Merge pull request #2640 from ianyfan/swaybar

Overhaul swaybar protocol handling (+fixes)

4 files changed, 222 insertions, 159 deletions

diff --git a/swaybar/event_loop.c b/swaybar/event_loop.c
index bc4053be..686b9962 100644
--- a/swaybar/event_loop.c
+++ b/swaybar/event_loop.c
@@ -105,7 +105,7 @@ bool remove_timer(timer_t timer) {
 	return false;
 }
 
-void event_loop_poll() {
+void event_loop_poll(void) {
 	poll(event_loop.fds.items, event_loop.fds.length, -1);
 
 	for (int i = 0; i < event_loop.fds.length; ++i) {
@@ -146,7 +146,7 @@ void event_loop_poll() {
 	}
 }
 
-void init_event_loop() {
+void init_event_loop(void) {
 	event_loop.fds.length = 0;
 	event_loop.fds.capacity = 10;
 	event_loop.fds.items = malloc(
diff --git a/swaybar/i3bar.c b/swaybar/i3bar.c
index 0becae5d..88404703 100644
--- a/swaybar/i3bar.c
+++ b/swaybar/i3bar.c
@@ -1,6 +1,7 @@
 #define _POSIX_C_SOURCE 200809L
 #include <json-c/json.h>
 #include <linux/input-event-codes.h>
+#include <ctype.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -24,24 +25,19 @@ void i3bar_block_unref(struct i3bar_block *block) {
 	}
 }
 
-static bool i3bar_parse_json(struct status_line *status, const char *text) {
+static void i3bar_parse_json(struct status_line *status,
+		struct json_object *json_array) {
 	struct i3bar_block *block, *tmp;
 	wl_list_for_each_safe(block, tmp, &status->blocks, link) {
 		wl_list_remove(&block->link);
 		i3bar_block_unref(block);
 	}
-	json_object *results = json_tokener_parse(text);
-	if (!results) {
-		status_error(status, "[failed to parse i3bar json]");
-		return false;
-	}
-	wlr_log(WLR_DEBUG, "Got i3bar json: '%s'", text);
-	for (size_t i = 0; i < json_object_array_length(results); ++i) {
+	for (size_t i = 0; i < json_object_array_length(json_array); ++i) {
 		json_object *full_text, *short_text, *color, *min_width, *align, *urgent;
 		json_object *name, *instance, *separator, *separator_block_width;
 		json_object *background, *border, *border_top, *border_bottom;
 		json_object *border_left, *border_right, *markup;
-		json_object *json = json_object_array_get_idx(results, i);
+		json_object *json = json_object_array_get_idx(json_array, i);
 		if (!json) {
 			continue;
 		}
@@ -110,96 +106,149 @@ static bool i3bar_parse_json(struct status_line *status, const char *text) {
 			json_object_get_int(border_right) : 1;
 		wl_list_insert(&status->blocks, &block->link);
 	}
-	json_object_put(results);
-	return true;
 }
 
 bool i3bar_handle_readable(struct status_line *status) {
-	struct i3bar_protocol_state *state = &status->i3bar_state;
-
-	char *cur = &state->buffer[state->buffer_index];
-	ssize_t n = read(status->read_fd, cur,
-			state->buffer_size - state->buffer_index);
-	if (n == -1) {
-		status_error(status, "[failed to read from status command]");
-		return false;
-	}
+	while (!status->started) { // look for opening bracket
+		for (size_t c = 0; c < status->buffer_index; ++c) {
+			if (status->buffer[c] == '[') {
+				status->started = true;
+				status->buffer_index -= ++c;
+				memmove(status->buffer, &status->buffer[c], status->buffer_index);
+				break;
+			} else if (!isspace(status->buffer[c])) {
+				status_error(status, "[invalid json]");
+				return true;
+			}
+		}
+		if (status->started) {
+			break;
+		}
 
