Add support for reading state data from stdin.

apachedex/__init__.py

@@ -993,10 +993,12 @@ def main():
   parser.add_argument('-Q', dest='extra_quiet', action='store_true',
     help='Suppress progress indication (file being parsed, lines counter). '
       'Does not imply -q.')
-  parser.add_argument('--state-file', nargs='+', default=[], type=file,
-    help='Use given JSON files as initial state. Mixing files generated with '
-      'different parameters is allowed, but no correction is made. Output may '
-      'be unusable (ex: different --apdex, different --period, ...).')
+  parser.add_argument('--state-file', nargs='+', default=[],
+    help='Use given JSON files as initial state. Use - for stdin. Loading'
+      'multiple files through stdin is not possible). Mixing '
+      'files generated with different parameters is allowed, but no '
+      'correction is made. Output may be unusable (ex: different --apdex, '
+      'different --period, ...).')
 
   group = parser.add_argument_group('generated content')
   group.add_argument('-a', '--apdex', default=1.0, type=float,
@@ -1132,32 +1134,40 @@ def main():
   error_detail = args.error_detail
   file_count = len(infile_list)
   per_site = {}
-  for state_file in args.state_file:
-    print >> sys.stderr, 'Loading', state_file.name, '...',
-    load_start = time.time()
-    state = json.load(state_file, encoding='ascii')
-    for url, site_state in state:
-      if url is None:
-        site = None
-        action = default_action
-      else:
-        for site, prefix_match, action in site_list:
-          if site == url:
-            break
-        else:
+  if '-' in args.state_file and '-' in infile_list:
+    print >> sys.stderr, 'stdin cannot be used both as log and state input.'
+    sys.exit(1)
+  for state_file_name in args.state_file:
+    print >> sys.stderr, 'Loading', state_file_name, '...',
+    if state_file_name == '-':
+      state_file = sys.stdin
+    else:
+      state_file = open(state_file_name)
+    with state_file:
+      load_start = time.time()
+      state = json.load(state_file, encoding='ascii')
+      for url, site_state in state:
+        if url is None:
           site = None
           action = default_action
-      if action is None:
-        print >> sys.stderr, 'Info: no prefix match %r, stats skipped' % url
-        continue
-      site_stats = action.func.fromJSONState(site_state,
-        getDuration, action.keywords['suffix'])
-      if site in per_site:
-        per_site[site].accumulateFrom(site_stats)
-      else:
-        per_site[site] = site_stats
-    print >> sys.stderr, 'done (%s)' % timedelta(seconds=time.time()
-      - load_start)
+        else:
+          for site, prefix_match, action in site_list:
+            if site == url:
+              break
+          else:
+            site = None
+            action = default_action
+        if action is None:
+          print >> sys.stderr, 'Info: no prefix match %r, stats skipped' % url
+          continue
+        site_stats = action.func.fromJSONState(site_state,
+          getDuration, action.keywords['suffix'])
+        if site in per_site:
+          per_site[site].accumulateFrom(site_stats)
+        else:
+          per_site[site] = site_stats
+      print >> sys.stderr, 'done (%s)' % timedelta(seconds=time.time()
+        - load_start)
   skip_user_agent = list(itertools.chain(*args.skip_user_agent))
   malformed_lines = 0
   skipped_lines = 0