added test to render file fragmentation

examples/Jamfile

@@ -23,4 +23,5 @@ exe dump_torrent : dump_torrent.cpp ;
 exe make_torrent : make_torrent.cpp ;
 exe enum_if : enum_if.cpp ;
 exe connection_tester : connection_tester.cpp ;
+exe fragmentation_test : fragmentation_test.cpp ;
 

examples/fragmentation_test.cpp

@@ -0,0 +1,127 @@
+/*
+
+Copyright (c) 2010, 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/storage.hpp"
+#include "libtorrent/file_pool.hpp"
+
+#include <boost/utility.hpp>
+
+#include <stdlib.h>
+
+using namespace libtorrent;
+
+int main(int argc, char const* argv[])
+{
+	if (argc != 3)
+	{
+		fprintf(stderr, "Usage: fragmentation_test torrent-file file-storage-path\n");
+		return 1;
+	}
+
+	error_code ec;
+	boost::intrusive_ptr<torrent_info> ti(new torrent_info(argv[1], ec));
+
+	if (ec)
+	{
+		fprintf(stderr, "Error while loading torrent file: %s\n", ec.message().c_str());
+		return 1;
+	}
+
+	file_pool fp;
+	boost::shared_ptr<storage_interface> st(default_storage_constructor(ti->files(), 0, argv[2], fp));
+
+	// the first field is the piece index, the second
+	// one is the physical location of the piece on disk
+	std::vector<std::pair<int, size_type> > pieces;
+
+	// make sure all the files are there
+	std::vector<std::pair<size_type, std::time_t> > files = get_filesizes(ti->files(), argv[2]);
+	for (int i = 0; i < ti->num_files(); ++i)
+	{
+		if (ti->file_at(i).size == files[i].first) continue;
+		fprintf(stderr, "Files for this torrent are missing or incomplete: %s was %"PRId64" bytes, expected %"PRId64" bytes\n"
+			, ti->file_at(i).path.c_str(), files[i].first, ti->file_at(i).size);
+		return 1;
+	}
+
+	for (int i = 0; i < ti->num_pieces(); ++i)
+	{
+		pieces.push_back(std::make_pair(i, st->physical_offset(i, 0)));
+		if (pieces.back().second == size_type(i) * ti->piece_length())
+		{
+			// this suggests that the OS doesn't support physical offset
+			// or that the file doesn't exist, or some other file error
+			fprintf(stderr, "Your operating system or filesystem "
+				"does not appear to support querying physical disk offset\n");
+			return 1;
+		}
+	}
+
+	FILE* f = fopen("fragmentation.log", "w+");
+	if (f == 0)
+	{
+		fprintf(stderr, "error while opening log file: %s\n", strerror(errno));
+		return 1;
+	}
+
+	for (int i = 0; i < ti->num_pieces(); ++i)
+	{
+		fprintf(f, "%d %"PRId64"\n", pieces[i].first, pieces[i].second);
+	}
+
+	fclose(f);
+
+	f = fopen("fragmentation.gnuplot", "w+");
+	if (f == 0)
+	{
+		fprintf(stderr, "error while opening gnuplot file: %s\n", strerror(errno));
+		return 1;
+	}
+
+	fprintf(f,
+		"set term png size 1200,800\n"
+		"set output \"fragmentation.png\"\n"
+		"set xrange [*:*]\n"
+		"set xlabel \"piece\"\n"
+		"set ylabel \"file position\"\n"
+		"set key box\n"
+		"set title \"fragmentation for '%s'\"\n"
+		"set tics nomirror\n"
+		"plot \"fragmentation.log\" using 1:2 with dots lt rgb \"#e07070\" notitle axis x1y1, x=0\n"
+		, ti->name().c_str());
+
+	fclose(f);
+
+	system("gnuplot fragmentation.gnuplot");
+}
+
+