Add caching for full_page and summary query

- FastAPI BackgroundTasks for caching
- Caching is on backend (in-memory), shared among all users but disappears when I restart the backend container, fair enough.
- Caching is tested, working as expected.
- Put the caching part in a background task, giving priority to returning the result.

main.py

@@ -1,10 +1,11 @@
-from fastapi import FastAPI
+from fastapi import FastAPI, BackgroundTasks
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse, HTMLResponse
 from pydantic import BaseModel, Field
 import requests
 from geopy.geocoders import Nominatim
 import geopy.distance
+from cachetools import TTLCache
 
 app = FastAPI()
 
@@ -25,12 +26,18 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
+summary_cache = TTLCache(maxsize=100, ttl=300)  # ttl time in seconds, then cache expires
+full_page_cache = TTLCache(maxsize=100, ttl=300)
+
 @app.get("/")
 def health_check():
     return {"status": "ok"}
 
 @app.get("/wiki/{page_name}")
-async def get_wiki_page(page_name: str):
+async def get_wiki_page(page_name: str, background_tasks: BackgroundTasks):
+    if page_name in summary_cache:
+        # print("Cache hit for summary:", page_name) #Working
+        return JSONResponse(content=summary_cache[page_name], status_code=200)
     response = requests.get(f"https://en.wikipedia.org/api/rest_v1/page/summary/{page_name}", timeout=10)
 
     if response.status_code != 200:
@@ -41,18 +48,27 @@ async def get_wiki_page(page_name: str):
     
     coords = loc.geocode(page_name)
     
-    return JSONResponse(
-        content={
+    result = {
             "title": page_name,
             "content": f"{response.json().get('extract', 'No content available')}",
             "latitude": coords.latitude if coords else None,
             "longitude": coords.longitude if coords else None
-        },
+        }
+    
+    background_tasks.add_task(lambda: summary_cache.__setitem__(page_name, result))
+
+
+    return JSONResponse(
+        content= result,
         status_code=200
     )
 
 @app.get("/wiki/search/{full_page}")
-def search_wiki(full_page: str):
+def search_wiki(full_page: str, background_tasks: BackgroundTasks):
+    if full_page in full_page_cache:
+        # print("Cache hit for full_page:", full_page) #Working
+        return JSONResponse(content=full_page_cache[full_page], status_code=200)
+    
     response = requests.get(f"https://en.wikipedia.org/wiki/{full_page}", timeout=10)
     try:
         if response.status_code != 200:
@@ -63,15 +79,20 @@ def search_wiki(full_page: str):
 
         coords = loc.geocode(full_page)
 
-        return JSONResponse(
-            content={
+        result = {
                         "title": full_page, 
                         "content": str(response.text),
                         "latitude": coords.latitude if coords else None,
                         "longitude": coords.longitude if coords else None
-                    },
+                }
+        
+        background_tasks.add_task(lambda: full_page_cache.__setitem__(full_page, result))
+
+        return JSONResponse(
+            content= result,
             status_code=200
         )
+    
     except Exception as e:
         return JSONResponse(
             content={"error": str(e), 'response': str(response)},
@@ -113,4 +134,15 @@ def get_geodistance(payload: Geodistance):
             "lon2": lon2
         },
         status_code=200
+    )
+
+@app.get("/random")
+def random():
+    import cachetools
+    return JSONResponse(
+        content={
+            "message": "This endpoint is not implemented yet.",
+            "cachetools": cachetools.__version__
+        },
+        status_code=501
     )

requirements.txt

@@ -8,4 +8,5 @@ pyjwt == 2.9.0
 pytest == 8.3.4
 geopy == 2.4.1
 gpxpy == 1.6.2
-requests == 2.30.0
+requests == 2.30.0
+cachetools == 5.5.1