Class: Ngt::Index

Inherits:
Object
  • Object
show all
Includes:
Utils
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.



5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
 
# File 'lib/ngt/index.rb', line 5

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 



92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
 
# File 'lib/ngt/index.rb', line 92

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(*args) ⇒ Object

private



139
140
141
 
# File 'lib/ngt/index.rb', line 139

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

.finalize(error) ⇒ Object 



143
144
145
146
147
148
149
 
# File 'lib/ngt/index.rb', line 143

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 



27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
 
# File 'lib/ngt/index.rb', line 27

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 



49
50
51
 
# File 'lib/ngt/index.rb', line 49

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

#close ⇒ Object 



88
89
90
 
# File 'lib/ngt/index.rb', line 88

def close
  FFI.ngt_close_index(@index)
end

#insert(object) ⇒ Object 



23
24
25
 
# File 'lib/ngt/index.rb', line 23

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

#object(id) ⇒ Object 



53
54
55
56
57
58
59
60
61
 
# File 'lib/ngt/index.rb', line 53

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 



63
64
65
 
# File 'lib/ngt/index.rb', line 63

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

#save(path: nil) ⇒ Object 



83
84
85
86
 
# File 'lib/ngt/index.rb', line 83

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

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



67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
 
# File 'lib/ngt/index.rb', line 67

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