Some applications, such as cat, dump as much data to the terminal as

2007-02-26  Chris Wilson  <chris@chris-wilson.co.uk>

	Some applications, such as cat, dump as much data to the terminal as
	possible. In these scenarios it is likely that we will read data from
	the child much faster than we can process it and the refresh will
	stutter.

	The ideal solution would be to speed up the data processing so that
	this overrun was impossible. However, the approach taken here is to
	estimate how much data we can actually process in our time slice and
	to stop reading once we have sufficient data.

	* src/vte-private.h:
	* src/vte.c: (_vte_invalidate_all),
	(vte_terminal_emit_contents_changed),
	(vte_terminal_match_contents_clear),
	(vte_terminal_match_contents_refresh),
	(vte_terminal_emit_adjustment_changed),
	(_vte_terminal_adjust_adjustments), (vte_terminal_scroll_pages),
	(vte_terminal_catch_child_exited), (vte_terminal_eof),
	(vte_terminal_process_incoming), (vte_terminal_io_read),
	(vte_terminal_handle_scroll), (vte_terminal_init),
	(vte_terminal_size_allocate), (need_processing), (process_timeout),
	(update_repeat_timeout), (update_timeout):
	* src/vteseq.c: (vte_sequence_handler_decset_internal):


svn path=/trunk/; revision=1755

4 files changed, 124 insertions, 91 deletions

diff --git a/ChangeLog b/ChangeLog
index e12b796e..be9d58cd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,31 @@
 2007-02-26  Chris Wilson  <chris@chris-wilson.co.uk>
 
+	Some applications, such as cat, dump as much data to the terminal as
+	possible. In these scenarios it is likely that we will read data from
+	the child much faster than we can process it and the refresh will
+	stutter.
+
+	The ideal solution would be to speed up the data processing so that
+	this overrun was impossible. However, the approach taken here is to
+	estimate how much data we can actually process in our time slice and
+	to stop reading once we have sufficient data.
+
+	* src/vte-private.h:
+	* src/vte.c: (_vte_invalidate_all),
+	(vte_terminal_emit_contents_changed),
+	(vte_terminal_match_contents_clear),
+	(vte_terminal_match_contents_refresh),
+	(vte_terminal_emit_adjustment_changed),
+	(_vte_terminal_adjust_adjustments), (vte_terminal_scroll_pages),
+	(vte_terminal_catch_child_exited), (vte_terminal_eof),
+	(vte_terminal_process_incoming), (vte_terminal_io_read),
+	(vte_terminal_handle_scroll), (vte_terminal_init),
+	(vte_terminal_size_allocate), (need_processing), (process_timeout),
+	(update_repeat_timeout), (update_timeout):
+	* src/vteseq.c: (vte_sequence_handler_decset_internal):
+
+2007-02-26  Chris Wilson  <chris@chris-wilson.co.uk>
+
 	Bug 411000 – Orca repeats old text in gnome-terminal
 
 	The deferred handling of the window scrolling had the unfortunate
diff --git a/src/vte-private.h b/src/vte-private.h
index 95a27c32..24d92a63 100644
--- a/src/vte-private.h
+++ b/src/vte-private.h
@@ -87,6 +87,7 @@ G_BEGIN_DECLS
 #define VTE_DISPLAY_TIMEOUT		10
 #define VTE_UPDATE_TIMEOUT		15
 #define VTE_UPDATE_REPEAT_TIMEOUT	30
+#define VTE_MAX_PROCESS_TIME		100
 #define VTE_CELL_BBOX_SLACK		1
 
 /* The structure we use to hold characters we're supposed to display -- this
@@ -191,6 +192,8 @@ struct _VteTerminalPrivate {
 	GSList *update_regions;
 	gboolean invalidated_all;	/* pending refresh of entire terminal */
 	GList *active;                  /* is the terminal processing data */
+	glong input_bytes;
+	glong max_input_bytes;
 
