Add msbuild tracker support

clcache/__main__.py

@@ -116,6 +116,44 @@ def normalizeBaseDir(baseDir):
         return None
 
 
+class SuspendTracker():
+    fileTracker = None
+    def __init__(self):
+        if not SuspendTracker.fileTracker:
+            if windll.kernel32.GetModuleHandleW("FileTracker.dll"):
+                SuspendTracker.fileTracker = windll.FileTracker
+            elif windll.kernel32.GetModuleHandleW("FileTracker32.dll"):
+                SuspendTracker.fileTracker = windll.FileTracker32
+
+    def __enter__(self):
+        SuspendTracker.suspend()
+
+    def __exit__(self, typ, value, traceback):
+        SuspendTracker.resume()
+
+    @staticmethod
+    def suspend():
+        if SuspendTracker.fileTracker:
+            SuspendTracker.fileTracker.SuspendTracking()
+
+    @staticmethod
+    def resume():
+        if SuspendTracker.fileTracker:
+            SuspendTracker.fileTracker.ResumeTracking()
+
+def isTrackerEnabled():
+    return 'TRACKER_ENABLED' in os.environ
+
+def untrackable(func):
+    if not isTrackerEnabled():
+        return func
+
+    def untrackedFunc(*args, **kwargs):
+        with SuspendTracker():
+            return func(*args, **kwargs)
+
+    return untrackedFunc
+
 @contextlib.contextmanager
 def atomicWrite(fileName):
     tempFileName = fileName + '.new'
@@ -193,6 +231,7 @@ def manifestPath(self, manifestHash):
     def manifestFiles(self):
         return filesBeneath(self.manifestSectionDir)
 
+    @untrackable
     def setManifest(self, manifestHash, manifest):
         manifestPath = self.manifestPath(manifestHash)
         printTraceStatement("Writing manifest with manifestHash = {} to {}".format(manifestHash, manifestPath))
@@ -203,6 +242,7 @@ def setManifest(self, manifestHash, manifest):
             jsonobject = {'entries': entries}
             json.dump(jsonobject, outFile, sort_keys=True, indent=2)
 
+    @untrackable
     def getManifest(self, manifestHash):
         fileName = self.manifestPath(manifestHash)
         if not os.path.exists(fileName):
@@ -741,13 +781,15 @@ def __init__(self, statsFile):
         self._stats = None
         self.lock = CacheLock.forPath(self._statsFile)
 
+    @untrackable
     def __enter__(self):
         self._stats = PersistentJSONDict(self._statsFile)
         for k in Statistics.RESETTABLE_KEYS | Statistics.NON_RESETTABLE_KEYS:
             if k not in self._stats:
                 self._stats[k] = 0
         return self
 
+    @untrackable
     def __exit__(self, typ, value, traceback):
         # Does not write to disc when unchanged
         self._stats.save()