tooling: adds a --profile=<file> option to fontbuild for profiling runs and adds misc/tools/fmtprofile.py for printing and inspecting profile results

2 files changed, 45 insertions, 1 deletions

diff --git a/misc/fontbuild b/misc/fontbuild
index 170057d1a..c649fc5e1 100755
--- a/misc/fontbuild
+++ b/misc/fontbuild
@@ -88,6 +88,9 @@ class Main(object):
     argparser.add_argument('-q', '--quiet', action='store_true',
       help='Only print errors')
 
+    argparser.add_argument('--profile', metavar='<file>',
+      help='Run in profiler for debugging, writing pstats data to <file>')
+
     argparser.add_argument('-C', metavar='<dir>', dest='chdir',
       help='Run as if %(prog)s started in <dir> instead of the '+\
            'current working directory.')
@@ -126,7 +129,24 @@ class Main(object):
     cmd = 'cmd_' + args.command.replace('-', '_')
     if not hasattr(self, cmd):
       fatal('Unrecognized command %s. Try --help' % args.command)
-    getattr(self, cmd)(argv[i:])
+    cmdfn = getattr(self, cmd)
+    if args.profile:
+      try:
+        import cProfile as profile
+      except:
+        import profile
+      import __main__
+      __main__.__dict__["cmdfn"] = cmdfn
+      __main__.__dict__["argv"] = argv[i:]
+      profile.run('cmdfn(argv)', args.profile)
+      print("")
+      print("profile saved to %r. You can now inspect it with for example:" %
+            args.profile)
+      print("misc/tools/fmtprofile.py -n 20 %r" % args.profile)
+      print("python3 -m pstats %r" % args.profile)
+      print("")
+    else:
+      cmdfn(argv[i:])
 
 
 
diff --git a/misc/tools/fmtprofile.py b/misc/tools/fmtprofile.py
new file mode 100755
index 000000000..695d88ee7
--- /dev/null
+++ b/misc/tools/fmtprofile.py
@@ -0,0 +1,24 @@
+#!/usr/bin/env python
+# encoding: utf8
+#
+# Formats a Python profile dump from for example `fontbuild --profile=file ...`
+#
+import argparse, pstats
+from pstats import SortKey
+
+def main():
+  argparser = argparse.ArgumentParser(description='Formats a Python profile dump')
+  argparser.add_argument('infile', metavar='<file>', type=str, help='Python pstats file')
+  argparser.add_argument('-n', '--limit', metavar='N', default=None, type=int,
+                         help='Only print the top N entries')
+  argparser.add_argument('--sort', metavar='<key>', default=['time'], nargs='+', type=str,
+                         help='Sort by keys (default is time.) Available keys: ' + ', '.join(SortKey))
+  args = argparser.parse_args()
+  p = pstats.Stats(args.infile)
+  p.strip_dirs()
+  p.sort_stats(SortKey(*args.sort))
+  p.print_stats(args.limit)
+
+
+if __name__ == '__main__':
+  main()