Fixed race condition in Sessions.create().

lib/sessions.rb

@@ -10,8 +10,7 @@ module Sessions
   end
 
   # get working directories
-  @path = @root + '/tmp/websocket'
+  @path = "#{@root}/tmp/websocket"
-  @pid  = @root + '/tmp/pids/sessionworker.pid'
 
   # create global vars for threads
   @@client_threads = {}
@@ -29,18 +28,27 @@ returns
 =end
 
   def self.create( client_id, session, meta )
-    path = @path + '/' + client_id.to_s
+    path         = "#{@path}/#{client_id}"
-    FileUtils.mkpath path
+    path_tmp     = "#{@path}/tmp/#{client_id}"
+    session_file = "#{path_tmp}/session"
+
+    # collect session data
     meta[:last_ping] = Time.new.to_i.to_s
     data = {
       user: session,
       meta: meta,
     }
-    content = data.to_s
+    content = data.to_json
-    File.open( path + '/session', 'wb' ) { |file|
+
+    # store session data in session file
+    FileUtils.mkpath path_tmp
+    File.open( session_file, 'wb' ) { |file|
       file.write content
     }
 
+    # move to destination directory
+    FileUtils.mv( path_tmp, path )
+
     # send update to browser
     if session && session['id']
       self.send(
@@ -66,7 +74,7 @@ returns
 =end
 
   def self.sessions
-    path = @path + '/'
+    path = "#{@path}/"
 
     # just make sure that spool path exists
     if !File::exist?( path )
@@ -75,7 +83,10 @@ returns
 
     data = []
     Dir.foreach( path ) do |entry|
-      next if entry == '.' || entry == '..' || entry == 'spool'
+      next if entry == '.'
+      next if entry == '..'
+      next if entry == 'tmp'
+      next if entry == 'spool'
       data.push entry.to_s
     end
     data
@@ -153,7 +164,7 @@ returns
 =end
 
   def self.destory( client_id )
-    path = @path + '/' + client_id.to_s
+    path = "#{@path}/#{client_id}"
     FileUtils.rm_rf path
   end
 
@@ -171,7 +182,7 @@ returns
 
   def self.destory_idle_sessions(idle_time_in_sec = 240)
     list_of_closed_sessions = []
-    clients = Sessions.list
+    clients                 = Sessions.list
     clients.each { |client_id, client|
       if !client[:meta] || !client[:meta][:last_ping] || ( client[:meta][:last_ping].to_i + idle_time_in_sec ) < Time.now.to_i
         list_of_closed_sessions.push client_id
@@ -196,10 +207,11 @@ returns
   def self.touch( client_id )
     data = self.get(client_id)
     return false if !data
-    path = @path + '/' + client_id.to_s
+    path = "#{@path}/#{client_id}"
     data[:meta][:last_ping] = Time.new.to_i.to_s
+    content = data.to_json
     File.open( path + '/session', 'wb' ) { |file|
-      file.write data.to_json
+      file.write content
     }
     true
   end
@@ -225,12 +237,12 @@ returns
 =end
 
   def self.get( client_id )
-    session_dir  = @path + '/' + client_id.to_s
+    session_dir  = "#{@path}/#{client_id}"
-    session_file = session_dir + '/session'
+    session_file = "#{session_dir}/session"
-    data = nil
+    data         = nil
     if !File.exist? session_file
       self.destory(client_id)
-      puts "ERROR: missing session file for '#{client_id.to_s}', remove session."
+      puts "ERROR: missing session file for '#{client_id}', remove session."
       return
     end
     begin
@@ -266,14 +278,14 @@ returns
 =end
 
   def self.send( client_id, data )
-    path = @path + '/' + client_id.to_s + '/'
+    path     = "#{@path}/#{client_id}/"
-    filename = 'send-' + Time.new().to_f.to_s# + '-' + rand(99999999).to_s
+    filename = "send-#{ Time.new().to_f }"
-    check = true
+    check    = true
-    count = 0
+    count    = 0
     while check
       if File::exist?( path + filename )
         count += 1
-        filename = filename + '-' + count
+        filename = "#{filename}-#{count}"
       else
         check = false
       end
@@ -361,15 +373,16 @@ returns
 =end
 
   def self.queue( client_id )
-    path = @path + '/' + client_id.to_s + '/'
+    path  = "#{@path}/#{client_id}/"
-    data = []
+    data  = []
     files = []
     Dir.foreach( path ) {|entry|
-      next if entry == '.' || entry == '..'
+      next if entry == '.'
+      next if entry == '..'
       files.push entry
     }
     files.sort.each {|entry|
-      filename = path + '/' + entry
+      filename = "#{path}/#{entry}"
       if /^send/.match( entry )
         data.push Sessions.queue_file_read( path, entry )
       end
@@ -378,10 +391,9 @@ returns
   end
 
   def self.queue_file_read( path, filename )
-    file_old = path + filename
+    file_old = "#{path}#{filename}"
-    file_new = path + 'a-' + filename
+    file_new = "#{path}a-#{filename}"
     FileUtils.mv( file_old, file_new )
-    data = nil
     all = ''
     File.open( file_new, 'rb' ) { |file|
       all = file.read
@@ -390,15 +402,17 @@ returns
     JSON.parse( all )
   end
 
-  def self.spool_cleanup
+  def self.cleanup
-    path = @path + '/spool/'
+    path = "#{@path}/spool/"
+    FileUtils.rm_rf path
+    path = "#{@path}/tmp/"
     FileUtils.rm_rf path
   end
 
   def self.spool_create( msg )
-    path = @path + '/spool/'
+    path = "#{@path}/spool/"
     FileUtils.mkpath path
-    file = Time.new.to_f.to_s + '-' + rand(99_999).to_s
+    file = "#{Time.new.to_f}-#{rand(99_999)}"
     File.open( path + '/' + file, 'wb' ) { |file|
       data = {
         msg: msg,
@@ -409,20 +423,21 @@ returns
   end
 
   def self.spool_list( timestamp, current_user_id )
-    path = @path + '/spool/'
+    path = "#{@path}/spool/"
     FileUtils.mkpath path
-    data = []
+    data      = []
     to_delete = []
-    files = []
+    files     = []
     Dir.foreach( path ) {|entry|
-      next if entry == '.' || entry == '..'
+      next if entry == '.'
+      next if entry == '..'
       files.push entry
     }
     files.sort.each {|entry|
-      filename = path + '/' + entry
+      filename = "#{path}/#{entry}"
       next if !File::exist?( filename )
       File.open( filename, 'rb' ) { |file|
-        all = file.read
+        all   = file.read
         spool = JSON.parse( all )
         begin
           message_parsed = JSON.parse( spool['msg'] )
@@ -433,7 +448,7 @@ returns
 
         # ignore message older then 48h
         if spool['timestamp'] + (2 * 86_400) < Time.now.to_i
-          to_delete.push path + '/' + entry
+          to_delete.push "#{path}/#{entry}"
           next
         end