 	/* Output data queue. */
 	struct _vte_buffer *outgoing;	/* pending input characters */
@@ -396,7 +399,6 @@ void _vte_terminal_insert_char(VteTerminal *terminal, gunichar c,
 			       gboolean invalidate_cells,
 			       gboolean paint_cells,
 			       gint forced_width);
-void _vte_terminal_match_contents_clear(VteTerminal *terminal);
 void _vte_terminal_scroll_region(VteTerminal *terminal,
 				 long row, glong count, glong delta);
 void _vte_terminal_set_default_attributes(VteTerminal *terminal);
diff --git a/src/vte.c b/src/vte.c
index 0ed89873..e44ea34c 100644
--- a/src/vte.c
+++ b/src/vte.c
@@ -75,6 +75,7 @@ static void vte_terminal_match_hilite_clear(VteTerminal *terminal);
 static void vte_terminal_match_hilite_hide(VteTerminal *terminal);
 static void vte_terminal_match_hilite_show(VteTerminal *terminal, double x, double y);
 static void vte_terminal_match_hilite_update(VteTerminal *terminal, double x, double y);
+static void vte_terminal_match_contents_clear(VteTerminal *terminal);
 static gboolean vte_terminal_background_update(VteTerminal *data);
 static void vte_terminal_queue_background_update(VteTerminal *terminal);
 static void vte_terminal_queue_adjustment_changed(VteTerminal *terminal);
@@ -446,6 +447,7 @@ _vte_invalidate_all(VteTerminal *terminal)
 	}
 
 	_vte_debug_print (VTE_DEBUG_WORK, "*");
+	_vte_debug_print (VTE_DEBUG_UPDATES, "Invalidating all.\n");
 
 	/* replace invalid regions with one covering the whole terminal */
 	reset_update_regions (terminal);
@@ -805,6 +807,9 @@ static void
 vte_terminal_emit_contents_changed(VteTerminal *terminal)
 {
 	if (terminal->pvt->contents_changed_pending) {
+		/* Clear dingus match set. */
+		vte_terminal_match_contents_clear(terminal);
+
 		_vte_debug_print(VTE_DEBUG_SIGNALS,
 				"Emitting `contents-changed'.\n");
 		g_signal_emit_by_name(terminal, "contents-changed");
@@ -1017,8 +1022,8 @@ vte_terminal_set_default_tabstops(VteTerminal *terminal)
 }
 
 /* Clear the cache of the screen contents we keep. */
-void
-_vte_terminal_match_contents_clear(VteTerminal *terminal)
+static void
+vte_terminal_match_contents_clear(VteTerminal *terminal)
 {
 	g_assert(VTE_IS_TERMINAL(terminal));
 	if (terminal->pvt->match_contents != NULL) {
@@ -1042,7 +1047,7 @@ static void
 vte_terminal_match_contents_refresh(VteTerminal *terminal)
 {
 	GArray *array;
-	_vte_terminal_match_contents_clear(terminal);
+	vte_terminal_match_contents_clear(terminal);
 	array = g_array_new(FALSE, FALSE, sizeof(struct _VteCharAttributes));
 	terminal->pvt->match_contents = vte_terminal_get_text(terminal,
 							      always_selected,
@@ -1539,10 +1544,39 @@ static void
 vte_terminal_emit_adjustment_changed(VteTerminal *terminal)
 {
 	if (terminal->pvt->adjustment_changed_pending) {
-		_vte_debug_print(VTE_DEBUG_SIGNALS,
-				"Emitting adjustment_changed.\n");
-		terminal->pvt->adjustment_changed_pending = FALSE;
-		gtk_adjustment_changed(terminal->adjustment);
+		VteScreen *screen = terminal->pvt->screen;
+		gboolean changed = FALSE;
+		glong v;
+
+		v = _vte_ring_delta (screen->row_data);
+		if (terminal->adjustment->lower != v) {
+			_vte_debug_print(VTE_DEBUG_IO,
+					"Changing lower bound from %.0f to %ld\n",
+					terminal->adjustment->lower,
+					v);
+			terminal->adjustment->lower = v;
+			changed = TRUE;
+		}
+
+		/* The upper value is the number of rows which might be visible.  (Add
+		 * one to the cursor offset because it's zero-based.) */
+		v = MAX(_vte_ring_next(screen->row_data),
+				screen->cursor_current.row + 1);
+		if (terminal->adjustment->upper != v) {
+			_vte_debug_print(VTE_DEBUG_IO,
+					"Changing upper bound from %.0f to %ld\n",
+					terminal->adjustment->upper,
+					v);
+			terminal->adjustment->upper = v;
+			changed = TRUE;
+		}
+
+		if (changed) {
+			_vte_debug_print(VTE_DEBUG_SIGNALS,
+					"Emitting adjustment_changed.\n");
+			terminal->pvt->adjustment_changed_pending = FALSE;
+			gtk_adjustment_changed(terminal->adjustment);
+		}
 	}
 	if (terminal->pvt->adjustment_value_changed_pending) {
 		glong v;
@@ -1585,32 +1619,17 @@ void
 _vte_terminal_adjust_adjustments(VteTerminal *terminal)
 {
 	VteScreen *screen;
-	gboolean changed;
 	long delta;
 	long rows;
 
