fs/output, fs/TextFile: move to fs/io/

10 files changed, 820 insertions, 0 deletions

diff --git a/src/fs/io/BufferedOutputStream.cxx b/src/fs/io/BufferedOutputStream.cxx
new file mode 100644
index 000000000..088a3e279
--- /dev/null
+++ b/src/fs/io/BufferedOutputStream.cxx
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "BufferedOutputStream.hxx"
+#include "OutputStream.hxx"
+
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+
+bool
+BufferedOutputStream::AppendToBuffer(const void *data, size_t size)
+{
+	auto r = buffer.Write();
+	if (r.size < size)
+		return false;
+
+	memcpy(r.data, data, size);
+	buffer.Append(size);
+	return true;
+}
+
+bool
+BufferedOutputStream::Write(const void *data, size_t size)
+{
+	if (gcc_unlikely(last_error.IsDefined()))
+		return false;
+
+	if (AppendToBuffer(data, size))
+		return true;
+
+	if (!Flush())
+		return false;
+
+	if (AppendToBuffer(data, size))
+		return true;
+
+	return os.Write(data, size, last_error);
+}
+
+bool
+BufferedOutputStream::Write(const char *p)
+{
+	return Write(p, strlen(p));
+}
+
+bool
+BufferedOutputStream::Format(const char *fmt, ...)
+{
+	if (gcc_unlikely(last_error.IsDefined()))
+		return false;
+
+	auto r = buffer.Write();
+	if (r.IsEmpty()) {
+		if (!Flush())
+			return false;
+
+		r = buffer.Write();
+	}
+
+	/* format into the buffer */
+	va_list ap;
+	va_start(ap, fmt);
+	size_t size = vsnprintf(r.data, r.size, fmt, ap);
+	va_end(ap);
+
+	if (gcc_unlikely(size >= r.size)) {
+		/* buffer was not large enough; flush it and try
+		   again */
+
+		if (!Flush())
+			return false;
+
+		r = buffer.Write();
+
+		if (gcc_unlikely(size >= r.size)) {
+			/* still not enough space: grow the buffer and
+			   try again */
+			r.size = size + 1;
+			r.data = buffer.Write(r.size);
+		}
+
+		/* format into the new buffer */
+		va_start(ap, fmt);
+		size = vsnprintf(r.data, r.size, fmt, ap);
+		va_end(ap);
+
+		/* this time, it must fit */
+		assert(size < r.size);
+	}
+
+	buffer.Append(size);
+	return true;
+}
+
+bool
+BufferedOutputStream::Flush()
+{
+	if (!Check())
+		return false;
+
+	auto r = buffer.Read();
+	if (r.IsEmpty())
+		return true;
+
+	bool success = os.Write(r.data, r.size, last_error);
+	if (gcc_likely(success))
+		buffer.Consume(r.size);
+	return success;
+}
+
+bool
+BufferedOutputStream::Flush(Error &error)
+{
+	if (!Check(error))
+		return false;
+
+	auto r = buffer.Read();
+	if (r.IsEmpty())
+		return true;
+
+	bool success = os.Write(r.data, r.size, error);
+	if (gcc_likely(success))
+		buffer.Consume(r.size);
+	return success;
+}
diff --git a/src/fs/io/BufferedOutputStream.hxx b/src/fs/io/BufferedOutputStream.hxx
new file mode 100644
index 000000000..f2de758a2
--- /dev/null
+++ b/src/fs/io/BufferedOutputStream.hxx
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_BUFFERED_OUTPUT_STREAM_HXX
+#define MPD_BUFFERED_OUTPUT_STREAM_HXX
+
+#include "check.h"
+#include "Compiler.h"
+#include "util/DynamicFifoBuffer.hxx"
+#include "util/Error.hxx"
+
+#include <stddef.h>
+
+class OutputStream;
+class Error;
+
+class BufferedOutputStream {
+	OutputStream &os;
+
+	DynamicFifoBuffer<char> buffer;
+
+	Error last_error;
+
+public:
+	BufferedOutputStream(OutputStream &_os)
+		:os(_os), buffer(32768) {}
+
+	bool Write(const void *data, size_t size);
+	bool Write(const char *p);
+
+	gcc_printf(2,3)
+	bool Format(const char *fmt, ...);
+
+	gcc_pure
+	bool Check() const {
+		return !last_error.IsDefined();
+	}
+
+	bool Check(Error &error) const {
