JezK
Edit File: parser_extras.rb
# frozen_string_literal: true require "thread" module Nokogiri module CSS class Parser < Racc::Parser # :nodoc: CACHE_SWITCH_NAME = :nokogiri_css_parser_cache_is_off @cache = {} @mutex = Mutex.new class << self # Return a thread-local boolean indicating whether the CSS-to-XPath cache is active. (Default is `true`.) def cache_on? !Thread.current[CACHE_SWITCH_NAME] end # Set a thread-local boolean to turn cacheing on and off. Truthy values turn the cache on, falsey values turn the cache off. def set_cache(value) # rubocop:disable Naming/AccessorMethodName Thread.current[CACHE_SWITCH_NAME] = !value end # Get the css selector in +string+ from the cache def [](string) return nil unless cache_on? @mutex.synchronize { @cache[string] } end # Set the css selector in +string+ in the cache to +value+ def []=(string, value) return value unless cache_on? @mutex.synchronize { @cache[string] = value } end # Clear the cache def clear_cache(create_new_object = false) @mutex.synchronize do if create_new_object @cache = {} else @cache.clear end end end # Execute +block+ without cache def without_cache(&block) original_cache_setting = cache_on? set_cache(false) yield ensure set_cache(original_cache_setting) end end # Create a new CSS parser with respect to +namespaces+ def initialize(namespaces = {}) @tokenizer = Tokenizer.new @namespaces = namespaces super() end def parse(string) @tokenizer.scan_setup(string) do_parse end def next_token @tokenizer.next_token end # Get the xpath for +string+ using +options+ def xpath_for(string, prefix, visitor) key = cache_key(string, prefix, visitor) self.class[key] ||= parse(string).map do |ast| ast.to_xpath(prefix, visitor) end end # On CSS parser error, raise an exception def on_error(error_token_id, error_value, value_stack) after = value_stack.compact.last raise SyntaxError, "unexpected '#{error_value}' after '#{after}'" end def cache_key(query, prefix, visitor) if self.class.cache_on? [query, prefix, @namespaces, visitor.config] end end end end end