Class: EntityStoreSequel::PostgresEntityStore

Inherits:
Object
  • Object
show all
Includes:
EntityStore::Logging
Defined in:
lib/entity_store_sequel/postgres_entity_store.rb

Class Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(database_connection = nil) ⇒ PostgresEntityStore

Returns a new instance of PostgresEntityStore.



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 44

def initialize(database_connection = nil)
  return unless database_connection

  @database_connection = database_connection
  @database_connection.extension :pg_json
end

Class Attribute Details

.connect_timeout=(value) ⇒ Object (writeonly)

Sets the attribute connect_timeout

Parameters:

  • value —

    the value to set the attribute connect_timeout to.



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 16

def connect_timeout=(value)
  @connect_timeout = value
end

.connection_string ⇒ Object

Returns the value of attribute connection_string.



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 15

def connection_string
  @connection_string
end

.native_json_hash ⇒ Object

Returns the value of attribute native_json_hash.



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 17

def native_json_hash
  @native_json_hash
end

Class Method Details

.database ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 19

def database
  return @_database if @_database

  self.database = Sequel.connect(connection_string)
end

.database=(db) ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 25

def database=(db)
  @_database = db

  if db.adapter_scheme == :postgres
    @_database.extension :pg_json
    self.native_json_hash = true
  else
    self.native_json_hash = false
  end

  @_database
end

.init ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 38

def init
  migration_path = File.expand_path("../../sequel/migrations", __FILE__)
  Sequel::Migrator.run(self.database, migration_path, table: :entity_store_schema_migration)
end

Instance Method Details

#add_entity(entity, id = BSON::ObjectId.new) ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 80

def add_entity(entity, id = BSON::ObjectId.new)
  entities.insert(:id => id.to_s, :_type => entity.class.name, :version => entity.version)
  id.to_s
end

#add_events(items) ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 127

def add_events(items)
  events_with_id = items.map { |e| [ BSON::ObjectId.new, e ] }
  add_events_with_ids(events_with_id)
end

#add_events_with_ids(event_id_map) ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 132

def add_events_with_ids(event_id_map)
  event_id_map.each do |id, event|
    doc = {
      :id => id.to_s,
      :_type => event.class.name,
      :_entity_id => event.entity_id.to_s,
      :entity_version => event.entity_version,
      :at => event.attributes[:at],
      :data => PigeonHole.generate(hash_without_keys(event.attributes, :entity_id, :at, :entity_version)),
    }
    events.insert(doc)
  end
end

#clear ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 63

def clear
  open.drop_table(:entities, :entity_events)
  @entities_collection = nil
  @events_collection = nil
end

#clear_entity_events(id, excluded_types) ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 72

def clear_entity_events(id, excluded_types)
  events.where(_entity_id: id).each do |event|
    next if excluded_types.include?(event[:_type])

    events.where(id: event[:id]).delete
  end
end

#ensure_indexes ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 69

def ensure_indexes
end

#entities ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 55

def entities
  @entities_collection ||= open[:entities]
end

#events ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 59

def events
  @events_collection ||= open[:entity_events]
end

#get_entities(ids, options = {}) ⇒ Object

Public: loads the entity from the store, including any available snapshots then loads the events to complete the state

ids - Array of Strings representation of BSON::ObjectId options - Hash of options (default: {})

:raise_exception - Boolean (default: true)

Returns an array of entities



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 154

def get_entities(ids, options={})
  ids.each do |id|
    begin
      BSON::ObjectId.from_string(id)
    rescue BSON::ObjectId::Invalid
      raise NotFound.new(id) if options.fetch(:raise_exception, true)
      nil
    end
  end

  entities.where(:id => ids).map do |attrs|
    begin
      entity_type = EntityStore::Config.load_type(attrs[:_type])

      # Check if there is a snapshot key in use
      if entity_type.respond_to? :entity_store_snapshot_key
        active_key = entity_type.entity_store_snapshot_key

        # Discard the snapshot if the keys don't match
        unless active_key == attrs[:snapshot_key]
          attrs.delete(:snapshot)
        end
      end

      if attrs[:snapshot]
        if self.class.native_json_hash
          hash = attrs[:snapshot].to_h
        else
          hash = PigeonHole.parse(attrs[:snapshot])
        end

        entity = entity_type.new(hash)
      else
        entity = entity_type.new({'id' => attrs[:id].to_s })
      end
    rescue => e
      log_error "Error loading type #{attrs[:_type]}", e
      raise
    end

    entity
  end

end

#get_events(criteria) ⇒ Object

Public: get events for an array of criteria objects

because each entity could have a different reference
version this allows optional criteria to be specifed

criteria - Hash :id mandatory, :since_version optional

Examples

get_events_for_criteria([ { id: “23232323”}, { id: “2398429834”, since_version: 4 } ] )

Returns Hash with id as key and Array of Event instances as value



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 211

def get_events(criteria)
  return {} if criteria.empty?

  query = events

  criteria.each_with_index do |item, i|
    filter_method = filter_method_name(i)
    if item[:since_version]
      query = query.send(filter_method, Sequel.lit('_entity_id = ? AND entity_version > ?', item[:id], item[:since_version]))
    else
      query = query.send(filter_method, Sequel.lit('_entity_id = ?', item[:id]))
    end
  end

  result = query.to_hash_groups(:_entity_id)

  result.each do |id, events|
    events.sort_by! { |attrs| [attrs[:entity_version], attrs[:id].to_s] }

    # Convert the attributes into event objects
    events.map! do |attrs|
      begin
        if self.class.native_json_hash
          hash = attrs[:data].to_h
        else
          hash = PigeonHole.parse(attrs[:data])
        end

        hash[:_id] = attrs[:id]
        hash[:entity_version] = attrs[:entity_version]
        hash[:entity_id] = attrs[:_entity_id]
        hash[:at] = attrs[:at]
        EntityStore::Config.load_type(attrs[:_type]).new(hash)
      rescue => e
        log_error "Error loading type #{attrs[:_type]}", e
        nil
      end
    end

    events.compact!
  end

  criteria.each do |item|
    result[item[:id].to_s] ||= []
  end

  result
end

#open ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 51

def open
  @database_connection || PostgresEntityStore.database
end

#remove_entity_snapshot(id) ⇒ Object

Public - remove the snapshot for an entity



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 111

def remove_entity_snapshot(id)
  entities.where(:id => id).update(:snapshot => nil)
end

#remove_snapshots(type = nil) ⇒ Object

Public: remove all snapshots

type - String optional class name for the entity



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 119

def remove_snapshots(type=nil)
  if type
    entities.where(:_type => type).update(:snapshot => nil)
  else
    entities.update(:snapshot => nil)
  end
end

#save_entity(entity) ⇒ Object 



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 85

def save_entity(entity)
  entities.where(:id => entity.id).update(:version => entity.version)
end

#snapshot_entity(entity) ⇒ Object

Public: create a snapshot of the entity and store in the entities collection



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# File 'lib/entity_store_sequel/postgres_entity_store.rb', line 91

def snapshot_entity(entity)
  if entity.class.respond_to? :entity_store_snapshot_key
    # If there is a snapshot key, store it too
    snapshot_key = entity.class.entity_store_snapshot_key
  else
    # Otherwise, make sure there isn't one set
    snapshot_key = nil
  end

  unless entities[:id => entity.id]
    entities.insert(:id => entity.id, :_type => entity.class.name, :version => entity.version)
  end

  entities
    .where(:id => entity.id)
    .update(:snapshot => PigeonHole.generate(entity.attributes), :snapshot_key => snapshot_key )
end