+		if (last_error.IsDefined()) {
+			error.Set(last_error);
+			return false;
+		} else
+			return true;
+	}
+
+	bool Flush();
+
+	bool Flush(Error &error);
+
+private:
+	bool AppendToBuffer(const void *data, size_t size);
+};
+
+#endif
diff --git a/src/fs/io/FileOutputStream.cxx b/src/fs/io/FileOutputStream.cxx
new file mode 100644
index 000000000..dc4456d1f
--- /dev/null
+++ b/src/fs/io/FileOutputStream.cxx
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "FileOutputStream.hxx"
+#include "fs/FileSystem.hxx"
+#include "system/fd_util.h"
+#include "util/Error.hxx"
+
+#ifdef WIN32
+
+FileOutputStream::FileOutputStream(Path _path, Error &error)
+	:path(_path),
+	 handle(CreateFile(path.c_str(), GENERIC_WRITE, 0, nullptr,
+			   TRUNCATE_EXISTING,
+			   FILE_ATTRIBUTE_NORMAL|FILE_FLAG_WRITE_THROUGH,
+			   nullptr))
+{
+	if (handle == INVALID_HANDLE_VALUE)
+		error.FormatLastError("Failed to create %s", path.c_str());
+}
+
+bool
+FileOutputStream::Write(const void *data, size_t size, Error &error)
+{
+	assert(IsDefined());
+
+	DWORD nbytes;
+	if (!WriteFile(handle, data, size, &nbytes, nullptr)) {
+		error.FormatLastError("Failed to write to %s", path.c_str());
+		return false;
+	}
+
+	if (size_t(nbytes) != size) {
+		error.FormatLastError(ERROR_DISK_FULL,
+				      "Failed to write to %s", path.c_str());
+		return false;
+	}
+
+	return true;
+}
+
+bool
+FileOutputStream::Commit(gcc_unused Error &error)
+{
+	assert(IsDefined());
+
+	CloseHandle(handle);
+	return true;
+}
+
+void
+FileOutputStream::Cancel()
+{
+	assert(IsDefined());
+
+	CloseHandle(handle);
+	RemoveFile(path);
+}
+
+#else
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+FileOutputStream::FileOutputStream(Path _path, Error &error)
+	:path(_path),
+	 fd(open_cloexec(path.c_str(),
+			 O_WRONLY|O_CREAT|O_TRUNC,
+			 0666))
+{
+	if (fd < 0)
+		error.FormatErrno("Failed to create %s", path.c_str());
+}
+
+bool
+FileOutputStream::Write(const void *data, size_t size, Error &error)
+{
+	assert(IsDefined());
+
+	ssize_t nbytes = write(fd, data, size);
+	if (nbytes < 0) {
+		error.FormatErrno("Failed to write to %s", path.c_str());
+		return false;
+	} else if ((size_t)nbytes < size) {
+		error.FormatErrno(ENOSPC,
+				  "Failed to write to %s", path.c_str());
+		return false;
+	}
+
+	return true;
+}
+
+bool
+FileOutputStream::Commit(Error &error)
+{
+	assert(IsDefined());
+
+	bool success = close(fd) == 0;
+	fd = -1;
+	if (!success)
+		error.FormatErrno("Failed to commit %s", path.c_str());
+
+	return success;
+}
+
+void
+FileOutputStream::Cancel()
+{
+	assert(IsDefined());
+
+	close(fd);
+	fd = -1;
+
+	RemoveFile(path);
+}
+
+#endif
diff --git a/src/fs/io/FileOutputStream.hxx b/src/fs/io/FileOutputStream.hxx
new file mode 100644
index 000000000..68174ec83
--- /dev/null
+++ b/src/fs/io/FileOutputStream.hxx
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_FILE_OUTPUT_STREAM_HXX
+#define MPD_FILE_OUTPUT_STREAM_HXX
+
+#include "check.h"
+#include "OutputStream.hxx"
+#include "fs/AllocatedPath.hxx"
+
+#include <assert.h>
+
+#ifdef WIN32
+#include <windows.h>
+#endif
+
+class Path;
+
+class FileOutputStream final : public OutputStream {
+	AllocatedPath path;
+
+#ifdef WIN32
+	HANDLE handle;
+#else
+	int fd;
+#endif
+
+public:
+	FileOutputStream(Path _path, Error &error);
+
+	~FileOutputStream() {
+		if (IsDefined())
+			Cancel();
+	}
+
+
+	bool IsDefined() const {
+#ifdef WIN32
+		return handle != INVALID_HANDLE_VALUE;
+#else
+		return fd >= 0;
+#endif
+	}
+
