Class: Eurydice::ColumnPage

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/eurydice/column_page.rb

Direct Known Subclasses

ForwardColumnPage, ReverseColumnPage

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(column_family, row_key, page_size, offset = FIRST_OFFSET) ⇒ ColumnPage

Returns a new instance of ColumnPage.



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# File 'lib/eurydice/column_page.rb', line 9

def initialize(column_family, row_key, page_size, offset=FIRST_OFFSET)
  @column_family = column_family
  @row_key = row_key
  @offset = offset
  @page_size = page_size
end

Instance Attribute Details

#page_size ⇒ Object (readonly)

Returns the value of attribute page_size.



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# File 'lib/eurydice/column_page.rb', line 7

def page_size
  @page_size
end

Instance Method Details

#each_column(&block) ⇒ Object Also known as: each 



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# File 'lib/eurydice/column_page.rb', line 46

def each_column(&block)
  return self unless block_given?
  slice.each.with_index do |item,i|
    yield item if i < @page_size
  end
end

#first? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/eurydice/column_page.rb', line 34

def first?
  @offset == FIRST_OFFSET
end

#last? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/eurydice/column_page.rb', line 38

def last?
  slice.size <= @page_size
end

#next_page ⇒ Object 



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# File 'lib/eurydice/column_page.rb', line 24

def next_page
  return nil if last?
  ForwardColumnPage.new(@column_family, @row_key, @page_size, next_page_offset)
end

#offset ⇒ Object 



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# File 'lib/eurydice/column_page.rb', line 16

def offset
  if @offset == FIRST_OFFSET
    slice.keys.first
  else
    @offset
  end
end

#prev_page ⇒ Object 



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# File 'lib/eurydice/column_page.rb', line 29

def prev_page
  return nil if first?
  ReverseColumnPage.new(@column_family, @row_key, @page_size, prev_page_offset)
end

#reverse? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/eurydice/column_page.rb', line 42

def reverse?
  false
end