transport: improve identity transport lifetime

cmd/http/main.ha

@@ -6,7 +6,7 @@ use net::uri;
 use os;
 
 export fn main() void = {
-	const client = http::newclient("Hare test client");
+	const client = http::newclient("Hare net::http test client");
 	defer http::client_finish(&client);
 
 	const target = match (uri::parse(os::args[1])) {
@@ -36,4 +36,5 @@ export fn main() void = {
 
 	const body = resp.body as *io::stream;
 	io::copy(os::stdout, body)!;
+	io::close(body)!;
 };

net/http/do.ha

@@ -14,6 +14,9 @@ use types;
 // Performs an HTTP [[request]] with the given [[client]]. The request is
 // performed synchronously; this function blocks until the server has returned
 // the response status and all HTTP headers associated with the response.
+//
+// If the provided [[response]] has a non-null body, the user must pass it to
+// [[io::close]] before calling [[response_finish]].
 export fn do(client: *client, req: *request) (response | error) = {
 	assert(req.target.scheme == "http"); // TODO: https
 	const conn = dial::dial_uri("tcp", req.target)?;
@@ -53,7 +56,7 @@ export fn do(client: *client, req: *request) (response | error) = {
 	};
 
 	let resp = response { ... };
-	const scan = bufio::newscanner_static(conn, buf);
+	const scan = bufio::newscanner(conn, 512);
 	read_statusline(&resp, &scan)?;
 	read_header(&resp.header, &scan)?;
 	resp.body = new_reader(conn, &resp, &scan)?;

net/http/response.ha

@@ -15,7 +15,9 @@ export type response = struct {
 	body: nullable *io::stream,
 };
 
-// Frees state associated with an HTTP [[response]].
+// Frees state associated with an HTTP [[response]]. If the response has a
+// non-null body, the user must call [[io::close]] prior to calling this
+// function.
 export fn response_finish(resp: *response) void = {
 	header_free(&resp.header);
 	free(resp.reason);

net/http/transport.ha

@@ -50,7 +50,7 @@ export type transport = struct {
 };
 
 fn new_reader(
-	conn: io::handle,
+	conn: io::file,
 	resp: *response,
 	scan: *bufio::scanner,
 ) (*io::stream | errors::unsupported | protoerr) = {
@@ -68,8 +68,7 @@ fn new_reader(
 				return protoerr;
 			};
 		};
-		const remain = bufio::scan_buffer(scan);
-		return new_identity_reader(conn, remain, length);
+		return new_identity_reader(conn, scan, length);
 	};
 
 	// TODO: Figure out the semantics for closing the stream
@@ -115,33 +114,32 @@ fn new_reader(
 
 type identity_reader = struct {
 	vtable: io::stream,
-	conn: io::handle,
-	buffer: [os::BUFSZ]u8,
-	pending: size,
-	length: size,
+	conn: io::file,
+	scan: *bufio::scanner,
+	src: io::limitstream,
 };
 
 const identity_reader_vtable = io::vtable {
 	reader = &identity_read,
+	closer = &identity_close,
 	...
 };
 
 // Creates a new reader that reads data until the response's Content-Length is
 // reached; i.e. the null Transport-Encoding.
 fn new_identity_reader(
-	conn: io::handle,
-	buffer: []u8,
+	conn: io::file,
+	scan: *bufio::scanner,
 	content_length: size,
 ) *io::stream = {
-	let rd = alloc(identity_reader {
+	const scan = alloc(*scan);
+	return alloc(identity_reader {
 		vtable = &identity_reader_vtable,
 		conn = conn,
-		length = content_length,
+		scan = scan,
+		src = io::limitreader(scan, content_length),
 		...
 	});
-	rd.buffer[..len(buffer)] = buffer[..];
-	rd.pending = len(buffer);
-	return rd;
 };
 
 fn identity_read(
@@ -150,34 +148,20 @@ fn identity_read(
 ) (size | io::EOF | io::error) = {
 	let rd = s: *identity_reader;
 	assert(rd.vtable == &identity_reader_vtable);
+	return io::read(&rd.src, buf)?;
+};
 
-	if (rd.length <= 0) {
-		return io::EOF;
-	};
+fn identity_close(s: *io::stream) (void | io::error) = {
+	let rd = s: *identity_reader;
+	assert(rd.vtable == &identity_reader_vtable);
 
-	if (rd.pending == 0) {
-		let nread = rd.length;
-		if (nread > len(rd.buffer)) {
-			nread = len(rd.buffer);
-		};
+	// Flush the remainder of the response in case the caller did not read
+	// it out entirely
+	io::copy(io::empty, &rd.src)?;
 
-		match (io::read(rd.conn, rd.buffer[..nread])?) {
-		case let n: size =>
-			rd.pending = n;
-		case io::EOF =>
-			return io::EOF;
-		};
-	};
-
-	let n = len(buf);
-	if (n > rd.pending) {
-		n = rd.pending;
-	};
-	buf[..n] = rd.buffer[..n];
-	rd.buffer[..len(rd.buffer) - n] = rd.buffer[n..];
-	rd.pending -= n;
-	rd.length -= n;
-	return n;
+	bufio::finish(rd.scan);
+	free(rd.scan);
+	io::close(rd.conn)?;
 };
 
 type chunk_state = enum {