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authorMax Kellermann <max@duempel.org>2014-08-11 20:42:51 +0200
committerMax Kellermann <max@duempel.org>2014-08-11 21:48:25 +0200
commit88a2f128ec9e72bb53a8d6646ce44d7053862f78 (patch)
tree252d3712ea1d23d1d68c0bb63c781ce5a3035612 /src
parent45c139cfb36fd0801faded97683aa7faa83809b1 (diff)
downloadmpd-88a2f128ec9e72bb53a8d6646ce44d7053862f78.tar.gz
mpd-88a2f128ec9e72bb53a8d6646ce44d7053862f78.tar.xz
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fs/io/AutoGunzipReader: new class
Diffstat (limited to 'src')
-rw-r--r--src/fs/io/AutoGunzipReader.cxx70
-rw-r--r--src/fs/io/AutoGunzipReader.hxx51
2 files changed, 121 insertions, 0 deletions
diff --git a/src/fs/io/AutoGunzipReader.cxx b/src/fs/io/AutoGunzipReader.cxx
new file mode 100644
index 000000000..2552f7b99
--- /dev/null
+++ b/src/fs/io/AutoGunzipReader.cxx
@@ -0,0 +1,70 @@
+/*
+ * 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 "AutoGunzipReader.hxx"
+#include "GunzipReader.hxx"
+#include "util/Error.hxx"
+
+AutoGunzipReader::~AutoGunzipReader()
+{
+ delete gunzip;
+}
+
+gcc_pure
+static bool
+IsGzip(const uint8_t data[4])
+{
+ return data[0] == 0x1f && data[1] == 0x8b && data[2] == 0x08 &&
+ (data[3] & 0xe0) == 0;
+}
+
+inline bool
+AutoGunzipReader::Detect(Error &error)
+{
+ const uint8_t *data = (const uint8_t *)peek.Peek(4, error);
+ if (data == nullptr) {
+ if (error.IsDefined())
+ return false;
+
+ next = &peek;
+ return true;
+ }
+
+ if (IsGzip(data)) {
+ gunzip = new GunzipReader(peek, error);
+ if (!gunzip->IsDefined())
+ return false;
+
+
+ next = gunzip;
+ } else
+ next = &peek;
+
+ return true;
+}
+
+size_t
+AutoGunzipReader::Read(void *data, size_t size, Error &error)
+{
+ if (next == nullptr && !Detect(error))
+ return false;
+
+ return next->Read(data, size, error);
+}
diff --git a/src/fs/io/AutoGunzipReader.hxx b/src/fs/io/AutoGunzipReader.hxx
new file mode 100644
index 000000000..0efd9d56c
--- /dev/null
+++ b/src/fs/io/AutoGunzipReader.hxx
@@ -0,0 +1,51 @@
+/*
+ * 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_AUTO_GUNZIP_READER_HXX
+#define MPD_AUTO_GUNZIP_READER_HXX
+
+#include "check.h"
+#include "PeekReader.hxx"
+
+#include <stdint.h>
+
+class GunzipReader;
+
+/**
+ * A filter that detects gzip compression and optionally inserts a
+ * #GunzipReader.
+ */
+class AutoGunzipReader final : public Reader {
+ Reader *next;
+ PeekReader peek;
+ GunzipReader *gunzip;
+
+public:
+ AutoGunzipReader(Reader &_next)
+ :next(nullptr), peek(_next), gunzip(nullptr) {}
+ ~AutoGunzipReader();
+
+ /* virtual methods from class Reader */
+ virtual size_t Read(void *data, size_t size, Error &error) override;
+
+private:
+ bool Detect(Error &error);
+};
+
+#endif