class Condenser::Server
Constants
- ALLOWED_REQUEST_METHODS
Public Class Methods
new(condenser, logger: nil)
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# File lib/condenser/server.rb, line 10 def initialize(condenser, logger: nil) @logger = logger || Logger.new($stdout, level: :info) @condenser = condenser end
Public Instance Methods
call(env)
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`call` implements the Rack 1.x specification which accepts an `env` Hash and returns a three item tuple with the status code, headers, and body.
Mapping your environment at a url prefix will serve all assets in the path.
map "/assets" do run Condenser::Server.new(condenser) end
A request for `“/assets/foo/bar.js”` will search your environment for `“foo/bar.js”`.
# File lib/condenser/server.rb, line 32 def call(env) start_time = Time.now.to_f time_elapsed = lambda { ((Time.now.to_f - start_time) * 1000).to_i } if !ALLOWED_REQUEST_METHODS.include?(env['REQUEST_METHOD']) return method_not_allowed_response end msg = "Served asset #{env['PATH_INFO']} -" # Extract the path from everything after the leading slash path = Rack::Utils.unescape(env['PATH_INFO'].to_s.sub(/^\//, '')) if !path.valid_encoding? return bad_request_response(env) end # Strip fingerprint if fingerprint = path_fingerprint(path) path = path.sub("-#{fingerprint}", '') end # URLs containing a `".."` are rejected for security reasons. if forbidden_request?(path) return forbidden_response(env) end if fingerprint if_match = fingerprint elsif env['HTTP_IF_MATCH'] if_match = env['HTTP_IF_MATCH'][/"(\w+)"$/, 1] end if env['HTTP_IF_NONE_MATCH'] if_none_match = env['HTTP_IF_NONE_MATCH'][/"(\w+)"$/, 1] end # Look up the asset. asset = @condenser.find_export(path) if asset.nil? status = :not_found elsif fingerprint && asset.etag != fingerprint status = :not_found elsif if_match && asset.etag != if_match status = :precondition_failed elsif if_none_match && asset.etag == if_none_match status = :not_modified else status = :ok end case status when :ok logger.info "#{msg} 200 OK (#{time_elapsed.call}ms)" ok_response(asset, env) when :not_modified logger.info "#{msg} 304 Not Modified (#{time_elapsed.call}ms)" not_modified_response(env, if_none_match) when :not_found logger.info "#{msg} 404 Not Found (#{time_elapsed.call}ms)" not_found_response(env) when :precondition_failed logger.info "#{msg} 412 Precondition Failed (#{time_elapsed.call}ms)" precondition_failed_response(env) end rescue StandardError, ScriptError => e logger.error "Error compiling asset #{path}:" logger.error "#{e.class.name}: #{e.message}" case File.extname(path) when ".js" # Re-throw JavaScript asset exceptions to the browser logger.info "#{msg} 500 Internal Server Error\n\n" return javascript_exception_response(e) when ".css" # Display CSS asset exceptions in the browser logger.info "#{msg} 500 Internal Server Error\n\n" return css_exception_response(e) else raise end end
logger()
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# File lib/condenser/server.rb, line 15 def logger @condenser.logger end
Private Instance Methods
absolute_path?(path)
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# File lib/condenser/server.rb, line 303 def absolute_path?(path) path.start_with?(File::SEPARATOR) end
bad_request_response(env)
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Returns a 400 Forbidden response tuple
# File lib/condenser/server.rb, line 143 def bad_request_response(env) if head_request?(env) [ 400, { "Content-Type" => "text/plain", "Content-Length" => "0" }, [] ] else [ 400, { "Content-Type" => "text/plain", "Content-Length" => "11" }, [ "Bad Request" ] ] end end
cache_headers(env, etag)
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# File lib/condenser/server.rb, line 251 def cache_headers(env, etag) headers = {} # Set caching headers headers["Cache-Control"] = String.new("public") headers["ETag"] = %("#{etag}") # If the request url contains a fingerprint, set a long # expires on the response if path_fingerprint(env["PATH_INFO"]) headers["Cache-Control"] << ", max-age=31536000, immutable" # Otherwise set `must-revalidate` since the asset could be modified. else headers["Cache-Control"] << ", must-revalidate" headers["Vary"] = "Accept-Encoding" end headers end
css_exception_response(exception)
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Returns a CSS response that hides all elements on the page and displays the exception
