Merge branch 'ew/http-backend-batch-headers'

The http-backend (the server-side component of smart-http
transport) used to trickle the HTTP header one at a time.  Now
these write(2)s are batched.

* ew/http-backend-batch-headers:
  http-backend: buffer headers before sending

1 files changed, 116 insertions, 104 deletions

diff --git a/http-backend.c b/http-backend.c
index 0d59499a51..adc8c8c3da 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -75,55 +75,57 @@ static void format_write(int fd, const char *fmt, ...)
 	write_or_die(fd, buffer, n);
 }
 
-static void http_status(unsigned code, const char *msg)
+static void http_status(struct strbuf *hdr, unsigned code, const char *msg)
 {
-	format_write(1, "Status: %u %s\r\n", code, msg);
+	strbuf_addf(hdr, "Status: %u %s\r\n", code, msg);
 }
 
-static void hdr_str(const char *name, const char *value)
+static void hdr_str(struct strbuf *hdr, const char *name, const char *value)
 {
-	format_write(1, "%s: %s\r\n", name, value);
+	strbuf_addf(hdr, "%s: %s\r\n", name, value);
 }
 
-static void hdr_int(const char *name, uintmax_t value)
+static void hdr_int(struct strbuf *hdr, const char *name, uintmax_t value)
 {
-	format_write(1, "%s: %" PRIuMAX "\r\n", name, value);
+	strbuf_addf(hdr, "%s: %" PRIuMAX "\r\n", name, value);
 }
 
-static void hdr_date(const char *name, unsigned long when)
+static void hdr_date(struct strbuf *hdr, const char *name, unsigned long when)
 {
 	const char *value = show_date(when, 0, DATE_MODE(RFC2822));
-	hdr_str(name, value);
+	hdr_str(hdr, name, value);
 }
 
-static void hdr_nocache(void)
+static void hdr_nocache(struct strbuf *hdr)
 {
-	hdr_str("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
-	hdr_str("Pragma", "no-cache");
-	hdr_str("Cache-Control", "no-cache, max-age=0, must-revalidate");
+	hdr_str(hdr, "Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
+	hdr_str(hdr, "Pragma", "no-cache");
+	hdr_str(hdr, "Cache-Control", "no-cache, max-age=0, must-revalidate");
 }
 
-static void hdr_cache_forever(void)
+static void hdr_cache_forever(struct strbuf *hdr)
 {
 	unsigned long now = time(NULL);
-	hdr_date("Date", now);
-	hdr_date("Expires", now + 31536000);
-	hdr_str("Cache-Control", "public, max-age=31536000");
+	hdr_date(hdr, "Date", now);
+	hdr_date(hdr, "Expires", now + 31536000);
+	hdr_str(hdr, "Cache-Control", "public, max-age=31536000");
 }
 
-static void end_headers(void)
+static void end_headers(struct strbuf *hdr)
 {
-	write_or_die(1, "\r\n", 2);
+	strbuf_add(hdr, "\r\n", 2);
+	write_or_die(1, hdr->buf, hdr->len);
+	strbuf_release(hdr);
 }
 
-__attribute__((format (printf, 1, 2)))
-static NORETURN void not_found(const char *err, ...)
+__attribute__((format (printf, 2, 3)))
+static NORETURN void not_found(struct strbuf *hdr, const char *err, ...)
 {
 	va_list params;
 
-	http_status(404, "Not Found");
-	hdr_nocache();
-	end_headers();
+	http_status(hdr, 404, "Not Found");
+	hdr_nocache(hdr);
+	end_headers(hdr);
 
 	va_start(params, err);
 	if (err && *err)
@@ -132,14 +134,14 @@ static NORETURN void not_found(const char *err, ...)
 	exit(0);
 }
 
-__attribute__((format (printf, 1, 2)))
-static NORETURN void forbidden(const char *err, ...)
+__attribute__((format (printf, 2, 3)))
+static NORETURN void forbidden(struct strbuf *hdr, const char *err, ...)
 {
 	va_list params;
 
-	http_status(403, "Forbidden");
-	hdr_nocache();
-	end_headers();
+	http_status(hdr, 403, "Forbidden");
+	hdr_nocache(hdr);
+	end_headers(hdr);
 
 	va_start(params, err);
 	if (err && *err)
@@ -148,21 +150,23 @@ static NORETURN void forbidden(const char *err, ...)
 	exit(0);
 }
 
