Do a fine-grained incremental run when loading from cache

Author: msullivan

mypy/build.py

@@ -1128,6 +1128,11 @@ def validate_meta(meta: Optional[CacheMeta], id: str, path: Optional[str],
     if not stat.S_ISREG(st.st_mode):
         manager.log('Metadata abandoned for {}: file {} does not exist'.format(id, path))
         return None
+
+    if manager.options.use_fine_grained_cache:
+        manager.log('Using potentially stale metadata for {}'.format(id))
+        return meta
+
     size = st.st_size
     if size != meta.size:
         manager.log('Metadata abandoned for {}: file {} has different size'.format(id, path))

mypy/dmypy_server.py

@@ -24,7 +24,7 @@
 from mypy.dmypy_util import STATUS_FILE, receive
 from mypy.gclogger import GcLogger
 from mypy.fscache import FileSystemCache
-from mypy.fswatcher import FileSystemWatcher
+from mypy.fswatcher import FileSystemWatcher, FileData
 
 
 def daemonize(func: Callable[[], None], log_file: Optional[str] = None) -> int:
@@ -266,11 +266,29 @@ def initialize_fine_grained(self, sources: List[mypy.build.BuildSource]) -> Dict
         manager = result.manager
         graph = result.graph
         self.fine_grained_manager = mypy.server.update.FineGrainedBuildManager(manager, graph)
-        status = 1 if messages else 0
-        self.previous_messages = messages[:]
         self.fine_grained_initialized = True
         self.previous_sources = sources
         self.fscache.flush()
+
+        # If we are using the fine-grained cache, build hasn't actually done
+        # the typechecking on the updated files yet.
+        # Run a fine-grained update starting from the cached data
+        if self.options.use_fine_grained_cache:
+            # Pull times and hashes out of the saved_cache and stick them into
+            # the fswatcher, so we pick up the changes.
+            for meta, mypyfile, type_map in manager.saved_cache.values():
+                if meta.mtime is None: continue
+                self.fswatcher.set_file_data(
+                    meta.path,
+                    FileData(st_mtime=float(meta.mtime), st_size=meta.size, md5=meta.hash))
+
+            # Run an update
+            changed = self.find_changed(sources)
+            if changed:
+                messages += self.fine_grained_manager.update(changed)
+
+        status = 1 if messages else 0
+        self.previous_messages = messages[:]
         return {'out': ''.join(s + '\n' for s in messages), 'err': '', 'status': status}
 
     def fine_grained_increment(self, sources: List[mypy.build.BuildSource]) -> Dict[str, Any]:

mypy/fswatcher.py

@@ -36,6 +36,9 @@ def __init__(self, fs: FileSystemCache) -> None:
     def paths(self) -> AbstractSet[str]:
         return self._paths
 
+    def set_file_data(self, path: str, data: FileData) -> None:
+        self._file_data[path] = data
+
     def add_watched_paths(self, paths: Iterable[str]) -> None:
         for path in paths:
             if path not in self._paths: