# class ActiveRecord::ConnectionAdapters::SchemaCache

### Attributes

connection[RW]
version[R]

### Public Class Methods

new(conn) click to toggle source

    # File lib/active_record/connection_adapters/schema_cache.rb, line 7
    def initialize(conn)
      @connection = conn

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

### Public Instance Methods

add(table_name) click to toggle source

Add internal cache for table with `table_name`.

    # File lib/active_record/connection_adapters/schema_cache.rb, line 53
    def add(table_name)
      if data_source_exists?(table_name)
        primary_keys(table_name)
        columns(table_name)
        columns_hash(table_name)
      end
    end

clear!() click to toggle source

Clears out internal caches

    # File lib/active_record/connection_adapters/schema_cache.rb, line 79
    def clear!
      @columns.clear
      @columns_hash.clear
      @primary_keys.clear
      @data_sources.clear
      @version = nil
    end

clear_data_source_cache!(name) click to toggle source

Clear out internal caches for the data source `name`.

    # File lib/active_record/connection_adapters/schema_cache.rb, line 92
    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) click to toggle source

Get the columns for a table

    # File lib/active_record/connection_adapters/schema_cache.rb, line 66
    def columns(table_name)
      @columns[table_name] ||= connection.columns(table_name)
    end

columns_hash(table_name) click to toggle source

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

    # File lib/active_record/connection_adapters/schema_cache.rb, line 72
    def columns_hash(table_name)
      @columns_hash[table_name] ||= Hash[columns(table_name).map { |col|
        [col.name, col]
      }]
    end

data_source_exists?(name) click to toggle source

A cached lookup for table existence.

    # File lib/active_record/connection_adapters/schema_cache.rb, line 45
    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) click to toggle source

    # File lib/active_record/connection_adapters/schema_cache.rb, line 61
    def data_sources(name)
      @data_sources[name]
    end

encode_with(coder) click to toggle source

    # File lib/active_record/connection_adapters/schema_cache.rb, line 24
    def encode_with(coder)
      coder["columns"] = @columns
      coder["columns_hash"] = @columns_hash
      coder["primary_keys"] = @primary_keys
      coder["data_sources"] = @data_sources
      coder["version"] = ActiveRecord::Migrator.current_version
    end

init_with(coder) click to toggle source

    # File lib/active_record/connection_adapters/schema_cache.rb, line 32
    def init_with(coder)
      @columns = coder["columns"]
      @columns_hash = coder["columns_hash"]
      @primary_keys = coder["primary_keys"]
      @data_sources = coder["data_sources"]
      @version = coder["version"]
    end

initialize_dup(other) click to toggle source
Calls superclass method

    # 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() click to toggle source

    # File lib/active_record/connection_adapters/schema_cache.rb, line 99
    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) click to toggle source

    # File lib/active_record/connection_adapters/schema_cache.rb, line 105
    def marshal_load(array)
      @version, @columns, @columns_hash, @primary_keys, @data_sources = array
    end

primary_keys(table_name) click to toggle source

    # File lib/active_record/connection_adapters/schema_cache.rb, line 40
    def primary_keys(table_name)
      @primary_keys[table_name] ||= data_source_exists?(table_name) ? connection.primary_key(table_name) : nil
    end

size() click to toggle source

    # File lib/active_record/connection_adapters/schema_cache.rb, line 87
    def size
      [@columns, @columns_hash, @primary_keys, @data_sources].map(&:size).inject :+
    end

### Private Instance Methods

prepare_data_sources() click to toggle source

    # File lib/active_record/connection_adapters/schema_cache.rb, line 111
    def prepare_data_sources
      connection.data_sources.each { |source| @data_sources[source] = true }
    end