[perf_skottiewasm_lottieweb] Script to parse and combine skottie/lottieweb perf CSVs

NoTry: true
Bug: skia:9237
Change-Id: I663a8b5ebdc789e3ba02291b5f801fb6fbbf5894
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/229763
Commit-Queue: Ravi Mistry <rmistry@google.com>
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
diff --git a/tools/skottie-wasm-perf/parse_perf_csvs.py b/tools/skottie-wasm-perf/parse_perf_csvs.py
new file mode 100644
index 0000000..89d27cd
--- /dev/null
+++ b/tools/skottie-wasm-perf/parse_perf_csvs.py
@@ -0,0 +1,114 @@
+#!/usr/bin/python2
+#
+# Copyright 2019 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# Helper script that takes as input 2 CSVs downloaded from perf.skia.org and
+# outputs a CSV with test_name, avg_value1 (from CSV1), avg_value2 (from CSV2),
+# perc_diff between avg_value1 and avg_value2.
+# This script also discards NUM_OUTLIERS_TO_REMOVE min values and
+# NUM_OUTLIERS_TO_REMOVE max values.
+
+
+import csv
+import optparse
+import sys
+import re
+
+
+MISSING_STR = 'N/A'
+NUM_OUTLIERS_TO_REMOVE = 2
+
+
+def read_from_csv(csv_file):
+  test_to_avg = {}
+  with open(csv_file, 'rb') as f:
+    csv_reader = csv.reader(f, delimiter=',')
+    # First row should contain headers. Validate that it does.
+    header_row = csv_reader.next()
+    if header_row[0] != 'id':
+      raise Exception('%s in unexpected format' % csv_file)
+    p = re.compile('^.*,test=(.*),$')
+    for v in csv_reader:
+      # Extract the test name.
+      result = p.search(v[0])
+      test_name = result.group(1)
+
+      vals = [float(i) for i in v[1:]]
+      vals.sort()
+      # Discard outliers.
+      vals = vals[NUM_OUTLIERS_TO_REMOVE:-NUM_OUTLIERS_TO_REMOVE]
+      # Find the avg val.
+      avg_val = reduce(lambda x, y: x+y, vals) / float(len(vals))
+      test_to_avg[test_name] = avg_val
+  return test_to_avg
+
+
+def combine_results(d1, d2):
+  test_to_result = {}
+  for test1, v1 in d1.items():
+    v2 = d2.get(test1, MISSING_STR)
+    perc_diff = MISSING_STR
+    if v2 != MISSING_STR:
+      diff = v2 - v1
+      avg = (v2 + v1)/2
+      perc_diff = 0 if avg == 0 else diff/avg * 100
+    result = {
+        'test_name': test1,
+        'csv1': v1,
+        'csv2': v2,
+        'perc_diff': perc_diff,
+    }
+    test_to_result[test1] = result
+
+  # Also add keys in d2 and not d1.
+  for test2, v2 in d2.items():
+    if test2 in test_to_result:
+      continue
+    test_to_result[test2] = {
+      'test_name': test2,
+      'csv1': MISSING_STR,
+      'csv2': v2,
+      'perc_diff': MISSING_STR,
+    }
+
+  return test_to_result
+
+
+def write_to_csv(output_dict, output_csv):
+  with open(output_csv, 'w') as f:
+    fieldnames = ['test_name', 'csv1', 'csv2', 'perc_diff']
+    writer = csv.DictWriter(f, fieldnames=fieldnames)
+    writer.writeheader()
+    tests = output_dict.keys()
+    tests.sort()
+    for test in tests:
+      writer.writerow(output_dict[test])
+
+
+def parse_and_output(csv1, csv2, output_csv):
+  test_to_avg1 = read_from_csv(csv1)
+  test_to_avg2 = read_from_csv(csv2)
+  output_dict = combine_results(test_to_avg1, test_to_avg2)
+  write_to_csv(output_dict, output_csv)
+
+
+def main():
+  option_parser = optparse.OptionParser()
+  option_parser.add_option(
+      '', '--csv1', type=str,
+      help='The first CSV to parse.')
+  option_parser.add_option(
+      '', '--csv2', type=str,
+      help='The second CSV to parse.')
+  option_parser.add_option(
+      '', '--output_csv', type=str,
+      help='The file to write the output CSV to.')
+  options, _ = option_parser.parse_args()
+  sys.exit(parse_and_output(options.csv1, options.csv2, options.output_csv))
+
+
+if __name__ == '__main__':
+  main()