Class: Newman::Store

Inherits:
Object
  • Object
show all
Defined in:
lib/newman/store.rb

Instance Method Summary collapse

Constructor Details

#initialize(filename) ⇒ Store

To initialize a Newman::Store object, a filename string must be provided, i.e.

store = Newman::Store.new("simple.store")

This filename will be used to initialize a PStore object after first running FileUtils.mkdir_p to create any directories within the path to the filename if they do not already exist. Once that PStore object is created, two root keys will be mapped to empty Hash objects if they are not set already: :indentifers and :columns.

While it's okay to treat the PStore object as an implementation detail, we will treat our interactions with it as part of Newman's external interface, so that we are more conservative about making backwards incompatible changes to the databases created by Newman::Store.



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# File 'lib/newman/store.rb', line 32

def initialize(filename)
  FileUtils.mkdir_p(File.dirname(filename))

  self.data = PStore.new(filename)

  write do
    data[:identifiers] ||= {} 
    data[:columns]     ||= {}
  end
end

Instance Method Details

#[](column_key) ⇒ Object

Newman::Store#[] is syntactic sugar for initializing a Newman::Recorder object, and is meant to be used for accessing and manipulating column data by column_key, i.e.

store[:subscriptions].create("[email protected]")

This method is functionally equivalent to the following code:

recorder = Newman::Recorder.new(:subscriptions, store)
recorder.create("[email protected]")

For aesthetic reasons and for forward compatibility, it is preferable to use Newman::Store#[] rather than instantiating a Newman::Recorder object directly.



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# File 'lib/newman/store.rb', line 60

def [](column_key)
  Recorder.new(column_key, self) 
end

#read ⇒ Object

Newman::Store#read initiates a read only transaction and then yields the underlying PStore object stored in the data field.



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# File 'lib/newman/store.rb', line 69

def read
  data.transaction(:read_only) { yield(data) }
end

#write ⇒ Object

Newman::Store#read initiates a read/write transaction and then yields the underlying PStore object stored in the data field.



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# File 'lib/newman/store.rb', line 78

def write
  data.transaction { yield(data) }
end