fixed incorrect asserts in storage (that were triggered by torrent with zero-size files). Fixed bug in resource distribution algorithm. Made an attempt to avoid an assert in msvc standard library caused by passing a non-printable character to isdigit().

ChangeLog

@@ -1,3 +1,7 @@
+	* fixed problem with the resource distribution algorithm
+	  (controlling e.g upload/download rates)
+	* fixed incorrect asserts in storage related to torrents with
+	  zero-sized files.
 	* added support for trackerless torrents (with kademlia DHT).
 	* support for torrents with the private flag set.
 	* support for torrents containing bootstrap nodes for the

include/libtorrent/bencode.hpp

@@ -256,7 +256,7 @@ namespace libtorrent
 			// ----------------------------------------------
 			// string
 			default:
-				if (isdigit(*in))
+				if (isdigit((unsigned char)*in))
 				{
 					std::string len_s = read_until(in, end, ':');
 					assert(*in == ':');

src/allocate_resources.cpp

@@ -158,6 +158,7 @@ namespace libtorrent
 			, It end
 			, resource_request T::* res)
 		{
+			assert(resources >= 0);
 	#ifndef NDEBUG
 			allocate_resources_contract_check<It, T> contract_check(
 				resources
@@ -197,7 +198,9 @@ namespace libtorrent
 			resources = std::max(resources, sum_min);
 			int resources_to_distribute = std::min(resources, sum_max) - sum_min;
 			assert(resources_to_distribute >= 0);
-
+#ifndef NDEBUG
+			int prev_resources_to_distribute = resources_to_distribute;
+#endif
 			while (resources_to_distribute > 0)
 			{
 				size_type total_used = 0;
@@ -215,11 +218,17 @@ namespace libtorrent
 
 				size_type kNumer = resources_to_distribute;
 				size_type kDenom = total_used;
+				assert(kNumer >= 0);
+				assert(kDenom >= 0);
+				assert(kNumer <= std::numeric_limits<int>::max());
+				assert(total_used < std::numeric_limits<int>::max());
 
 				if (kNumer * max_used <= kDenom)
 				{
 					kNumer = 1;
 					kDenom = max_used;
+					assert(kDenom >= 0);
+					assert(kDenom <= std::numeric_limits<int>::max());
 				}
 
 				for (It i = start; i != end && resources_to_distribute > 0; ++i)
@@ -241,6 +250,10 @@ namespace libtorrent
 				}
 
 				assert(resources_to_distribute >= 0);
+				assert(resources_to_distribute < prev_resources_to_distribute);
+#ifndef NDEBUG
+				prev_resources_to_distribute = resources_to_distribute;
+#endif
 			}
 		}
 

src/storage.cpp

@@ -684,32 +684,37 @@ namespace libtorrent
 			if (file_offset + read_bytes > file_iter->size)
 				read_bytes = static_cast<int>(file_iter->size - file_offset);
 
+			if (read_bytes > 0)
+			{
 #ifndef NDEBUG
-			assert(int(slices.size()) > counter);
-			size_type slice_size = slices[counter].size;
-			assert(slice_size == read_bytes);
-			assert(m_pimpl->info.file_at(slices[counter].file_index).path
-				== file_iter->path);
+				assert(int(slices.size()) > counter);
+				size_type slice_size = slices[counter].size;
+				assert(slice_size == read_bytes);
+				assert(m_pimpl->info.file_at(slices[counter].file_index).path
+					== file_iter->path);
 #endif
 
-			size_type actual_read = in->read(buf + buf_pos, read_bytes);
+				size_type actual_read = in->read(buf + buf_pos, read_bytes);
 
-			if (read_bytes != actual_read)
-			{
-				// the file was not big enough
-				throw file_error("slot has no storage");
+				if (read_bytes != actual_read)
+				{
+					// the file was not big enough
+					throw file_error("slot has no storage");
+				}
+
+				left_to_read -= read_bytes;
+				buf_pos += read_bytes;
+				assert(buf_pos >= 0);
+				file_offset += read_bytes;
 			}
 
-			left_to_read -= read_bytes;
-			buf_pos += read_bytes;
-			assert(buf_pos >= 0);
-			file_offset += read_bytes;
-
 			if (left_to_read > 0)
 			{
 				++file_iter;
 #ifndef NDEBUG
-				++counter;
+				// empty files are not returned by map_block, so if
+				// this file was empty, don't increment the slice counter
+				if (read_bytes > 0) ++counter;
 #endif
 				path path = m_pimpl->save_path / file_iter->path;
 
@@ -799,32 +804,35 @@ namespace libtorrent
 				write_bytes = static_cast<int>(file_iter->size - file_offset);
 			}
 
-			assert(int(slices.size()) > counter);
-			assert(slices[counter].size == write_bytes);
-			assert(m_pimpl->info.file_at(slices[counter].file_index).path
-				== file_iter->path);
-
-			assert(buf_pos >= 0);
-			assert(write_bytes >= 0);
-			size_type written = out->write(buf + buf_pos, write_bytes);
-
-			if (written != write_bytes)
+			if (write_bytes > 0)
 			{
-				std::stringstream s;
-				s << "no storage for slot " << slot;
-				throw file_error(s.str());
-			}
+				assert(int(slices.size()) > counter);
+				assert(slices[counter].size == write_bytes);
+				assert(m_pimpl->info.file_at(slices[counter].file_index).path
+					== file_iter->path);
 
-			left_to_write -= write_bytes;
-			buf_pos += write_bytes;
-			assert(buf_pos >= 0);
-			file_offset += write_bytes;
-			assert(file_offset <= file_iter->size);
+				assert(buf_pos >= 0);
+				assert(write_bytes >= 0);
+				size_type written = out->write(buf + buf_pos, write_bytes);
+
+				if (written != write_bytes)
+				{
+					std::stringstream s;
+					s << "no storage for slot " << slot;
+					throw file_error(s.str());
+				}
+
+				left_to_write -= write_bytes;
+				buf_pos += write_bytes;
+				assert(buf_pos >= 0);
+				file_offset += write_bytes;
+				assert(file_offset <= file_iter->size);
+			}
 
 			if (left_to_write > 0)
 			{
 			#ifndef NDEBUG
-				++counter;
+				if (write_bytes > 0) ++counter;
 			#endif
 				++file_iter;
 

test/test_storage.cpp

@@ -19,7 +19,10 @@ int test_main()
 	torrent_info info;
 	info.set_piece_size(piece_size);
 	info.add_file("temp_storage/test1.tmp", 17);
-	info.add_file("temp_storage/test2.tmp", 613);
+	info.add_file("temp_storage/test2.tmp", 612);
+	info.add_file("temp_storage/test3.tmp", 0);
+	info.add_file("temp_storage/test4.tmp", 0);
+	info.add_file("temp_storage/test5.tmp", 1);
 
 	char piece0[piece_size] =
 	{ 6, 6, 6, 6, 6, 6, 6, 6
@@ -41,7 +44,7 @@ int test_main()
 
 	create_directory(initial_path() / "temp_storage");
 
-	int num_pieces = (613 + 17 + piece_size - 1) / piece_size;
+	int num_pieces = (1 + 612 + 17 + piece_size - 1) / piece_size;
 	TEST_CHECK(info.num_pieces() == num_pieces);
 
 	char piece[piece_size];