Class: Ngt::Index

Inherits:
Object
  • Object
show all
Defined in:
lib/ngt/index.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path) ⇒ Index

Returns a new instance of Index.



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# File 'lib/ngt/index.rb', line 3

def initialize(path)
  @path = path
  @error = FFI.ngt_create_error_object
  @index = ffi(:ngt_open_index, path)

  property = ffi(:ngt_create_property)
  ffi(:ngt_get_property, @index, property)

  @dimension = ffi(:ngt_get_property_dimension, property)

  object_type = ffi(:ngt_get_property_object_type, property)
  @float = FFI.ngt_is_property_object_type_float(object_type)

  @object_space = ffi(:ngt_get_object_space, @index)

  ObjectSpace.define_finalizer(self, self.class.finalize(@error))
end

Class Method Details

.create(path, dimension, edge_size_for_creation: 10, edge_size_for_search: 40, object_type: "Float", distance_type: "L2") ⇒ Object 



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# File 'lib/ngt/index.rb', line 83

def self.create(path, dimension, edge_size_for_creation: 10,
    edge_size_for_search: 40, object_type: "Float", distance_type: "L2")

  error = FFI.ngt_create_error_object
  property = ffi(:ngt_create_property, error)
  ffi(:ngt_set_property_dimension, property, dimension, error)
  ffi(:ngt_set_property_edge_size_for_creation, property, edge_size_for_creation, error)
  ffi(:ngt_set_property_edge_size_for_search, property, edge_size_for_search, error)

  case object_type.to_s
  when "Float", "float"
    ffi(:ngt_set_property_object_type_float, property, error)
  when "Integer", "integer"
    ffi(:ngt_set_property_object_type_integer, property, error)
  else
    raise ArgumentError, "Unknown object type: #{object_type}"
  end

  case distance_type.to_s
  when "L1"
    ffi(:ngt_set_property_distance_type_l1, property, error)
  when "L2"
    ffi(:ngt_set_property_distance_type_l2, property, error)
  when "Angle"
    ffi(:ngt_set_property_distance_type_angle, property, error)
  when "Hamming"
    ffi(:ngt_set_property_distance_type_hamming, property, error)
  when "Jaccard"
    ffi(:ngt_set_property_distance_type_jaccard, property, error)
  when "Cosine"
    ffi(:ngt_set_property_distance_type_cosine, property, error)
  else
    raise ArgumentError, "Unknown distance type: #{distance_type}"
  end

  index = ffi(:ngt_create_graph_and_tree, path, property, error)
  FFI.ngt_close_index(index)
  index = nil

  Index.new(path)
ensure
  FFI.ngt_destroy_error_object(error) if error
  FFI.ngt_destroy_property(property) if property
  FFI.ngt_close_index(index) if index
end

.ffi(method, *args) ⇒ Object

private

Raises:



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# File 'lib/ngt/index.rb', line 130

def self.ffi(method, *args)
  res = FFI.send(method, *args)
  message = FFI.ngt_get_error_string(args.last)
  raise Error, message unless message.empty?
  res
end

.finalize(error) ⇒ Object 



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# File 'lib/ngt/index.rb', line 137

def self.finalize(error)
  # must use proc instead of stabby lambda
  proc do
    # TODO clean-up more objects
    FFI.ngt_destroy_error_object(error)
  end
end

Instance Method Details

#batch_insert(objects, num_threads: 8) ⇒ Object

TODO make more performant for Numo



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# File 'lib/ngt/index.rb', line 26

def batch_insert(objects, num_threads: 8)
  objects = objects.to_a
  flat_objects = objects.flatten
  obj = ::FFI::MemoryPointer.new(:float, flat_objects.size)
  obj.write_array_of_float(flat_objects)

  ids = ::FFI::MemoryPointer.new(:uint32, objects.size)
  ffi(:ngt_batch_insert_index, @index, obj, objects.size, ids)

  build_index(num_threads: num_threads)

  ids.read_array_of_uint32(objects.size)
end

#build_index(num_threads: 8) ⇒ Object 



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# File 'lib/ngt/index.rb', line 40

def build_index(num_threads: 8)
  ffi(:ngt_create_index, @index, num_threads)
end

#close ⇒ Object 



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# File 'lib/ngt/index.rb', line 79

def close
  FFI.ngt_close_index(@index)
end

#insert(object) ⇒ Object 



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# File 'lib/ngt/index.rb', line 21

def insert(object)
  ffi(:ngt_insert_index, @index, c_object(object.to_a), @dimension)
end

#object(id) ⇒ Object 



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# File 'lib/ngt/index.rb', line 44

def object(id)
  if float?
    res = ffi(:ngt_get_object_as_float, @object_space, id)
    res.read_array_of_float(@dimension)
  else
    res = ffi(:ngt_get_object_as_integer, @object_space, id)
    res.read_array_of_uint8(@dimension)
  end
end

#remove(id) ⇒ Object 



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# File 'lib/ngt/index.rb', line 54

def remove(id)
  ffi(:ngt_remove_index, @index, id)
end

#save(path: nil) ⇒ Object 



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# File 'lib/ngt/index.rb', line 74

def save(path: nil)
  path ||= @path
  ffi(:ngt_save_index, @index, path)
end

#search(query, size: 20, epsilon: 0.1, radius: nil) ⇒ Object 



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# File 'lib/ngt/index.rb', line 58

def search(query, size: 20, epsilon: 0.1, radius: nil)
  radius ||= -1.0
  results = ffi(:ngt_create_empty_results)
  ffi(:ngt_search_index, @index, c_object(query.to_a), @dimension, size, epsilon, radius, results)
  result_size = ffi(:ngt_get_result_size, results)
  ret = []
  result_size.times do |i|
    res = ffi(:ngt_get_result, results, i)
    ret << {
      id: res[:id],
      distance: res[:distance]
    }
  end
  ret
end