refactor: WIP replace vec_u8 with memstream

runtime/include/http_session.h

@@ -15,6 +15,7 @@
 #include "http_parser.h"
 #include "http_parser_settings.h"
 #include "tenant.h"
+#include "unistd.h"
 #include "vec.h"
 #include "http_session_perf_log.h"
 
@@ -46,7 +47,9 @@ struct http_session {
 	int                     socket;
 	struct http_parser      http_parser;
 	struct http_request     http_request;
-	struct vec_u8           request_buffer;
+	FILE                   *request_handle;
+	char                   *request_buffer;
+	size_t                  request_size;
 	char                    response_header[HTTP_SESSION_RESPONSE_HEADER_CAPACITY];
 	size_t                  response_header_length;
 	size_t                  response_header_written;
@@ -95,8 +98,8 @@ http_session_init(struct http_session *session, int socket_descriptor, const str
 
 	http_session_parser_init(session);
 
-	int rc = vec_u8_init(&session->request_buffer, HTTP_SESSION_DEFAULT_REQUEST_RESPONSE_SIZE);
-	if (rc < 0) return -1;
+	session->request_handle = open_memstream(&session->request_buffer, &session->request_size);
+	if (session->request_handle == NULL) return -1;
 
 	/* Defer allocating response until we've matched a route */
 	session->response_buffer.buffer = NULL;
@@ -114,7 +117,13 @@ http_session_init_response_buffer(struct http_session *session, size_t capacity)
 
 	int rc = vec_u8_init(&session->response_buffer, capacity);
 	if (rc < 0) {
-		vec_u8_deinit(&session->request_buffer);
+		fclose(session->request_handle);
+		session->request_handle = NULL;
+		if (session->request_buffer != NULL) {
+			free(session->request_buffer);
+			session->request_buffer = NULL;
+		}
+		session->request_size = 0;
 		return -1;
 	}
 
@@ -149,7 +158,14 @@ http_session_deinit(struct http_session *session)
 {
 	assert(session);
 
-	vec_u8_deinit(&session->request_buffer);
+	fclose(session->request_handle);
+	session->request_handle = NULL;
+	if (session->request_buffer != NULL) {
+		free(session->request_buffer);
+		session->request_buffer = NULL;
+	}
+	session->request_size = 0;
+
 	vec_u8_deinit(&session->response_buffer);
 }
 
@@ -253,45 +269,6 @@ http_session_send_response_body(struct http_session *session, void_star_cb on_ea
 	return 0;
 }
 
-static inline bool
-http_session_request_buffer_is_full(struct http_session *session)
-{
-	return session->request_buffer.length == session->request_buffer.capacity;
-}
-
-static inline int
-http_session_request_buffer_grow(struct http_session *session)
-{
-	/* We have not yet fully parsed the header, so we don't know content-length, so just grow
-	 * (double) the buffer */
-	uint8_t *old_buffer = session->request_buffer.buffer;
-
-	if (vec_u8_grow(&session->request_buffer) != 0) {
-		debuglog("Failed to grow request buffer\n");
-		return -1;
-	}
-
-	/* buffer moved, so invalidate to reparse */
-	if (old_buffer != session->request_buffer.buffer) { http_session_parser_init(session); }
-
-	return 0;
-}
-
-static inline int
-http_session_request_buffer_resize(struct http_session *session, int required_size)
-{
-	uint8_t *old_buffer = session->request_buffer.buffer;
-	if (vec_u8_resize(&session->request_buffer, required_size) != 0) {
-		debuglog("Failed to resize request vector to %d bytes\n", required_size);
-		return -1;
-	}
-
-	/* buffer moved, so invalidate to reparse */
-	if (old_buffer != session->request_buffer.buffer) { http_session_parser_init(session); }
-
-	return 0;
-}
-
 typedef void (*http_session_cb)(struct http_session *);
 
