class Moneta::Adapters::Mongo

MongoDB backend

Supports expiration, documents will be automatically removed starting with mongodb >= 2.2 (see {docs.mongodb.org/manual/tutorial/expire-data/}).

You can store hashes directly using this adapter.

@example Store hashes

db = Moneta::Adapters::MongoOfficial.new
db['key'] = {a: 1, b: 2}

@api public

Public Class Methods

new(options = {}) click to toggle source

@param [Hash] options @option options [String] :collection (‘moneta’) MongoDB collection name @option options [String] :host (‘127.0.0.1’) MongoDB server host @option options [String] :user Username used to authenticate @option options [String] :password Password used to authenticate @option options [Integer] :port (MongoDB default port) MongoDB server port @option options [String] :database (‘moneta’) MongoDB database @option options [Integer] :expires Default expiration time @option options [String] :expires_field (‘expiresAt’) Document field to store expiration time @option options [String] :value_field (‘value’) Document field to store value @option options [String] :type_field (‘type’) Document field to store value type @option options [::Mongo::Client] :backend Use existing backend instance @option options Other options passed to ‘Mongo::MongoClient#new`

Calls superclass method Moneta::Adapter::new
# File lib/moneta/adapters/mongo.rb, line 58
def initialize(options = {})
  super

  @database = backend.use(config.database)
  @collection = @database[config.collection]

  if @database.command(buildinfo: 1).documents.first['version'] >= '2.2'
    @collection.indexes.create_one({ config.expires_field => 1 }, expire_after: 0)
  else
    warn 'Moneta::Adapters::Mongo - You are using MongoDB version < 2.2, expired documents will not be deleted'
  end
end

Public Instance Methods

clear(options = {}) click to toggle source

(see Proxy#clear)

# File lib/moneta/adapters/mongo.rb, line 136
def clear(options = {})
  @collection.delete_many
  self
end
close() click to toggle source

(see Proxy#close)

# File lib/moneta/adapters/mongo.rb, line 142
def close
  @database.close
  nil
end
create(key, value, options = {}) click to toggle source

(see Proxy#create)

# File lib/moneta/adapters/mongo.rb, line 126
def create(key, value, options = {})
  key = to_binary(key)
  @collection.insert_one(value_to_doc(key, value, options))
  true
rescue ::Mongo::Error::OperationFailure => error
  raise unless error.code == 11000 # duplicate key error
  false
end
delete(key, options = {}) click to toggle source

(see Proxy#delete)

# File lib/moneta/adapters/mongo.rb, line 106
def delete(key, options = {})
  key = to_binary(key)
  if doc = @collection.find(_id: key).find_one_and_delete and
      !doc[config.expires_field] || doc[config.expires_field] >= Time.now
    doc_to_value(doc)
  end
end
each_key() { |from_binary(doc)| ... } click to toggle source

(see Proxy#each_key)

# File lib/moneta/adapters/mongo.rb, line 99
def each_key
  return enum_for(:each_key) unless block_given?
  @collection.find.each { |doc| yield from_binary(doc[:_id]) }
  self
end
fetch_values(*keys, **options) { |key| ... } click to toggle source

(see Proxy#fetch_values)

# File lib/moneta/adapters/mongo.rb, line 183
def fetch_values(*keys, **options)
  return values_at(*keys, **options) unless block_given?
  hash = Hash[slice(*keys, **options)]
  keys.map do |key|
    if hash.key?(key)
      hash[key]
    else
      yield key
    end
  end
end
increment(key, amount = 1, options = {}) click to toggle source

(see Proxy#increment)

# File lib/moneta/adapters/mongo.rb, line 115
def increment(key, amount = 1, options = {})
  @collection.find_one_and_update({ :$and => [{ _id: to_binary(key) }, not_expired] },
                                  { :$inc => { config.value_field => amount } },
                                  return_document: :after,
                                  upsert: true)[config.value_field]
rescue ::Mongo::Error::OperationFailure
  tries ||= 0
  (tries += 1) < 3 ? retry : raise
end
load(key, options = {}) click to toggle source

(see Proxy#load)

# File lib/moneta/adapters/mongo.rb, line 72
def load(key, options = {})
  view = @collection.find(:$and => [
                            { _id: to_binary(key) },
                            not_expired
                          ])

  doc = view.limit(1).first

  if doc
    update_expiry(options, nil) do |expires|
      view.update_one(:$set => { config.expires_field => expires })
    end

    doc_to_value(doc)
  end
end
merge!(pairs, options = {}) { |key, existing, value| ... } click to toggle source

(see Proxy#merge!)