-	if (n == (ssize_t)(state->buffer_size - state->buffer_index)) {
-		state->buffer_size = state->buffer_size * 2;
-		char *new_buffer = realloc(state->buffer, state->buffer_size);
-		if (!new_buffer) {
-			free(state->buffer);
-			status_error(status, "[failed to allocate buffer]");
+		errno = 0;
+		ssize_t read_bytes = read(status->read_fd, status->buffer, status->buffer_size);
+		if (read_bytes > -1) {
+			status->buffer_index = read_bytes;
+		} else if (errno == EAGAIN) {
+			return false;
+		} else {
+			status_error(status, "[error reading from status command]");
 			return true;
 		}
-		state->current_node += new_buffer - state->buffer;
-		cur += new_buffer - state->buffer;
-		state->buffer = new_buffer;
 	}
 
-	cur[n] = '\0';
-	bool redraw = false;
-	while (*cur) {
-		if (state->nodes[state->depth] == JSON_NODE_STRING) {
-			if (!state->escape && *cur == '"') {
-				--state->depth;
+	struct json_object *last_object = NULL;
+	struct json_object *test_object;
+	size_t buffer_pos = 0;
+	while (true) {
+		// since the incoming stream is an infinite array
+		// parsing is split into two parts
+		// first, attempt to parse the current object, reading more if the
+		// parser indicates that the current object is incomplete, and failing
+		// if the parser fails
+		// second, look for separating comma, ignoring whitespace, failing if
+		// any other characters are encountered
+		if (status->expecting_comma) {
+			for (; buffer_pos < status->buffer_index; ++buffer_pos) {
+				if (status->buffer[buffer_pos] == ',') {
+					status->expecting_comma = false;
+					++buffer_pos;
+					break;
+				} else if (!isspace(status->buffer[buffer_pos])) {
+					status_error(status, "[invalid i3bar json]");
+					return true;
+				}
+			}
+			if (buffer_pos < status->buffer_index) {
+				continue; // look for new object without reading more input
 			}
-			state->escape = !state->escape && *cur == '\\';
+			buffer_pos = status->buffer_index = 0;
 		} else {
-			switch (*cur) {
-			case '[':
-				++state->depth;
-				if (state->depth >
-						sizeof(state->nodes) / sizeof(state->nodes[0])) {
-					status_error(status, "[i3bar json too deep]");
-					return false;
-				}
-				state->nodes[state->depth] = JSON_NODE_ARRAY;
-				if (state->depth == 1) {
-					state->current_node = cur;
+			test_object = json_tokener_parse_ex(status->tokener,
+					&status->buffer[buffer_pos], status->buffer_index - buffer_pos);
+			if (json_tokener_get_error(status->tokener) == json_tokener_success) {
+				if (json_object_get_type(test_object) == json_type_array) {
+					if (last_object) {
+						json_object_put(last_object);
+					}
+					last_object = test_object;
+				} else {
+					json_object_put(test_object);
 				}
-				break;
-			case ']':
-				if (state->nodes[state->depth] != JSON_NODE_ARRAY) {
-					status_error(status, "[failed to parse i3bar json]");
-					return false;
+
+				// in order to print the json for debugging purposes
+				// the last character is temporarily replaced with a null character
+				// (the last character is used in case the buffer is full)
+				char *last_char_pos =
+					&status->buffer[buffer_pos + status->tokener->char_offset - 1];
+				char last_char = *last_char_pos;
+				while (isspace(last_char)) {
+					last_char = *--last_char_pos;
 				}
-				--state->depth;
-				if (state->depth == 0) {
-					// cur[1] is valid since cur[0] != '\0'
-					char p = cur[1];
-					cur[1] = '\0';
-					redraw = i3bar_parse_json(
-							status, state->current_node) || redraw;
-					cur[1] = p;
-					memmove(state->buffer, cur,
-							state->buffer_size - (cur - state->buffer));
-					cur = state->buffer;
-					state->current_node = cur + 1;
+				*last_char_pos = '\0';
+				size_t offset = strspn(&status->buffer[buffer_pos], " \f\n\r\t\v");
+				wlr_log(WLR_DEBUG, "Received i3bar json: '%s%c'",
+						&status->buffer[buffer_pos + offset], last_char);
+				*last_char_pos = last_char;
+
+				buffer_pos += status->tokener->char_offset;
+				status->expecting_comma = true;
+
+				if (buffer_pos < status->buffer_index) {
+					continue; // look for comma without reading more input
 				}
-				break;
-			case '"':
-				++state->depth;
-				if (state->depth >
-						sizeof(state->nodes) / sizeof(state->nodes[0])) {
-					status_error(status, "[i3bar json too deep]");
-					return false;
+				buffer_pos = status->buffer_index = 0;
+			} else if (json_tokener_get_error(status->tokener) == json_tokener_continue) {
+				if (status->buffer_index < status->buffer_size) {
+					// move the object to the start of the buffer
+					status->buffer_index -= buffer_pos;
+					memmove(status->buffer, &status->buffer[buffer_pos],
+							status->buffer_index);
+				} else {
+					// expand buffer
+					status->buffer_size *= 2;
+					char *new_buffer = realloc(status->buffer, status->buffer_size);
+					if (new_buffer) {
+						status->buffer = new_buffer;
+					} else {
+						free(status->buffer);
+						status_error(status, "[failed to allocate buffer]");
+						return true;
+					}
 				}
-				state->nodes[state->depth] = JSON_NODE_STRING;
-				break;
+			} else {
+				status_error(status, "[failed to parse i3bar json]");
+				return true;
 			}
 		}
-		++cur;
+
+		errno = 0;
+		ssize_t read_bytes = read(status->read_fd, &status->buffer[status->buffer_index],
+				status->buffer_size - status->buffer_index);
+		if (read_bytes > -1) {
+			status->buffer_index += read_bytes;
+		} else if (errno == EAGAIN) {
+			break;
+		} else {
+			status_error(status, "[error reading from status command]");
+			return true;
+		}
+	}
+
+	if (last_object) {
+		wlr_log(WLR_DEBUG, "Rendering last received json");
+		i3bar_parse_json(status, last_object);
+		json_object_put(last_object);
+		return true;
+	} else {
+		return false;
 	}
-	state->buffer_index = cur - state->buffer;
-	return redraw;
 }
 
