Class: Lotus::Model::Adapters::Dynamodb::Collection Private

Inherits:
Object
  • Object
show all
Includes:
AWS::DynamoDB::Types
Defined in:
lib/lotus/model/adapters/dynamodb/collection.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Acts like table, using AWS::DynamoDB::Client.

Since:

  • 0.1.0

Defined Under Namespace

Classes: Response

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(client, coercer, name, identity) ⇒ Collection

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Initialize a collection.

Parameters:

  • client (AWS::DynamoDB::Client) —

    DynamoDB client

  • coercer (Lotus::Model::Adapters::Dynamodb::Coercer)
  • name (Symbol) —

    the name of the collection (eg. ‘:users`)

  • identity (Symbol) —

    the primary key of the collection (eg. ‘:id`).

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 52

def initialize(client, coercer, name, identity)
  @client, @coercer = client, coercer
  @name, @identity = name.to_s, identity
  @key_schema = {}
end

Instance Attribute Details

#identity ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 40

def identity
  @identity
end

#name ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 33

def name
  @name
end

Instance Method Details

#create(entity) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Creates a record for the given entity and returns a primary key.

Parameters:

  • entity (Object) —

    the entity to persist

Returns:

  • the primary key of the just created record.

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 69

def create(entity)
  entity[identity] ||= SecureRandom.uuid

  @client.put_item(
    table_name: name,
    item: serialize_item(entity),
  )

  entity[identity]
end

#delete(entity) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Deletes the record corresponding to the given entity.

Parameters:

  • entity (Object) —

    the entity to delete

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 106

def delete(entity)
  @client.delete_item(
    table_name: name,
    key: serialize_key(entity),
  )
end

#deserialize_item(record) ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Deserialize item from DynamoDB response.

Parameters:

  • item (Hash) —

    the serialized item

Returns:

  • (Hash) —

    the deserialized record

See Also:

  • AWS::DynamoDB::Types

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 320

def deserialize_item(record)
  Lotus::Utils::Hash.new(values_from_response_hash(record)).symbolize!
end

#deserialize_response(response, previous_response = nil) ⇒ Response

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Deserialize DynamoDB scan/query response.

Parameters:

  • response (Hash) —

    the serialized response

  • previous_response (Response) (defaults to: nil) —

    deserialized response from a previous operation

Returns:

  • (Response) —

    the deserialized response

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 298

def deserialize_response(response, previous_response = nil)
  current_response = previous_response || Response.new
  current_response.count += response[:count]

  current_response.entities += response[:member].map do |item|
    deserialize_item(item)
  end if response[:member]

  current_response.last_evaluated_key = response[:last_evaluated_key]
  current_response
end

#format_attribute(column, value) ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Coerce and format attribute value to match DynamoDB type.

Parameters:

  • column (String) —

    the attribute column

  • value (Object) —

    the attribute value

Returns:

  • (Hash) —

    the formatted attribute

See Also:

  • AWS::DynamoDB::Types

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 235

def format_attribute(column, value)
  value = @coercer.public_send(:"serialize_#{ column }", value)
  format_attribute_value(value)
end

#get(key) ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns an unique record from the given collection, with the given id.

Parameters:

  • key (Array) —

    the identity of the object

Returns:

  • (Hash) —

    the serialized record

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 125

def get(key)
  return if key.any? { |v| v.to_s == "" }
  return if key.count != key_schema.count

  response = @client.get_item(
    table_name: name,
    key: serialize_key(key),
  )

  deserialize_item(response[:item]) if response[:item]
end

#key?(column, index = nil) ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Checks if given column is in key schema or not.

Parameters:

  • column (String) —

    column to check

  • index (String) (defaults to: nil) —

    index to check (defaults to table itself)

Returns:

  • (Boolean)

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 220

def key?(column, index = nil)
  key_schema(index).has_key?(column)
end

#key_schema(index = nil) ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Maps table key schema to hash with attribute name as key and key type as value.

Parameters:

  • index (String) (defaults to: nil) —

    index to check (defaults to table itself)

Returns:

  • (Hash) —

    key schema definition

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 192

def key_schema(index = nil)
  return @key_schema[index] if @key_schema[index]

  current_schema = if index
    everything = Array(schema[:local_secondary_indexes]) +
                 Array(schema[:global_secondary_indexes])
    indexes = Hash[everything.map { |i| [i[:index_name], i] }]
    indexes[index][:key_schema]
  else
    schema[:key_schema]
  end

  @key_schema[index] ||= Hash[current_schema.to_a.map do |key|
    [key[:attribute_name].to_sym, key[:key_type]]
  end]
end

#query(options = {}, previous_response = nil) ⇒ Array<Hash>

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Performs DynamoDB query operation.

Parameters:

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

    AWS::DynamoDB::Client options

  • previous_response (Response) (defaults to: nil) —

    deserialized response from a previous operation

Returns:

  • (Array<Hash>) —

    the serialized entities

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 148

def query(options = {}, previous_response = nil)
  response = @client.query(options.merge(table_name: name))
  deserialize_response(response, previous_response)
end

#scan(options = {}, previous_response = nil) ⇒ Array<Hash>

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Performs DynamoDB scan operation.

Parameters:

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

    AWS::DynamoDB::Client options

  • previous_response (Response) (defaults to: nil) —

    deserialized response from a previous operation

Returns:

  • (Array<Hash>) —

    the serialized entities

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 164

def scan(options = {}, previous_response = nil)
  response = @client.scan(options.merge(table_name: name))
  deserialize_response(response, previous_response)
end

#schema ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Fetches DynamoDB table schema.

Returns:

  • (Hash) —

    table schema definition

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 177

def schema
  @schema ||= @client.describe_table(table_name: name).fetch(:table)
end

#serialize_attributes(entity) ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Serialize given entity to exclude key schema attributes.

Parameters:

  • entity (Hash) —

    the entity

Returns:

  • (Hash) —

    the serialized attributes

See Also:

  • AWS::DynamoDB::Types

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 282

def serialize_attributes(entity)
  keys = key_schema.keys
  Hash[entity.reject { |k, _| keys.include?(k) }.map do |k, v|
    [k.to_s, { value: format_attribute_value(v), action: "PUT" }]
  end]
end

#serialize_item(record) ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Serialize given record to have proper attributes for ‘item’ query.

Parameters:

  • record (Hash) —

    the serialized record

Returns:

  • (Hash) —

    the serialized item

See Also:

  • AWS::DynamoDB::Types

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 250

def serialize_item(record)
  Hash[record.map { |k, v| [k.to_s, format_attribute_value(v)] }]
end

#serialize_key(record) ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Serialize given record or primary key to have proper attributes for ‘key’ query.

Parameters:

  • record (Hash, Array) —

    the serialized record or primary key

Returns:

  • (Hash) —

    the serialized key

See Also:

  • AWS::DynamoDB::Types

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 265

def serialize_key(record)
  Hash[key_schema.keys.each_with_index.map do |k, idx|
    v = record.is_a?(Hash) ? record[k] : record[idx]
    [k.to_s, format_attribute(k, v)]
  end]
end

#update(entity) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Updates the record corresponding to the given entity.

Parameters:

  • entity (Object) —

    the entity to persist

See Also:

Since:

  • 0.1.0



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# File 'lib/lotus/model/adapters/dynamodb/collection.rb', line 89

def update(entity)
  @client.update_item(
    table_name: name,
    key: serialize_key(entity),
    attribute_updates: serialize_attributes(entity),
  )
end