input/TextInputStream: return char*

Revert to the old API before commit e9e55b08, removing unnecessary
bloat.

src/input/TextInputStream.cxx

@@ -27,9 +27,10 @@
 #include <assert.h>
 #include <string.h>
 
-bool TextInputStream::ReadLine(std::string &line)
+char *
+TextInputStream::ReadLine()
 {
-	const char *src, *p;
+	char *src, *p;
 
 	do {
 		size_t nbytes;
@@ -46,33 +47,33 @@ bool TextInputStream::ReadLine(std::string &line)
 				buffer.Append(nbytes);
 			else if (error.IsDefined()) {
 				LogError(error);
-				return false;
+				return nullptr;
 			}
 		} else
 			nbytes = 0;
 
 		auto src_p = buffer.Read();
 		if (src_p.IsEmpty())
-			return false;
+			return nullptr;
 
 		src = src_p.data;
 
-		p = reinterpret_cast<const char*>(memchr(src, '\n', src_p.size));
+		p = reinterpret_cast<char*>(memchr(src, '\n', src_p.size));
 		if (p == nullptr && nbytes == 0) {
 			/* end of file (or line too long): terminate
 			   the current line */
 			dest = buffer.Write();
 			assert(!dest.IsEmpty());
-			dest[0] = '\n';
-			buffer.Append(1);
+			dest[0] = 0;
+			buffer.Clear();
+			return src;
 		}
 	} while (p == nullptr);
 
-	size_t length = p - src + 1;
+	buffer.Consume(p - src + 1);
+
 	while (p > src && IsWhitespaceOrNull(p[-1]))
 		--p;
-
-	line = std::string(src, p - src);
-	buffer.Consume(length);
-	return true;
+	*p = 0;
+	return src;
 }

src/input/TextInputStream.hxx

@@ -22,8 +22,6 @@
 
 #include "util/StaticFifoBuffer.hxx"
 
-#include <string>
-
 class InputStream;
 
 class TextInputStream {
@@ -46,11 +44,9 @@ public:
 	/**
 	 * Reads the next line from the stream with newline character stripped.
 	 *
-	 * @param line a string to put result to
-	 * @return true if line is read successfully, false on end of file
-	 * or error
+	 * @return a pointer to the line, or nullptr on end-of-file or error
 	 */
-	bool ReadLine(std::string &line);
+	char *ReadLine();
 };
 
 #endif

src/playlist/plugins/CuePlaylistPlugin.cxx

@@ -52,9 +52,9 @@ CuePlaylist::NextSong()
 	if (song != nullptr)
 		return song;
 
-	std::string line;
-	while (tis.ReadLine(line)) {
-		parser.Feed(line.c_str());
+	const char *line;
+	while ((line = tis.ReadLine()) != nullptr) {
+		parser.Feed(line);
 		song = parser.Get();
 		if (song != nullptr)
 			return song;

src/playlist/plugins/ExtM3uPlaylistPlugin.cxx

@@ -39,9 +39,8 @@ public:
 	}
 
 	bool CheckFirstLine() {
-		std::string line;
-		return tis.ReadLine(line) &&
-			strcmp(line.c_str(), "#EXTM3U") == 0;
+		const char *line = tis.ReadLine();
+		return line != nullptr && strcmp(line, "#EXTM3U") == 0;
 	}
 
 	virtual DetachedSong *NextSong() override;
@@ -105,15 +104,13 @@ DetachedSong *
 ExtM3uPlaylist::NextSong()
 {
 	Tag tag;
-	std::string line;
 	const char *line_s;
 
 	do {
-		if (!tis.ReadLine(line))
+		line_s = tis.ReadLine();
+		if (line_s == nullptr)
 			return nullptr;
 
-		line_s = line.c_str();
-
 		if (StringStartsWith(line_s, "#EXTINF:")) {
 			tag = extm3u_parse_tag(line_s + 8);
 			continue;

src/playlist/plugins/M3uPlaylistPlugin.cxx

@@ -45,14 +45,13 @@ m3u_open_stream(InputStream &is)
 DetachedSong *
 M3uPlaylist::NextSong()
 {
-	std::string line;
 	const char *line_s;
 
 	do {
-		if (!tis.ReadLine(line))
+		line_s = tis.ReadLine();
+		if (line_s == nullptr)
 			return nullptr;
 
-		line_s = line.c_str();
 		line_s = strchug_fast(line_s);
 	} while (line_s[0] == '#' || *line_s == 0);
 

test/dump_text_file.cxx

@@ -43,9 +43,9 @@
 static void
 dump_text_file(TextInputStream &is)
 {
-	std::string line;
-	while (is.ReadLine(line))
-		printf("'%s'\n", line.c_str());
+	const char *line;
+	while ((line = is.ReadLine()) != nullptr)
+		printf("'%s'\n", line);
 }
 
 static int