 enum hotspot_event_handling i3bar_block_send_click(struct status_line *status,
 		struct i3bar_block *block, int x, int y, enum x11_button button) {
 	wlr_log(WLR_DEBUG, "block %s clicked", block->name ? block->name : "(nil)");
-	if (!block->name || !status->i3bar_state.click_events) {
+	if (!block->name || !status->click_events) {
 		return HOTSPOT_PROCESS;
 	}
 
@@ -214,7 +263,7 @@ enum hotspot_event_handling i3bar_block_send_click(struct status_line *status,
 	json_object_object_add(event_json, "button", json_object_new_int(button));
 	json_object_object_add(event_json, "x", json_object_new_int(x));
 	json_object_object_add(event_json, "y", json_object_new_int(y));
-	if (dprintf(status->write_fd, "%s\n",
+	if (dprintf(status->write_fd, "%s,\n",
 				json_object_to_json_string(event_json)) < 0) {
 		status_error(status, "[failed to write click event]");
 	}
diff --git a/swaybar/render.c b/swaybar/render.c
index 2d848bfa..97690338 100644
--- a/swaybar/render.c
+++ b/swaybar/render.c
@@ -120,14 +120,14 @@ static void i3bar_block_unref_callback(void *data) {
 }
 
 static uint32_t render_status_block(cairo_t *cairo,
-		struct swaybar_config *config, struct swaybar_output *output,
-		struct i3bar_block *block, double *x,
+		struct swaybar_output *output, struct i3bar_block *block, double *x,
 		uint32_t surface_height, bool focused, bool edge) {
 	if (!block->full_text || !*block->full_text) {
 		return 0;
 	}
 
 	uint32_t height = surface_height * output->scale;
+	struct swaybar_config *config = output->bar->config;
 
 	int text_width, text_height;
 	get_text_size(cairo, config->font, &text_width, &text_height, NULL,
@@ -177,16 +177,18 @@ static uint32_t render_status_block(cairo_t *cairo,
 		*x -= margin;
 	}
 