-static void select_getanyfile(void)
+static void select_getanyfile(struct strbuf *hdr)
 {
 	if (!getanyfile)
-		forbidden("Unsupported service: getanyfile");
+		forbidden(hdr, "Unsupported service: getanyfile");
 }
 
-static void send_strbuf(const char *type, struct strbuf *buf)
+static void send_strbuf(struct strbuf *hdr,
+			const char *type, struct strbuf *buf)
 {
-	hdr_int(content_length, buf->len);
-	hdr_str(content_type, type);
-	end_headers();
+	hdr_int(hdr, content_length, buf->len);
+	hdr_str(hdr, content_type, type);
+	end_headers(hdr);
 	write_or_die(1, buf->buf, buf->len);
 }
 
-static void send_local_file(const char *the_type, const char *name)
+static void send_local_file(struct strbuf *hdr, const char *the_type,
+				const char *name)
 {
 	char *p = git_pathdup("%s", name);
 	size_t buf_alloc = 8192;
@@ -172,14 +176,14 @@ static void send_local_file(const char *the_type, const char *name)
 
 	fd = open(p, O_RDONLY);
 	if (fd < 0)
-		not_found("Cannot open '%s': %s", p, strerror(errno));
+		not_found(hdr, "Cannot open '%s': %s", p, strerror(errno));
 	if (fstat(fd, &sb) < 0)
 		die_errno("Cannot stat '%s'", p);
 
-	hdr_int(content_length, sb.st_size);
-	hdr_str(content_type, the_type);
-	hdr_date(last_modified, sb.st_mtime);
-	end_headers();
+	hdr_int(hdr, content_length, sb.st_size);
+	hdr_str(hdr, content_type, the_type);
+	hdr_date(hdr, last_modified, sb.st_mtime);
+	end_headers(hdr);
 
 	for (;;) {
 		ssize_t n = xread(fd, buf, buf_alloc);
@@ -194,32 +198,32 @@ static void send_local_file(const char *the_type, const char *name)
 	free(p);
 }
 
-static void get_text_file(char *name)
+static void get_text_file(struct strbuf *hdr, char *name)
 {
-	select_getanyfile();
-	hdr_nocache();
-	send_local_file("text/plain", name);
+	select_getanyfile(hdr);
+	hdr_nocache(hdr);
+	send_local_file(hdr, "text/plain", name);
 }
 
-static void get_loose_object(char *name)
+static void get_loose_object(struct strbuf *hdr, char *name)
 {
-	select_getanyfile();
-	hdr_cache_forever();
-	send_local_file("application/x-git-loose-object", name);
+	select_getanyfile(hdr);
+	hdr_cache_forever(hdr);
+	send_local_file(hdr, "application/x-git-loose-object", name);
 }
 
-static void get_pack_file(char *name)
+static void get_pack_file(struct strbuf *hdr, char *name)
 {
-	select_getanyfile();
-	hdr_cache_forever();
-	send_local_file("application/x-git-packed-objects", name);
+	select_getanyfile(hdr);
+	hdr_cache_forever(hdr);
+	send_local_file(hdr, "application/x-git-packed-objects", name);
 }
 
-static void get_idx_file(char *name)
+static void get_idx_file(struct strbuf *hdr, char *name)
 {
-	select_getanyfile();
-	hdr_cache_forever();
-	send_local_file("application/x-git-packed-objects-toc", name);
+	select_getanyfile(hdr);
+	hdr_cache_forever(hdr);
+	send_local_file(hdr, "application/x-git-packed-objects-toc", name);
 }
 
 static void http_config(void)
@@ -241,14 +245,14 @@ static void http_config(void)
 	strbuf_release(&var);
 }
 
-static struct rpc_service *select_service(const char *name)
+static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
 {
 	const char *svc_name;
 	struct rpc_service *svc = NULL;
 	int i;
 
 	if (!skip_prefix(name, "git-", &svc_name))
-		forbidden("Unsupported service: '%s'", name);
+		forbidden(hdr, "Unsupported service: '%s'", name);
 
 	for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
 		struct rpc_service *s = &rpc_service[i];
@@ -259,14 +263,14 @@ static struct rpc_service *select_service(const char *name)
 	}
 
 	if (!svc)
-		forbidden("Unsupported service: '%s'", name);
+		forbidden(hdr, "Unsupported service: '%s'", name);
 
 	if (svc->enabled < 0) {
 		const char *user = getenv("REMOTE_USER");
 		svc->enabled = (user && *user) ? 1 : 0;
 	}
 	if (!svc->enabled)
-		forbidden("Service not enabled: '%s'", svc->name);
+		forbidden(hdr, "Service not enabled: '%s'", svc->name);
 	return svc;
 }
 
