Class: DataMapper::Adapters::MnesiaAdapter

Inherits:
AbstractAdapter
  • Object
show all
Defined in:
lib/dm-mnesia-adapter.rb

Defined Under Namespace

Classes: ConnectError, ReadError, WriteError

Instance Method Summary collapse

Constructor Details

#initialize(name, options) ⇒ MnesiaAdapter

Initialize the adapter with the given options

  1. hostname: location of the rbridge server as an Ip or url, default is localhost

  2. port: the port to comunicate with rbridge, default is 9900

  3. mod: rbridge offers several modes of operation.

  4. ids_table: the table in mnesia that will handle the ids of each record created

  5. id_function: in case an erlang function is wished to be used for record id generations, it can be set here. If the id is a BinaryString, this is required



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# File 'lib/dm-mnesia-adapter.rb', line 15

def initialize(name, options)
  super                                       

  @hosname = @options[:hostname] ||= "localhost"         
  @port = @options[:port]        ||= 9900 
  @mod = @options[:mod] 
  @ids_table = @options[:ids_table]
  @id_function = @options[:id_function]
  @con = con
  @table_attributes = nil

  ## Refreshes the spec table so that spec test run properly
  con.erl("mnesia:clear_table(heffalump).") if name == :default
end

Instance Method Details

#con(&blk) ⇒ Object

Initializes the connection to the rbridge server



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# File 'lib/dm-mnesia-adapter.rb', line 31

def con(&blk)
  # connect to the server
  if @con.nil?
    @con = RBridge.new(@mod,@hostname, @port)
    if @con.erl("1*1.") != 1
       raise "Error opening connection to database: #{@con.erl("1*1.")}"
    end
  end
  @con
end

#create(resources) ⇒ Object

Create function required by the adapter spec



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# File 'lib/dm-mnesia-adapter.rb', line 43

def create(resources)
    resources.each do |resource|
      initialize_identity_field(resource,get_key(resource))
      save(con, parse_resource(resource))
  end
end

#delete(collection) ⇒ Object

Delete function required by the adapter spec



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# File 'lib/dm-mnesia-adapter.rb', line 73

def delete(collection)
    collection.each do |resource|
      erl_delete(resource.model,resource.key.first)
    end
end

#read(query) ⇒ Object

Read function required by the adapter spec TODO change query so that the mnesia filters the results and does not bring all records on the table every time



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# File 'lib/dm-mnesia-adapter.rb', line 53

def read(query)
    temp_records = erl_read(query)
    records = []
    temp_records.each do |value|
      records << value if value
    end
  result = query.filter_records(records.reverse)
  result
end

#update(attributes, collection) ⇒ Object

Update function required by the adapter spec



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# File 'lib/dm-mnesia-adapter.rb', line 64

def update(attributes, collection)
  attributes = attributes_as_fields(attributes)
  collection.each do |resource|
      attributes = resource.attributes(:field).merge(attributes)
      save(con, parse_resource(resource))
    end
end