 	g_assert(terminal->pvt->screen != NULL);
 	g_assert(terminal->pvt->screen->row_data != NULL);
 
-	/* Adjust the vertical, uh, adjustment. */
-	changed = FALSE;
+	vte_terminal_queue_adjustment_changed(terminal);
 
 	/* The lower value should be the first row in the buffer. */
 	screen = terminal->pvt->screen;
 	delta = _vte_ring_delta(screen->row_data);
-	_vte_debug_print(VTE_DEBUG_IO,
-			"Changing adjustment values "
-			"(delta = %ld, scroll = %ld).\n",
-			delta, screen->scroll_delta);
-	if (terminal->adjustment->lower != delta) {
-		_vte_debug_print(VTE_DEBUG_IO,
-				"Changing lower bound from %lf to %ld\n",
-				terminal->adjustment->lower,
-				delta);
-		terminal->adjustment->lower = delta;
-		changed = TRUE;
-	}
-
 	/* Snap the insert delta and the cursor position to be in the visible
 	 * area.  Leave the scrolling delta alone because it will be updated
 	 * when the adjustment changes. */
@@ -1618,28 +1637,6 @@ _vte_terminal_adjust_adjustments(VteTerminal *terminal)
 	screen->cursor_current.row = MAX(screen->cursor_current.row,
 					 screen->insert_delta);
 
-	/* The upper value is the number of rows which might be visible.  (Add
-	 * one to the cursor offset because it's zero-based.) */
-	rows = MAX(_vte_ring_next(screen->row_data),
-			screen->cursor_current.row + 1);
-	if (terminal->adjustment->upper != rows) {
-		_vte_debug_print(VTE_DEBUG_IO,
-				"Changing upper bound from %f to %ld\n",
-				terminal->adjustment->upper,
-				rows);
-		terminal->adjustment->upper = rows;
-		changed = TRUE;
-	}
-
-	/* If anything changed, signal that there was a change. */
-	if (changed == TRUE) {
-		_vte_debug_print(VTE_DEBUG_IO,
-				"Changed adjustment values "
-				"(delta = %ld, scroll = %ld).\n",
-				delta, screen->scroll_delta);
-		vte_terminal_queue_adjustment_changed(terminal);
-	}
-
 	if (screen->scroll_delta > screen->insert_delta) {
 		vte_terminal_queue_adjustment_value_changed(terminal,
 				screen->insert_delta);
@@ -1762,8 +1759,6 @@ vte_terminal_scroll_pages(VteTerminal *terminal, gint pages)
 	/* Tell the scrollbar to adjust itself. */
 	vte_terminal_queue_adjustment_value_changed (terminal,
 			destination);
-	/* Clear dingus match set. */
-	_vte_terminal_match_contents_clear(terminal);
 	/* Notify viewers that the contents have changed. */
 	_vte_terminal_queue_contents_changed(terminal);
 }
@@ -2691,9 +2686,13 @@ vte_terminal_catch_child_exited(VteReaper *reaper, int pid, int status,
 		 * then flush the buffers in case we're about to run a new
 		 * command, disconnecting the timeout. */
 		if (terminal->pvt->incoming != NULL) {
-			vte_terminal_process_incoming(terminal);
+			gboolean again;
+			do {
+				again = vte_terminal_process_incoming(terminal);
+			} while (again);
 			_vte_incoming_chunks_release (terminal->pvt->incoming);
 			terminal->pvt->incoming = NULL;
+			terminal->pvt->input_bytes = 0;
 		}
 		g_array_set_size(terminal->pvt->pending, 0);
 		vte_terminal_stop_processing (terminal);
@@ -2999,7 +2998,11 @@ vte_terminal_eof(GIOChannel *channel, VteTerminal *terminal)
 	 * disconnecting the timeout. */
 	vte_terminal_stop_processing (terminal);
 	if (terminal->pvt->incoming) {
-		vte_terminal_process_incoming(terminal);
+		gboolean again;
+		do {
+			again = vte_terminal_process_incoming(terminal);
+		} while (again);
+		terminal->pvt->input_bytes = 0;
 		vte_terminal_emit_pending_signals (terminal);
 	}
 	g_array_set_size(terminal->pvt->pending, 0);
@@ -3102,9 +3105,10 @@ vte_terminal_process_incoming(VteTerminal *terminal)
 	struct _vte_incoming_chunk *chunk, *next_chunk, *achunk = NULL;
 