@@ -442,23 +446,23 @@ static int show_text_ref(const char *name, const struct object_id *oid,
 	return 0;
 }
 
-static void get_info_refs(char *arg)
+static void get_info_refs(struct strbuf *hdr, char *arg)
 {
 	const char *service_name = get_parameter("service");
 	struct strbuf buf = STRBUF_INIT;
 
-	hdr_nocache();
+	hdr_nocache(hdr);
 
 	if (service_name) {
 		const char *argv[] = {NULL /* service name */,
 			"--stateless-rpc", "--advertise-refs",
 			".", NULL};
-		struct rpc_service *svc = select_service(service_name);
+		struct rpc_service *svc = select_service(hdr, service_name);
 
 		strbuf_addf(&buf, "application/x-git-%s-advertisement",
 			svc->name);
-		hdr_str(content_type, buf.buf);
-		end_headers();
+		hdr_str(hdr, content_type, buf.buf);
+		end_headers(hdr);
 
 		packet_write(1, "# service=git-%s\n", svc->name);
 		packet_flush(1);
@@ -467,9 +471,9 @@ static void get_info_refs(char *arg)
 		run_service(argv, 0);
 
 	} else {
-		select_getanyfile();
+		select_getanyfile(hdr);
 		for_each_namespaced_ref(show_text_ref, &buf);
-		send_strbuf("text/plain", &buf);
+		send_strbuf(hdr, "text/plain", &buf);
 	}
 	strbuf_release(&buf);
 }
@@ -494,24 +498,24 @@ static int show_head_ref(const char *refname, const struct object_id *oid,
 	return 0;
 }
 
-static void get_head(char *arg)
+static void get_head(struct strbuf *hdr, char *arg)
 {
 	struct strbuf buf = STRBUF_INIT;
 
-	select_getanyfile();
+	select_getanyfile(hdr);
 	head_ref_namespaced(show_head_ref, &buf);
-	send_strbuf("text/plain", &buf);
+	send_strbuf(hdr, "text/plain", &buf);
 	strbuf_release(&buf);
 }
 
-static void get_info_packs(char *arg)
+static void get_info_packs(struct strbuf *hdr, char *arg)
 {
 	size_t objdirlen = strlen(get_object_directory());
 	struct strbuf buf = STRBUF_INIT;
 	struct packed_git *p;
 	size_t cnt = 0;
 
-	select_getanyfile();
+	select_getanyfile(hdr);
 	prepare_packed_git();
 	for (p = packed_git; p; p = p->next) {
 		if (p->pack_local)
@@ -525,12 +529,12 @@ static void get_info_packs(char *arg)
 	}
 	strbuf_addch(&buf, '\n');
 
-	hdr_nocache();
-	send_strbuf("text/plain; charset=utf-8", &buf);
+	hdr_nocache(hdr);
+	send_strbuf(hdr, "text/plain; charset=utf-8", &buf);
 	strbuf_release(&buf);
 }
 
-static void check_content_type(const char *accepted_type)
+static void check_content_type(struct strbuf *hdr, const char *accepted_type)
 {
 	const char *actual_type = getenv("CONTENT_TYPE");
 
@@ -538,9 +542,9 @@ static void check_content_type(const char *accepted_type)
 		actual_type = "";
 
 	if (strcmp(actual_type, accepted_type)) {
-		http_status(415, "Unsupported Media Type");
-		hdr_nocache();
-		end_headers();
+		http_status(hdr, 415, "Unsupported Media Type");
+		hdr_nocache(hdr);
+		end_headers(hdr);
 		format_write(1,
 			"Expected POST with Content-Type '%s',"
 			" but received '%s' instead.\n",
@@ -549,23 +553,23 @@ static void check_content_type(const char *accepted_type)
 	}
 }
 
-static void service_rpc(char *service_name)
+static void service_rpc(struct strbuf *hdr, char *service_name)
 {
 	const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
-	struct rpc_service *svc = select_service(service_name);
+	struct rpc_service *svc = select_service(hdr, service_name);
 	struct strbuf buf = STRBUF_INIT;
 
 	strbuf_reset(&buf);
 	strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
-	check_content_type(buf.buf);
+	check_content_type(hdr, buf.buf);
 
