report: add option for continuous report serving (#421)

When running experiments locally the workflow is to continuously rebuild
the static pages while having a http server launched. This is a bit
inconvenient. This commit adds an option to the web module such that
both a http server is launched and the static generator continues to
generate files as long as the http server is launched.

---------

Signed-off-by: David Korczynski <[email protected]>

report/web.py

@@ -17,14 +17,20 @@
 import argparse
 import logging
 import os
+import threading
+import time
 import urllib.parse
 from functools import partial
+from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
 from typing import Any, Dict, List, Optional
 
 import jinja2
 
 from report.common import Benchmark, FileSystem, Results, Sample, Target
 
+LOCAL_HOST = '127.0.0.1'
+LOCAL_PORT = 8012
+
 
 class JinjaEnv:
   """JinjaEnv wraps the set up of a jinja2 environment."""
@@ -168,6 +174,27 @@ def _write_benchmark_sample(self, benchmark: Benchmark, sample: Sample,
                     sample.id, e)
 
 
+def generate_report(args: argparse.Namespace) -> None:
+  """Generates static web server files."""
+  logging.info('Generating web page files in %s', args.output_dir)
+  results = Results(results_dir=args.results_dir,
+                    benchmark_set=args.benchmark_set)
+  jinja_env = JinjaEnv(template_globals={'model': args.model})
+  gr = GenerateReport(results=results,
+                      jinja_env=jinja_env,
+                      output_dir=args.output_dir)
+  gr.generate()
+
+
+def launch_webserver(args):
+  """Launches a local web server to browse results."""
+  logging.info('Launching webserver at %s:%d', LOCAL_HOST, LOCAL_PORT)
+  server = ThreadingHTTPServer((LOCAL_HOST, LOCAL_PORT),
+                               partial(SimpleHTTPRequestHandler,
+                                       directory=args.output_dir))
+  server.serve_forever()
+
+
 def _parse_arguments() -> argparse.Namespace:
   """Parses command line args."""
   parser = argparse.ArgumentParser(description=(
@@ -191,20 +218,33 @@ def _parse_arguments() -> argparse.Namespace:
                       '-m',
                       help='Model used for the experiment.',
                       default='')
+  parser.add_argument('--serve',
+                      '-s',
+                      help='Will launch a web server if set.',
+                      action='store_true')
 
   return parser.parse_args()
 
 
 def main():
   args = _parse_arguments()
 
-  results = Results(results_dir=args.results_dir,
-                    benchmark_set=args.benchmark_set)
-  jinja_env = JinjaEnv(template_globals={'model': args.model})
-  gr = GenerateReport(results=results,
-                      jinja_env=jinja_env,
-                      output_dir=args.output_dir)
-  gr.generate()
+  if not args.serve:
+    generate_report(args)
+  else:
+    logging.getLogger().setLevel(os.environ.get('LOGLEVEL', 'INFO').upper())
+    # Launch web server
+    thread = threading.Thread(target=launch_webserver, args=(args,))
+    thread.start()
+
+    # Generate results continuously while the process runs.
+    while True:
+      generate_report(args)
+      try:
+        time.sleep(90)
+      except KeyboardInterrupt:
+        logging.info('Exiting.')
+        os._exit(0)
 
 
 if __name__ == '__main__':