-	struct swaybar_hotspot *hotspot = calloc(1, sizeof(struct swaybar_hotspot));
-	hotspot->x = *x;
-	hotspot->y = 0;
-	hotspot->width = width;
-	hotspot->height = height;
-	hotspot->callback = block_hotspot_callback;
-	hotspot->destroy = i3bar_block_unref_callback;
-	hotspot->data = block;
-	block->ref_count++;
-	wl_list_insert(&output->hotspots, &hotspot->link);
+	if (output->bar->status->click_events) {
+		struct swaybar_hotspot *hotspot = calloc(1, sizeof(struct swaybar_hotspot));
+		hotspot->x = *x;
+		hotspot->y = 0;
+		hotspot->width = width;
+		hotspot->height = height;
+		hotspot->callback = block_hotspot_callback;
+		hotspot->destroy = i3bar_block_unref_callback;
+		hotspot->data = block;
+		block->ref_count++;
+		wl_list_insert(&output->hotspots, &hotspot->link);
+	}
 
 	double pos = *x;
 	if (block->background) {
@@ -268,7 +270,7 @@ static uint32_t render_status_line_i3bar(cairo_t *cairo,
 	bool edge = true;
 	struct i3bar_block *block;
 	wl_list_for_each(block, &status->blocks, link) {
-		uint32_t h = render_status_block(cairo, config, output,
+		uint32_t h = render_status_block(cairo, output,
 				block, x, surface_height, focused, edge);
 		max_height = h > max_height ? h : max_height;
 		edge = false;
diff --git a/swaybar/status_line.c b/swaybar/status_line.c
index 3ba990bd..401bf6f6 100644
--- a/swaybar/status_line.c
+++ b/swaybar/status_line.c
@@ -7,86 +7,102 @@
 #include <unistd.h>
 #include <wlr/util/log.h>
 #include "swaybar/config.h"
+#include "swaybar/event_loop.h"
 #include "swaybar/status_line.h"
 #include "readline.h"
 
+static void status_line_close_fds(struct status_line *status) {
+	if (status->read_fd != -1) {
+		remove_event(status->read_fd);
+		close(status->read_fd);
+		status->read_fd = -1;
+	}
+	if (status->write_fd != -1) {
+		close(status->write_fd);
+		status->write_fd = -1;
+	}
+}
+
 void status_error(struct status_line *status, const char *text) {
-	close(status->read_fd);
-	close(status->write_fd);
+	status_line_close_fds(status);
 	status->protocol = PROTOCOL_ERROR;
 	status->text = text;
 }
 
 bool status_handle_readable(struct status_line *status) {
-	char *line;
+	ssize_t read_bytes = 1;
 	switch (status->protocol) {
-	case PROTOCOL_ERROR:
-		return false;
-	case PROTOCOL_I3BAR:
-		if (i3bar_handle_readable(status) > 0) {
-			return true;
-		}
-		break;
-	case PROTOCOL_TEXT:
-		line = read_line_buffer(status->read,
-				status->text_state.buffer, status->text_state.buffer_size);
-		if (!line) {
-			status_error(status, "[error reading from status command]");
-		} else {
-			status->text = line;
-		}
-		return true;
 	case PROTOCOL_UNDEF:
-		line = read_line_buffer(status->read,
-				status->text_state.buffer, status->text_state.buffer_size);
-		if (!line) {
+		errno = 0;
+		read_bytes = getline(&status->buffer,
+				&status->buffer_size, status->read);
+		if (errno == EAGAIN) {
+			clearerr(status->read);
+		} else if (errno) {
 			status_error(status, "[error reading from status command]");
-			return false;
+			return true;
 		}
-		if (line[0] == '{') {
-			json_object *proto = json_tokener_parse(line);
-			if (proto) {
-				json_object *version;
-				if (json_object_object_get_ex(proto, "version", &version)
-							&& json_object_get_int(version) == 1) {
-					wlr_log(WLR_DEBUG, "Switched to i3bar protocol.");
-					status->protocol = PROTOCOL_I3BAR;
-				}
-				json_object *click_events;
-				if (json_object_object_get_ex(
-							proto, "click_events", &click_events)
-						&& json_object_get_boolean(click_events)) {
-					wlr_log(WLR_DEBUG, "Enabled click events.");
-					status->i3bar_state.click_events = true;
-					const char *events_array = "[\n";
-					ssize_t len = strlen(events_array);
-					if (write(status->write_fd, events_array, len) != len) {
-						status_error(status,
-								"[failed to write to status command]");
-					}
+
+		// the header must be sent completely the first time round
+		json_object *header, *version;
+		if (status->buffer[read_bytes - 1] == '\n'
+				&& (header = json_tokener_parse(status->buffer))
+				&& json_object_object_get_ex(header, "version", &version)
+				&& json_object_get_int(version) == 1) {
+			wlr_log(WLR_DEBUG, "Using i3bar protocol.");
+			status->protocol = PROTOCOL_I3BAR;
+
+			json_object *click_events;
+			if (json_object_object_get_ex(header, "click_events", &click_events)
+					&& json_object_get_boolean(click_events)) {
+				wlr_log(WLR_DEBUG, "Enabling click events.");
+				status->click_events = true;
+				if (write(status->write_fd, "[\n", 2) != 2) {
+					status_error(status, "[failed to write to status command]");
+					json_object_put(header);
+					return true;
 				}
-				json_object_put(proto);
 			}
+			json_object_put(header);
 
