/* * vim:ts=4:sw=4:expandtab * * i3bar - an xcb-based status- and ws-bar for i3 * © 2010-2012 Axel Wagner and contributors (see also: LICENSE) * * parse_json_header.c: Parse the JSON protocol header to determine * protocol version and features. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "common.h" static enum { KEY_VERSION, KEY_STOP_SIGNAL, KEY_CONT_SIGNAL, NO_KEY } current_key; #if YAJL_MAJOR >= 2 static int header_integer(void *ctx, long long val) { #else static int header_integer(void *ctx, long val) { #endif i3bar_child *child = ctx; switch (current_key) { case KEY_VERSION: child->version = val; break; case KEY_STOP_SIGNAL: child->stop_signal = val; break; case KEY_CONT_SIGNAL: child->cont_signal = val; break; default: break; } return 1; } #define CHECK_KEY(name) (stringlen == strlen(name) && \ STARTS_WITH((const char*)stringval, stringlen, name)) #if YAJL_MAJOR >= 2 static int header_map_key(void *ctx, const unsigned char *stringval, size_t stringlen) { #else static int header_map_key(void *ctx, const unsigned char *stringval, unsigned int stringlen) { #endif if (CHECK_KEY("version")) { current_key = KEY_VERSION; } else if (CHECK_KEY("stop_signal")) { current_key = KEY_STOP_SIGNAL; } else if (CHECK_KEY("cont_signal")) { current_key = KEY_CONT_SIGNAL; } return 1; } static yajl_callbacks version_callbacks = { NULL, /* null */ NULL, /* boolean */ &header_integer, NULL, /* double */ NULL, /* number */ NULL, /* string */ NULL, /* start_map */ &header_map_key, NULL, /* end_map */ NULL, /* start_array */ NULL /* end_array */ }; static void child_init(i3bar_child *child) { child->version = 0; child->stop_signal = SIGSTOP; child->cont_signal = SIGCONT; } /* * Parse the JSON protocol header to determine protocol version and features. * In case the buffer does not contain a valid header (invalid JSON, or no * version field found), the 'correct' field of the returned header is set to * false. The amount of bytes consumed by parsing the header is returned in * *consumed (if non-NULL). * */ void parse_json_header(i3bar_child *child, const unsigned char *buffer, int length, unsigned int *consumed) { child_init(child); current_key = NO_KEY; #if YAJL_MAJOR >= 2 yajl_handle handle = yajl_alloc(&version_callbacks, NULL, child); /* Allow trailing garbage. yajl 1 always behaves that way anyways, but for * yajl 2, we need to be explicit. */ yajl_config(handle, yajl_allow_trailing_garbage, 1); #else yajl_parser_config parse_conf = { 0, 0 }; yajl_handle handle = yajl_alloc(&version_callbacks, &parse_conf, NULL, child); #endif yajl_status state = yajl_parse(handle, buffer, length); if (state != yajl_status_ok) { child_init(child); if (consumed != NULL) *consumed = 0; } else { if (consumed != NULL) *consumed = yajl_get_bytes_consumed(handle); } yajl_free(handle); }