Add caching support

.gitignore

@@ -1,3 +1,6 @@
+# Cache files
+url_map.pickle
+
 # Output graphs
 output/
 

src/__main__.py

@@ -1,5 +1,7 @@
 import asyncio
+import pickle
 import re
+from pathlib import Path
 from time import perf_counter
 
 import httpx
@@ -10,6 +12,7 @@ from src.visualization import display_top_urls
 
 URL = httpx.URL("https://ailab.fai.utb.cz")
 ALLOWED_HOSTS_RE = re.compile(r"(?:.*\.)?utb\.cz")
+CACHE_RESULTS_DIR = Path.cwd() / "url_map.pickle"
 
 
 async def main() -> None:
@@ -21,14 +24,22 @@ async def main() -> None:
     print("Scraping...")
     start = perf_counter()
 
-    async with httpx.AsyncClient() as client:
-        url_map = await get_urlmap(
-            client,
-            URL,
-            max_depth=2,
-            filter_condition=lambda url: ALLOWED_HOSTS_RE.fullmatch(url.host) is not None,
-            suppress_exception=standard_urlmap_exception_suppressor,
-        )
+    if CACHE_RESULTS_DIR.exists():
+        print("> Using cached URLs")
+        with CACHE_RESULTS_DIR.open("rb") as fp:
+            url_map = pickle.load(fp)  # noqa: S301
+    else:
+        async with httpx.AsyncClient() as client:
+            url_map = await get_urlmap(
+                client,
+                URL,
+                max_depth=2,
+                filter_condition=lambda url: ALLOWED_HOSTS_RE.fullmatch(url.host) is not None,
+                suppress_exception=standard_urlmap_exception_suppressor,
+            )
+
+        with CACHE_RESULTS_DIR.open("wb") as fp:
+            pickle.dump(url_map, fp)
 
     took = perf_counter() - start
     print(f"Took: {round(took, 2)} seconds")