Class: StrokeDB::MapVolume

Inherits:
Object show all
Defined in:
lib/strokedb/volumes/map_volume.rb

Constant Summary collapse

HEADER_SIZE = 
512
MAGIC_SIGNATURE = 
"\x11\x12\x19\x81"
VERSION = 
"00"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ MapVolume

Returns a new instance of MapVolume.



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# File 'lib/strokedb/volumes/map_volume.rb', line 12

def initialize(options = {})
  @options = options.stringify_keys
  initialize_file
end

Instance Attribute Details

#first_available_position ⇒ Object

Returns the value of attribute first_available_position.



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# File 'lib/strokedb/volumes/map_volume.rb', line 10

def first_available_position
  @first_available_position
end

Instance Method Details

#available?(position) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/strokedb/volumes/map_volume.rb', line 56

def available?(position)
  read_map_byte(position) & (1 << (position % 8)) == 0
end

#bitmap_extension_pace ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 68

def bitmap_extension_pace
  @options['bitmap_extension_pace']||8192
end

#close! ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 76

def close!
  @bitmap_file.close
  @data_file.close
end

#delete!(position) ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 51

def delete!(position)
  self.first_available_position = -1
  increment_available_capacity!(position)
end

#elastic_insert!(record) ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 22

def elastic_insert!(record)
  position = find_first_available_chunk_position((record.size + 4) % 8)
  elastic_write!(position,record)
end

#elastic_read(position) ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 45

def elastic_read(position)
  @data_file.seek(position*record_size)
  size = @data_file.read(4).unpack('N').first
  @data_file.read(size)
end

#elastic_write!(position, record) ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 34

def elastic_write!(position,record)
  decrement_available_chunk!(position,(record.size + 4) % 8)
  elastic_write_at_position!(position,record)
  position
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/strokedb/volumes/map_volume.rb', line 60

def empty?
  read_map == "\x00" * map_size
end

#insert!(record) ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 17

def insert!(record)
  position = find_first_available_position
  write!(position,record)
end

#map_size ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 81

def map_size
  return @map_size if @map_size
  pos = @bitmap_file.pos
  @bitmap_file.seek(0,IO::SEEK_END)
  size = @bitmap_file.pos - HEADER_SIZE
  @bitmap_file.seek(pos)
  @map_size = size
end

#path ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 72

def path
  @options['path']
end

#read(position) ⇒ Object

Raises:



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# File 'lib/strokedb/volumes/map_volume.rb', line 40

def read(position)
  raise InvalidRecordPositionError if available?(position)
  read_at_position(position)
end

#record_size ⇒ Object 



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# File 'lib/strokedb/volumes/map_volume.rb', line 64

def record_size
  @options['record_size']
end

#write!(position, record) ⇒ Object

Raises:



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# File 'lib/strokedb/volumes/map_volume.rb', line 27

def write!(position,record)
  raise InvalidRecordSizeError if record.size != record_size
  decrement_available_capacity!(position)
  write_at_position!(position,record)
  position
end