swaybar: rewrite i3bar protocol handling

This now correctly handles an incoming json infinite array by shifting
most of the heavy listing to the json-c parser, as well as sending
multiple statuses at once. It also removes the struct
i3bar_protocol_state and moves its members into the status_line struct,
allowing the same buffer to be used for both protocols.
This commit is contained in:
Ian Fan 2018-09-17 14:10:57 +01:00
parent 8cbce77e1d
commit 7882ac66ef
4 changed files with 128 additions and 118 deletions

View File

@ -1,5 +1,6 @@
#ifndef _SWAYBAR_STATUS_LINE_H
#define _SWAYBAR_STATUS_LINE_H
#include <json-c/json.h>
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>
@ -12,23 +13,6 @@ enum status_protocol {
PROTOCOL_I3BAR,
};
enum json_node_type {
JSON_NODE_UNKNOWN,
JSON_NODE_ARRAY,
JSON_NODE_STRING,
};
struct i3bar_protocol_state {
bool click_events;
char *buffer;
size_t buffer_size;
size_t buffer_index;
const char *current_node;
bool escape;
size_t depth;
enum json_node_type nodes[16];
};
struct i3bar_block {
struct wl_list link;
int ref_count;
@ -58,9 +42,13 @@ struct status_line {
const char *text;
struct wl_list blocks; // i3bar_block::link
bool click_events;
char *buffer;
size_t buffer_size;
struct i3bar_protocol_state i3bar_state;
size_t buffer_index;
bool started;
bool expecting_comma;
json_tokener *tokener;
};
struct status_line *status_line_init(char *cmd);

View File

@ -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 +106,133 @@ 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;
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;
}
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;
}
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;
}
}
state->escape = !state->escape && *cur == '\\';
if (buffer_pos < status->buffer_index) {
continue; // look for new object without reading more input
}
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;
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);
}
state->nodes[state->depth] = JSON_NODE_ARRAY;
if (state->depth == 1) {
state->current_node = cur;
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 ']':
if (state->nodes[state->depth] != JSON_NODE_ARRAY) {
status_error(status, "[failed to parse i3bar json]");
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->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;
}
break;
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_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) {
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;
}

View File

@ -177,7 +177,7 @@ static uint32_t render_status_block(cairo_t *cairo,
*x -= margin;
}
if (output->bar->status->i3bar_state.click_events) {
if (output->bar->status->click_events) {
struct swaybar_hotspot *hotspot = calloc(1, sizeof(struct swaybar_hotspot));
hotspot->x = *x;
hotspot->y = 0;

View File

@ -32,11 +32,6 @@ void status_error(struct status_line *status, const char *text) {
bool status_handle_readable(struct status_line *status) {
ssize_t read_bytes = 1;
switch (status->protocol) {
case PROTOCOL_I3BAR:
if (i3bar_handle_readable(status) > 0) {
return true;
}
break;
case PROTOCOL_UNDEF:
errno = 0;
read_bytes = getline(&status->buffer,
@ -61,7 +56,7 @@ bool status_handle_readable(struct status_line *status) {
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->i3bar_state.click_events = true;
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);
@ -70,13 +65,11 @@ bool status_handle_readable(struct status_line *status) {
}
json_object_put(header);
status->protocol = PROTOCOL_I3BAR;
free(status->buffer);
wl_list_init(&status->blocks);
status->i3bar_state.buffer_size = 4096;
status->i3bar_state.buffer =
malloc(status->i3bar_state.buffer_size);
return false;
status->tokener = json_tokener_new();
status->buffer_index = getdelim(&status->buffer,
&status->buffer_size, EOF, status->read);
return i3bar_handle_readable(status);
}
wlr_log(WLR_DEBUG, "Using text protocol.");
@ -99,10 +92,11 @@ bool status_handle_readable(struct status_line *status) {
return true;
}
}
case PROTOCOL_I3BAR:
return i3bar_handle_readable(status);
default:
return false;
}
return false;
}
struct status_line *status_line_init(char *cmd) {
@ -147,19 +141,14 @@ struct status_line *status_line_init(char *cmd) {
void status_line_free(struct status_line *status) {
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->buffer);
break;
}
json_tokener_free(status->tokener);
free(status->buffer);
free(status);
}