+	bool Commit(Error &error);
+	void Cancel();
+
+	/* virtual methods from class OutputStream */
+	bool Write(const void *data, size_t size, Error &error) override;
+};
+
+#endif
diff --git a/src/fs/io/GzipOutputStream.cxx b/src/fs/io/GzipOutputStream.cxx
new file mode 100644
index 000000000..d05645d9e
--- /dev/null
+++ b/src/fs/io/GzipOutputStream.cxx
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "GzipOutputStream.hxx"
+#include "util/Error.hxx"
+#include "util/Domain.hxx"
+
+const Domain zlib_domain("zlib");
+
+GzipOutputStream::GzipOutputStream(OutputStream &_next, Error &error)
+	:next(_next)
+{
+	z.next_in = nullptr;
+	z.avail_in = 0;
+	z.zalloc = Z_NULL;
+	z.zfree = Z_NULL;
+	z.opaque = Z_NULL;
+
+	constexpr int windowBits = 15;
+	constexpr int gzip_encoding = 16;
+
+	int result = deflateInit2(&z, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
+				  windowBits | gzip_encoding,
+				  8, Z_DEFAULT_STRATEGY);
+	if (result != Z_OK) {
+		z.opaque = this;
+		error.Set(zlib_domain, result, zError(result));
+	}
+}
+
+GzipOutputStream::~GzipOutputStream()
+{
+	if (IsDefined())
+		deflateEnd(&z);
+}
+
+bool
+GzipOutputStream::Flush(Error &error)
+{
+	/* no more input */
+	z.next_in = nullptr;
+	z.avail_in = 0;
+
+	while (true) {
+		Bytef output[4096];
+		z.next_out = output;
+		z.avail_out = sizeof(output);
+
+		int result = deflate(&z, Z_FINISH);
+		if (z.next_out > output &&
+		    !next.Write(output, z.next_out - output, error))
+			return false;
+
+		if (result == Z_STREAM_END)
+			return true;
+		else if (result != Z_OK) {
+			error.Set(zlib_domain, result, zError(result));
+			return false;
+		}
+    }
+}
+
+bool
+GzipOutputStream::Write(const void *_data, size_t size, Error &error)
+{
+	/* zlib's API requires non-const input pointer */
+	void *data = const_cast<void *>(_data);
+
+	z.next_in = reinterpret_cast<Bytef *>(data);
+	z.avail_in = size;
+
+	while (z.avail_in > 0) {
+		Bytef output[4096];
+		z.next_out = output;
+		z.avail_out = sizeof(output);
+
+		int result = deflate(&z, Z_NO_FLUSH);
+		if (result != Z_OK) {
+			error.Set(zlib_domain, result, zError(result));
+			return false;
+		}
+
+		if (z.next_out > output &&
+		    !next.Write(output, z.next_out - output, error))
+			return false;
+	}
+
+	return true;
+}
diff --git a/src/fs/io/GzipOutputStream.hxx b/src/fs/io/GzipOutputStream.hxx
new file mode 100644
index 000000000..4f6d8b357
--- /dev/null
+++ b/src/fs/io/GzipOutputStream.hxx
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_GZIP_OUTPUT_STREAM_HXX
+#define MPD_GZIP_OUTPUT_STREAM_HXX
+
+#include "check.h"
+#include "OutputStream.hxx"
+
+#include <assert.h>
+#include <zlib.h>
+
+class Error;
+class Domain;
+
+extern const Domain zlib_domain;
+
+/**
+ * A filter that compresses data written to it using zlib, forwarding
+ * compressed data in the "gzip" format.
+ *
+ * Don't forget to call Flush() before destructing this object.
+ */
+class GzipOutputStream final : public OutputStream {
+	OutputStream &next;
+
+	z_stream z;
+
+public:
+	/**
+	 * Construct the filter.  Call IsDefined() to check whether
+	 * the constructor has succeeded.  If not, #error will hold
+	 * information about the failure.
+	 */
+	GzipOutputStream(OutputStream &_next, Error &error);
+	~GzipOutputStream();
+
+	/**
+	 * Check whether the constructor has succeeded.
+	 */
+	bool IsDefined() const {
+		return z.opaque == nullptr;
+	}
+
+	/**
+	 * Finish the file and write all data remaining in zlib's
+	 * output buffer.
