Factor out header line splitting into split_headerline in utils/strfuns.hpp

Author: tstenner

src/util/strfuns.cpp

@@ -25,3 +25,32 @@ std::vector<std::string> lsl::splitandtrim(
 	}
 	return parts;
 }
+
+bool lsl::split_headerline(char *buf, std::size_t bufsize, std::string &type, std::string &value) {
+	char *end = buf + bufsize, *middle_it = nullptr;
+
+	buf = trim_begin(buf, end);
+	// find the end of the header line, i.e. the end of the buffer or the start of a comment
+	for (auto it = buf; it != end; ++it) {
+		if(!*it || *it == ';') {
+			end = it;
+			break;
+		}
+		else if(*it == ':') middle_it = it;
+	}
+
+	// no separator found?
+	if (middle_it == nullptr) return false;
+
+	auto *value_begin = middle_it + 1;
+	trim(value_begin, end);
+
+	// convert to lowercase
+	for (auto it = buf; it != end; ++it)
+		if (*it >= 'A' && *it <= 'Z') *it += 'a' - 'A';
+
+	type.assign(buf, trim_end(buf, middle_it));
+	value.assign(value_begin, end);
+
+	return true;
+}

src/util/strfuns.hpp

@@ -25,6 +25,9 @@ template <typename IteratorType> void trim(IteratorType &begin, IteratorType &en
 	begin = trim_begin(begin, end);
 }
 
+/// split a header line ("Foo-Bar: 512 ; some comment") into type ("foo-bar") and value ("512")
+bool split_headerline(char *buf, std::size_t bufsize, std::string &type, std::string &value);
+
 /// return a string with whitespace at the beginning and end trimmed
 inline std::string trim(const std::string &input) {
 	std::string::const_iterator begin = input.begin(), end = input.end();

testing/int/stringfuncs.cpp

@@ -34,3 +34,26 @@ TEST_CASE("trim functions", "[string][basic]") {
 	CHECK(lsl::trim(testcase) == "Hello World\t\n  123");
 	CHECK(lsl::trim("") == "");
 }
+
+inline bool test_split_headerline(
+	std::string str, const char *expected_key, const char *expected_value) {
+	std::string key, value;
+	bool result = lsl::split_headerline(&str[0], str.size(), key, value);
+	INFO(str);
+	CHECK(key == expected_key);
+	CHECK(value == expected_value);
+	return result;
+}
+
+TEST_CASE("split_headerline", "[string][basic]") {
+	std::string basic[] = {{"a:b"}, {"	a	:	b	\r\n"}, {"a: b;not c"}};
+	for(auto &str: basic)
+		CHECK(test_split_headerline(str, "a", "b"));
+
+	// empty line
+	CHECK(!test_split_headerline("", "", ""));
+	// empty key+val
+	CHECK(test_split_headerline(":", "", ""));
+	// comment in key (?!)
+	CHECK(!test_split_headerline("wha;t:??", "", ""));
+}