    async def connect(self):
+        self._connection = await aiosqlite.connect(self._uri, uri=True)
+
+    async def disconnect(self):
+        await self._connection.close()
+        self._connection = None
+
+    async def execute(self, sql: str, params: Params = ()):
+        return await self._connection.execute(sql, params)
+
+    async def executemany(self, sql: str, params: Iterable[Params]):
+        return await self._connection.executemany(sql, params)
+
+
+database = Database(settings.SQLITE_URI)
diff --git a/ter/main.py b/ter/main.py
index 9135924..dcf9805 100644
--- a/ter/main.py
+++ b/ter/main.py
@@ -1,15 +1,32 @@
+import contextlib as ctx
+
 from fastapi import FastAPI
 from fastapi.staticfiles import StaticFiles
 
 from ter.config import Settings
+from ter.helpers import database
 from ter.routes import router
 
 settings = Settings()
 
 
+@ctx.asynccontextmanager
+async def lifespan(app: FastAPI):
+    await database.connect()
+    yield
+    await database.disconnect()
+
+
 def get_app() -> FastAPI:
-    app = FastAPI(**settings.FASTAPI_PROPERTIES)
-    app.mount("/static", StaticFiles(directory=settings.STATIC_DIR), name="static")
+    app = FastAPI(
+        **settings.FASTAPI_PROPERTIES,
+        lifespan=lifespan,
+    )
+    app.mount(
+        "/static",
+        StaticFiles(directory=settings.STATIC_DIR),
+        name="static",
+    )
     app.include_router(router)
 
     return app
diff --git a/ter/routes.py b/ter/routes.py
index b38bedb..1f2b7e2 100644
--- a/ter/routes.py
+++ b/ter/routes.py
@@ -3,7 +3,7 @@ from jinja2_fragments.fastapi import Jinja2Blocks
 
 
 from ter.config import Settings
-from ter.helpers import connect_db
+from ter.helpers import database
 
 settings = Settings()
 router = APIRouter()
@@ -11,11 +11,11 @@ templates = Jinja2Blocks(settings.TEMPLATE_DIR)
 
 
 @router.get("/")
-def index(request: Request):
+async def index(request: Request):
     """Home page."""
 
-    with connect_db() as db:
-        agencies = db.execute("SELECT * FROM agency").fetchall()
+    cursor = await database.execute("SELECT * FROM agency")
+    agencies = await cursor.fetchall()
 
     context = {"request": request, "agencies": agencies}