fs/io/TextFile: split into class FileLineReader and AutoGunzipFileLineReader

Detangle dependencies.

src/lib/zlib/AutoGunzipFileLineReader.cxx

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright The Music Player Daemon Project
+
+#include "AutoGunzipFileLineReader.hxx"
+#include "io/FileReader.hxx"
+#include "io/BufferedReader.hxx"
+#include "lib/zlib/AutoGunzipReader.hxx"
+#include "fs/Path.hxx"
+
+#include <cassert>
+
+AutoGunzipFileLineReader::AutoGunzipFileLineReader(Path path_fs)
+	:file_reader(std::make_unique<FileReader>(path_fs)),
+#ifdef ENABLE_ZLIB
+	 gunzip_reader(std::make_unique<AutoGunzipReader>(*file_reader)),
+#endif
+	 buffered_reader(std::make_unique<BufferedReader>(*
+#ifdef ENABLE_ZLIB
+							  gunzip_reader
+#else
+							  file_reader
+#endif
+							  ))
+{
+}
+
+AutoGunzipFileLineReader::~AutoGunzipFileLineReader() noexcept = default;
+
+char *
+AutoGunzipFileLineReader::ReadLine()
+{
+	assert(buffered_reader != nullptr);
+
+	return buffered_reader->ReadLine();
+}

src/lib/zlib/AutoGunzipFileLineReader.hxx

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright The Music Player Daemon Project
+
+#pragma once
+
+#include "config.h"
+
+#ifdef ENABLE_ZLIB
+
+#include "io/LineReader.hxx"
+
+#include <memory>
+
+class Path;
+class FileReader;
+class AutoGunzipReader;
+class BufferedReader;
+
+class AutoGunzipFileLineReader final : public LineReader {
+	const std::unique_ptr<FileReader> file_reader;
+
+	const std::unique_ptr<AutoGunzipReader> gunzip_reader;
+
+	const std::unique_ptr<BufferedReader> buffered_reader;
+
+public:
+	explicit AutoGunzipFileLineReader(Path path_fs);
+
+	AutoGunzipFileLineReader(const AutoGunzipFileLineReader &other) = delete;
+
+	~AutoGunzipFileLineReader() noexcept;
+
+	/* virtual methods from class LineReader */
+	char *ReadLine() override;
+};
+
+#else
+
+#include "io/FileLineReader.hxx"
+
+using AutoGunzipFileLineReader = FileLineReader;
+
+#endif

src/lib/zlib/meson.build

@@ -10,6 +10,7 @@ zlib = static_library(
   'GunzipReader.cxx',
   'GzipOutputStream.cxx',
   'AutoGunzipReader.cxx',
+  'AutoGunzipFileLineReader.cxx',
   include_directories: inc,
   dependencies: [
     zlib_dep,