+	 */
+	bool Flush(Error &error);
+
+	/* virtual methods from class OutputStream */
+	bool Write(const void *data, size_t size, Error &error) override;
+};
+
+#endif
diff --git a/src/fs/io/OutputStream.hxx b/src/fs/io/OutputStream.hxx
new file mode 100644
index 000000000..71311c71f
--- /dev/null
+++ b/src/fs/io/OutputStream.hxx
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_OUTPUT_STREAM_HXX
+#define MPD_OUTPUT_STREAM_HXX
+
+#include "check.h"
+#include "Compiler.h"
+
+#include <stddef.h>
+
+class Error;
+
+class OutputStream {
+public:
+	OutputStream() = default;
+	OutputStream(const OutputStream &) = delete;
+
+	virtual bool Write(const void *data, size_t size, Error &error) = 0;
+};
+
+#endif
diff --git a/src/fs/io/StdioOutputStream.hxx b/src/fs/io/StdioOutputStream.hxx
new file mode 100644
index 000000000..e00db922f
--- /dev/null
+++ b/src/fs/io/StdioOutputStream.hxx
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_STDIO_OUTPUT_STREAM_HXX
+#define MPD_STDIO_OUTPUT_STREAM_HXX
+
+#include "check.h"
+#include "OutputStream.hxx"
+#include "fs/AllocatedPath.hxx"
+
+#include <stdio.h>
+
+class StdioOutputStream final : public OutputStream {
+	FILE *const file;
+
+public:
+	StdioOutputStream(FILE *_file):file(_file) {}
+
+	/* virtual methods from class OutputStream */
+	bool Write(const void *data, size_t size,
+		   gcc_unused Error &error) override {
+		fwrite(data, 1, size, file);
+
+		/* this class is debug-only and ignores errors */
+		return true;
+	}
+};
+
+#endif
diff --git a/src/fs/io/TextFile.cxx b/src/fs/io/TextFile.cxx
new file mode 100644
index 000000000..b1a92b9cc
--- /dev/null
+++ b/src/fs/io/TextFile.cxx
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "TextFile.hxx"
+#include "util/Alloc.hxx"
+#include "fs/Path.hxx"
+#include "fs/FileSystem.hxx"
+
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+
+TextFile::TextFile(Path path_fs)
+	:file(FOpen(path_fs, FOpenMode::ReadText)),
+	 buffer((char *)xalloc(step)), capacity(step), length(0) {}
+
+TextFile::~TextFile()
+{
+	free(buffer);
+
+	if (file != nullptr)
+		fclose(file);
+}
+
+char *
+TextFile::ReadLine()
+{
+	assert(file != nullptr);
+
+	while (true) {
+		if (length >= capacity) {
+			if (capacity >= max_length)
+				/* too large already - bail out */
+				return nullptr;
+
+			capacity <<= 1;
+			char *new_buffer = (char *)realloc(buffer, capacity);
+			if (new_buffer == nullptr)
+				/* out of memory - bail out */
+				return nullptr;
+		}
+
+		char *p = fgets(buffer + length, capacity - length, file);
+		if (p == nullptr) {
+			if (length == 0 || ferror(file))
+				return nullptr;
+			break;
+		}
+
+		length += strlen(buffer + length);
+		if (buffer[length - 1] == '\n')
+			break;
+	}
+
+	/* remove the newline characters */
+	if (buffer[length - 1] == '\n')
+		--length;
+	if (buffer[length - 1] == '\r')
+		--length;
+
+	buffer[length] = 0;
+	length = 0;
+	return buffer;
+}
diff --git a/src/fs/io/TextFile.hxx b/src/fs/io/TextFile.hxx
new file mode 100644
index 000000000..e3a712a88
--- /dev/null
+++ b/src/fs/io/TextFile.hxx
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_TEXT_FILE_HXX
+#define MPD_TEXT_FILE_HXX
+
+#include "Compiler.h"
+
+#include <stdio.h>
+#include <stddef.h>
+
+class Path;
+
+class TextFile {
+	static constexpr size_t max_length = 512 * 1024;
+	static constexpr size_t step = 1024;
+
+	FILE *const file;
+
+	char *buffer;
+	size_t capacity, length;
+
+public:
+	TextFile(Path path_fs);
+
+	TextFile(const TextFile &other) = delete;
+
+	~TextFile();
+
+	bool HasFailed() const {
+		return gcc_unlikely(file == nullptr);
+	}
+
+	/**
+	 * Reads a line from the input file, and strips trailing
+	 * space.  There is a reasonable maximum line length, only to
+	 * prevent denial of service.
+	 *
+	 * @param file the source file, opened in text mode
+	 * @param buffer an allocator for the buffer
+	 * @return a pointer to the line, or nullptr on end-of-file or error
+	 */
+	char *ReadLine();
+};
+
+#endif