diff --git a/src/socket.c b/src/socket.c index 5f6bb50..586c98c 100644 --- a/src/socket.c +++ b/src/socket.c @@ -281,6 +281,7 @@ static void start_tls_p3( conn_t *conn, int ok ) #endif /* HAVE_LIBSSL */ static void socket_fd_cb( int, void * ); +static void socket_fake_cb( void * ); static void socket_connect_one( conn_t * ); static void socket_connect_failed( conn_t * ); @@ -293,12 +294,14 @@ socket_open_internal( conn_t *sock, int fd ) sock->fd = fd; fcntl( fd, F_SETFL, O_NONBLOCK ); init_notifier( &sock->notify, fd, socket_fd_cb, sock ); + init_wakeup( &sock->fd_fake, socket_fake_cb, sock ); } static void socket_close_internal( conn_t *sock ) { wipe_notifier( &sock->notify ); + wipe_wakeup( &sock->fd_fake ); close( sock->fd ); sock->fd = -1; } @@ -500,6 +503,8 @@ socket_close( conn_t *sock ) #endif while (sock->write_buf) dispose_chunk( sock ); + free( sock->append_buf ); + sock->append_buf = 0; } static void @@ -609,8 +614,6 @@ dispose_chunk( conn_t *conn ) buff_chunk_t *bc = conn->write_buf; if (!(conn->write_buf = bc->next)) conn->write_buf_append = &conn->write_buf; - if (bc->data != bc->buf) - free( bc->data ); free( bc ); } @@ -641,48 +644,69 @@ do_queued_write( conn_t *conn ) } static void -do_append( conn_t *conn, char *buf, int len, ownership_t takeOwn ) +do_append( conn_t *conn, buff_chunk_t *bc ) { - buff_chunk_t *bc; - - if (takeOwn == GiveOwn) { - bc = nfmalloc( offsetof(buff_chunk_t, buf) ); - bc->data = buf; - } else { - bc = nfmalloc( offsetof(buff_chunk_t, buf) + len ); - bc->data = bc->buf; - memcpy( bc->data, buf, len ); - } - bc->len = len; bc->next = 0; *conn->write_buf_append = bc; conn->write_buf_append = &bc->next; } +/* This is big enough to avoid excessive chunking, but is + * sufficiently small to keep SSL latency low with a slow uplink. */ +#define WRITE_CHUNK_SIZE 1024 + int socket_write( conn_t *conn, conn_iovec_t *iov, int iovcnt ) { - for (; iovcnt; iovcnt--, iov++) { - if (conn->write_buf) { - do_append( conn, iov->buf, iov->len, iov->takeOwn ); + int i, buf_avail, len, offset = 0, total = 0; + buff_chunk_t *bc, *exwb = conn->write_buf; + + for (i = 0; i < iovcnt; i++) + total += iov[i].len; + bc = conn->append_buf; + if (bc && total >= WRITE_CHUNK_SIZE) { + /* If the new data is too big, queue the pending buffer to avoid latency. */ + do_append( conn, bc ); + bc = 0; + } + while (total) { + if (!bc) { + buf_avail = total > WRITE_CHUNK_SIZE ? total : WRITE_CHUNK_SIZE; + bc = nfmalloc( offsetof(buff_chunk_t, data) + buf_avail ); + bc->len = 0; } else { - int n = do_write( conn, iov->buf, iov->len ); - if (n < 0) { - do { - if (iov->takeOwn == GiveOwn) - free( iov->buf ); - iovcnt--, iov++; - } while (iovcnt); - return -1; + /* A pending buffer will always be of standard size - over-sized + * buffers are immediately filled and queued. */ + buf_avail = WRITE_CHUNK_SIZE - bc->len; + } + while (total) { + len = iov->len - offset; + if (len > buf_avail) + len = buf_avail; + memcpy( bc->data + bc->len, iov->buf + offset, len ); + bc->len += len; + buf_avail -= len; + offset += len; + total -= len; + if (offset == iov->len) { + if (iov->takeOwn == GiveOwn) + free( iov->buf ); + iov++; + offset = 0; } - if (n != iov->len) { - conn->write_offset = n; - do_append( conn, iov->buf, iov->len, iov->takeOwn ); - } else if (iov->takeOwn == GiveOwn) { - free( iov->buf ); + if (!buf_avail) { + do_append( conn, bc ); + bc = 0; + break; } } } + conn->append_buf = bc; + /* Queue the pending write once the main loop goes idle. */ + conf_wakeup( &conn->fd_fake, bc ? 0 : -1 ); + /* If no writes were queued before, ensure that flushing commences. */ + if (!exwb) + return do_queued_write( conn ); return 0; } @@ -733,6 +757,19 @@ socket_fd_cb( int events, void *aux ) socket_fill( conn ); } +static void +socket_fake_cb( void *aux ) +{ + conn_t *conn = (conn_t *)aux; + + buff_chunk_t *exwb = conn->write_buf; + do_append( conn, conn->append_buf ); + conn->append_buf = 0; + /* If no writes were queued before, ensure that flushing commences. */ + if (!exwb) + do_queued_write( conn ); +} + #ifdef HAVE_LIBSSL static void ssl_fake_cb( void *aux ) diff --git a/src/socket.h b/src/socket.h index 4d51a34..efecce6 100644 --- a/src/socket.h +++ b/src/socket.h @@ -57,9 +57,8 @@ typedef struct server_conf { typedef struct buff_chunk { struct buff_chunk *next; - char *data; int len; - char buf[1]; + char data[1]; } buff_chunk_t; typedef struct { @@ -88,8 +87,10 @@ typedef struct { void *callback_aux; notifier_t notify; + wakeup_t fd_fake; /* writing */ + buff_chunk_t *append_buf; /* accumulating buffer */ buff_chunk_t *write_buf, **write_buf_append; /* buffer head & tail */ int write_offset; /* offset into buffer head */