Class: Fuzzzy::Ngram::Searcher

Inherits:
Base show all
Defined in:
lib/fuzzzy/methods/ngram/searcher.rb

Constant Summary collapse

SEGMENT_POINTS =

Ruby implementation: def segment_points index

right = distance + index
left = index > distance ? (index - distance) : 0
i = left
while i <= right do
  yield i
  i += 1
end

end

<<-EOC
VALUE 
_segment_points(VALUE self, VALUE _index) 
{
  int index, distance, left, right, i;

  index = NUM2INT(_index);
  distance = NUM2INT(rb_funcall(self, rb_intern("distance"), 0));
  right = index + distance;

  if(index > distance) {
    left = index - distance;
  } else {
    left = 0;
  }

  for(i = left; i <= right; i++) {
    rb_yield(INT2NUM(i));
  }

  return Qnil;
}
EOC

Constants included from Redis

Redis::INDEX_KEY

Instance Attribute Summary

Attributes inherited from MethodBase

#context

Instance Method Summary collapse

Methods inherited from Base

#index_type, #ngrams

Methods inherited from MethodBase

#index_name, #prepare_string, #stopwords, #with_context

Methods included from Redis

counter_key, #counter_key, #dictionary_key, #redis, #shared_key

Instance Method Details

#distance ⇒ Object 



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# File 'lib/fuzzzy/methods/ngram/searcher.rb', line 74

def distance
  context[:distance] ||= 0
end

#index_keys ⇒ Object 



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# File 'lib/fuzzzy/methods/ngram/searcher.rb', line 64

def index_keys
  keys = []
  ngrams.each_with_index do |ngram, index|
    segment_points(index) do |i|
      keys << index_key(ngram, i)
    end
  end
  keys
end

#query_index_string ⇒ Object 



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# File 'lib/fuzzzy/methods/ngram/searcher.rb', line 90

def query_index_string
  context[:prepared_query] ||= prepare_string(context[:query])
end

#result ⇒ Object 



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# File 'lib/fuzzzy/methods/ngram/searcher.rb', line 78

def result
  context[:result] ||= []
end

#search(cntx) ⇒ Object 



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# File 'lib/fuzzzy/methods/ngram/searcher.rb', line 42

def search cntx
  with_context(cntx) do
    return [] if query_index_string.empty?
    if ids = redis.sunion(*index_keys)
      ids.each do |id|
        string = redis.get(dictionary_key(id))
        dist = Levenshtein.distance(query_index_string, string)
        result << {
          :id => id,
          :distance => dist,
          :alpha => string
        } if dist <= distance
      end
      result.sort_by!{|item|item[sort_by]} if sort_by
      result.map!{|item|item[:id]} unless with_cache?
      result
    else
      []
    end
  end
end

#sort_by ⇒ Object 



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# File 'lib/fuzzzy/methods/ngram/searcher.rb', line 86

def sort_by
  context[:sort_by]
end

#with_cache? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fuzzzy/methods/ngram/searcher.rb', line 82

def with_cache?
  context[:with_cache] ||= false
end