-	hdr_nocache();
+	hdr_nocache(hdr);
 
 	strbuf_reset(&buf);
 	strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
-	hdr_str(content_type, buf.buf);
+	hdr_str(hdr, content_type, buf.buf);
 
-	end_headers();
+	end_headers(hdr);
 
 	argv[0] = svc->name;
 	run_service(argv, svc->buffer_input);
@@ -576,11 +580,13 @@ static int dead;
 static NORETURN void die_webcgi(const char *err, va_list params)
 {
 	if (dead <= 1) {
+		struct strbuf hdr = STRBUF_INIT;
+
 		vreportf("fatal: ", err, params);
 
-		http_status(500, "Internal Server Error");
-		hdr_nocache();
-		end_headers();
+		http_status(&hdr, 500, "Internal Server Error");
+		hdr_nocache(&hdr);
+		end_headers(&hdr);
 	}
 	exit(0); /* we successfully reported a failure ;-) */
 }
@@ -617,7 +623,7 @@ static char* getdir(void)
 static struct service_cmd {
 	const char *method;
 	const char *pattern;
-	void (*imp)(char *);
+	void (*imp)(struct strbuf *, char *);
 } services[] = {
 	{"GET", "/HEAD$", get_head},
 	{"GET", "/info/refs$", get_info_refs},
@@ -632,6 +638,21 @@ static struct service_cmd {
 	{"POST", "/git-receive-pack$", service_rpc}
 };
 
+static int bad_request(struct strbuf *hdr, const struct service_cmd *c)
+{
+	const char *proto = getenv("SERVER_PROTOCOL");
+
+	if (proto && !strcmp(proto, "HTTP/1.1")) {
+		http_status(hdr, 405, "Method Not Allowed");
+		hdr_str(hdr, "Allow",
+			!strcmp(c->method, "GET") ? "GET, HEAD" : c->method);
+	} else
+		http_status(hdr, 400, "Bad Request");
+	hdr_nocache(hdr);
+	end_headers(hdr);
+	return 0;
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	char *method = getenv("REQUEST_METHOD");
@@ -639,6 +660,7 @@ int cmd_main(int argc, const char **argv)
 	struct service_cmd *cmd = NULL;
 	char *cmd_arg = NULL;
 	int i;
+	struct strbuf hdr = STRBUF_INIT;
 
 	set_die_routine(die_webcgi);
 	set_die_is_recursing_routine(die_webcgi_recursing);
@@ -659,18 +681,8 @@ int cmd_main(int argc, const char **argv)
 		if (!regexec(&re, dir, 1, out, 0)) {
 			size_t n;
 
-			if (strcmp(method, c->method)) {
-				const char *proto = getenv("SERVER_PROTOCOL");
-				if (proto && !strcmp(proto, "HTTP/1.1")) {
-					http_status(405, "Method Not Allowed");
-					hdr_str("Allow", !strcmp(c->method, "GET") ?
-						"GET, HEAD" : c->method);
-				} else
-					http_status(400, "Bad Request");
-				hdr_nocache();
-				end_headers();
-				return 0;
-			}
+			if (strcmp(method, c->method))
+				return bad_request(&hdr, c);
 
 			cmd = c;
 			n = out[0].rm_eo - out[0].rm_so;
@@ -682,19 +694,19 @@ int cmd_main(int argc, const char **argv)
 	}
 
 	if (!cmd)
-		not_found("Request not supported: '%s'", dir);
+		not_found(&hdr, "Request not supported: '%s'", dir);
 
 	setup_path();
 	if (!enter_repo(dir, 0))
-		not_found("Not a git repository: '%s'", dir);
+		not_found(&hdr, "Not a git repository: '%s'", dir);
 	if (!getenv("GIT_HTTP_EXPORT_ALL") &&
 	    access("git-daemon-export-ok", F_OK) )
-		not_found("Repository not exported: '%s'", dir);
+		not_found(&hdr, "Repository not exported: '%s'", dir);
 
 	http_config();
 	max_request_buffer = git_env_ulong("GIT_HTTP_MAX_REQUEST_BUFFER",
 					   max_request_buffer);
 
-	cmd->imp(cmd_arg);
+	cmd->imp(&hdr, cmd_arg);
 	return 0;
 }