Module: Aqua::Store::CouchDB::StorageMethods::ClassMethods

Defined in:
lib/aqua/store/couch_db/storage_methods.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#parent_class ⇒ Object Also known as: design_name

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.

Accessor for maintaining connection to aquatic class



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 105

def parent_class
  @parent_class
end

Instance Method Details

#attachment(document_id, attachment_id) ⇒ Tempfile

Retrieves an attachment when provided the document id and attachment id, or the combined id

Returns:



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 99

def attachment( document_id, attachment_id )
  new( :id => document_id ).attachments.get!( attachment_id )
end

#average(index, opts = {}) ⇒ Object Also known as: avg 



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 209

def average( index, opts={} )
  sum(index, opts) / count(index, opts).to_f
end

#count(index, opts = {}) ⇒ Object 



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 186

def count( index, opts={} )
  opts = Mash.new(opts)
  opts[:reduce] = "
    function (key, values, rereduce) {
        return sum(values);
    }" unless opts[:reduce]
  reduced_query(:count, index, opts)
end

#create(hash) ⇒ Aqua::Storage, false

Initializes a new storage document and saves it without raising any errors

Parameters:

Returns:

  • (Aqua::Storage, false) —

    On success it returns an aqua storage object. On failure it returns false.



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 29

def create( hash )
  doc = new( hash )
  doc.save
end

#create!(hash) ⇒ Aqua::Storage

Initializes a new storage document and saves it raising any errors.

Parameters:

Returns:

  • (Aqua::Storage) —

    On success it returns an aqua storage object.

Raises:

  • Any of the CouchDB exceptions



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 41

def create!( hash )
  doc = new( hash )
  doc.save!
end

#database ⇒ Aqua::Database

TODO:

Look to CouchDB database strategy to determine if there is a database per class or just one big database for all classes

Sets default database for class. This can be overwritten by individual documents

Returns:

  • (Aqua::Database) 


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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 53

def database
  @database ||= Database.create # defaults to 'aqua' 
end

#database=(db) ⇒ Aqua::Database

Setter for the database per class. Used to override default per class or default strategy.

Returns:

  • (Aqua::Database) 


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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 62

def database=( db )
  db = Database.create( db ) if db.class == String
  @database = db
end

#design_document(reload = false) ⇒ Object

Finds or creates design document based on aqua parent class name



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 111

def design_document( reload=false )
  @design_document = nil if reload 
  @design_document ||= design_name ? DesignDocument.find_or_create( design_name ) : nil
end

#find_or_create(id) ⇒ Hash Also known as: get!

Will find a document by id, or create it if it doesn’t exist. Alias is :get!

Parameters:

Returns:

  • (Hash) —

    representing the CouchDB resource



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 84

def find_or_create( id )
  begin
    get( id )
  rescue
    create!( :id => id )
  end    
end

#get(id) ⇒ Hash

Gets a document from the database based on id

Parameters:

Returns:

  • (Hash) —

    representing the CouchDB data



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 71

def get( id )
  resource = begin # this is just in case the developer has already escaped the name
    CouchDB.get( "#{database.uri}/#{CGI.escape(id)}" )
  rescue
    CouchDB.get( "#{database.uri}/#{id}" )  
  end
  new( resource ) 
end

#index_on(field, opts = {}) ⇒ Object

Stores stores a map name for a given index, allowing the same map to be used for various reduce functions. This means only one index is created.

Parameters:

  • field (String) —

    being indexed, or the sub field

  • Hash (Hash, Mash) —

    of functions used to create views

  • opts (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (opts):

  • :map (String) —

    Javascript/CouchDB map function

  • :reduce (String) —

    Javascript/CouchDB reduce function



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 124

def index_on( field, opts={} )
  opts = Mash.new( opts )
  design_document(true).add!( opts.merge!(:name => field) )
  unless indexes.include?( field )
    indexes << field.to_sym  
    indexes << field.to_s 
  end  
  self     
end

#index_on_ivar(field) ⇒ 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.

This is an aqua specific indexer whereas index_on is a more generic CouchDB indexer. This method seeks out the designated ivar in an Aqua structured document. Future iterations should go deeper into the ivar to reduce the overall size of the index, and make for more usable searches.



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 140

def index_on_ivar( field ) 
  index_on( field,
    :map => "
      function(doc) {
        if( doc['class'] == '#{parent_class}' &&
            doc['ivars'] && doc['ivars']['@#{field}']    ){
          emit( doc['ivars']['@#{field}'], 1 );
        }
      }
    "
  )
end

#indexes ⇒ Object

A list of index names that can be used to build other reduce functions.



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 155

def indexes
  @indexes ||= []
end

#max(index, opts = {}) ⇒ Object Also known as: maximum 



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 230

def max( index, opts={} )
  opts = Mash.new(opts)
  opts[:reduce] = "
    function (keys, values, rereduce) {
      var key_values = []
      keys.forEach( function(key) {
        key_values[key_values.length] = key[0]
      });
      return Math.max.apply( Math, key_values ); ;
    }" unless opts[:reduce]
  reduced_query(:max, index, opts)
end

#min(index, opts = {}) ⇒ Object Also known as: minimum 



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 215

def min( index, opts={} )
  opts = Mash.new(opts)
  opts[:reduce] = "
    function (keys, values, rereduce) {
      var key_values = []
      keys.forEach( function(key) {
        key_values[key_values.length] = key[0]
      });
      return Math.min.apply( Math, key_values ); ;
    }" unless opts[:reduce]
  reduced_query(:min, index, opts)
end

#query(index, opts = {}) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 160

def query( index, opts={} )
  raise ArgumentError, 'Index not found' unless views.include?( index.to_s )
  opts = Mash.new(opts)
  opts.merge!(:document_class => self) unless opts[:document_class]
  opts.merge!(:reduced => design_document.views[index][:reduce] ? true : false )
  design_document.query( index, opts )
end

#reduced_query(reduce_type, index, opts) ⇒ Object 



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 168

def reduced_query( reduce_type, index, opts)
  view =  "#{index}_#{reduce_type}" 
  unless views.include?( view )
    design_document(true).add!(
      :name => view, 
      :map => design_document.views[ index.to_s ][:map],
      :reduce => opts[:reduce]
    )
  end  
  query( view, opts.merge!( :select => "index only" ) )
end

#sum(index, opts = {}) ⇒ Object 



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 196

def sum( index, opts={} )
  opts = Mash.new(opts)
  opts[:reduce] = "
    function (keys, values, rereduce) {
      var key_values = []
      keys.forEach( function(key) {
        key_values[key_values.length] = key[0]
      });
      return sum( key_values );
    }" unless opts[:reduce]
  reduced_query(:sum, index, opts)
end

#views ⇒ Object 



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# File 'lib/aqua/store/couch_db/storage_methods.rb', line 181

def views
  design_document.views.keys
end