Merge "liblog: event log tags cache miss call logd for update" (364bf6db) · Commits · e / os / android_system_core

liblog/event_tag_map.cpp

+79 −7

Original line number	Diff line number	Diff line
		@@ -227,19 +227,30 @@ int EventTagMap::find(MapString&& tag) const {
		// successful return, it will be pointing to the last character in the
		// tag line (i.e. the character before the start of the next line).
		//
		// lineNum = 0 removes verbose comments and requires us to cache the
		// content rather than make direct raw references since the content
		// will disappear after the call. A non-zero lineNum means we own the
		// data and it will outlive the call.
		//
		// Returns 0 on success, nonzero on failure.
		static int scanTagLine(EventTagMap* map, char** pData, int lineNum) {
		char* cp;
		unsigned long val = strtoul(*pData, &cp, 10);
		if (cp == *pData) {
		fprintf(stderr, OUT_TAG ": malformed tag number on line %d\n", lineNum);
		if (lineNum) {
		fprintf(stderr, OUT_TAG ": malformed tag number on line %d\n",
		lineNum);
		}
		errno = EINVAL;
		return -1;
		}

		uint32_t tagIndex = val;
		if (tagIndex != val) {
		fprintf(stderr, OUT_TAG ": tag number too large on line %d\n", lineNum);
		if (lineNum) {
		fprintf(stderr, OUT_TAG ": tag number too large on line %d\n",
		lineNum);
		}
		errno = ERANGE;
		return -1;
		}
		@@ -248,7 +259,10 @@ static int scanTagLine(EventTagMap* map, char** pData, int lineNum) {
		}

		if (*cp == '\n') {
		fprintf(stderr, OUT_TAG ": missing tag string on line %d\n", lineNum);
		if (lineNum) {
		fprintf(stderr, OUT_TAG ": missing tag string on line %d\n",
		lineNum);
		}
		errno = EINVAL;
		return -1;
		}
		@@ -259,7 +273,10 @@ static int scanTagLine(EventTagMap* map, char** pData, int lineNum) {
		size_t tagLen = cp - tag;

		if (!isspace(*cp)) {
		fprintf(stderr, OUT_TAG ": invalid tag chars on line %d\n", lineNum);
		if (lineNum) {
		fprintf(stderr, OUT_TAG ": invalid tag chars on line %d\n",
		lineNum);
		}
		errno = EINVAL;
		return -1;
		}
		@@ -293,10 +310,19 @@ static int scanTagLine(EventTagMap* map, char** pData, int lineNum) {
		#endif
		*pData = cp;

		if (lineNum) {
		if (map->emplaceUnique(tagIndex, TagFmt(std::make_pair(
		MapString(tag, tagLen), MapString(fmt, fmtLen))), verbose)) {
		return 0;
		}
		} else {
		// cache
		if (map->emplaceUnique(tagIndex, TagFmt(std::make_pair(
		MapString(std::string(tag, tagLen)),
		MapString(std::string(fmt, fmtLen)))))) {
		return 0;
		}
		}
		errno = EMLINK;
		return -1;
		}
		@@ -455,12 +481,55 @@ LIBLOG_ABI_PUBLIC void android_closeEventTagMap(EventTagMap* map) {
		if (map) delete map;
		}

		// Cache miss, go to logd to acquire a public reference.
		// Because we lack access to a SHARED PUBLIC /dev/event-log-tags file map?
		static const TagFmt* __getEventTag(EventTagMap* map, unsigned int tag) {
		// call event tag service to arrange for a new tag
		char *buf = NULL;
		// Can not use android::base::StringPrintf, asprintf + free instead.
		static const char command_template[] = "getEventTag id=%u";
		int ret = asprintf(&buf, command_template, tag);
		if (ret > 0) {
		// Add some buffer margin for an estimate of the full return content.
		char *cp;
		size_t size = ret - strlen(command_template) +
		strlen("65535\n4294967295\t?\t\t\t?\t# uid=32767\n\n\f?success?");
		if (size > (size_t)ret) {
		cp = static_cast<char*>(realloc(buf, size));
		if (cp) {
		buf = cp;
		} else {
		size = ret;
		}
		} else {
		size = ret;
		}
		// Ask event log tag service for an existing entry
		if (__send_log_msg(buf, size) >= 0) {
		buf[size - 1] = '\0';
		unsigned long val = strtoul(buf, &cp, 10); // return size
		if ((buf != cp) && (val > 0) && (*cp == '\n')) { // truncation OK
		++cp;
		if (!scanTagLine(map, &cp, 0)) {
		free(buf);
		return map->find(tag);
		}
		}
		}
		free(buf);
		}
		return NULL;
		}

		// Look up an entry in the map.
		LIBLOG_ABI_PUBLIC const char* android_lookupEventTag_len(const EventTagMap* map,
		size_t *len,
		unsigned int tag) {
		if (len) *len = 0;
		const TagFmt* str = map->find(tag);
		if (!str) {
		str = __getEventTag(const_cast<EventTagMap*>(map), tag);
		}
		if (!str) return NULL;
		if (len) *len = str->first.length();
		return str->first.data();
		@@ -471,6 +540,9 @@ LIBLOG_ABI_PUBLIC const char* android_lookupEventFormat_len(
		const EventTagMap* map, size_t *len, unsigned int tag) {
		if (len) *len = 0;
		const TagFmt* str = map->find(tag);
		if (!str) {
		str = __getEventTag(const_cast<EventTagMap*>(map), tag);
		}
		if (!str) return NULL;
		if (len) *len = str->second.length();
		return str->second.data();