Class: ActiveRecord::ConnectionAdapters::SchemaCache

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

Instance Attribute Summary collapse

Class Method 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 30

def initialize(conn)
  @connection = conn

  @columns      = {}
  @columns_hash = {}
  @primary_keys = {}
  @data_sources = {}
  @indexes      = {}
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 28

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 27

def version
  @version
end

Class Method Details

.load_from(filename) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 8

def self.load_from(filename)
  return unless File.file?(filename)

  read(filename) do |file|
    filename.include?(".dump") ? Marshal.load(file) : YAML.load(file)
  end
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 88

def add(table_name)
  if data_source_exists?(table_name)
    primary_keys(table_name)
    columns(table_name)
    columns_hash(table_name)
    indexes(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 132

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

#clear_data_source_cache!(name) ⇒ Object

Clear out internal caches for the data source name.


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 147

def clear_data_source_cache!(name)
  @columns.delete name
  @columns_hash.delete name
  @primary_keys.delete name
  @data_sources.delete name
  @indexes.delete 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 102

def columns(table_name)
  @columns.fetch(table_name) do
    @columns[deep_deduplicate(table_name)] = deep_deduplicate(connection.columns(table_name))
  end
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 110

def columns_hash(table_name)
  @columns_hash.fetch(table_name) do
    @columns_hash[deep_deduplicate(table_name)] = columns(table_name).index_by(&:name)
  end
end

#columns_hash?(table_name) ⇒ Boolean

Checks whether the columns hash is already cached for a table.

Returns:

  • (Boolean)

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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 117

def columns_hash?(table_name)
  @columns_hash.key?(table_name)
end

#data_source_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 80

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

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

#data_sources(name) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 97

def data_sources(name)
  @data_sources[name]
end

#database_versionObject

:nodoc:


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 127

def database_version # :nodoc:
  @database_version ||= connection.get_database_version
end

#dump_to(filename) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 155

def dump_to(filename)
  clear!
  connection.data_sources.each { |table| add(table) }
  open(filename) { |f|
    if filename.include?(".dump")
      f.write(Marshal.dump(self))
    else
      f.write(YAML.dump(self))
    end
  }
end

#encode_with(coder) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 49

def encode_with(coder)
  reset_version!

  coder["columns"]          = @columns
  coder["primary_keys"]     = @primary_keys
  coder["data_sources"]     = @data_sources
  coder["indexes"]          = @indexes
  coder["version"]          = @version
  coder["database_version"] = database_version
end

#indexes(table_name) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 121

def indexes(table_name)
  @indexes.fetch(table_name) do
    @indexes[deep_deduplicate(table_name)] = deep_deduplicate(connection.indexes(table_name))
  end
end

#init_with(coder) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 60

def init_with(coder)
  @columns          = coder["columns"]
  @primary_keys     = coder["primary_keys"]
  @data_sources     = coder["data_sources"]
  @indexes          = coder["indexes"] || {}
  @version          = coder["version"]
  @database_version = coder["database_version"]

  derive_columns_hash_and_deduplicate_values
end

#initialize_dup(other) ⇒ Object


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

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

#marshal_dumpObject


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 167

def marshal_dump
  reset_version!

  [@version, @columns, {}, @primary_keys, @data_sources, @indexes, database_version]
end

#marshal_load(array) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 173

def marshal_load(array)
  @version, @columns, _columns_hash, @primary_keys, @data_sources, @indexes, @database_version = array
  @indexes ||= {}

  derive_columns_hash_and_deduplicate_values
end

#primary_keys(table_name) ⇒ Object


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 71

def primary_keys(table_name)
  @primary_keys.fetch(table_name) do
    if data_source_exists?(table_name)
      @primary_keys[deep_deduplicate(table_name)] = deep_deduplicate(connection.primary_key(table_name))
    end
  end
end

#sizeObject


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# File 'activerecord/lib/active_record/connection_adapters/schema_cache.rb', line 142

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