Class: ActiveRecord::ConnectionAdapters::SchemaCache

Inherits:
Object
  • Object
show all
Defined in:
activerecord/lib/active_record/connection_adapters/schema_cache.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(conn) ⇒ SchemaCache

Returns a new instance of SchemaCache.


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 7

def initialize(conn)
  @connection = conn

  @columns      = {}
  @columns_hash = {}
  @primary_keys = {}
  @tables       = {}
end

Instance Attribute Details

#connectionObject

Returns the value of attribute connection


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 5

def connection
  @connection
end

#versionObject (readonly)

Returns the value of attribute version


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 4

def version
  @version
end

Instance Method Details

#add(table_name) ⇒ Object

Add internal cache for table with table_name.


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 29

def add(table_name)
  if table_exists?(table_name)
    primary_keys(table_name)
    columns(table_name)
    columns_hash(table_name)
  end
end

#clear!Object

Clears out internal caches


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 55

def clear!
  @columns.clear
  @columns_hash.clear
  @primary_keys.clear
  @tables.clear
  @version = nil
end

#clear_table_cache!(table_name) ⇒ Object

Clear out internal caches for table with table_name.


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 70

def clear_table_cache!(table_name)
  @columns.delete table_name
  @columns_hash.delete table_name
  @primary_keys.delete table_name
  @tables.delete table_name
end

#columns(table_name) ⇒ Object

Get the columns for a table


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 42

def columns(table_name)
  @columns[table_name] ||= connection.columns(table_name)
end

#columns_hash(table_name) ⇒ Object

Get the columns for a table as a hash, key is the column name value is the column object.


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 48

def columns_hash(table_name)
  @columns_hash[table_name] ||= Hash[columns(table_name).map { |col|
    [col.name, col]
  }]
end

#marshal_dumpObject


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 77

def marshal_dump  # if we get current version during initialization, it happens stack over flow.

  @version = ActiveRecord::Migrator.current_version
  [@version, @columns, @columns_hash, @primary_keys, @tables]
end

#marshal_load(array) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 83

def marshal_load(array)
  @version, @columns, @columns_hash, @primary_keys, @tables = array
end

#primary_keys(table_name) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 16

def primary_keys(table_name)
  @primary_keys[table_name] ||= table_exists?(table_name) ? connection.primary_key(table_name) : nil
end

#sizeObject


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 63

def size
  [@columns, @columns_hash, @primary_keys, @tables].map { |x|
    x.size
  }.inject :+
end

#table_exists?(name) ⇒ Boolean

A cached lookup for table existence.

Returns:

  • (Boolean)

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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 21

def table_exists?(name)
  prepare_tables if @tables.empty?
  return @tables[name] if @tables.key? name

  @tables[name] = connection.table_exists?(name)
end

#tables(name) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 37

def tables(name)
  @tables[name]
end