From 0208f3bfd132d58c31d5db06db6378277fa71c7b Mon Sep 17 00:00:00 2001
From: Eric Wong <normalperson@yhbt.net>
Date: Sun, 1 Sep 2013 02:06:51 +0000
Subject: player: add "state dump" command to serialize state

This helps in case dtas-player is hit with SIGKILL or the system
crashes.  This does not fsync(2) as that could introduce delays on
slow filesystems.  Users should open the file manually and fsync
themselves if they need to.
---
 lib/dtas/player.rb                |  2 ++
 lib/dtas/player/client_handler.rb | 21 +++++++++++++++++++++
 lib/dtas/state_file.rb            |  2 ++
 3 files changed, 25 insertions(+)

(limited to 'lib')

diff --git a/lib/dtas/player.rb b/lib/dtas/player.rb
index ba42490..3571a7f 100644
--- a/lib/dtas/player.rb
+++ b/lib/dtas/player.rb
@@ -212,6 +212,8 @@ class DTAS::Player # :nodoc:
       io.emit("OK")
     when "source"
       source_handler(io, msg)
+    when "state"
+      state_file_handler(io, msg)
     when "cd"
       chdir_handler(io, msg)
     when "pwd"
diff --git a/lib/dtas/player/client_handler.rb b/lib/dtas/player/client_handler.rb
index f601d46..bbdc1c5 100644
--- a/lib/dtas/player/client_handler.rb
+++ b/lib/dtas/player/client_handler.rb
@@ -479,5 +479,26 @@ module DTAS::Player::ClientHandler # :nodoc:
     # echo(%W(cd msg[0])) # should we broadcast this?
     io.emit("OK")
   end
+
+  def state_file_handler(io, msg)
+    case msg.shift
+    when "dump"
+      dest = msg.shift
+      if dest
+        sf = DTAS::StateFile.new(dest, false)
+      elsif @state_file
+        sf = @state_file
+        dest = sf.path
+      else
+        return io.emit("ERR no state file configured")
+      end
+      begin
+        sf.dump(self)
+      rescue => e
+        return io.emit("ERR dumping to #{xs(Array(dest))} #{e.message}")
+      end
+    end
+    io.emit("OK")
+  end
 end
 # :startdoc:
diff --git a/lib/dtas/state_file.rb b/lib/dtas/state_file.rb
index c009797..0ba876f 100644
--- a/lib/dtas/state_file.rb
+++ b/lib/dtas/state_file.rb
@@ -3,6 +3,8 @@
 require 'yaml'
 require 'tempfile'
 class DTAS::StateFile # :nodoc:
+  attr_reader :path
+
   def initialize(path, do_fsync = false)
     @path = path
     @do_fsync = do_fsync
-- 
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