Python: Copy Python extractor to codeql repo

python/extractor/semmle/profiling.py

@@ -0,0 +1,70 @@
+from . import util
+import os.path
+import sys
+from time import time
+import collections
+
+__all__ = [ 'get_profiler' ]
+
+class NoProfiler(object):
+    '''Dummy profiler'''
+
+    def __init__(self):
+        pass
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        pass
+
+class StatProfiler(object):
+    ''' statprof based statistical profiler'''
+
+    def __init__(self, outpath):
+        self.outpath = outpath
+
+    def __enter__(self):
+        statprof.start()
+        return self
+
+    def __exit__(self, *args):
+        statprof.stop()
+        with open(self.outpath, "w") as fd:
+            statprof.display(fd)
+
+
+def get_profiler(options, id, logger):
+    '''Returns a profile based on options and version. `id` is used to
+    label the output file.'''
+    global statprof
+    if options.profile_out:
+        if sys.version_info >= (3,0):
+            logger.warning("Cannot create profiler: statprof is Python2 only.")
+        else:
+            try:
+                import statprof
+                util.makedirs(options.profile_out)
+                outpath = os.path.join(options.profile_out, "profile-%s.txt" % id)
+                logger.info("Writing profile information to %s", outpath)
+                return StatProfiler(outpath)
+            except ImportError:
+                logger.warning("Cannot create profiler: no statprof module.")
+            except Exception as ex:
+                logger.warning("Cannot create profiler: %s", ex)
+    return NoProfiler()
+
+class MillisecondTimer(object):
+
+    def __init__(self):
+        self.elapsed = 0.0
+
+    def __enter__(self):
+        self.start = time()
+        return self
+
+    def __exit__(self, *_):
+        self.elapsed += (time() - self.start)*1000
+
+
+timers = collections.defaultdict(MillisecondTimer)