Class: PackedModel::List

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/packed_model/list.rb

Instance Method Summary collapse

Constructor Details

#initialize(row_class, values = nil) ⇒ List

Returns a new instance of List.

Raises:



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# File 'lib/packed_model/list.rb', line 5

def initialize(row_class, values=nil)
  raise InvalidPackedModelException.new("row_class must be fixed width") unless row_class.fixed_width?
  @row_class = row_class
  @buffer = values
end

Instance Method Details

#<<(row) ⇒ Object 



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# File 'lib/packed_model/list.rb', line 24

def <<(row)
  row.changed!
  rows << row
end

#[](idx) ⇒ Object

the data in each row is only unpacked when it is accessed from here



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# File 'lib/packed_model/list.rb', line 12

def [](idx)
  if (row = rows[idx]).is_a?(String)
    row = rows[idx] = @row_class.new(row)
  end
  row
end

#[]=(idx, row) ⇒ Object 



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# File 'lib/packed_model/list.rb', line 19

def []=(idx, row)
  row.changed!
  rows[idx] = row
end

#bytesize ⇒ Object 



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# File 'lib/packed_model/list.rb', line 83

def bytesize
  row_bytesize * size
end

#each ⇒ Object 



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# File 'lib/packed_model/list.rb', line 87

def each
  self.size.times do |idx|
    yield self[idx]
  end
end

#find_in_buffer(val) ⇒ Object

to search the buffer the first field must be a marker and the 2nd is the what you are searching for Example: class TestSearchableModel < PackedModel::Base

  attribute :magic, :type => :marker, :value => 20130502
  attribute :id, :type => :integer
  attribute :name, :type => :char, :size => 20
end



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# File 'lib/packed_model/list.rb', line 69

def find_in_buffer(val)
  return nil unless @buffer
  @results ||= {}
  return @results[val] if @results.has_key?(val)
  index = @buffer.index search_string(val)
  return (@results[val] = nil) unless index
  index = index / row_bytesize
  @results[val] = self[index]
end

#pack ⇒ Object 



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# File 'lib/packed_model/list.rb', line 34

def pack
  return repack if @must_repack
  return @buffer unless @rows
  @buffer ||= ''
  start = 0
  @rows.each_with_index do |row, idx|
    # only updated dirty rows
    if ! row.is_a?(String) && row.changed?
      @buffer[start...(start+row_bytesize)] = row.pack
      row.not_changed!
    end
    start += row_bytesize
  end
  @buffer
end

#remove(idx) ⇒ Object 



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# File 'lib/packed_model/list.rb', line 29

def remove(idx)
  @must_repack = true
  rows[idx] = nil
end

#repack ⇒ Object

repacks the buffer



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# File 'lib/packed_model/list.rb', line 51

def repack
  @buffer = ''
  self.each do |row|
    next unless row
    @buffer << row.pack
  end
  remove_instance_variable "@rows"
  remove_instance_variable("@must_repack") if defined?(@must_repack)
  remove_instance_variable("@results") if defined?(@results)
  @buffer
end

#size ⇒ Object 



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# File 'lib/packed_model/list.rb', line 79

def size
  rows.size
end