Module: Redwood::InteractiveLock

Included in:
Index
Defined in:
lib/sup/interactive_lock.rb

Overview

wrap a nice interactive layer on top of anything that has a #lock method which throws a LockError which responds to #user, #host, #mtim, #pname, and #pid.

Constant Summary collapse

DELAY =

seconds

5

Instance Method Summary collapse

Instance Method Details

#lock_interactively(stream = $stderr) ⇒ Object 



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# File 'lib/sup/interactive_lock.rb', line 24

def lock_interactively stream=$stderr
  begin
    Index.lock
  rescue Index::LockError => e
    begin
      Process.kill 0, e.pid.to_i # 0 signal test the existence of PID
      stream.puts <<EOS
Error: the index is locked by another process! User '#{e.user}' on
host '#{e.host}' is running #{e.pname} with pid #{e.pid}.
The process was alive as of at least #{time_ago_in_words e.mtime} ago.

EOS
      stream.print "Should I ask that process to kill itself (y/n)? "
      stream.flush
      if $stdin.gets =~ /^\s*y(es)?\s*$/i
        Process.kill "TERM", e.pid.to_i
        sleep DELAY
        stream.puts "Let's try that again."
        begin
          Index.lock
        rescue Index::LockError => e
          stream.puts "I couldn't lock the index. The lockfile might just be stale."
          stream.print "Should I just remove it and continue? (y/n) "
          stream.flush
          if $stdin.gets =~ /^\s*y(es)?\s*$/i
            begin
              FileUtils.rm e.path
            rescue Errno::ENOENT
              stream.puts "The lockfile doesn't exists. We continue."
            end
            stream.puts "Let's try that one more time."
            begin
              Index.lock
            rescue Index::LockError => e
              stream.puts "I couldn't unlock the index."
              return false
            end
            return true
          end
        end
      end
    rescue Errno::ESRCH # no such process
      stream.puts "I couldn't lock the index. The lockfile might just be stale."
      begin
        FileUtils.rm e.path
      rescue Errno::ENOENT
        stream.puts "The lockfile doesn't exists. We continue."
      end
      stream.puts "Let's try that one more time."
      begin
        sleep DELAY
        Index.lock
      rescue Index::LockError => e
        stream.puts "I couldn't unlock the index."
        return false
      end
      return true
    end
    stream.puts "Sorry, couldn't unlock the index."
    return false
  end
  return true
end

#pluralize(number_of, kind) ⇒ Object 



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# File 'lib/sup/interactive_lock.rb', line 10

def pluralize number_of, kind; "#{number_of} #{kind}" + (number_of == 1 ? "" : "s") end

#time_ago_in_words(time) ⇒ Object 



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# File 'lib/sup/interactive_lock.rb', line 12

def time_ago_in_words time
  secs = (Time.now - time).to_i
  mins = secs / 60
  time = if mins == 0
    pluralize secs, "second"
  else
    pluralize mins, "minute"
  end
end