Hash with table alias symbol keys and primary key symbol values (or arrays of primary key symbols for composite key tables)
This class is the internal implementation of eager_graph. It is responsible for taking an array of plain hashes and returning an array of model objects with all eager_graphed associations already set in the association cache.
Hash with table alias symbol keys and subhash values mapping column_alias symbols to the symbol of the real name of the column
Recursive hash with table alias symbol keys mapping to hashes with dependent table alias symbol keys.
Hash with table alias symbol keys and callable values used to create model instances The table alias symbol for the primary model
Hash with table alias symbol keys and primary key symbol values (or arrays of primary key symbols for composite key tables)
Hash with table alias symbol keys and reciprocal association symbol values, used for setting reciprocals for one_to_many associations.
Hash with table alias symbol keys and subhash values mapping primary key symbols (or array of symbols) to model instances. Used so that only a single model instance is created for each object.
Hash with table alias symbol keys and true/false values, where true means the association represented by the table alias uses an array of values instead of a single value (i.e. true => *_many, false => *_to_one).
Initialize all of the data structures used during loading.
# File lib/sequel/model/associations.rb, line 2252 def initialize(dataset) opts = dataset.opts eager_graph = opts[:eager_graph] @master = eager_graph[:master] requirements = eager_graph[:requirements] reflection_map = @reflection_map = eager_graph[:reflections] reciprocal_map = @reciprocal_map = eager_graph[:reciprocals] @unique = eager_graph[:cartesian_product_number] > 1 alias_map = @alias_map = {} type_map = @type_map = {} after_load_map = @after_load_map = {} limit_map = @limit_map = {} reflection_map.each do |k, v| alias_map[k] = v[:name] type_map[k] = v.returns_array? after_load_map[k] = v[:after_load] unless v[:after_load].empty? limit_map[k] = v.limit_and_offset if v[:limit] end # Make dependency map hash out of requirements array for each association. # This builds a tree of dependencies that will be used for recursion # to ensure that all parts of the object graph are loaded into the # appropriate subordinate association. @dependency_map = {} # Sort the associations by requirements length, so that # requirements are added to the dependency hash before their # dependencies. requirements.sort_by{|a| a[1].length}.each do |ta, deps| if deps.empty? dependency_map[ta] = {} else deps = deps.dup hash = dependency_map[deps.shift] deps.each do |dep| hash = hash[dep] end hash[ta] = {} end end # This mapping is used to make sure that duplicate entries in the # result set are mapped to a single record. For example, using a # single one_to_many association with 10 associated records, # the main object column values appear in the object graph 10 times. # We map by primary key, if available, or by the object's entire values, # if not. The mapping must be per table, so create sub maps for each table # alias. records_map = {@master=>{}} alias_map.keys.each{|ta| records_map[ta] = {}} @records_map = records_map datasets = opts[:graph][:table_aliases].to_a.reject{|ta,ds| ds.nil?} column_aliases = opts[:graph_aliases] || opts[:graph][:column_aliases] primary_keys = {} column_maps = {} models = {} row_procs = {} datasets.each do |ta, ds| models[ta] = ds.model primary_keys[ta] = [] column_maps[ta] = {} row_procs[ta] = ds.row_proc end column_aliases.each do |col_alias, tc| ta, column = tc column_maps[ta][col_alias] = column end column_maps.each do |ta, h| pk = models[ta].primary_key if pk.is_a?(Array) primary_keys[ta] = [] h.select{|ca, c| primary_keys[ta] << ca if pk.include?(c)} else h.select{|ca, c| primary_keys[ta] = ca if pk == c} end end @column_maps = column_maps @primary_keys = primary_keys @row_procs = row_procs # For performance, create two special maps for the master table, # so you can skip a hash lookup. @master_column_map = column_maps[master] @master_primary_keys = primary_keys[master] # Add a special hash mapping table alias symbols to 5 element arrays that just # contain the data in other data structures for that table alias. This is # used for performance, to get all values in one hash lookup instead of # separate hash lookups for each data structure. ta_map = {} alias_map.keys.each do |ta| ta_map[ta] = [records_map[ta], row_procs[ta], alias_map[ta], type_map[ta], reciprocal_map[ta]] end @ta_map = ta_map end
Return an array of primary model instances with the associations cache prepopulated for all model objects (both primary and associated).
# File lib/sequel/model/associations.rb, line 2351 def load(hashes) master = master() # Assign to local variables for speed increase rp = row_procs[master] rm = records_map[master] dm = dependency_map # This will hold the final record set that we will be replacing the object graph with. records = [] hashes.each do |h| unless key = master_pk(h) key = hkey(master_hfor(h)) end unless primary_record = rm[key] primary_record = rm[key] = rp.call(master_hfor(h)) # Only add it to the list of records to return if it is a new record records.push(primary_record) end # Build all associations for the current object and it's dependencies _load(dm, primary_record, h) end # Remove duplicate records from all associations if this graph could possibly be a cartesian product # Run after_load procs if there are any post_process(records, dm) if @unique || !after_load_map.empty? || !limit_map.empty? records end
Generated with the Darkfish Rdoc Generator 2.