lib/logger.rb: Add Logger#reopen

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52620 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -121,6 +121,10 @@ Mon Nov 16 21:27:54 2015  Naohisa Goto  <ngotogenome@gmail.com>
 	* test/dtrace/helper.rb (Dtrace::TestCase#trap_probe): dtrace buffer
 	  size is set as 8m on Solaris (default 4m). [Bug #11697]
 
+Mon Nov 16 20:03:14 2015  Naotoshi Seo  <sonots@gmail.com>
+
+	* lib/logger.rb: Add Logger#reopen
+
 Mon Nov 16 18:21:52 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* object.c (rb_obj_dig): dig in nested structs too.

NEWS

@@ -77,6 +77,9 @@ with all sufficient information, see the ChangeLog file.
   * Kernel#loop, when stopped by a StopIteration exception, returns
     what the enumerator has returned instead of nil. [Feature #11498]
 
+* Logger
+  * Logger#reopen is added to reopen a log device. [Feature #11696]
+
 * Module
   * Module#deprecate_constant [Feature #11398]
 

lib/logger.rb

@@ -320,6 +320,26 @@ class Logger
     end
   end
 
+  #
+  # :call-seq:
+  #   Logger#reopen
+  #   Logger#reopen(logdev)
+  #
+  # === Args
+  #
+  # +logdev+::
+  #   The log device.  This is a filename (String) or IO object (typically
+  #   +STDOUT+, +STDERR+, or an open file).
+  #
+  # === Description
+  #
+  # Reopen a log device.
+  #
+  def reopen(logdev = nil)
+    @logdev.reopen(logdev)
+    self
+  end
+
   #
   # :call-seq:
   #   Logger#add(severity, message = nil, progname = nil) { ... }
@@ -580,12 +600,8 @@ private
     def initialize(log = nil, opt = {})
       @dev = @filename = @shift_age = @shift_size = nil
       @mutex = LogDeviceMutex.new
-      if log.respond_to?(:write) and log.respond_to?(:close)
-        @dev = log
-      else
-        @dev = open_logfile(log)
-        @dev.sync = true
-        @filename = log
+      set_dev(log)
+      if @filename
         @shift_age = opt[:shift_age] || 7
         @shift_size = opt[:shift_size] || 1048576
         @next_rotate_time = next_rotate_time(Time.now, @shift_age) unless @shift_age.is_a?(Integer)
@@ -623,8 +639,33 @@ private
       end
     end
 
+    def reopen(log = nil)
+      # reopen the same filename if no argument, do nothing for IO
+      log ||= @filename if @filename
+      if log
+        @mutex.synchronize do
+          if @filename and @dev
+            @dev.close rescue nil # close only file opened by Logger
+            @filename = nil
+          end
+          set_dev(log)
+        end
+      end
+      self
+    end
+
   private
 
+    def set_dev(log)
+      if log.respond_to?(:write) and log.respond_to?(:close)
+        @dev = log
+      else
+        @dev = open_logfile(log)
+        @dev.sync = true
+        @filename = log
+      end
+    end
+
     def open_logfile(filename)
       begin
         open(filename, (File::WRONLY | File::APPEND))

test/logger/test_logdevice.rb

@@ -99,6 +99,72 @@ class TestLogDevice < Test::Unit::TestCase
     r.close
   end
 
+  def test_reopen_io
+    logdev  = d(STDERR)
+    old_dev = logdev.dev
+    logdev.reopen
+    assert_equal(STDERR, logdev.dev)
+    assert(!old_dev.closed?)
+  end
+
+  def test_reopen_io_by_io
+    logdev  = d(STDERR)
+    old_dev = logdev.dev
+    logdev.reopen(STDOUT)
+    assert_equal(STDOUT, logdev.dev)
+    assert(!old_dev.closed?)
+  end
+
+  def test_reopen_io_by_file
+    logdev  = d(STDERR)
+    old_dev = logdev.dev
+    logdev.reopen(@filename)
+    begin
+      assert(File.exist?(@filename))
+      assert_equal(@filename, logdev.filename)
+      assert(!old_dev.closed?)
+    ensure
+      logdev.close
+    end
+  end
+
+  def test_reopen_file
+    logdev = d(@filename)
+    old_dev = logdev.dev
+    File.unlink(@filename) if File.exist?(@filename) # remove once, then reopen
+    logdev.reopen
+    begin
+      assert(File.exist?(@filename))
+      assert_equal(@filename, logdev.filename)
+      assert(old_dev.closed?)
+    ensure
+      logdev.close
+    end
+  end
+
+  def test_reopen_file_by_io
+    logdev = d(@filename)
+    old_dev = logdev.dev
+    logdev.reopen(STDOUT)
+    assert_equal(STDOUT, logdev.dev)
+    assert_nil(logdev.filename)
+    assert(old_dev.closed?)
+  end
+
+  def test_reopen_file_by_file
+    logdev = d(@filename)
+    old_dev = logdev.dev
+    File.unlink(@filename) if File.exist?(@filename) # remove once, then reopen
+    logdev.reopen(@filename)
+    begin
+      assert(File.exist?(@filename))
+      assert_equal(@filename, logdev.filename)
+      assert(old_dev.closed?)
+    ensure
+      logdev.close
+    end
+  end
+
   def test_shifting_size
     tmpfile = Tempfile.new([File.basename(__FILE__, '.*'), '_1.log'])
     logfile = tmpfile.path

test/logger/test_logger.rb

@@ -121,6 +121,12 @@ class TestLogger < Test::Unit::TestCase
     assert_nil(logger.datetime_format)
   end
 
+  def test_reopen
+    logger = Logger.new(STDERR)
+    logger.reopen(STDOUT)
+    assert_equal(STDOUT, logger.instance_variable_get(:@logdev).dev)
+  end
+
   def test_add
     logger = Logger.new(nil)
     logger.progname = "my_progname"