Class: Refile::Postgres::Backend

Inherits:
Object
  • Object
show all
Extended by:
BackendMacros
Includes:
SmartTransaction
Defined in:
lib/refile/postgres/backend.rb,
lib/refile/postgres/backend/reader.rb

Defined Under Namespace

Classes: Reader

Constant Summary collapse

RegistryTableDoesNotExistError = 
Class.new(StandardError)
DEFAULT_REGISTRY_TABLE = 
"refile_attachments"
DEFAULT_NAMESPACE = 
"default"
PG_LARGE_OBJECT_METADATA_TABLE = 
"pg_largeobject_metadata"
READ_CHUNK_SIZE = 
3000
INIT_CONNECTION_ARG_ERROR_MSG = 
"When initializing new Refile::Postgres::Backend first argument should be an instance of PG::Connection or a lambda/proc that returns it. When using ActiveRecord it is available as ActiveRecord::Base.connection.raw_connection"

Constants included from SmartTransaction

SmartTransaction::PQTRANS_INTRANS

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from SmartTransaction

#ensure_in_transaction, #smart_transaction

Constructor Details

#initialize(connection_or_proc, max_size: nil, namespace: DEFAULT_NAMESPACE, registry_table: DEFAULT_REGISTRY_TABLE) ⇒ Backend

Returns a new instance of Backend.



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# File 'lib/refile/postgres/backend.rb', line 13

def initialize(connection_or_proc, max_size: nil, namespace: DEFAULT_NAMESPACE, registry_table: DEFAULT_REGISTRY_TABLE)
  @connection_or_proc = connection_or_proc
  @namespace = namespace.to_s
  @registry_table = registry_table
  @registry_table_validated = false
  @max_size = max_size
end

Instance Attribute Details

#max_size ⇒ Object (readonly)

Returns the value of attribute max_size.



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# File 'lib/refile/postgres/backend.rb', line 21

def max_size
  @max_size
end

#namespace ⇒ Object (readonly)

Returns the value of attribute namespace.



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# File 'lib/refile/postgres/backend.rb', line 21

def namespace
  @namespace
end

Instance Method Details

#clear!(confirm = nil) ⇒ Object

Raises:

  • (Refile::Confirm) 


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# File 'lib/refile/postgres/backend.rb', line 115

def clear!(confirm = nil)
  raise Refile::Confirm unless confirm == :confirm
  registry_table
  ensure_in_transaction do
    connection.exec_params(%{
      SELECT * FROM #{registry_table}
      INNER JOIN #{PG_LARGE_OBJECT_METADATA_TABLE} ON #{registry_table}.id = #{PG_LARGE_OBJECT_METADATA_TABLE}.oid
      WHERE #{registry_table}.namespace = $1::varchar;
    }, [namespace]) do |result|
      result.each_row do |row|
        connection.lo_unlink(row[0].to_s.to_i)
      end
    end
    connection.exec_params("DELETE FROM #{registry_table} WHERE namespace = $1::varchar;", [namespace])
  end
end

#connection ⇒ Object 



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# File 'lib/refile/postgres/backend.rb', line 38

def connection
  if has_active_connection?
    @connection
  else
    obtain_new_connection
  end
end

#registry_table ⇒ Object 



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# File 'lib/refile/postgres/backend.rb', line 23

def registry_table
  unless @registry_table_validated
    connection.exec %{
      SELECT count(*) from pg_catalog.pg_tables
      WHERE tablename = '#{@registry_table}';
    } do |result|
      unless result[0]["count"].to_i > 0
        raise RegistryTableDoesNotExistError.new(%{Please create a table "#{@registry_table}" where backend could store list of attachments})
      end
    end
    @registry_table_validated = true
  end
  @registry_table
end