# File lib/condenser/server.rb, line 191 def css_exception_response(exception) message = "\n#{exception.class.name}: #{exception.message}" backtrace = "\n #{exception.backtrace.first}" body = <<-CSS html { padding: 18px 36px; } head { display: block; } body { margin: 0; padding: 0; } body > * { display: none !important; } head:after, body:before, body:after { display: block !important; } head:after { font-family: sans-serif; font-size: large; font-weight: bold; content: "Error compiling CSS asset"; } body:before, body:after { font-family: monospace; white-space: pre-wrap; } body:before { font-weight: bold; content: "#{escape_css_content(message)}"; } body:after { content: "#{escape_css_content(backtrace)}"; } CSS [ 200, { "Content-Type" => "text/css; charset=utf-8", "Content-Length" => body.bytesize.to_s }, [ body ] ] end
escape_css_content(content)
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Escape special characters for use inside a CSS content(“…”) string
# File lib/condenser/server.rb, line 243 def escape_css_content(content) content. gsub('\\', '\\\\005c '). gsub("\n", '\\\\000a '). gsub('"', '\\\\0022 '). gsub('/', '\\\\002f ') end
forbidden_request?(path)
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# File lib/condenser/server.rb, line 116 def forbidden_request?(path) # Prevent access to files elsewhere on the file system # # http://example.org/assets/../../../etc/passwd # path.include?("..") || absolute_path?(path) end
forbidden_response(env)
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Returns a 403 Forbidden response tuple
# File lib/condenser/server.rb, line 152 def forbidden_response(env) if head_request?(env) [ 403, { "Content-Type" => "text/plain", "Content-Length" => "0" }, [] ] else [ 403, { "Content-Type" => "text/plain", "Content-Length" => "9" }, [ "Forbidden" ] ] end end
head_request?(env)
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# File lib/condenser/server.rb, line 124 def head_request?(env) env['REQUEST_METHOD'] == 'HEAD' end
headers(env, asset, length)
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# File lib/condenser/server.rb, line 272 def headers(env, asset, length) headers = {} # Set content length header headers["Content-Length"] = length.to_s if asset&.sourcemap headers['SourceMap'] = env['SCRIPT_NAME'] + env['PATH_INFO'] + '.map' end # Set content type header if type = asset.content_type # Set charset param for text/* mime types if type.start_with?("text/") && asset.charset type += "; charset=#{asset.charset}" end headers["Content-Type"] = type end headers.merge(cache_headers(env, asset.etag)) end
javascript_exception_response(exception)
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Returns a JavaScript response that re-throws a Ruby exception in the browser
# File lib/condenser/server.rb, line 183 def javascript_exception_response(exception) err = "#{exception.class.name}: #{exception.message}\n (in #{exception.backtrace[0]})" body = "throw Error(#{err.inspect})" [ 200, { "Content-Type" => "application/javascript", "Content-Length" => body.bytesize.to_s }, [ body ] ] end
method_not_allowed_response()
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# File lib/condenser/server.rb, line 169 def method_not_allowed_response [ 405, { "Content-Type" => "text/plain", "Content-Length" => "18" }, [ "Method Not Allowed" ] ] end
not_found_response(env)
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Returns a 404 Not Found response tuple
# File lib/condenser/server.rb, line 161 def not_found_response(env) if head_request?(env) [ 404, { "Content-Type" => "text/plain", "Content-Length" => "0", "X-Cascade" => "pass" }, [] ] else [ 404, { "Content-Type" => "text/plain", "Content-Length" => "9", "X-Cascade" => "pass" }, [ "Not found" ] ] end end
not_modified_response(env, etag)
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Returns a 304 Not Modified response tuple
# File lib/condenser/server.rb, line 138 def not_modified_response(env, etag) [ 304, cache_headers(env, etag), [] ] end
ok_response(asset, env)
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Returns a 200 OK response tuple
# File lib/condenser/server.rb, line 129 def ok_response(asset, env) if head_request?(env) [ 200, headers(env, asset, 0), [] ] else [ 200, headers(env, asset, asset.length), [asset.to_s] ] end end
path_fingerprint(path)
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Gets ETag fingerprint.
"foo-0aa2105d29558f3eb790d411d7d8fb66.js" # => "0aa2105d29558f3eb790d411d7d8fb66"
# File lib/condenser/server.rb, line 299 def path_fingerprint(path) path[/-([0-9a-f]{7,128})\.[^.]+\z/, 1] end
precondition_failed_response(env)
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# File lib/condenser/server.rb, line 173 def precondition_failed_response(env) if head_request?(env) [ 412, { "Content-Type" => "text/plain", "Content-Length" => "0", "X-Cascade" => "pass" }, [] ] else [ 412, { "Content-Type" => "text/plain", "Content-Length" => "19", "X-Cascade" => "pass" }, [ "Precondition Failed" ] ] end end