Class: BitDatabase

Inherits:
Object
  • Object
show all
Defined in:
lib/chem/utils/bitdb.rb

Constant Summary collapse

ARCH = 
32

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(filename, bit_length) ⇒ BitDatabase

Returns a new instance of BitDatabase.



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# File 'lib/chem/utils/bitdb.rb', line 19

def initialize(filename, bit_length)
  @out = File.open(filename + ".dat", "w")
  @idx = File.open(filename + ".inf", "w")
  @bit_length = bit_length
  @n_bytes    = (bit_length - 1) / ARCH + 1
  @idx.write [@bit_length, @n_bytes].pack("l*")
  @current    = 0
end

Instance Attribute Details

#bit_length ⇒ Object (readonly)

Returns the value of attribute bit_length.



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# File 'lib/chem/utils/bitdb.rb', line 17

def bit_length
  @bit_length
end

Class Method Details

.open(filename, bit_length) {|db| ... } ⇒ Object

Yields:

  • (db) 


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# File 'lib/chem/utils/bitdb.rb', line 43

def self.open(filename, bit_length)
  db = new(filename, bit_length)
  yield db
  db.close
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/chem/utils/bitdb.rb', line 37

def close
  @idx.write [@current * 1000].pack("l*")
  @idx.close
  @out.close
end

#push(ary) ⇒ Object 



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# File 'lib/chem/utils/bitdb.rb', line 28

def push(ary)
  @current += 1
  @out.write ary.inject(Array.new(@n_bytes, 0)){|ret, num|
    raise Exception if num > @bit_length
    ret[num / ARCH] += (1 << (num % ARCH))
    ret
  }.pack('l*')
end