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|
# frozen_string_literal: true
require_relative "../explicit_require"
Bootsnap::ExplicitRequire.with_gems("msgpack") { require "msgpack" }
module Bootsnap
module LoadPathCache
class Store
VERSION_KEY = "__bootsnap_ruby_version__"
CURRENT_VERSION = "#{VERSION}-#{RUBY_REVISION}-#{RUBY_PLATFORM}".freeze # rubocop:disable Style/RedundantFreeze
NestedTransactionError = Class.new(StandardError)
SetOutsideTransactionNotAllowed = Class.new(StandardError)
def initialize(store_path, readonly: false)
@store_path = store_path
@txn_mutex = Mutex.new
@dirty = false
@readonly = readonly
load_data
end
def get(key)
@data[key]
end
def fetch(key)
raise(SetOutsideTransactionNotAllowed) unless @txn_mutex.owned?
v = get(key)
unless v
v = yield
mark_for_mutation!
@data[key] = v
end
v
end
def set(key, value)
raise(SetOutsideTransactionNotAllowed) unless @txn_mutex.owned?
if value != @data[key]
mark_for_mutation!
@data[key] = value
end
end
def transaction
raise(NestedTransactionError) if @txn_mutex.owned?
@txn_mutex.synchronize do
yield
ensure
commit_transaction
end
end
private
def mark_for_mutation!
@dirty = true
@data = @data.dup if @data.frozen?
end
def commit_transaction
if @dirty && !@readonly
dump_data
@dirty = false
end
end
def load_data
@data = begin
data = File.open(@store_path, encoding: Encoding::BINARY) do |io|
MessagePack.load(io, freeze: true)
end
if data.is_a?(Hash) && data[VERSION_KEY] == CURRENT_VERSION
data
else
default_data
end
# handle malformed data due to upgrade incompatibility
rescue Errno::ENOENT, MessagePack::MalformedFormatError, MessagePack::UnknownExtTypeError, EOFError
default_data
rescue ArgumentError => error
if error.message =~ /negative array size/
default_data
else
raise
end
end
end
def dump_data
# Change contents atomically so other processes can't get invalid
# caches if they read at an inopportune time.
tmp = "#{@store_path}.#{Process.pid}.#{(rand * 100_000).to_i}.tmp"
mkdir_p(File.dirname(tmp))
exclusive_write = File::Constants::CREAT | File::Constants::EXCL | File::Constants::WRONLY
# `encoding:` looks redundant wrt `binwrite`, but necessary on windows
# because binary is part of mode.
File.open(tmp, mode: exclusive_write, encoding: Encoding::BINARY) do |io|
MessagePack.dump(@data, io)
end
File.rename(tmp, @store_path)
rescue Errno::EEXIST
retry
rescue SystemCallError
end
def default_data
{VERSION_KEY => CURRENT_VERSION}
end
def mkdir_p(path)
stack = []
until File.directory?(path)
stack.push path
path = File.dirname(path)
end
stack.reverse_each do |dir|
Dir.mkdir(dir)
rescue SystemCallError
# Check for broken symlinks. Calling File.realpath will raise Errno::ENOENT if that is the case
File.realpath(dir) if File.symlink?(dir)
raise unless File.directory?(dir)
end
end
end
end
end
|
