remove left-overs from disk buffer pool allocator

include/libtorrent/aux_/session_impl.hpp

@@ -729,7 +729,6 @@ namespace aux {
 			void update_queued_disk_bytes();
 			void update_alert_queue_size();
 			void update_disk_threads();
-			void update_cache_buffer_chunk_size();
 			void update_report_web_seed_downloads();
 			void update_outgoing_interfaces();
 			void update_listen_interfaces();

include/libtorrent/disk_buffer_pool.hpp

@@ -131,8 +131,6 @@ namespace libtorrent {
 
 		mutable std::mutex m_pool_mutex;
 
-		int m_cache_buffer_chunk_size;
-
 		// this is specifically exempt from release_asserts
 		// since it's a quite costly check. Only for debug
 		// builds.

include/libtorrent/settings_pack.hpp

@@ -963,20 +963,18 @@ namespace libtorrent {
 			// physical RAM available in the machine divided by 8. If the amount
 			// of physical RAM cannot be determined, it's set to 1024 (= 16 MiB).
 			//
-			// Disk buffers are allocated using a pool allocator, the number of
-			// blocks that are allocated at a time when the pool needs to grow can
-			// be specified in ``cache_buffer_chunk_size``. Lower numbers saves
-			// memory at the expense of more heap allocations. If it is set to 0,
-			// the effective chunk size is proportional to the total cache size,
-			// attempting to strike a good balance between performance and memory
-			// usage. It defaults to 0. ``cache_expiry`` is the number of seconds
-			// from the last cached write to a piece in the write cache, to when
-			// it's forcefully flushed to disk. Default is 60 second.
+			// ``cache_expiry`` is the number of seconds from the last cached write
+			// to a piece in the write cache, to when it's forcefully flushed to
+			// disk. Default is 60 second.
 			//
 			// On 32 bit builds, the effective cache size will be limited to 3/4 of
 			// 2 GiB to avoid exceeding the virtual address space limit.
 			cache_size,
+#ifndef TORRENT_NO_DEPRECATE
 			cache_buffer_chunk_size,
+#else
+			deprecated25,
+#endif
 			cache_expiry,
 
 			// determines how files are opened when they're in read only mode

src/disk_buffer_pool.cpp

@@ -76,7 +76,6 @@ namespace libtorrent {
 		, m_trigger_cache_trim(trigger_trim)
 		, m_exceeded_max_size(false)
 		, m_ios(ios)
-		, m_cache_buffer_chunk_size(0)
 	{
 #if TORRENT_USE_ASSERTS
 		m_magic = 0x1337;
@@ -292,10 +291,6 @@ namespace libtorrent {
 	{
 		std::unique_lock<std::mutex> l(m_pool_mutex);
 
-		// 0 cache_buffer_chunk_size means 'automatic' (i.e.
-		// proportional to the total disk cache size)
-		m_cache_buffer_chunk_size = sett.get_int(settings_pack::cache_buffer_chunk_size);
-
 		int const cache_size = sett.get_int(settings_pack::cache_size);
 		if (cache_size < 0)
 		{
@@ -356,8 +351,6 @@ namespace libtorrent {
 			m_exceeded_max_size = true;
 			m_trigger_cache_trim();
 		}
-		if (m_cache_buffer_chunk_size > m_max_use)
-			m_cache_buffer_chunk_size = m_max_use;
 
 #if TORRENT_USE_ASSERTS
 		m_settings_set = true;

src/session.cpp

@@ -102,7 +102,6 @@ namespace libtorrent {
 
 		// don't use any disk cache
 		set.set_int(settings_pack::cache_size, 0);
-		set.set_int(settings_pack::cache_buffer_chunk_size, 1);
 		set.set_bool(settings_pack::use_read_cache, false);
 
 		set.set_bool(settings_pack::close_redundant_connections, true);
@@ -166,7 +165,6 @@ namespace libtorrent {
 		// use 1 GB of cache
 		set.set_int(settings_pack::cache_size, 32768 * 2);
 		set.set_bool(settings_pack::use_read_cache, true);
-		set.set_int(settings_pack::cache_buffer_chunk_size, 0);
 		set.set_int(settings_pack::read_cache_line_size, 32);
 		set.set_int(settings_pack::write_cache_line_size, 256);
 		// 30 seconds expiration to save cache

src/session_impl.cpp

@@ -6235,12 +6235,6 @@ namespace {
 #endif
 	}
 
-	void session_impl::update_cache_buffer_chunk_size()
-	{
-		if (m_settings.get_int(settings_pack::cache_buffer_chunk_size) <= 0)
-			m_settings.set_int(settings_pack::cache_buffer_chunk_size, 1);
-	}
-
 	void session_impl::update_report_web_seed_downloads()
 	{
 		// if this flag changed, update all web seed connections

src/settings_pack.cpp

@@ -238,7 +238,7 @@ constexpr int CLOSE_FILE_INTERVAL = 0;
 		SET(choking_algorithm, settings_pack::fixed_slots_choker, nullptr),
 		SET(seed_choking_algorithm, settings_pack::round_robin, nullptr),
 		SET(cache_size, 1024, nullptr),
-		SET(cache_buffer_chunk_size, 0, &session_impl::update_cache_buffer_chunk_size),
+		DEPRECATED_SET(cache_buffer_chunk_size, 0, nullptr),
 		SET(cache_expiry, 300, nullptr),
 		SET(disk_io_write_mode, settings_pack::enable_os_cache, nullptr),
 		SET(disk_io_read_mode, settings_pack::enable_os_cache, nullptr),