Class: Garcon::Stash::Journal Private

Inherits:
Queue show all
Defined in:
lib/garcon/stash/journal.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Stash::Io handles background io, compaction and is the arbiter of multiprocess safety.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Queue

#<<, #first, #flush, #pop

Constructor Details

#initialize(file, format, serializer, &block) ⇒ Journal

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of Journal.



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# File 'lib/garcon/stash/journal.rb', line 29

def initialize(file, format, serializer, &block)
  super()
  @file, @format, @serializer, @emit = file, format, serializer, block
  open
  @worker = Thread.new(&method(:worker))
  @worker.priority = -1
  load
end

Instance Attribute Details

#file ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/garcon/stash/journal.rb', line 27

def file
  @file
end

#size ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/garcon/stash/journal.rb', line 27

def size
  @size
end

Instance Method Details

#bytesize ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Return byte size of journal



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# File 'lib/garcon/stash/journal.rb', line 107

def bytesize
  @fd.stat.size
end

#clear ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Clear the database log and yield



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# File 'lib/garcon/stash/journal.rb', line 74

def clear
  flush
  with_tmpfile do |path, file|
    file.write(@format.header)
    file.close
    with_flock(File::LOCK_EX) do
      File.rename(path, @file)
    end
  end
  open
end

#close ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Clear the queue and close the file handler



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# File 'lib/garcon/stash/journal.rb', line 46

def close
  self << nil
  @worker.join
  @fd.close
  super
end

#closed? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Is the journal closed?

Returns:



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# File 'lib/garcon/stash/journal.rb', line 40

def closed?
  @fd.closed?
end

#compact ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Compact the logfile to represent the in-memory state



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# File 'lib/garcon/stash/journal.rb', line 88

def compact
  load
  with_tmpfile do |path, file|
    # Compactified database has the same size -> return
    return self if @pos == file.write(dump(yield, @format.header))
    with_flock(File::LOCK_EX) do
      if @pos != nil
        file.write(read)
        file.close
        File.rename(path, @file)
      end
    end
  end
  open
  replay
end

#load ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Load new journal entries



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# File 'lib/garcon/stash/journal.rb', line 55

def load
  flush
  replay
end

#lock ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Lock the logfile across thread and process boundaries



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# File 'lib/garcon/stash/journal.rb', line 62

def lock
  flush
  with_flock(File::LOCK_EX) do
    replay
    result = yield
    flush
    result
  end
end