# File lib/moneta/adapters/mongo.rb, line 163
def merge!(pairs, options = {})
  existing = Hash[slice(*pairs.map { |key, _| key })]
  update_pairs, insert_pairs = pairs.partition { |key, _| existing.key?(key) }

  unless insert_pairs.empty?
    @collection.insert_many(insert_pairs.map do |key, value|
      value_to_doc(to_binary(key), value, options)
    end)
  end

  update_pairs.each do |key, value|
    value = yield(key, existing[key], value) if block_given?
    binary = to_binary(key)
    @collection.replace_one({ _id: binary }, value_to_doc(binary, value, options))
  end

  self
end
slice(*keys, **options) click to toggle source

(see Proxy#slice)

# File lib/moneta/adapters/mongo.rb, line 148
def slice(*keys, **options)
  view = @collection.find(:$and => [
                            { _id: { :$in => keys.map(&method(:to_binary)) } },
                            not_expired
                          ])
  pairs = view.map { |doc| [from_binary(doc[:_id]), doc_to_value(doc)] }

  update_expiry(options, nil) do |expires|
    view.update_many(:$set => { config.expires_field => expires })
  end

  pairs
end
store(key, value, options = {}) click to toggle source

(see Proxy#store)

# File lib/moneta/adapters/mongo.rb, line 90
def store(key, value, options = {})
  key = to_binary(key)
  @collection.replace_one({ _id: key },
                          value_to_doc(key, value, options),
                          upsert: true)
  value
end
values_at(*keys, **options) click to toggle source

(see Proxy#values_at)

# File lib/moneta/adapters/mongo.rb, line 196
def values_at(*keys, **options)
  hash = Hash[slice(*keys, **options)]
  keys.map { |key| hash[key] }
end

Private Instance Methods

doc_to_value(doc) click to toggle source
# File lib/moneta/adapters/mongo.rb, line 203
def doc_to_value(doc)
  case doc[config.type_field]
  when 'Hash'
    doc = doc.dup
    doc.delete('_id')
    doc.delete(config.type_field)
    doc.delete(config.expires_field)
    doc
  when 'Number'
    doc[config.value_field]
  else
    # In ruby_bson version 2 (and probably up), #to_s no longer returns the binary data
    from_binary(doc[config.value_field])
  end
end
from_binary(binary) click to toggle source
# File lib/moneta/adapters/mongo.rb, line 252
def from_binary(binary)
  binary.is_a?(::BSON::Binary) ? binary.data : binary.to_s
end
not_expired() click to toggle source
# File lib/moneta/adapters/mongo.rb, line 256
def not_expired
  {
    :$or => [
      { config.expires_field => nil },
      { config.expires_field => { :$gte => Time.now } }
    ]
  }
end
to_binary(str) click to toggle source

BSON will use String#force_encoding to make the string 8-bit ASCII. This could break unicode text so we should dup in this case, and it also fails with frozen strings.

# File lib/moneta/adapters/mongo.rb, line 247
def to_binary(str)
  str = str.dup if str.frozen? || str.encoding != Encoding::ASCII_8BIT
  ::BSON::Binary.new(str)
end
update_expiry(options, default) { |expires || nil| ... } click to toggle source
# File lib/moneta/adapters/mongo.rb, line 265
def update_expiry(options, default)
  if (expires = expires_at(options, default)) != nil
    yield(expires || nil)
  end
end
value_to_doc(key, value, options) click to toggle source
# File lib/moneta/adapters/mongo.rb, line 219
def value_to_doc(key, value, options)
  case value
  when Hash
    value.merge('_id' => key,
                config.type_field => 'Hash',
                # expires_field must be a Time object (BSON date datatype)
                config.expires_field => expires_at(options) || nil)
  when Float, Integer
    { '_id' => key,
      config.type_field => 'Number',
      config.value_field => value,
      # expires_field must be a Time object (BSON date datatype)
      config.expires_field => expires_at(options) || nil }
  when String
    intvalue = value.to_i
    { '_id' => key,
      config.type_field => 'String',
      config.value_field => intvalue.to_s == value ? intvalue : to_binary(value),
      # @expires_field must be a Time object (BSON date datatype)
      config.expires_field => expires_at(options) || nil }
  else
    raise ArgumentError, "Invalid value type: #{value.class}"
  end
end