[multiple] perf: write headers to backend write cq

write headers directly to dynamic backend write chunkqueue
(mod_proxy, mod_fastcgi, mod_scgi)

src/mod_fastcgi.c

@@ -103,7 +103,7 @@ static int fcgi_env_add(void *venv, const char *key, size_t key_len, const char
 	len += key_len > 127 ? 4 : 1;
 	len += val_len > 127 ? 4 : 1;
 
-	if (buffer_string_length(env) + len >= FCGI_MAX_LENGTH) {
+	if (buffer_string_length(env) + len >= FCGI_MAX_LENGTH + sizeof(FCGI_BeginRequestRecord) + sizeof(FCGI_Header)) {
 		/**
 		 * we can't append more headers, ignore it
 		 */
@@ -210,7 +210,7 @@ static handler_t fcgi_create_env(server *srv, handler_ctx *hctx) {
 	FCGI_Header header;
 	int request_id;
 
-	buffer *fcgi_env = buffer_init();
+	buffer *b = chunkqueue_prepend_buffer_open(hctx->wb);
 	gw_host *host = hctx->host;
 
 	connection *con   = hctx->remote_conn;
@@ -238,30 +238,28 @@ static handler_t fcgi_create_env(server *srv, handler_ctx *hctx) {
 	beginRecord.body.flags = 0;
 	memset(beginRecord.body.reserved, 0, sizeof(beginRecord.body.reserved));
 
+	buffer_copy_string_len(b, (const char *)&beginRecord, sizeof(beginRecord));
+	fcgi_header(&header, FCGI_PARAMS, request_id, 0, 0); /*(set aside space to fill in later)*/
+	buffer_append_string_len(b, (const char *)&header, sizeof(header));
+
 	/* send FCGI_PARAMS */
-	buffer_string_prepare_copy(fcgi_env, 1023);
 
-	if (0 != http_cgi_headers(srv, con, &opts, fcgi_env_add, fcgi_env)) {
+	if (0 != http_cgi_headers(srv, con, &opts, fcgi_env_add, b)) {
 		con->http_status = 400;
 		con->mode = DIRECT;
-		buffer_free(fcgi_env);
+		buffer_string_set_length(b, 0);
+		chunkqueue_remove_finished_chunks(hctx->wb);
 		return HANDLER_FINISHED;
 	} else {
-		buffer *b = buffer_init();
-
-		buffer_copy_string_len(b, (const char *)&beginRecord, sizeof(beginRecord));
-
-		fcgi_header(&(header), FCGI_PARAMS, request_id, buffer_string_length(fcgi_env), 0);
-		buffer_append_string_len(b, (const char *)&header, sizeof(header));
-		buffer_append_string_buffer(b, fcgi_env);
-		buffer_free(fcgi_env);
+		fcgi_header(&(header), FCGI_PARAMS, request_id,
+			    buffer_string_length(b) - sizeof(FCGI_BeginRequestRecord) - sizeof(FCGI_Header), 0);
+		memcpy(b->ptr+sizeof(FCGI_BeginRequestRecord), (const char *)&header, sizeof(header));
 
 		fcgi_header(&(header), FCGI_PARAMS, request_id, 0, 0);
 		buffer_append_string_len(b, (const char *)&header, sizeof(header));
 
 		hctx->wb_reqlen = buffer_string_length(b);
-		chunkqueue_append_buffer(hctx->wb, b);
-		buffer_free(b);
+		chunkqueue_prepend_buffer_commit(hctx->wb);
 	}
 
 	if (con->request.content_length) {

src/mod_proxy.c

@@ -708,12 +708,11 @@ static void proxy_set_Forwarded(connection *con, const unsigned int flags) {
 static handler_t proxy_create_env(server *srv, gw_handler_ctx *gwhctx) {
 	handler_ctx *hctx = (handler_ctx *)gwhctx;
 	connection *con = hctx->gw.remote_conn;
-	buffer *b = buffer_init();
+	buffer *b = chunkqueue_prepend_buffer_open(hctx->gw.wb);
 	const int remap_headers = (NULL != hctx->conf.header.urlpaths
 				   || NULL != hctx->conf.header.hosts_request);
 	const int upgrade = hctx->conf.header.upgrade
 	    && (NULL != http_header_request_get(con, HTTP_HEADER_UPGRADE, CONST_STR_LEN("Upgrade")));
-	buffer_string_prepare_copy(b, 8192-1);
 
