Class: Bmg::Redis::Relation

Inherits:
Object
  • Object
show all
Includes:
Bmg::Relation
Defined in:
lib/bmg/redis/relation.rb

Constant Summary collapse

DEFAULT_OPTIONS = 
{
  serializer: :marshal
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(type, options) ⇒ Relation

Returns a new instance of Relation.



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# File 'lib/bmg/redis/relation.rb', line 10

def initialize(type, options)
  @type = type
  @options = DEFAULT_OPTIONS.merge(options)

  serializer!
  candidate_key!
end

Instance Attribute Details

#type ⇒ Object

Returns the value of attribute type.



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# File 'lib/bmg/redis/relation.rb', line 17

def type
  @type
end

Instance Method Details

#_restrict(type, predicate) ⇒ Object

optimization



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# File 'lib/bmg/redis/relation.rb', line 34

def _restrict(type, predicate)
  return super unless key = full_and_only_key?(predicate)

  redis_key = extract_key(key)
  if tuple_str = redis.get(redis_key)
    tuple = serializer.deserialize(tuple_str)
    Singleton.new(type, self, tuple)
  else
    Bmg::Relation.empty
  end
end

#delete(predicate = Predicate.tautology) ⇒ Object 



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# File 'lib/bmg/redis/relation.rb', line 77

def delete(predicate = Predicate.tautology)
  keys = restrict(predicate).each.map{|t| extract_key(t) }
  redis.multi do |transaction|
    keys.each_slice(1000) do |slice|
      transaction.del(*slice)
    end
  end
  self
end

#each ⇒ Object 



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# File 'lib/bmg/redis/relation.rb', line 22

def each
  return to_enum unless block_given?

  redis.scan_each(match: "#{key_prefix}:*") do |key|
    tuple_str = redis.get(key)
    tuple = serializer.deserialize(tuple_str)
    yield(tuple)
  end
end

#insert(tuple_or_tuples) ⇒ Object 



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# File 'lib/bmg/redis/relation.rb', line 48

def insert(tuple_or_tuples)
  case tuple_or_tuples
  when Hash
    insert_one(tuple_or_tuples, redis)
  else
    redis.multi do |transaction|
      tuple_or_tuples.each do |tuple|
        insert_one(tuple, transaction)
      end
    end
  end
  self
end

#update(updating, predicate = Predicate.tautology) ⇒ Object 



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# File 'lib/bmg/redis/relation.rb', line 70

def update(updating, predicate = Predicate.tautology)
  updates = restrict(predicate).map do |tuple|
    tuple.merge(updating)
  end
  insert(updates)
end