[PATCH 2/3] use CPU rlimit to limit soxi||ffprobe run time

[Eric Wong <e@80x24.org>]

soxi or ffprobe may infinite loop on bad files, so be sure to
let these processes timeout properly.
---
 bin/dtas-readahead              | 2 +-
 lib/dtas/source/av_ff_common.rb | 2 +-
 lib/dtas/source/sox.rb          | 3 ++-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/bin/dtas-readahead b/bin/dtas-readahead
index f2ab514..c61d317 100755
--- a/bin/dtas-readahead
+++ b/bin/dtas-readahead
@@ -25,7 +25,7 @@
 c = DTAS::UNIXClient.new
 @max_ra = 30 * 1024 * 1024
 null = DTAS.null
-@redir = { err: null, out: null, in: null }.freeze
+@redir = { err: null, out: null, in: null, rlimit_cpu: [ 1, 2 ] }.freeze
 require 'pp'
 
 def seek_to_cur_pos(cur_pid, fp)
diff --git a/lib/dtas/source/av_ff_common.rb b/lib/dtas/source/av_ff_common.rb
index c600c48..7f197e0 100644
--- a/lib/dtas/source/av_ff_common.rb
+++ b/lib/dtas/source/av_ff_common.rb
@@ -92,7 +92,7 @@ def av_ff_ok?
 
       err = "".b
       begin
-        s = qx(@env, cmd, err_str: err, no_raise: true)
+        s = qx(@env, cmd, err_str: err, no_raise: true, rlimit_cpu: [ 1, 2 ])
       rescue Errno::ENOENT # avprobe/ffprobe not installed
         return false
       end
diff --git a/lib/dtas/source/sox.rb b/lib/dtas/source/sox.rb
index c03477e..365c7b6 100644
--- a/lib/dtas/source/sox.rb
+++ b/lib/dtas/source/sox.rb
@@ -39,7 +39,8 @@ def initialize(mcache = nil)
   def mcache_lookup(infile)
     (@mcache ||= DTAS::Mcache.new).lookup(infile) do |input, dst|
       err = ''.b
-      out = qx(@env.dup, %W(soxi #{input}), err_str: err, no_raise: true)
+      out = qx(@env.dup, %W(soxi #{input}), err_str: err, no_raise: true,
+                rlimit_cpu: [ 1, 2 ])
       return soxi_failed(infile, out) if Process::Status === out
       return soxi_failed(infile, err) if err =~ /soxi FAIL formats:/
       out =~ /^Duration\s*:[^=]*= (\d+) samples /n