 	/* build header */
 
@@ -832,8 +831,7 @@ static handler_t proxy_create_env(server *srv, gw_handler_ctx *gwhctx) {
 		buffer_append_string_len(b, CONST_STR_LEN("Connection: close, upgrade\r\n\r\n"));
 
 	hctx->gw.wb_reqlen = buffer_string_length(b);
-	chunkqueue_append_buffer(hctx->gw.wb, b);
-	buffer_free(b);
+	chunkqueue_prepend_buffer_commit(hctx->gw.wb);
 
 	if (con->request.content_length) {
 		chunkqueue_append_chunkqueue(hctx->gw.wb, con->request_content_queue);

src/mod_scgi.c

@@ -142,58 +142,61 @@ static int scgi_env_add_uwsgi(void *venv, const char *key, size_t key_len, const
 
 
 static handler_t scgi_create_env(server *srv, handler_ctx *hctx) {
-	buffer *b;
-
-	buffer *scgi_env = buffer_init();
+	buffer *b = chunkqueue_prepend_buffer_open(hctx->wb);
 	gw_host *host = hctx->host;
-
-	connection *con   = hctx->remote_conn;
-
+	connection *con = hctx->remote_conn;
 	http_cgi_opts opts = { 0, 0, host->docroot, NULL };
-
 	http_cgi_header_append_cb scgi_env_add = hctx->conf.proto == LI_PROTOCOL_SCGI
 	  ? scgi_env_add_scgi
 	  : scgi_env_add_uwsgi;
+	size_t offset;
 
-	buffer_string_prepare_copy(scgi_env, 1023);
+        /* save space for 9 digits (plus ':'), though incoming HTTP request
+	 * currently limited to 64k (65535, so 5 chars) */
+	buffer_copy_string_len(b, CONST_STR_LEN("          "));
 
-	if (0 != http_cgi_headers(srv, con, &opts, scgi_env_add, scgi_env)) {
-		buffer_free(scgi_env);
+	if (0 != http_cgi_headers(srv, con, &opts, scgi_env_add, b)) {
 		con->http_status = 400;
 		con->mode = DIRECT;
+		buffer_string_set_length(b, 0);
+		chunkqueue_remove_finished_chunks(hctx->wb);
 		return HANDLER_FINISHED;
 	}
 
 	if (hctx->conf.proto == LI_PROTOCOL_SCGI) {
-		scgi_env_add(scgi_env, CONST_STR_LEN("SCGI"), CONST_STR_LEN("1"));
-		b = buffer_init();
-		buffer_append_int(b, buffer_string_length(scgi_env));
-		buffer_append_string_len(b, CONST_STR_LEN(":"));
-		buffer_append_string_buffer(b, scgi_env);
+		size_t len;
+		scgi_env_add(b, CONST_STR_LEN("SCGI"), CONST_STR_LEN("1"));
+		buffer_string_set_length(srv->tmp_buf, 0);
+		buffer_append_int(srv->tmp_buf, buffer_string_length(b)-10);
+		buffer_append_string_len(srv->tmp_buf, CONST_STR_LEN(":"));
+		len = buffer_string_length(srv->tmp_buf);
+		offset = 10 - len;
+		memcpy(b->ptr+offset, srv->tmp_buf->ptr, len);
 		buffer_append_string_len(b, CONST_STR_LEN(","));
-		buffer_free(scgi_env);
 	} else { /* LI_PROTOCOL_UWSGI */
 		/* http://uwsgi-docs.readthedocs.io/en/latest/Protocol.html */
-		size_t len = buffer_string_length(scgi_env);
+		size_t len = buffer_string_length(b)-10;
 		uint32_t uwsgi_header;
 		if (len > USHRT_MAX) {
-			buffer_free(scgi_env);
 			con->http_status = 431; /* Request Header Fields Too Large */
 			con->mode = DIRECT;
+			buffer_string_set_length(b, 0);
+			chunkqueue_remove_finished_chunks(hctx->wb);
 			return HANDLER_FINISHED;
 		}
-		b = buffer_init();
-		buffer_string_prepare_copy(b, 4 + len);
+		offset = 10 - 4;
 		uwsgi_header = ((uint32_t)uwsgi_htole16((uint16_t)len)) << 8;
-		memcpy(b->ptr, (char *)&uwsgi_header, 4);
-		buffer_commit(b, 4);
-		buffer_append_string_buffer(b, scgi_env);
-		buffer_free(scgi_env);
+		memcpy(b->ptr+offset, (char *)&uwsgi_header, 4);
 	}
 
-	hctx->wb_reqlen = buffer_string_length(b);
-	chunkqueue_append_buffer(hctx->wb, b);
-	buffer_free(b);
+	hctx->wb_reqlen = buffer_string_length(b) - offset;
+	chunkqueue_prepend_buffer_commit(hctx->wb);
+      #if 0
+	hctx->wb->first->offset += (off_t)offset;
+	hctx->wb->bytes_in -= (off_t)offset;
+      #else
+	chunkqueue_mark_written(hctx->wb, offset);
+      #endif
 
 	if (con->request.content_length) {
 		chunkqueue_append_chunkqueue(hctx->wb, con->request_content_queue);