cli: Add --retry-streams and --retry-open options.

Resolves #333.

Author: chrippa

docs/cli.rst

@@ -276,6 +276,15 @@ Command line options
 
     Do not check for new Livestreamer releases
 
+.. cmdoption:: --retry-streams delay
+
+    Will retry fetching streams until streams are found
+    while waiting <delay> (seconds) between each attempt
+
+.. cmdoption:: --retry-open attempts
+
+    Will try <attempts> to open the stream until giving up
+
 
 HTTP options
 ^^^^^^^^^^^^

src/livestreamer_cli/argparser.py

@@ -66,6 +66,11 @@ def func(p):
                          "disable log output, useful for external scripting")
 parser.add_argument("--no-version-check", action="store_true",
                     help="Do not check for new Livestreamer releases")
+parser.add_argument("--retry-streams", metavar="delay", type=float,
+                    help="Will retry fetching streams until streams are found "
+                         "while waiting <delay> (seconds) between each attempt")
+parser.add_argument("--retry-open", metavar="attempts", type=int, default=1,
+                    help="Will try <attempts> to open the stream until giving up")
 parser.add_argument("--yes-run-as-root", action="store_true",
                     help=argparse.SUPPRESS)
 

src/livestreamer_cli/main.py

@@ -226,10 +226,13 @@ def open_stream(stream):
 def output_stream(stream):
     """Open stream, create output and finally write the stream to output."""
 
-    try:
-        stream_fd, prebuffer = open_stream(stream)
-    except StreamError as err:
-        console.logger.error("{0}", err)
+    for i in range(args.retry_open):
+        try:
+            stream_fd, prebuffer = open_stream(stream)
+            break
+        except StreamError as err:
+            console.logger.error("{0}", err)
+    else:
         return
 
     output = create_output()
@@ -371,6 +374,29 @@ def fetch_streams(plugin):
                               sorting_excludes=args.stream_sorting_excludes)
 
 
+def fetch_streams_infinite(plugin, interval):
+    """Attempts to fetch streams until some are returned."""
+
+    try:
+        streams = fetch_streams(plugin)
+    except PluginError as err:
+        console.logger.error("{0}", err)
+        streams = None
+
+    if not streams:
+        console.logger.info("Waiting for streams, retrying every {0} "
+                            "second(s)", args.retry_streams)
+    while not streams:
+        sleep(args.retry_streams)
+
+        try:
+            streams = fetch_streams(plugin)
+        except PluginError as err:
+            console.logger.error("{0}", err)
+
+    return streams
+
+
 def resolve_stream_name(streams, stream_name):
     """Returns the real stream name of a synonym."""
 
@@ -424,7 +450,11 @@ def handle_url():
         plugin = livestreamer.resolve_url(args.url)
         console.logger.info("Found matching plugin {0} for URL {1}",
                             plugin.module, args.url)
-        streams = fetch_streams(plugin)
+
+        if args.retry_streams:
+            streams = fetch_streams_infinite(plugin, args.retry_streams)
+        else:
+            streams = fetch_streams(plugin)
     except NoPluginError:
         console.exit("No plugin can handle URL: {0}", args.url)
     except PluginError as err: