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diff --git a/src/input/cache/Manager.hxx b/src/input/cache/Manager.hxx
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+/*
+ * Copyright 2003-2019 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_INPUT_CACHE_MANAGER_HXX
+#define MPD_INPUT_CACHE_MANAGER_HXX
+
+#include "input/Offset.hxx"
+#include "thread/Mutex.hxx"
+#include "util/Compiler.h"
+
+#include <boost/intrusive/set.hpp>
+#include <boost/intrusive/list.hpp>
+
+class InputStream;
+class InputCacheItem;
+class InputCacheLease;
+struct InputCacheConfig;
+
+/**
+ * A class which caches files in RAM.  It is supposed to prefetch
+ * files before they are played.
+ */
+class InputCacheManager {
+	const size_t max_total_size;
+
+	mutable Mutex mutex;
+
+	size_t total_size = 0;
+
+	struct ItemCompare {
+		gcc_pure
+		bool operator()(const InputCacheItem &a,
+				const char *b) const noexcept;
+
+		gcc_pure
+		bool operator()(const char *a,
+				const InputCacheItem &b) const noexcept;
+
+		gcc_pure
+		bool operator()(const InputCacheItem &a,
+				const InputCacheItem &b) const noexcept;
+	};
+
+	boost::intrusive::list<InputCacheItem,
+			       boost::intrusive::base_hook<boost::intrusive::list_base_hook<boost::intrusive::link_mode<boost::intrusive::auto_unlink>>>,
+			       boost::intrusive::constant_time_size<false>> items_by_time;
+
+	using UriMap =
+		boost::intrusive::set<InputCacheItem,
+				      boost::intrusive::base_hook<boost::intrusive::set_base_hook<boost::intrusive::link_mode<boost::intrusive::normal_link>>>,
+				      boost::intrusive::compare<ItemCompare>,
+				      boost::intrusive::constant_time_size<false>>;
+
+	UriMap items_by_uri;
+
+public:
+	explicit InputCacheManager(const InputCacheConfig &config) noexcept;
+	~InputCacheManager() noexcept;
+
+	gcc_pure
+	bool Contains(const char *uri) noexcept;
+
+	/**
+	 * Throws if opening the #InputStream fails.
+	 *
+	 * @param create if true, then the cache item will be created
+	 * if it did not exist
+	 * @return a lease of the new item or nullptr if the file is
+	 * not eligible for caching
+	 */
+	InputCacheLease Get(const char *uri, bool create);
+
+	/**
+	 * Shortcut for "Get(uri,true)", discarding the returned
+	 * lease.
+	 */
+	void Prefetch(const char *uri);
+
+private:
+	/**
+	 * Check whether the given #InputStream can be stored in this
+	 * cache.
+	 */
+	bool IsEligible(const InputStream &input) noexcept;
+
+	void Remove(InputCacheItem &item) noexcept;
+	void Delete(InputCacheItem *item) noexcept;
+
+	InputCacheItem *FindOldestUnused() noexcept;
+
+	/**
+	 * @return true if one item has been evicted, false if no
+	 * unused item was found
+	 */
+	bool EvictOldestUnused() noexcept;
+};
+
+#endif