Merge: nitcorn: fix bug with binary files

Downloading binary files from a nitcorn server works as expected once again.

The API should be enough for most users but there is a few features lacking. Namely alternating custom text with files and writing custom data. We could merge the `body` and `files` attributes into a sequence of `Bytables` to send, with support for `Bytes`.

You can test the result on xymus.net, either by downloading the latest WBTW at http://xymus.net/pub/wbtw-v0.4-110-g668b261.tar.gz or by playing a clone of Super Hexagon (mostly made by @ablondin) at http://xymus.net/pub/hex/.

Pull-Request: #1817
Reviewed-by: Jean Privat <jean@pryen.org>

lib/libevent.nit

@@ -162,19 +162,34 @@ class Connection
 
 	redef fun write_byte(byte) do native_buffer_event.write_byte(byte)
 
+	redef fun write_bytes(bytes) do native_buffer_event.write(bytes.items, bytes.length)
+
 	# Write a file to the connection
 	#
-	# require: `path.file_exists`
+	# If `not path.file_exists`, the method returns.
 	fun write_file(path: String)
 	do
-		assert path.file_exists
-
 		var file = new FileReader.open(path)
-		var output = native_buffer_event.output_buffer
-		var fd = file.fd
-		var length = file.file_stat.size
+		if file.last_error != null then
+			var error = new IOError("Failed to open file at '{path}'")
+			error.cause = file.last_error
+			self.last_error = error
+			file.close
+			return
+		end
+
+		var stat = file.file_stat
+		if stat == null then
+			last_error = new IOError("Failed to stat file at '{path}'")
+			file.close
+			return
+		end
 
-		output.add_file(fd, 0, length)
+		var err = native_buffer_event.output_buffer.add_file(file.fd, 0, stat.size)
+		if err then
+			last_error = new IOError("Failed to add file at '{path}'")
+			file.close
+		end
 	end
 end
 
@@ -209,6 +224,12 @@ extern class NativeBufferEvent `{ struct bufferevent * `}
 
 	# The input buffer associated to `self`
 	fun input_buffer: InputNativeEvBuffer `{ return bufferevent_get_input(self); `}
+
+	# Read data from this buffer
+	fun read_buffer(buf: NativeEvBuffer): Int `{ return bufferevent_read_buffer(self, buf); `}
+
+	# Write data to this buffer
+	fun write_buffer(buf: NativeEvBuffer): Int `{ return bufferevent_write_buffer(self, buf); `}
 end
 
 # A single buffer

lib/nitcorn/examples/Makefile

@@ -1,6 +1,6 @@
 all:
 	mkdir -p bin/
-	../../../bin/nitc --dir bin src/nitcorn_hello_world.nit src/file_server_on_port_80.nit
+	../../../bin/nitc --dir bin src/nitcorn_hello_world.nit src/simple_file_server.nit
 
 xymus.net:
 	mkdir -p bin/

lib/nitcorn/examples/src/file_server_on_port_80.nit → lib/nitcorn/examples/src/simple_file_server.nit

@@ -14,22 +14,22 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Basic file server on port 80, usually requires `root` to execute
+# Basic file server on port 80 by default, may require `root` to execute
 #
 # To be safe, it is recommended to run this program with its own username:
 # `sudo file_server -u nitcorn:www`
-module file_server_on_port_80
+module simple_file_server
 
 import nitcorn
 import privileges
 
 # Prepare options
 var opts = new OptionContext
 var opt_drop = new OptionUserAndGroup.for_dropping_privileges
-opt_drop.mandatory = true
+var opt_port = new OptionInt("Server port", 80, "--port", "-p")
 var opt_help = new OptionBool("Print this message", "--help", "-h")
-opts.add_option(opt_drop, opt_help)
-opts.parse(args)
+opts.add_option(opt_drop, opt_port, opt_help)
+opts.parse args
 
 # Check options errors and help
 if not opts.errors.is_empty or opt_help.value then
@@ -40,7 +40,7 @@ if not opts.errors.is_empty or opt_help.value then
 end
 
 # Serve everything with a standard FilesHandler
-var vh = new VirtualHost("localhost:80")
+var vh = new VirtualHost("localhost:{opt_port.value}")
 vh.routes.add new Route(null, new FileServer("www/hello_world/"))
 var factory = new HttpFactory.and_libevent
 factory.config.virtual_hosts.add vh

lib/nitcorn/file_server.nit

@@ -145,8 +145,7 @@ class FileServer
 					response.header["Content-Type"] = media_types["html"].as(not null)
 				else
 					# It's a single file
-					var file = new FileReader.open(local_file)
-					response.body = file.read_all
+					response.files.add local_file
 
 					var ext = local_file.file_extension
 					if ext != null then
@@ -155,8 +154,6 @@ class FileServer
 							response.header["Content-Type"] = media_type
 						else response.header["Content-Type"] = "application/octet-stream"
 					end
-
-					file.close
 				end
 
 			else response = new HttpResponse(404)

lib/nitcorn/http_response.nit

@@ -37,12 +37,36 @@ class HttpResponse
 	# Body of this response
 	var body = "" is writable
 
+	# Files appended after `body`
+	var files = new Array[String]
+
 	# Finalize this response before sending it over HTTP
 	fun finalize
 	do
 		# Set the content length if not already set
 		if not header.keys.has("Content-Length") then
-			header["Content-Length"] = body.bytelen.to_s
+			# Size of the body
+			var len = body.bytelen
+
+			# Size of included files
+			for path in files do
+				# TODO handle these error cases elsewhere, an error here will result in an invalid response
+				if not path.file_exists then
+					print_error "File does not exists at '{path}'"
+					continue
+				end
+
+				var stat = path.file_stat
+				if stat == null then
+					print_error "Failed to stat file at '{path}'"
+					continue
+				end
+
+				len += stat.size
+			end
+
+			# Set header
+			header["Content-Length"] = len.to_s
 		end
 
 		# Set server ID

lib/nitcorn/reactor.nit

@@ -85,6 +85,8 @@ class HttpServer
 
 		# Send back a response
 		write response.to_s
+		for path in response.files do write_file path
+
 		close
 	end
 end

tests/sav/simple_file_server.res

@@ -0,0 +1 @@
+libevent warning: Opening localhost:80 failed