/
schema_cache.rb
256 lines (221 loc) · 7.38 KB
/
schema_cache.rb
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# frozen_string_literal: true
require "active_support/core_ext/file/atomic"
module ActiveRecord
module ConnectionAdapters
class SchemaCache
def self.load_from(filename)
return unless File.file?(filename)
read(filename) do |file|
if filename.include?(".dump")
Marshal.load(file)
else
if YAML.respond_to?(:unsafe_load)
YAML.unsafe_load(file)
else
YAML.load(file)
end
end
end
end
def self.read(filename, &block)
if File.extname(filename) == ".gz"
Zlib::GzipReader.open(filename) { |gz|
yield gz.read
}
else
yield File.read(filename)
end
end
private_class_method :read
attr_reader :version
attr_accessor :connection
def initialize(conn)
@connection = conn
@columns = {}
@columns_hash = {}
@primary_keys = {}
@data_sources = {}
@indexes = {}
end
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
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
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
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
# A cached lookup for table existence.
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
# Add internal cache for table with +table_name+.
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
def data_sources(name)
@data_sources[name]
end
# Get the columns for a table
def columns(table_name)
@columns.fetch(table_name) do
@columns[deep_deduplicate(table_name)] = deep_deduplicate(connection.columns(table_name))
end
end
# Get the columns for a table as a hash, key is the column name
# value is the column object.
def columns_hash(table_name)
@columns_hash.fetch(table_name) do
@columns_hash[deep_deduplicate(table_name)] = columns(table_name).index_by(&:name).freeze
end
end
# Checks whether the columns hash is already cached for a table.
def columns_hash?(table_name)
@columns_hash.key?(table_name)
end
def indexes(table_name)
@indexes.fetch(table_name) do
@indexes[deep_deduplicate(table_name)] = deep_deduplicate(connection.indexes(table_name))
end
end
def database_version # :nodoc:
@database_version ||= connection.get_database_version
end
# Clears out internal caches
def clear!
@columns.clear
@columns_hash.clear
@primary_keys.clear
@data_sources.clear
@indexes.clear
@version = nil
@database_version = nil
end
def size
[@columns, @columns_hash, @primary_keys, @data_sources].sum(&:size)
end
# Clear out internal caches for the data source +name+.
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
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
def marshal_dump
reset_version!
[@version, @columns, {}, @primary_keys, @data_sources, @indexes, database_version]
end
def marshal_load(array)
@version, @columns, _columns_hash, @primary_keys, @data_sources, @indexes, @database_version = array
@indexes ||= {}
derive_columns_hash_and_deduplicate_values
end
private
def reset_version!
@version = connection.migration_context.current_version
end
def derive_columns_hash_and_deduplicate_values
@columns = deep_deduplicate(@columns)
@columns_hash = @columns.transform_values { |columns| columns.index_by(&:name) }
@primary_keys = deep_deduplicate(@primary_keys)
@data_sources = deep_deduplicate(@data_sources)
@indexes = deep_deduplicate(@indexes)
end
if RUBY_VERSION < "2.7"
def deep_deduplicate(value)
case value
when Hash
value.transform_keys { |k| deep_deduplicate(k) }.transform_values { |v| deep_deduplicate(v) }
when Array
value.map { |i| deep_deduplicate(i) }
when String
if value.tainted?
# Ruby 2.6 and 2.7 have slightly different implementations of the String#-@ method.
# In Ruby 2.6, the receiver of the String#-@ method is modified under certain
# circumstances, and this was later identified as a bug
# (https://bugs.ruby-lang.org/issues/15926) and only fixed in Ruby 2.7.
value = value.dup
end
-value
when Deduplicable
-value
else
value
end
end
else
def deep_deduplicate(value)
case value
when Hash
value.transform_keys { |k| deep_deduplicate(k) }.transform_values { |v| deep_deduplicate(v) }
when Array
value.map { |i| deep_deduplicate(i) }
when String, Deduplicable
-value
else
value
end
end
end
def prepare_data_sources
connection.data_sources.each { |source| @data_sources[source] = true }
end
def open(filename)
File.atomic_write(filename) do |file|
if File.extname(filename) == ".gz"
zipper = Zlib::GzipWriter.new file
yield zipper
zipper.flush
zipper.close
else
yield file
end
end
end
end
end
end