removed temporary assert and factored file_pool out of storage to prepare for a per session file pool

src/file_pool.cpp

@@ -0,0 +1,104 @@
+/*
+
+Copyright (c) 2006, Arvid Norberg
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include "libtorrent/file_pool.hpp"
+
+namespace libtorrent
+{
+	using boost::multi_index::nth_index;
+	using boost::multi_index::get;
+
+	boost::shared_ptr<file> file_pool::open_file(void* st, fs::path const& p, file::open_mode m)
+	{
+	
+		assert(st != 0);
+		assert(p.is_complete());
+		typedef nth_index<file_set, 0>::type path_view;
+		path_view& pt = get<0>(m_files);
+		path_view::iterator i = pt.find(p);
+		if (i != pt.end())
+		{
+			lru_file_entry e = *i;
+			e.last_use = pt::second_clock::universal_time();
+
+			// if you hit this assert, you probably have more than one
+			// storage/torrent using the same file at the same time!
+			assert(e.key == st);
+
+			e.key = st;
+			if ((e.mode & m) != m)
+			{
+				// close the file before we open it with
+				// the new read/write privilages
+				i->file_ptr.reset();
+				assert(e.file_ptr.unique());
+				e.file_ptr.reset();
+				e.file_ptr.reset(new file(p, m));
+				e.mode = m;
+			}
+			pt.replace(i, e);
+			return e.file_ptr;
+		}
+		// the file is not in our cache
+		if ((int)m_files.size() >= m_size)
+		{
+			// the file cache is at its maximum size, close
+			// the least recently used (lru) file from it
+			typedef nth_index<file_set, 1>::type lru_view;
+			lru_view& lt = get<1>(m_files);
+			lru_view::iterator i = lt.begin();
+			// the first entry in this view is the least recently used
+			assert(lt.size() == 1 || (i->last_use <= boost::next(i)->last_use));
+			lt.erase(i);
+		}
+		lru_file_entry e(boost::shared_ptr<file>(new file(p, m)));
+		e.mode = m;
+		e.key = st;
+		e.file_path = p;
+		pt.insert(e);
+		return e.file_ptr;
+	}
+
+	void file_pool::release(void* st)
+	{
+		assert(st != 0);
+		using boost::tie;
+
+		typedef nth_index<file_set, 2>::type key_view;
+		key_view& kt = get<2>(m_files);
+
+		key_view::iterator start, end;
+		tie(start, end) = kt.equal_range(st);
+		kt.erase(start, end);
+	}
+
+}