Class: ActiveRecord::ConnectionAdapters::SchemaCache

Inherits:
Object
  • Object
show all
Defined in:
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 'lib/active_record/connection_adapters/schema_cache.rb', line 7

def initialize(conn)
  @connection = conn

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

Instance Attribute Details

#connection ⇒ Object

Returns the value of attribute connection.



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

def connection
  @connection
end

#version ⇒ Object (readonly)

Returns the value of attribute version.



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# File '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 'lib/active_record/connection_adapters/schema_cache.rb', line 40

def add(table_name)
  if data_source_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 'lib/active_record/connection_adapters/schema_cache.rb', line 68

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

#clear_data_source_cache!(name) ⇒ Object Also known as: clear_table_cache!

Clear out internal caches for the data source name.



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# File 'lib/active_record/connection_adapters/schema_cache.rb', line 81

def clear_data_source_cache!(name)
  @columns.delete name
  @columns_hash.delete name
  @primary_keys.delete name
  @data_sources.delete name
end

#columns(table_name) ⇒ Object

Get the columns for a table



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

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 'lib/active_record/connection_adapters/schema_cache.rb', line 61

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

#data_source_exists?(name) ⇒ Boolean Also known as: table_exists?

A cached lookup for table existence.

Returns:

  • (Boolean) 


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

def data_source_exists?(name)
  prepare_data_sources if @data_sources.empty?
  return @data_sources[name] if @data_sources.key? name

  @data_sources[name] = connection.data_source_exists?(name)
end

#data_sources(name) ⇒ Object Also known as: tables 



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

def data_sources(name)
  @data_sources[name]
end

#initialize_dup(other) ⇒ Object 



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

def initialize_dup(other)
  super
  @columns      = @columns.dup
  @columns_hash = @columns_hash.dup
  @primary_keys = @primary_keys.dup
  @data_sources = @data_sources.dup
end

#marshal_dump ⇒ Object 



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# File 'lib/active_record/connection_adapters/schema_cache.rb', line 90

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, @data_sources]
end

#marshal_load(array) ⇒ Object 



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# File 'lib/active_record/connection_adapters/schema_cache.rb', line 96

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

#primary_keys(table_name) ⇒ Object 



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# File 'lib/active_record/connection_adapters/schema_cache.rb', line 24

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

#size ⇒ Object 



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# File 'lib/active_record/connection_adapters/schema_cache.rb', line 76

def size
  [@columns, @columns_hash, @primary_keys, @data_sources].map(&:size).inject :+
end