Add string helpers in util/strfuns.hpp

Author: tstenner

CMakeLists.txt

@@ -98,6 +98,8 @@ add_library(lslobj OBJECT
 	src/util/cast.cpp
 	src/util/inireader.hpp
 	src/util/inireader.cpp
+	src/util/strfuns.hpp
+	src/util/strfuns.cpp
 	src/util/uuid.hpp
 	thirdparty/loguru/loguru.cpp
 	$<$<BOOL:${LSL_LEGACY_CPP_ABI}>:src/legacy/legacy_abi.cpp src/legacy/legacy_abi.h>

src/api_config.cpp

@@ -1,6 +1,7 @@
 #include "api_config.h"
 #include "common.h"
 #include "util/inireader.hpp"
+#include "util/strfuns.hpp"
 #include <algorithm>
 #include <cstdlib>
 #include <exception>

src/common.cpp

@@ -78,34 +78,3 @@ void lsl::ensure_lsl_initialized() {
 #endif
 	}
 }
-
-std::vector<std::string> lsl::splitandtrim(
-	const std::string &input, char separator, bool keepempty) {
-	std::vector<std::string> parts;
-	auto it = input.cbegin();
-	while (true) {
-		// Skip whitespace in the beginning
-		while (it != input.cend() && std::isspace(*it)) ++it;
-
-		// find the next separator or end of string
-		auto endit = std::find(it, input.cend(), separator);
-		// mark beginning of next part if not at the end
-		auto next = endit;
-
-		// shrink the range so it doesn't include whitespace at the end
-		while (it < endit && std::isspace(*(endit - 1))) --endit;
-		if (endit != it || keepempty) parts.emplace_back(it, endit);
-
-		if (next != input.cend())
-			it = next + 1;
-		else
-			break;
-	}
-	return parts;
-}
-
-std::string lsl::trim(const std::string &input) {
-	auto first = input.find_first_not_of(" \t\r\n"), last = input.find_last_not_of(" \t\r\n");
-	if (first == std::string::npos || last == std::string::npos) return "";
-	return input.substr(first, last - first + 1);
-}

src/common.h

@@ -83,9 +83,6 @@ class LIBLSL_CPP_API timeout_error : public std::runtime_error {
 	explicit timeout_error(const std::string &msg) : std::runtime_error(msg) {}
 };
 
-std::string trim(const std::string &input);
-std::vector<std::string> splitandtrim(
-	const std::string &input, char separator = ',', bool keepempty = false);
 } // namespace lsl
 
 #endif

src/data_receiver.cpp

@@ -5,6 +5,7 @@
 #include "sample.h"
 #include "socket_utils.h"
 #include "util/cast.hpp"
+#include "util/strfuns.hpp"
 #include <chrono>
 #include <exception>
 #include <iostream>

src/resolve_attempt_udp.cpp

@@ -2,6 +2,7 @@
 #include "api_config.h"
 #include "resolver_impl.h"
 #include "socket_utils.h"
+#include "util/strfuns.hpp"
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/ip/address.hpp>
 #include <boost/asio/ip/multicast.hpp>
@@ -102,16 +103,16 @@ void resolve_attempt_udp::handle_receive_outcome(err_t err, std::size_t len) {
 	if (!err) {
 		try {
 			// first parse & check the query id
-			std::istringstream is(std::string(resultbuf_, len));
-			std::string returned_id;
-			getline(is, returned_id);
-			returned_id = trim(returned_id);
-			if (returned_id == query_id_) {
+			char *bufend = resultbuf_ + len;
+			char *newlinepos = resultbuf_;
+			// find the end of the line
+			while (newlinepos != bufend && *newlinepos != '\n') ++newlinepos;
+			std::string returned_id(resultbuf_, trim_end(resultbuf_, newlinepos));
+
+			if (returned_id == query_id_ && newlinepos != bufend) {
 				// parse the rest of the query into a stream_info
 				stream_info_impl info;
-				std::ostringstream os;
-				os << is.rdbuf();
-				info.from_shortinfo_message(os.str());
+				info.from_shortinfo_message(std::string(newlinepos, bufend));
 				std::string uid = info.uid();
 				{
 					// update the results

src/tcp_server.cpp

@@ -6,6 +6,7 @@
 #include "socket_utils.h"
 #include "stream_info_impl.h"
 #include "util/cast.hpp"
+#include "util/strfuns.hpp"
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/ip/host_name.hpp>
 #include <boost/asio/ip/tcp.hpp>

src/udp_server.cpp

@@ -1,11 +1,12 @@
 #include "udp_server.h"
 #include "socket_utils.h"
 #include "stream_info_impl.h"
+#include "util/strfuns.hpp"
+#include <boost/asio/io_context.hpp>
 #include <boost/asio/ip/address.hpp>
+#include <boost/asio/ip/address_v4.hpp>
 #include <boost/asio/ip/multicast.hpp>
 #include <boost/asio/ip/udp.hpp>
-#include <boost/asio/io_context.hpp>
-#include <boost/asio/ip/address_v4.hpp>
 #include <exception>
 #include <loguru.hpp>
 #include <sstream>

src/util/strfuns.cpp

@@ -0,0 +1,27 @@
+#include "strfuns.hpp"
+
+std::vector<std::string> lsl::splitandtrim(
+	const std::string &input, char separator, bool keepempty) {
+	std::vector<std::string> parts;
+	auto it = input.cbegin();
+	while (true) {
+		// Skip whitespace in the beginning
+		it = lsl::trim_begin(it, input.cend());
+
+		// find the next separator or end of string
+		auto endit = it;
+		while (endit != input.end() && *endit != separator) ++endit;
+		// mark beginning of next part if not at the end
+		auto next = endit;
+
+		// shrink the range so it doesn't include whitespace at the end
+		endit = trim_end(it, endit);
+		if (endit != it || keepempty) parts.emplace_back(it, endit);
+
+		if (next != input.cend())
+			it = next + 1;
+		else
+			break;
+	}
+	return parts;
+}

src/util/strfuns.hpp

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace lsl {
+
+inline bool isspace(char c) { return c == ' ' || c == '\t' || c == '\r' || c == '\n'; }
+
+/// trim whitespace at the beginning of a sequence, return position of first non-whitespace character
+template <typename IteratorType> IteratorType trim_begin(IteratorType begin, IteratorType end) {
+	while (begin != end && lsl::isspace(*begin)) ++begin;
+	return begin;
+}
+
+/// trim whitespace at the end of a sequence, return position one past the last non-whitespace character
+template <typename IteratorType> IteratorType trim_end(IteratorType begin, IteratorType end) {
+	while (end > begin && lsl::isspace(*(end - 1))) --end;
+	return end;
+}
+
+/// remove whitespace from the beginning and end of a sequence, modifying both start and end iterators
+template <typename IteratorType> void trim(IteratorType &begin, IteratorType &end) {
+	end = trim_end(begin, end);
+	begin = trim_begin(begin, end);
+}
+
+/// 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();
+	lsl::trim(begin, end);
+	return std::string(begin, end);
+}
+
+/// split a separated string like "this,is a,list" into its parts
+std::vector<std::string> splitandtrim(
+	const std::string &input, char separator = ',', bool keepempty = false);
+
+} // namespace lsl