for perf table updating, handle the case where there is no perf.csv. …

…run.py might not have created it because of an earlier error, for example.

scripts/mr_unit.py

@@ -2,23 +2,30 @@
 import csv
 import MySQLdb
 import traceback
+import os.path
 
 def add_perf_results_to_mr_unit(args):
     mr_unit = MySQLdb.connect(host='mr-0x8', user='root', passwd=args[1], db='mr_unit')
     mr_unit.autocommit(False)
     cursor = mr_unit.cursor()
     try:
-        for row in csv.reader(file(os.path.join(args[2], "perf.csv"))):
-            row = [r.strip() for r in row]
-            row[3] = row[3].split("/")[-1]
-            cursor.execute('INSERT INTO perf(date, build_id, git_hash, git_branch, machine_ip, test_name, start_time, '
-                           'end_time, pass, ncpu, os, job_name) VALUES("{0}", "{1}", "{2}", "{3}", "{4}", "{5}", "{6}"'
-                           ', "{7}", "{8}", "{9}", "{10}", "{11}")'.format(*row))
-        mr_unit.commit()
+        perf_csv_name = os.path.join(args[2], "perf.csv")
+        if os.path.isfile(perf_csv_name):
+            for row in csv.reader(file(perf_csv_name)):
+                row = [r.strip() for r in row]
+                row[3] = row[3].split("/")[-1]
+                cursor.execute('INSERT INTO perf(date, build_id, git_hash, git_branch, machine_ip, test_name, '
+                               'start_time, end_time, pass, ncpu, os, job_name) VALUES("{0}", "{1}", "{2}", "{3}", '
+                               '"{4}", "{5}", "{6}", "{7}", "{8}", "{9}", "{10}", "{11}")'.format(*row))
+            mr_unit.commit()
+        else:
+            print "perf.csv does not exist in {0}, so mr_unit.py has nothing to do here. Maybe run.py failed before " \
+                  "it created this file".format(perf_csv_name)
     except:
         traceback.print_exc()
         mr_unit.rollback()
-        assert False, "Failed to add performance results to mr_unit!"
+        print "Failed to add performance results to perf table in mr_unit database!"
+        raise
 
 if __name__ == '__main__':
     add_perf_results_to_mr_unit(sys.argv)