pmb.parse.apkindex.parse(): Use caching

Big speed improvement for buildinfo.json files, down from 30-60s to 1-5s.

pmb/parse/apkindex.py

@@ -170,6 +170,15 @@ def parse(args, path, strict=False):
                 }, ...
               }
     """
+
+    # Try to get a cached result first
+    lastmod = os.path.getmtime(path)
+    if path in args.cache["apkindex"]:
+        cache = args.cache["apkindex"][path]
+        if cache["lastmod"] == lastmod:
+            return cache["ret"]
+
+    # Parse the whole APKINDEX.tar.gz file
     ret = {}
     start = [0]
     with tarfile.open(path, "r:gz") as tar:
@@ -188,6 +197,9 @@ def parse(args, path, strict=False):
                         if len(split) == 2:
                             parse_add_block(path, strict, ret, block,
                                             split[0], split[1])
+    # Update the cache
+    args.cache["apkindex"][path] = {"lastmod": lastmod, "ret": ret}
+
     return ret
 
 

pmb/parse/arguments.py

@@ -199,6 +199,9 @@ def arguments():
     # Add convinience shortcuts
     setattr(args, "arch_native", pmb.parse.arch.alpine_native())
 
+    # Add a caching dict
+    setattr(args, "cache", {"apkindex": {}})
+
     # Add and verify the deviceinfo (only after initialization)
     if args.action != "init":
         setattr(args, "deviceinfo", pmb.parse.deviceinfo(args))