chore: add script to bench different git branches (#232)

Co-authored-by: liuqiang <liuqiang.06@bytedance.com>

bench.py

@@ -0,0 +1,114 @@
+#!/usr/bin/env python3
+
+# Copyright 2021 ByteDance Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import tempfile
+import os
+import subprocess
+import argparse
+
+repeat_time = 10
+gbench_prefix = "SONIC_NO_ASYNC_GC=1 go test -benchmem -run=none -count=%d "%(repeat_time)
+
+def run(cmd):
+    print(cmd)
+    if os.system(cmd):
+        print ("Failed to run cmd: %s"%(cmd))
+        exit(1)
+
+def run_r(cmd):
+    print (cmd)
+    try:
+        cmds = cmd.split(' ')
+        data = subprocess.check_output(cmds, stderr=subprocess.STDOUT)
+    except subprocess.CalledProcessError as e:
+        if e.returncode:
+            print (e.output)
+            exit(1)
+    return data.decode("utf-8") 
+
+def compare(args):
+    # detech current branch.
+    result = run_r("git branch")
+    current_branch = None
+    for br in result.split('\n'):
+        if br.startswith("* "):
+            current_branch = br.lstrip('* ')
+            break
+
+    if not current_branch:
+        print ("Failed to detech current branch")
+        return None
+    
+    # get the current diff
+    (fd, diff) = tempfile.mkstemp()
+    run("git diff > %s"%diff)
+
+    # early return if currrent is main branch and not diff found.
+    # notice that, the new file won't be counted in.
+    print ("Current branch: %s"%(current_branch))
+    if current_branch == "main" and os.stat(diff).st_size == 0:
+        print ("No change found.")
+        return None
+
+    # benchmark current branch    
+    (fd, target) = tempfile.mkstemp(".target.txt")
+    run("%s %s ./... 2>&1 | tee %s" %(gbench_prefix, args, target))
+
+    # trying to switch to the latest main branch
+    run("git checkout -- .")
+    if current_branch != "main":
+        run("git checkout main")
+    run("git pull origin main")
+
+    # benchmark main branch
+    (fd, main) = tempfile.mkstemp(".main.txt")
+    run("%s %s ./... 2>&1 | tee %s" %(gbench_prefix, args, main))
+
+    # diff the result
+    benchstat = "go get golang.org/x/perf/cmd/benchstat && go install golang.org/x/perf/cmd/benchstat"
+    run( "%s && benchstat -sort=delta %s %s"%(benchstat, main, target))
+    run("git checkout -- .")
+
+    # restore branch
+    if current_branch != "main":
+        run("git checkout %s"%(current_branch))
+    run("patch -p1 < %s" % (diff))
+    return target
+
+def main():
+    argparser = argparse.ArgumentParser(description='Tools to test the performance. Example: ./bench.py -b Decoder_Generic_Sonic -c')
+    argparser.add_argument('-b', '--bench', dest='filter', required=False,
+        help='Specify the filter for golang benchmark')
+    argparser.add_argument('-c', '--compare', dest='compare', action='store_true', required=False,
+        help='Compare with the main benchmarking')
+    args = argparser.parse_args()
+    
+    if args.filter:
+        gbench_args = "-bench=%s"%(args.filter)
+    else:
+        gbench_args = "-bench=."
+
+    if args.compare:
+        target = compare(gbench_args)
+    else:
+        target = None
+
+    if not target:
+        (fd, target) = tempfile.mkstemp(".target.txt")
+        run("%s %s ./... 2>&1 | tee %s" %(gbench_prefix, gbench_args, target))
+
+if __name__ == "__main__":
+    main()