Module: Dynamoid::Indexes::ClassMethods

Defined in:
lib/dynamoid/indexes.rb

Instance Method Summary collapse

Instance Method Details

#find_index(hash, range = nil) ⇒ Object 



96
97
98
99
 
# File 'lib/dynamoid/indexes.rb', line 96

def find_index(hash, range=nil)
  index = self.indexes[index_key(hash, range)]
  index
end

#global_secondary_index(options = {}) ⇒ Object

Defines a Global Secondary index on a table. Keys can be specified as hash-only, or hash & range.

Parameters:

  • options (Hash) (defaults to: {}) —

    options to pass for this table

Options Hash (options):

  • :name (Symbol) —

    the name for the index; this still gets namespaced. If not specified, will use a default name.

  • :hash_key (Symbol) —

    the index hash key column.

  • :range_key (Symbol) —

    the index range key column (if applicable).

  • :projected_attributes (Symbol, Array<Symbol>) —

    table attributes to project for this index. Can be :keys_only, :all or an array of included fields. If not specified, defaults to :keys_only.

  • :read_capacity (Integer) —

    set the read capacity for the index; does not work on existing indexes.

  • :write_capacity (Integer) —

    set the write capacity for the index; does not work on existing indexes.



30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
 
# File 'lib/dynamoid/indexes.rb', line 30

def global_secondary_index(options={})
  unless options.present?
    raise Dynamoid::Errors::InvalidIndex.new('empty index definition')
  end

  unless options[:hash_key].present?
    raise Dynamoid::Errors::InvalidIndex.new(
      'A global secondary index requires a :hash_key to be specified'
    )
  end

  index_opts = {
      read_capacity: Dynamoid::Config.read_capacity,
      write_capacity: Dynamoid::Config.write_capacity
  }.merge(options)

  index_opts[:dynamoid_class] = self
  index_opts[:type] = :global_secondary

  index = Dynamoid::Indexes::Index.new(index_opts)
  gsi_key = index_key(options[:hash_key], options[:range_key])
  self.global_secondary_indexes[gsi_key] = index
  self
end

#index_key(hash, range = nil) ⇒ String

Generates a convenient lookup key name for a hash/range index. Should normally not be used directly.

Parameters:

  • hash (Symbol) —

    hash key name.

  • range (Symbol) (defaults to: nil) —

    range key name.

Returns:

  • (String) —

    returns “hash” if hash only, “hash_range” otherwise.



129
130
131
132
133
134
135
 
# File 'lib/dynamoid/indexes.rb', line 129

def index_key(hash, range=nil)
  name = hash.to_s
  if range.present?
    name += "_#{range.to_s}"
  end
  name
end

#index_name(hash, range = nil) ⇒ String

Generates a default index name.

Parameters:

  • hash (Symbol) —

    hash key name.

  • range (Symbol) (defaults to: nil) —

    range key name.

Returns:

  • (String) —

    index name of the form “table_name_index_index_key”.



142
143
144
 
# File 'lib/dynamoid/indexes.rb', line 142

def index_name(hash, range=nil)
  "#{self.table_name}_index_#{self.index_key(hash, range)}"
end

#indexed_hash_keys ⇒ Object 



154
155
156
157
158
 
# File 'lib/dynamoid/indexes.rb', line 154

def indexed_hash_keys
  self.global_secondary_indexes.map do |name, index|
    index.hash_key.to_s
  end
end

#indexes ⇒ Hash<String, Object>

Convenience method to return all indexes on the table.

Returns:

  • (Hash<String, Object>) —

    the combined hash of global and local secondary indexes.



150
151
152
 
# File 'lib/dynamoid/indexes.rb', line 150

def indexes
  self.local_secondary_indexes.merge(self.global_secondary_indexes)
end

#is_global_secondary_index?(hash, range = nil) ⇒ Boolean

Returns true iff the provided hash key combo is a global secondary index.

Parameters:

  • hash (Symbol) —

    hash key name.

  • range (Symbol) (defaults to: nil) —

    range key name.

Returns:

  • (Boolean) —

    true iff provided keys correspond to a global secondary index.



119
120
121
 
# File 'lib/dynamoid/indexes.rb', line 119

def is_global_secondary_index?(hash, range=nil)
  self.global_secondary_indexes[index_key(hash, range)].present?
end

#is_local_secondary_index?(hash, range = nil) ⇒ Boolean

Returns true iff the provided hash key combo is a local secondary index.

Parameters:

  • hash (Symbol) —

    hash key name.

  • range (Symbol) (defaults to: nil) —

    range key name.

Returns:

  • (Boolean) —

    true iff provided keys correspond to a local secondary index.



108
109
110
 
# File 'lib/dynamoid/indexes.rb', line 108

def is_local_secondary_index?(hash, range=nil)
  self.local_secondary_indexes[index_key(hash, range)].present?
end

#local_secondary_index(options = {}) ⇒ Object

Defines a local secondary index on a table. Will use the same primary hash key as the table.

Parameters:

  • options (Hash) (defaults to: {}) —

    options to pass for this index.

Options Hash (options):

  • :name (Symbol) —

    the name for the index; this still gets namespaced. If not specified, a name is automatically generated.

  • :range_key (Symbol) —

    the range key column for the index.

  • :projected_attributes (Symbol, Array<Symbol>) —

    table attributes to project for this index. Can be :keys_only, :all or an array of included fields. If not specified, defaults to :keys_only.



66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
 
# File 'lib/dynamoid/indexes.rb', line 66

def local_secondary_index(options={})
  unless options.present?
    raise Dynamoid::Errors::InvalidIndex.new('empty index definition')
  end

  primary_hash_key = self.hash_key
  primary_range_key = self.range_key
  index_range_key = options[:range_key]

  unless index_range_key.present?
    raise Dynamoid::Errors::InvalidIndex.new('A local secondary index '\
      'requires a :range_key to be specified')
  end

  if primary_range_key.present? && index_range_key == primary_range_key
    raise Dynamoid::Errors::InvalidIndex.new('A local secondary index'\
      ' must use a different :range_key than the primary key')
  end

  index_opts = options.merge(
    dynamoid_class: self,
    type: :local_secondary,
    hash_key: primary_hash_key)

  index = Dynamoid::Indexes::Index.new(index_opts)
  key = index_key(primary_hash_key, index_range_key)
  self.local_secondary_indexes[key] = index
  self
end