fs/GzipOutputStream: new class wrapping zlib

1 files changed, 71 insertions, 0 deletions

diff --git a/src/fs/output/GzipOutputStream.hxx b/src/fs/output/GzipOutputStream.hxx
new file mode 100644
index 000000000..4f6d8b357
--- /dev/null
+++ b/src/fs/output/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