Class: Ngt::Index

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(index, path) ⇒ Index

Returns a new instance of Index.



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# File 'lib/ngt/index.rb', line 7

def initialize(index, path)
  @index = index
  @path = path

  @error = FFI.ngt_create_error_object
  @property = ffi(:ngt_create_property)
  ffi(:ngt_get_property, @index, @property)

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

Instance Attribute Details

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/ngt/index.rb', line 5

def path
  @path
end

Class Method Details

.create(path, dimensions, **options) ⇒ Object 



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# File 'lib/ngt/index.rb', line 173

def self.create(path, dimensions, **options)
  warn "[ngt] create is deprecated - use new instead"
  new(dimensions, path: path, **options)
end

.ffi(*args) ⇒ Object

private



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# File 'lib/ngt/index.rb', line 179

def self.ffi(*args)
  Utils.ffi(*args)
end

.finalize(error, index, property) ⇒ Object 



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# File 'lib/ngt/index.rb', line 183

def self.finalize(error, index, property)
  # must use proc instead of stabby lambda
  proc do
    FFI.ngt_destroy_error_object(error)
    FFI.ngt_close_index(index)
    FFI.ngt_destroy_property(property)
  end
end

.load(path) ⇒ Object 



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# File 'lib/ngt/index.rb', line 169

def self.load(path)
  new(nil, path: path)
end

.new(dimensions, path: nil, 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 112

def self.new(dimensions, path: nil, edge_size_for_creation: 10,
    edge_size_for_search: 40, object_type: :float, distance_type: :l2)

  error = FFI.ngt_create_error_object

  if path && dimensions.nil?
    index = ffi(:ngt_open_index, path, error)
  else
    property = ffi(:ngt_create_property, error)
    ffi(:ngt_set_property_dimension, property, dimensions, 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.downcase
    when "float"
      ffi(:ngt_set_property_object_type_float, property, error)
    when "integer"
      ffi(:ngt_set_property_object_type_integer, property, error)
    else
      raise ArgumentError, "Unknown object type: #{object_type}"
    end

    case distance_type.to_s.downcase
    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)
    when "normalized_angle"
      ffi(:ngt_set_property_distance_type_normalized_angle, property, error)
    when "normalized_cosine"
      ffi(:ngt_set_property_distance_type_normalized_cosine, property, error)
    else
      raise ArgumentError, "Unknown distance type: #{distance_type}"
    end

    index =
      if path
        ffi(:ngt_create_graph_and_tree, path, property, error)
      else
        ffi(:ngt_create_graph_and_tree_in_memory, property, error)
      end
  end

  super(index, path)
ensure
  FFI.ngt_destroy_error_object(error) if error
  FFI.ngt_destroy_property(property) if property
end

Instance Method Details

#batch_insert(objects, num_threads: 8) ⇒ Object 



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# File 'lib/ngt/index.rb', line 45

def batch_insert(objects, num_threads: 8)
  if narray?(objects)
    objects = objects.cast_to(Numo::SFloat) unless objects.is_a?(Numo::SFloat)
    count = objects.shape[0]
    obj = ::FFI::MemoryPointer.new(:char, objects.byte_size)
    obj.write_bytes(objects.to_binary)
  else
    objects = objects.to_a
    count = objects.size
    flat_objects = objects.flatten
    obj = ::FFI::MemoryPointer.new(:float, flat_objects.size)
    obj.write_array_of_float(flat_objects)
  end

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

  build_index(num_threads: num_threads)

  ids.read_array_of_uint32(count)
end

#build_index(num_threads: 8) ⇒ Object 



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# File 'lib/ngt/index.rb', line 67

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 108

def close
  FFI.ngt_close_index(@index)
end

#dimensions ⇒ Object 



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# File 'lib/ngt/index.rb', line 18

def dimensions
  @dimensions ||= ffi(:ngt_get_property_dimension, @property)
end

#distance_type ⇒ Object 



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# File 'lib/ngt/index.rb', line 22

def distance_type
  @distance_type ||= ffi(:ngt_get_property_distance_type, @property)
end

#edge_size_for_creation ⇒ Object 



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

def edge_size_for_creation
  @edge_size_for_creation ||= ffi(:ngt_get_property_edge_size_for_creation, @property)
end

#edge_size_for_search ⇒ Object 



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# File 'lib/ngt/index.rb', line 30

def edge_size_for_search
  @edge_size_for_search ||= ffi(:ngt_get_property_edge_size_for_search, @property)
end

#insert(object) ⇒ Object 



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# File 'lib/ngt/index.rb', line 41

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

#object(id) ⇒ Object 



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# File 'lib/ngt/index.rb', line 71

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

#object_type ⇒ Object 



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# File 'lib/ngt/index.rb', line 34

def object_type
  @object_type ||= begin
    object_type = ffi(:ngt_get_property_object_type, @property)
    FFI.ngt_is_property_object_type_float(object_type) ? :float : :integer
  end
end

#remove(id) ⇒ Object 



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# File 'lib/ngt/index.rb', line 81

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

#save(path = nil) ⇒ Object 



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# File 'lib/ngt/index.rb', line 103

def save(path = nil)
  @path = path || @path || Dir.mktmpdir
  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 85

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), dimensions, 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
ensure
  FFI.ngt_destroy_results(results) if results
end