Further speedup by making cycle stamp access faster.

xlap/analyse/latency.py

@@ -4,20 +4,11 @@ from xlap.analyse.util import get_outlier_threshold, extract_durations, box
 from scipy.stats.stats import pearsonr
 import sys
 
-def _get_cyclestamp(df, event, idx):
-    """
-    get the cyclestamp related to an *_T event
-    """
-    # TODO: this function is probably terribly slow
-    cname = str(event)[:-2] + "_C"
-    cycleevent = [x for x in list(df) if str(x) == cname][0]
-    return df[cycleevent].iloc[idx]
 
 def _get_thread_for_event(config, e):
     name = str(e)[:-2]
     try:
-        question = config["stamps"][name]["Thread"]
-        return question
+        return config["stamps"][name]["Thread"]
     except KeyError:
         print("Cannot find %s".format(name), file=sys.stderr)
         return None
@@ -31,14 +22,16 @@ def _happens_before(df, a, b, config):
     # concurrent.
     ta = _get_thread_for_event(config, a)
     tb = _get_thread_for_event(config, b)
+    cname_a = str(a)[:-2] + "_C"
+    cname_b = str(b)[:-2] + "_C"
     if (ta == tb and ta != None and tb != None):
         for i in range(l):
             tsa = df[a].iloc[i]
             tsb = df[b].iloc[i]
             if tsa > tsb:
                 return False
-            csa = _get_cyclestamp(df, a, i)
-            csb = _get_cyclestamp(df, b, i)
+            csa = df[cname_a].iloc[i]
+            csb = df[cname_b].iloc[i]
             if tsa == tsb and csa > csb and csb != 0:
                 return False
         return True