 	_vte_debug_print(VTE_DEBUG_IO,
-			"Handler processing %d bytes over %d chunks.\n",
+			"Handler processing %d bytes over %d chunks + %d bytes pendnig.\n",
 			_vte_incoming_chunks_length(terminal->pvt->incoming),
-			_vte_incoming_chunks_count(terminal->pvt->incoming));
+			_vte_incoming_chunks_count(terminal->pvt->incoming),
+			terminal->pvt->pending->len);
 	_vte_debug_print (VTE_DEBUG_WORK, "(");
 
 	screen = terminal->pvt->screen;
@@ -3435,7 +3439,6 @@ next_match:
 
 	if (modified || (screen != terminal->pvt->screen)) {
 		/* Signal that the visible contents changed. */
-		_vte_terminal_match_contents_clear(terminal);
 		_vte_terminal_queue_contents_changed(terminal);
 	}
 
@@ -3473,7 +3476,7 @@ next_match:
 	return again;
 }
 
-static gboolean
+static inline void
 _vte_terminal_enable_input_source (VteTerminal *terminal)
 {
 	if (terminal->pvt->pty_input_source == VTE_INVALID_SOURCE) {
@@ -3485,7 +3488,6 @@ _vte_terminal_enable_input_source (VteTerminal *terminal)
 					    terminal,
 					    (GDestroyNotify) mark_input_source_invalid);
 	}
-	return FALSE;
 }
 static void
 _vte_terminal_feed_chunks (VteTerminal *terminal, struct _vte_incoming_chunk *chunks)
@@ -3519,10 +3521,10 @@ vte_terminal_io_read(GIOChannel *channel,
 		struct _vte_incoming_chunk *chunk, *chunks = NULL;
 		const int fd = g_io_channel_unix_get_fd (channel);
 		guchar *bp;
-		int rem;
+		int rem, len;
 		gboolean active = FALSE;
 		chunk = terminal->pvt->incoming;
-		if (!chunk || chunk->len == sizeof (chunk->data)) {
+		if (!chunk || chunk->len >= sizeof (chunk->data) - VTE_MAX_INPUT_READ / 4) {
 			chunk = get_chunk ();
 			chunk->next = chunks;
 			chunks = chunk;
@@ -3530,6 +3532,7 @@ vte_terminal_io_read(GIOChannel *channel,
 		rem = sizeof (chunk->data) - chunk->len;
 		rem = MIN (rem, VTE_MAX_INPUT_READ);
 		bp = chunk->data + chunk->len;
+		len = 0;
 		do {
 			int ret = read (fd, bp, rem);
 			switch (ret){
@@ -3542,12 +3545,14 @@ vte_terminal_io_read(GIOChannel *channel,
 				default:
 					bp += ret;
 					rem -= ret;
+					len += ret;
 					active = TRUE;
 					break;
 			}
 		} while (rem);
 out:
-		chunk->len = bp - chunk->data;
+		terminal->pvt->input_bytes += len;
+		chunk->len += len;
 		if (chunk->len == 0 && chunk == chunks) {
 			chunks = chunks->next;
 			release_chunk (chunk);
@@ -3561,7 +3566,7 @@ out:
 			vte_terminal_add_process_timeout (terminal);
 			GDK_THREADS_LEAVE ();
 		}
-		terminal->pvt->pty_input_active = active;
+		terminal->pvt->pty_input_active = len != 0;
 	}
 
