Class: Sparrow::Queues::Disk

Inherits:
Object
  • Object
show all
Includes:
Miscel
Defined in:
lib/sparrow/queues/disk.rb

Constant Summary collapse

TRX_CMD_PUSH = 
"\000".freeze
TRX_CMD_POP = 
"\001".freeze
TRX_PUSH = 
"\000%s%s".freeze
TRX_POP = 
"\001".freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Miscel

#base_dir, #log_path, #logger, #options, #options=, #pid_dir

Constructor Details

#initialize(queue_name) ⇒ Disk

Returns a new instance of Disk.



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# File 'lib/sparrow/queues/disk.rb', line 19

def initialize(queue_name)
  self.queue_name = queue_name
  self.count_pop = 0
  self.count_push = 0
  open_queue
end

Instance Attribute Details

#count_pop ⇒ Object

Returns the value of attribute count_pop.



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# File 'lib/sparrow/queues/disk.rb', line 16

def count_pop
  @count_pop
end

#count_push ⇒ Object

Returns the value of attribute count_push.



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# File 'lib/sparrow/queues/disk.rb', line 17

def count_push
  @count_push
end

#queue_name ⇒ Object

Returns the value of attribute queue_name.



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# File 'lib/sparrow/queues/disk.rb', line 13

def queue_name
  @queue_name
end

#trxr ⇒ Object

Returns the value of attribute trxr.



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# File 'lib/sparrow/queues/disk.rb', line 14

def trxr
  @trxr
end

#trxw ⇒ Object

Returns the value of attribute trxw.



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# File 'lib/sparrow/queues/disk.rb', line 15

def trxw
  @trxw
end

Instance Method Details

#clear ⇒ Object 



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# File 'lib/sparrow/queues/disk.rb', line 69

def clear
  dirs = Dir.glob(queue_path) | Dir.glob(queue_path + '.*')
  FileUtils.rm_rf(dirs) unless dirs.empty?
end

#count ⇒ Object 



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# File 'lib/sparrow/queues/disk.rb', line 74

def count
  self.count_push - self.count_pop
end

#pop ⇒ Object 



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# File 'lib/sparrow/queues/disk.rb', line 38

def pop        
  while !trxr.eof?
    s_pos = trxr.pos
    cmd = trxr.read(1)
    if cmd != TRX_CMD_POP and cmd != TRX_CMD_PUSH
      logger.fatal 'Corrupt queue'
      return
    end
    raw_size = trxr.read(4)
    size = raw_size.unpack("I").first
    value = trxr.read(size)
    next if cmd == TRX_CMD_POP
    e_pos = trxr.pos
    trxr.seek(s_pos, IO::SEEK_SET)
    trxr.write(TRX_POP)
    # trxr.fsync
    trxr.pos = e_pos
    next unless value
    self.count_pop += 1
    return value
  end
  
  if trxr.path == queue_path
    File.truncate(trxr.path, 0)
  else
    FileUtils.rm_rf trxr.path
  end
  open_reader
  nil
end

#push(value) ⇒ Object 



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# File 'lib/sparrow/queues/disk.rb', line 26

def push(value)
  value = value.to_s
  size = [value.size].pack("I")
  data = sprintf(TRX_PUSH, size, value)
  trxw.seek(0, IO::SEEK_END)
  trxw.write data
  # trxw.fsync
  rotate_queue if trxw.pos > max_log_size
  self.count_push += 1
  value
end