-			status->protocol = PROTOCOL_I3BAR;
-			free(status->text_state.buffer);
 			wl_list_init(&status->blocks);
-			status->i3bar_state.buffer_size = 4096;
-			status->i3bar_state.buffer =
-				malloc(status->i3bar_state.buffer_size);
-		} else {
-			status->protocol = PROTOCOL_TEXT;
-			status->text = line;
+			status->tokener = json_tokener_new();
+			status->buffer_index = getdelim(&status->buffer,
+					&status->buffer_size, EOF, status->read);
+			return i3bar_handle_readable(status);
 		}
-		return true;
+
+		wlr_log(WLR_DEBUG, "Using text protocol.");
+		status->protocol = PROTOCOL_TEXT;
+		status->text = status->buffer;
+		// intentional fall-through
+	case PROTOCOL_TEXT:
+		errno = 0;
+		while (true) {
+			if (status->buffer[read_bytes - 1] == '\n') {
+				status->buffer[read_bytes - 1] = '\0';
+			}
+			read_bytes = getline(&status->buffer,
+					&status->buffer_size, status->read);
+			if (errno == EAGAIN) {
+				clearerr(status->read);
+				return true;
+			} else if (errno) {
+				status_error(status, "[error reading from status command]");
+				return true;
+			}
+		}
+	case PROTOCOL_I3BAR:
+		return i3bar_handle_readable(status);
+	default:
+		return false;
 	}
-	return false;
 }
 
 struct status_line *status_line_init(char *cmd) {
 	struct status_line *status = calloc(1, sizeof(struct status_line));
-	status->text_state.buffer_size = 8192;
-	status->text_state.buffer = malloc(status->text_state.buffer_size);
+	status->buffer_size = 8192;
+	status->buffer = malloc(status->buffer_size);
 
 	int pipe_read_fd[2];
 	int pipe_write_fd[2];
@@ -123,20 +139,16 @@ struct status_line *status_line_init(char *cmd) {
 }
 
 void status_line_free(struct status_line *status) {
-	close(status->read_fd);
-	close(status->write_fd);
+	status_line_close_fds(status);
 	kill(status->pid, SIGTERM);
-	switch (status->protocol) {
-	case PROTOCOL_I3BAR:;
+	if (status->protocol == PROTOCOL_I3BAR) {
 		struct i3bar_block *block, *tmp;
 		wl_list_for_each_safe(block, tmp, &status->blocks, link) {
+			wl_list_remove(&block->link);
 			i3bar_block_unref(block);
 		}
-		free(status->i3bar_state.buffer);
-		break;
-	default:
-		free(status->text_state.buffer);
-		break;
+		json_tokener_free(status->tokener);
 	}
+	free(status->buffer);
 	free(status);
 }