 	/* Error? */
@@ -3593,7 +3598,9 @@ out:
 		}
 	}
 
-	return !eof && (!active_terminals || !active_terminals->next);
+	return !eof &&
+		terminal->pvt->input_bytes < terminal->pvt->max_input_bytes &&
+		(!active_terminals || !active_terminals->next);
 }
 
 /**
@@ -6856,7 +6863,6 @@ vte_terminal_handle_scroll(VteTerminal *terminal)
 	if (dy != 0) {
 		_vte_debug_print(VTE_DEBUG_IO,
 			    "Scrolling by %ld\n", dy);
-		_vte_terminal_match_contents_clear(terminal);
 		_vte_terminal_scroll_region(terminal, screen->scroll_delta,
 					   terminal->row_count, -dy);
 		vte_terminal_emit_text_scrolled(terminal, dy);
@@ -7194,6 +7200,7 @@ vte_terminal_init(VteTerminal *terminal)
 					      terminal);
 	pvt->incoming = NULL;
 	pvt->pending = g_array_new(FALSE, FALSE, sizeof(gunichar));
+	pvt->max_input_bytes = G_MAXLONG;
 	pvt->cursor_blink_tag = VTE_INVALID_SOURCE;
 	pvt->outgoing = _vte_buffer_new();
 	pvt->outgoing_conv = VTE_INVALID_CONV;
@@ -7396,7 +7403,6 @@ vte_terminal_size_allocate(GtkWidget *widget, GtkAllocation *allocation)
 				_vte_ring_delta (screen->row_data),
 				_vte_ring_next (screen->row_data)- 1);
 		/* Notify viewers that the contents have changed. */
-		_vte_terminal_match_contents_clear(terminal);
 		_vte_terminal_queue_contents_changed(terminal);
 	}
 
@@ -11814,8 +11820,7 @@ vte_terminal_stop_processing (VteTerminal *terminal)
 static inline gboolean
 need_processing (VteTerminal *terminal)
 {
-	return terminal->pvt->incoming != NULL ||
-		terminal->pvt->pending->len > 0;
+	return terminal->pvt->incoming != NULL;
 }
 
 /* Emit an "icon-title-changed" signal. */
@@ -11903,11 +11908,15 @@ process_timeout (gpointer data)
 				vte_terminal_io_read(terminal->pvt->pty_input,
 						G_IO_IN, terminal);
 			}
+			_vte_terminal_enable_input_source(terminal);
 		}
 		again = FALSE;
-		if (need_processing (terminal)) do {
-			again = vte_terminal_process_incoming(terminal);
-		} while (again && need_processing (terminal));
+		if (need_processing (terminal)) {
+			do {
+				again = vte_terminal_process_incoming(terminal);
+			} while (again);
+			terminal->pvt->input_bytes = 0;
+		}
 		vte_terminal_emit_pending_signals (terminal);
 		if (!again && terminal->pvt->update_regions == NULL) {
 			if (terminal->pvt->active != NULL) {
@@ -11916,9 +11925,6 @@ process_timeout (gpointer data)
 						terminal->pvt->active);
 				terminal->pvt->active = NULL;
 			}
-			if (terminal->pvt->pty_input) {
-				_vte_terminal_enable_input_source(terminal);
-			}
 		}
 	}
 