 static inline ssize_t
@@ -359,8 +336,7 @@ static inline int
 http_session_receive_request(struct http_session *session, void_star_cb on_eagain)
 {
 	assert(session != NULL);
-	assert(session->request_buffer.capacity > 0);
-	assert(session->request_buffer.length <= session->request_buffer.capacity);
+	assert(session->request_handle != NULL);
 	assert(session->state == HTTP_SESSION_INITIALIZED || session->state == HTTP_SESSION_RECEIVE_REQUEST_BLOCKED);
 
 	session->state = HTTP_SESSION_RECEIVING_REQUEST;
@@ -368,25 +344,7 @@ http_session_receive_request(struct http_session *session, void_star_cb on_eagai
 	int rc = 0;
 
 	while (!session->http_request.message_end) {
-		/* If we know the header size and content-length, resize exactly. Otherwise double */
-		if (session->http_request.header_end && session->http_request.body) {
-			int header_size   = (uint8_t *)session->http_request.body - session->request_buffer.buffer;
-			int required_size = header_size + session->http_request.body_length;
-
-			if (required_size > session->request_buffer.capacity) {
-				rc = http_session_request_buffer_resize(session, required_size);
-				if (rc != 0) goto err_nobufs;
-			}
-		} else if (http_session_request_buffer_is_full(session)) {
-			rc = http_session_request_buffer_grow(session);
-			if (rc != 0) goto err_nobufs;
-		}
-
-		ssize_t bytes_received =
-		  tcp_session_recv(session->socket,
-		                   (char *)&session->request_buffer.buffer[session->request_buffer.length],
-		                   session->request_buffer.capacity - session->request_buffer.length, on_eagain,
-		                   session);
+		ssize_t bytes_received = tcp_session_recv(session->socket, session->request_handle, on_eagain, session);
 		if (unlikely(bytes_received == -EAGAIN))
 			goto err_eagain;
 		else if (unlikely(bytes_received < 0))
@@ -396,9 +354,6 @@ http_session_receive_request(struct http_session *session, void_star_cb on_eagai
 			goto err;
 
 		assert(bytes_received > 0);
-		assert(session->request_buffer.length < session->request_buffer.capacity);
-
-		session->request_buffer.length += bytes_received;
 
 		ssize_t bytes_parsed = http_session_parse(session, bytes_received);
 		if (bytes_parsed == -1) goto err;

runtime/include/tcp_session.h

@@ -59,7 +59,7 @@ tcp_session_send(int client_socket, const char *buffer, size_t buffer_len, void_
 }
 
 /**
- * Writes buffer to the client socket
+ * Reads client socket into memstream
  * @param client_socket - the client
  * @param buffer - buffer to reach the socket into
  * @param buffer_len - buffer to reach the socket into
@@ -67,20 +67,31 @@ tcp_session_send(int client_socket, const char *buffer, size_t buffer_len, void_
  * @returns nwritten on success, -errno on error, -eagain on block
  */
 static inline ssize_t
-tcp_session_recv(int client_socket, char *buffer, size_t buffer_len, void_star_cb on_eagain, void *dataptr)
+tcp_session_recv(int client_socket, FILE *handle, void_star_cb on_eagain, void *dataptr)
 {
-	assert(buffer != NULL);
-	assert(buffer_len > 0);
+	assert(handle != NULL);
 
-	ssize_t received = read(client_socket, buffer, buffer_len);
-	if (received < 0) {
-		if (errno == EAGAIN || errno == EWOULDBLOCK) {
-			if (on_eagain != NULL) on_eagain(dataptr);
-			return -EAGAIN;
-		} else {
-			return -errno;
+	char    buf[BUFSIZ];
+	ssize_t received = 0;
+	do {
+		received = read(client_socket, buf, BUFSIZ);
+		if (received < 0) {
+			if (errno == EAGAIN || errno == EWOULDBLOCK) {
+				if (on_eagain != NULL) on_eagain(dataptr);
+				return -EAGAIN;
+			} else {
+				return -errno;
+			}
 		}
-	}
+
+		/* TODO: Validate memory stream error handling  */
+		size_t written = fwrite(buf, 1, received, handle);
+		assert(written == received);
+
+	} while (received != 0);
+
+	int rc = fflush(handle);
+	if (rc < 0) { return -errno; };
 
 	return received;
 }