Start of diff script

tools/profiling/microbenchmarks/bm_diff.py

@@ -0,0 +1,47 @@
+#!/usr/bin/env python2.7
+
+import sys
+import json
+import bm_json
+
+with open(sys.argv[1]) as f:
+  js_new_ctr = json.loads(f.read())
+with open(sys.argv[2]) as f:
+  js_new_opt = json.loads(f.read())
+with open(sys.argv[3]) as f:
+  js_old_ctr = json.loads(f.read())
+with open(sys.argv[4]) as f:
+  js_old_opt = json.loads(f.read())
+
+new = {}
+old = {}
+
+for row in bm_json.expand_json(js_new_ctr, js_new_opt):
+  new[row['cpp_name']] = row
+for row in bm_json.expand_json(js_old_ctr, js_old_opt):
+  old[row['cpp_name']] = row
+
+def min_change(pct):
+  return lambda n, o: abs((n-o)/o - 1) > pct/100
+
+_INTERESTING = (
+  ('cpu_time', min_change(5)),
+  ('real_time', min_change(5)),
+)
+
+for bm in sorted(new.keys()):
+  if bm not in old: continue
+  hdr = False
+  n = new[bm]
+  o = old[bm]
+  print n
+  print o
+  for fld, chk in _INTERESTING:
+    if fld not in n or fld not in o: continue
+    if chk(n[fld], o[fld]):
+      if not hdr:
+        print '%s shows changes:' % bm
+        hdr = True
+      print '   %s changed %r --> %r' % (fld, o[fld], n[fld])
+  sys.exit(0)
+