[PATCH 3/3] player: support "source restart" command

[Eric Wong]

This becomes useful for systems without inotify when we're editing
YAML (or whatever) files frequently and want changes to be reflected
right away during playback.  This is a weaker version of the plain
"restart" command, which restarts the entire playback chain.
---
 Documentation/dtas-player_protocol.txt | 12 +++++++++++-
 lib/dtas/player/client_handler.rb      |  6 +++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/Documentation/dtas-player_protocol.txt 
b/Documentation/dtas-player_protocol.txt
index b8f8264..ff8f7ae 100644
--- a/Documentation/dtas-player_protocol.txt
+++ b/Documentation/dtas-player_protocol.txt
@@ -169,7 +169,9 @@ Commands here should be alphabetized according to `LC_ALL=C 
sort'
 * restart - restarts all processes in the current pipeline.  Playback
   will be momentarily interrupted while this change occurs.  This is
   necessary if one of the commands (e.g. sox or ecasound) or loaded
-  libraries (e.g. a LADSPA plugin) is upgraded.
+  libraries (e.g. a LADSPA plugin) is upgraded.  Use "source restart"
+  instead to only restart the source chain, leaving the sinks
+  untouched.
 
 * rg RGARGS - configure ReplayGain support
   All FLOAT values may be adjusted via '+=' or '-=' instead of simple
@@ -233,6 +235,14 @@ Commands here should be alphabetized according to 
`LC_ALL=C sort'
         1. input type (flac/opus/mp3/etc)
         2. transport protocol (local FS/http/ftp/sftp/etc)
 
+* source ls - dump the names of sources sorted by tryorder
+
+* source restart - restart the current source command
+  This can be useful if the source file is changed during playback
+  and the current player process is holding onto an unlinked inode.
+  This is advantageous over a full "restart" as there is no audible
+  gap on most systems.
+
 * state dump [FILENAME]
   Immediately dump the state of the player.  If a FILENAME is specified,
   the state is written to that file.  Otherwise, the default state file
diff --git a/lib/dtas/player/client_handler.rb 
b/lib/dtas/player/client_handler.rb
index 37357f7..35f85c2 100644
--- a/lib/dtas/player/client_handler.rb
+++ b/lib/dtas/player/client_handler.rb
@@ -463,7 +463,11 @@ module DTAS::Player::ClientHandler # :nodoc:
   def source_handler(io, msg)
     map = @source_map
     op = msg.shift
-    if op == "ls"
+    case op
+    when "restart"
+      __current_requeue
+      return io.emit("OK")
+    when "ls"
       s = map.keys.sort { |a,b| map[a].tryorder <=> map[b].tryorder }
       return io.emit(s.join(' '))
     end
-- 
EW