Add a script to find the best match for caf kernels

Change-Id: Ibd0f5b031861471c24235eca8ddc7758ccb2a6bf

1 files changed, 115 insertions, 0 deletions

diff --git a/best-caf-kernel/best-caf-kernel.py b/best-caf-kernel/best-caf-kernel.py
new file mode 100644
index 0000000..540aac1
--- /dev/null
+++ b/best-caf-kernel/best-caf-kernel.py
@@ -0,0 +1,115 @@
+#!/usr/bin/env python
+
+from __future__ import print_function
+
+import sys
+import time
+from multiprocessing import Event, Pool, Process, Queue
+from subprocess import PIPE, Popen
+
+try:
+    from Queue import Empty as Queue_Empty
+except ImportError:
+    from queue import Empty as Queue_Empty
+
+
+def run_subprocess(cmd):
+    sp = Popen(cmd, stdout=PIPE, stderr=PIPE,
+               shell=True, universal_newlines=True)
+    comm = sp.communicate()
+    exit_code = sp.returncode
+    if exit_code != 0:
+        print("There was an error running the subprocess.\n"
+              "cmd: %s\n"
+              "exit code: %d\n"
+              "stdout: %s\n"
+              "stderr: %s" % (cmd, exit_code, comm[0], comm[1]))
+    return comm
+
+
+def get_tags(tag_name):
+    cmd = "git tag -l %s" % tag_name
+    comm = run_subprocess(cmd)
+    return comm[0].strip("\n").split("\n")
+
+
+def get_total_changes(tag_name):
+    cmd = "git diff %s --shortstat" % tag_name
+    comm = run_subprocess(cmd)
+    try:
+        a, d = comm[0].split(",")[1:]
+        a = int(a.strip().split()[0])
+        d = int(d.strip().split()[0])
+    except ValueError:
+        total = None
+    else:
+        total = a + d
+    return total
+
+
+def worker(tag_name):
+    tc = get_total_changes(tag_name)
+    worker.q.put((tag_name, tc))
+
+
+def worker_init(q):
+    worker.q = q
+
+
+def background(q, e, s):
+    best = 9999999999999
+    tag = ""
+    while True:
+        try:
+            tn, tc = q.get(False)
+        except Queue_Empty:
+            if e.is_set():
+                break
+        else:
+            if not s:
+                print("%s has %d lines changed" % (tn, tc))
+            if best > tc:
+                best = tc
+                tag = tn
+                if not s:
+                    print("%s is the new best match with %d lines changed" % (tn, tc))
+    print("Best match")
+    print("TAG: %s" % tag)
+    print("Lines changed: %d" % best)
+
+
+def main():
+    import argparse  # Only needed for main()
+    parser = argparse.ArgumentParser()
+    parser.add_argument("-j", action="store", dest="jobs", default=1, type=int,
+                        metavar="N", help="number of jobs to run at once")
+    parser.add_argument("-s", action="store_true", dest="silent", default=False,
+                        help="reduce the verbosity of the output")
+    parser.add_argument("tag_name", metavar="<Tag Name>",
+                        help="tag name to search for (can contain wildcards)")
+    args = parser.parse_args()
+
+    tags = get_tags(args.tag_name)
+    if not tags:
+        print("No tags to check. bailing.")
+        sys.exit(1)
+    if not args.silent:
+        print("number of tags to check: %d" % len(tags))
+
+    queue = Queue()
+    event = Event()
+
+    b = Process(target=background, args=(queue, event, args.silent))
+    b.start()
+
+    pool = Pool(args.jobs, worker_init, [queue])
+    pool.map(worker, tags)
+
+    pool.close()
+    pool.join()
+    event.set()
+    b.join()
+
+
+if __name__ == '__main__':
+    main()