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sleepy, multi-threaded, non-blocking application server for Ruby
blob 59baa85a86938eddc61a7b4298b5c629648237e1 2122 bytes (raw)
$ git show v0.0.1:lib/yahns/log.rb	# shows this blob on the CLI

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# -*- encoding: binary -*-
# Copyright (C) 2013, Eric Wong <normalperson@yhbt.net> and all contributors
# License: GPLv3 or later (https://www.gnu.org/licenses/gpl-3.0.txt)

# logging-related utility functions for all of yahns
module Yahns::Log # :nodoc:
  def self.exception(logger, prefix, exc)
    message = exc.message
    message = message.dump if /[[:cntrl:]]/ =~ message # prevent code injection
    logger.error "#{prefix}: #{message} (#{exc.class})"
    exc.backtrace.each { |line| logger.error(line) }
  end

  def self.is_log?(fp)
    append_flags = IO::WRONLY | IO::APPEND

    ! fp.closed? &&
      fp.stat.file? &&
      fp.sync &&
      (fp.fcntl(Fcntl::F_GETFL) & append_flags) == append_flags
  rescue IOError, Errno::EBADF
    false
  end

  def self.chown_all(uid, gid)
    ObjectSpace.each_object(File) do |fp|
      fp.chown(uid, gid) if is_log?(fp)
    end
  end

  # This reopens ALL logfiles in the process that have been rotated
  # using logrotate(8) (without copytruncate) or similar tools.
  # A +File+ object is considered for reopening if it is:
  #   1) opened with the O_APPEND and O_WRONLY flags
  #   2) the current open file handle does not match its original open path
  #   3) unbuffered (as far as userspace buffering goes, not O_SYNC)
  # Returns the number of files reopened
  def self.reopen_all
    to_reopen = []
    nr = 0
    ObjectSpace.each_object(File) { |fp| is_log?(fp) and to_reopen << fp }

    to_reopen.each do |fp|
      orig_st = begin
        fp.stat
      rescue IOError, Errno::EBADF
        next
      end

      begin
        b = File.stat(fp.path)
        next if orig_st.ino == b.ino && orig_st.dev == b.dev
      rescue Errno::ENOENT
      end

      begin
        File.open(fp.path, 'a') { |tmpfp| fp.reopen(tmpfp) }
        fp.sync = true
        new_st = fp.stat

        # this should only happen in the master:
        if orig_st.uid != new_st.uid || orig_st.gid != new_st.gid
          fp.chown(orig_st.uid, orig_st.gid)
        end

        nr += 1
      rescue IOError, Errno::EBADF
        # not much we can do...
      end
    end
    nr
  end
end

git clone git://yhbt.net/yahns.git
git clone https://yhbt.net/yahns.git