@@ -11926,12 +11932,6 @@ process_timeout (gpointer data)
 
 	if (active_terminals && update_timeout_tag == VTE_INVALID_SOURCE) {
 		again = TRUE;
-		if (active_terminals->next == NULL) {
-			VteTerminal *terminal = active_terminals->data;
-			if (terminal->pvt->pty_input) {
-				_vte_terminal_enable_input_source (terminal);
-			}
-		}
 	} else {
 		process_timeout_tag = VTE_INVALID_SOURCE;
 		again = FALSE;
@@ -12018,10 +12018,20 @@ update_repeat_timeout (gpointer data)
 				vte_terminal_io_read (terminal->pvt->pty_input,
 						G_IO_IN, terminal);
 			}
+			_vte_terminal_enable_input_source (terminal);
 		}
-		again = TRUE;
-		while (again && need_processing (terminal)) {
-			again = vte_terminal_process_incoming (terminal);
+		if (need_processing (terminal)) {
+			GTimer *process = g_timer_new ();
+			gdouble elapsed;
+			glong target;
+			do {
+				again = vte_terminal_process_incoming (terminal);
+			} while (again);
+			elapsed = g_timer_elapsed (process, NULL) * 1000;
+			target = VTE_MAX_PROCESS_TIME / elapsed * terminal->pvt->input_bytes;
+			terminal->pvt->max_input_bytes = (terminal->pvt->max_input_bytes  + target) / 2;
+			terminal->pvt->input_bytes = 0;
+			g_timer_destroy (process);
 		}
 		if (terminal->pvt->bg_update_pending) {
 			vte_terminal_background_update (terminal);
@@ -12036,12 +12046,10 @@ update_repeat_timeout (gpointer data)
 						terminal->pvt->active);
 				terminal->pvt->active = NULL;
 			}
-			if (terminal->pvt->pty_input) {
-				_vte_terminal_enable_input_source (terminal);
-			}
 		}
 	}
 
+
 	if (active_terminals != NULL) {
 		gdk_window_process_all_updates ();
 	}
@@ -12055,11 +12063,6 @@ update_repeat_timeout (gpointer data)
 	if (active_terminals == NULL) {
 		update_timeout_tag = VTE_INVALID_SOURCE;
 		again = FALSE;
-	} else if (active_terminals->next == NULL) {
-		VteTerminal *terminal = active_terminals->data;
-		if (terminal->pvt->pty_input) {
-			_vte_terminal_enable_input_source (terminal);
-		}
 	}
 
 	GDK_THREADS_LEAVE();
@@ -12108,10 +12111,13 @@ update_timeout (gpointer data)
 				vte_terminal_io_read(terminal->pvt->pty_input,
 						G_IO_IN, terminal);
 			}
+			_vte_terminal_enable_input_source (terminal);
 		}
-		again = TRUE;
-		while (again && need_processing (terminal)) {
-			again = vte_terminal_process_incoming (terminal);
+		if (need_processing (terminal)) {
+			do {
+				again = vte_terminal_process_incoming (terminal);
+			} while (again);
+			terminal->pvt->input_bytes = 0;
 		}
 		if (terminal->pvt->bg_update_pending) {
 			vte_terminal_background_update (terminal);
diff --git a/src/vteseq.c b/src/vteseq.c
index e13f75fd..5b324a7d 100644
--- a/src/vteseq.c
+++ b/src/vteseq.c
@@ -722,7 +722,6 @@ vte_sequence_handler_decset_internal(VteTerminal *terminal,
 		terminal->pvt->adjustment_value_changed_pending = TRUE;
 		vte_terminal_set_scrollback_lines(terminal,
 				terminal->pvt->scrollback_lines);
-		_vte_terminal_match_contents_clear(terminal);
 		_vte_terminal_queue_contents_changed(terminal);
 		_vte_invalidate_all (terminal);
 		break;