Add type hints to spack.installer (#38872)

lib/spack/spack/database.py

@@ -36,6 +36,8 @@
     _use_uuid = False
     pass
 
+from typing import Optional, Tuple
+
 import llnl.util.filesystem as fs
 import llnl.util.lang as lang
 import llnl.util.tty as tty
@@ -178,9 +180,9 @@ class InstallRecord:
     dependents left.
 
     Args:
-        spec (spack.spec.Spec): spec tracked by the install record
-        path (str): path where the spec has been installed
-        installed (bool): whether or not the spec is currently installed
+        spec: spec tracked by the install record
+        path: path where the spec has been installed
+        installed: whether or not the spec is currently installed
         ref_count (int): number of specs that depend on this one
         explicit (bool or None): whether or not this spec was explicitly
             installed, or pulled-in as a dependency of something else
@@ -189,14 +191,14 @@ class InstallRecord:
 
     def __init__(
         self,
-        spec,
-        path,
-        installed,
-        ref_count=0,
-        explicit=False,
-        installation_time=None,
-        deprecated_for=None,
-        in_buildcache=False,
+        spec: "spack.spec.Spec",
+        path: str,
+        installed: bool,
+        ref_count: int = 0,
+        explicit: bool = False,
+        installation_time: Optional[float] = None,
+        deprecated_for: Optional["spack.spec.Spec"] = None,
+        in_buildcache: bool = False,
         origin=None,
     ):
         self.spec = spec
@@ -407,7 +409,7 @@ def __init__(
             self.lock = lk.Lock(
                 self._lock_path, default_timeout=self.db_lock_timeout, desc="database"
             )
-        self._data = {}
+        self._data: Dict[str, InstallRecord] = {}
 
         # For every installed spec we keep track of its install prefix, so that
         # we can answer the simple query whether a given path is already taken
@@ -710,7 +712,9 @@ def db_for_spec_hash(self, hash_key):
             if hash_key in db._data:
                 return db
 
-    def query_by_spec_hash(self, hash_key, data=None):
+    def query_by_spec_hash(
+        self, hash_key: str, data: Optional[Dict[str, InstallRecord]] = None
+    ) -> Tuple[bool, Optional[InstallRecord]]:
         """Get a spec for hash, and whether it's installed upstream.
 
         Return:

lib/spack/spack/package_base.py

@@ -639,7 +639,7 @@ class PackageBase(WindowsRPath, PackageViewMixin, metaclass=PackageMeta):
 
     def __init__(self, spec):
         # this determines how the package should be built.
-        self.spec = spec
+        self.spec: "spack.spec.Spec" = spec
 
         # Allow custom staging paths for packages
         self.path = None

lib/spack/spack/util/timer.py

@@ -25,10 +25,7 @@
 global_timer_name = "_global"
 
 
-class NullTimer:
-    """Timer interface that does nothing, useful in for "tell
-    don't ask" style code when timers are optional."""
-
+class BaseTimer:
     def start(self, name=global_timer_name):
         pass
 
@@ -53,11 +50,14 @@ def write_tty(self, out=sys.stdout):
         pass
 
 
-#: instance of a do-nothing timer
-NULL_TIMER = NullTimer()
+class NullTimer(BaseTimer):
+    """Timer interface that does nothing, useful in for "tell
+    don't ask" style code when timers are optional."""
+
+    pass
 
 
-class Timer:
+class Timer(BaseTimer):
     """Simple interval timer"""
 
     def __init__(self, now=time.time):
@@ -153,3 +153,7 @@ def write_tty(self, out=sys.stdout):
         # Write to out
         for name, duration in formatted:
             out.write(f"    {name:10s} {pretty_seconds(duration):>10s}\n")
+
+
+#: instance of a do-nothing timer
+NULL_TIMER = NullTimer()