Class: DoubleKeyMap

Inherits:
Object show all
Defined in:
lib/double_key_map.rb

Overview

Sometimes we need to map a key to a value but key is two pieces of data.

This nested hash table saves creating a single key each time we access
map; avoids mem creation.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ DoubleKeyMap

Returns a new instance of DoubleKeyMap.



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# File 'lib/double_key_map.rb', line 35

def initialize
    #	Map<Key1, Map<Key2, Value>> data = new LinkedHashMap<Key1, Map<Key2, Value>>();
    @data = Hash.new
end

Instance Method Details

#get(k1, k2 = nil) ⇒ Object 



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# File 'lib/double_key_map.rb', line 53

def get(k1, k2=nil) 
	data2 = @data[k1]
	return nil if data2.nil? 
   if k2.nil? then
     data2
   else
 		data2[k2]
   end
end

#keySet(k1 = nil) ⇒ Object

/** get all secondary keys associated with a primary key */



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# File 'lib/double_key_map.rb', line 71

def keySet(k1=nil) 
   #	/** get all primary keys 
   return @data.keys if k1.nil?
	data2 = @data[k1]
	return nil if data2.nil? 
	data2.keys
end

#put(k1, k2, v) ⇒ Object 



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# File 'lib/double_key_map.rb', line 40

def put(k1, k2, v) 
	data2 = @data.get(k1)
	prev = nil
	if data2.nil? then
		data2 = Hash.new
		@data[k1] = data2 
	else 
		prev = data2[k2]
	end
	data2[k2] = v
	return prev;
end

#values(k1) ⇒ Object

/** Get all values associated with primary key */



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# File 'lib/double_key_map.rb', line 64

def values(k1) 
	data2 = @data[k1]
	return nil if data2.nil? 
	data2.values();
end