add all_set() function on bitfield and automatically call inc_refcount_all or dec_refcount_all if all bits are set in a bitfield

include/libtorrent/bitfield.hpp

@@ -81,6 +81,28 @@ namespace libtorrent
 			m_bytes[index / 8] &= ~(0x80 >> (index & 7));
 		}
 
+		// returns true if all bits in the bitfield are set
+		bool all_set() const
+		{
+			const int num_words = m_size / 32;
+			const int num_bytes = m_size / 8;
+			boost::uint32_t* bits = (boost::uint32_t*)m_bytes;
+			for (int i = 0; i < num_words; ++i)
+			{
+				if (bits[i] != 0xffffffff) return false;
+			}
+
+			for (int i = num_words * 4; i < num_bytes; ++i)
+			{
+				if (m_bytes[i] != 0xff) return false;
+			}
+			int rest = m_size - num_bytes * 8;
+			boost::uint8_t mask = 0xff << (8-rest);
+			if (rest > 0 && (m_bytes[num_bytes] & mask) != mask)
+				return false;
+			return true;
+		}
+
 		void set_bit(int index)
 		{
 			TORRENT_ASSERT(index >= 0);

include/libtorrent/torrent.hpp

@@ -539,7 +539,10 @@ namespace libtorrent
 		{
 			if (has_picker())
 			{
-				m_picker->inc_refcount(bits);
+				if (bits.all_set())
+					m_picker->inc_refcount_all();
+				else
+					m_picker->inc_refcount(bits);
 			}
 #ifdef TORRENT_DEBUG
 			else
@@ -567,7 +570,10 @@ namespace libtorrent
 		{
 			if (has_picker())
 			{
-				m_picker->dec_refcount(bits);
+				if (bits.all_set())
+					m_picker->dec_refcount_all();
+				else
+					m_picker->dec_refcount(bits);
 			}
 #ifdef TORRENT_DEBUG
 			else

test/test_primitives.cpp

@@ -1797,6 +1797,7 @@ int test_main()
 	test1.set_bit(1);
 	test1.set_bit(9);
 	TEST_CHECK(test1.count() == 3);
+	TEST_CHECK(test1.all_set() == false);
 	test1.clear_bit(2);
 	TEST_CHECK(test1.count() == 2);
 	int distance = std::distance(test1.begin(), test1.end());
@@ -1818,6 +1819,9 @@ int test_main()
 	test1.set_bit(1);
 	test1.resize(1);
 	TEST_CHECK(test1.count() == 1);
+
+	test1.resize(100, true);
+	TEST_CHECK(test1.all_set() == true);
 	return 0;
 }