Add support for passing client_data_t to flush_cache

include/libtorrent/alert_types.hpp

@@ -13,6 +13,7 @@ Copyright (c) 2019, ghbplayer
 Copyright (c) 2020, AllSeeingEyeTolledEweSew
 Copyright (c) 2020, Fonic
 Copyright (c) 2020, Viktor Elofsson
+Copyright (c) 2023, Joris Carrier
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -1891,11 +1892,16 @@ TORRENT_VERSION_NAMESPACE_3
  struct TORRENT_EXPORT cache_flushed_alert final : torrent_alert
  {
  // internal
- TORRENT_UNEXPORT cache_flushed_alert(aux::stack_allocator& alloc, torrent_handle const& h);
+ TORRENT_UNEXPORT cache_flushed_alert(aux::stack_allocator& alloc,
+ torrent_handle const& h, client_data_t userdata = {});
 
  TORRENT_DEFINE_ALERT_PRIO(cache_flushed_alert, 58, alert_priority::high)
 
  static constexpr alert_category_t static_category = alert_category::storage;
+
+ // '`userdata`` as set in torrent_handle::flush_cache on call.
+ // This can be used to associate the call with related data.
+ client_data_t userdata;
  };
 
 #if TORRENT_ABI_VERSION == 1

include/libtorrent/torrent.hpp

@@ -12,6 +12,7 @@ Copyright (c) 2018, d-komarov
 Copyright (c) 2019, ghbplayer
 Copyright (c) 2020, Paul-Louis Ageneau
 Copyright (c) 2021, AdvenT
+Copyright (c) 2023, Joris Carrier
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -563,7 +564,7 @@ namespace libtorrent {
  bool has_error() const { return !!m_error; }
  error_code error() const { return m_error; }
 
- void flush_cache();
+ void flush_cache(client_data_t userdata = {});
  void pause(pause_flags_t flags = {});
  void resume();
 
@@ -1307,7 +1308,7 @@ namespace libtorrent {
  void on_file_renamed(std::string const& filename
  , file_index_t file_idx
  , storage_error const& error);
- void on_cache_flushed(bool manually_triggered);
+ void on_cache_flushed(bool manually_triggered, client_data_t userdata = {});
 
  // this is used when a torrent is being removed.It synchronizes with the
  // disk thread

include/libtorrent/torrent_handle.hpp

@@ -9,6 +9,7 @@ Copyright (c) 2017, 2020, AllSeeingEyeTolledEweSew
 Copyright (c) 2017, Falcosc
 Copyright (c) 2019, Andrei Kurushin
 Copyright (c) 2019, ghbplayer
+Copyright (c) 2023, Joris Carrier
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -652,13 +653,15 @@ namespace aux {
 
  // Instructs libtorrent to flush all the disk caches for this torrent and
  // close all file handles. This is done asynchronously and you will be
- // notified that it's complete through cache_flushed_alert.
+ // notified that it's complete through cache_flushed_alert
+ // with custom data (client_data_t) to be associated with this operation.
  //
  // Note that by the time you get the alert, libtorrent may have cached
  // more data for the torrent, but you are guaranteed that whatever cached
  // data libtorrent had by the time you called
- // ``torrent_handle::flush_cache()`` has been written to disk.
- void flush_cache() const;
+ // ``torrent_handle::flush_cache(client_data_t)`` with the provided client_data_t
+ // has been written to disk.
+ void flush_cache(client_data_t userdata = {}) const;
 
  // ``force_recheck`` puts the torrent back in a state where it assumes to
  // have no resume data. All peers will be disconnected and the torrent

src/alert.cpp

@@ -1561,8 +1561,9 @@ namespace {
 #endif // TORRENT_ABI_VERSION
 
  cache_flushed_alert::cache_flushed_alert(aux::stack_allocator& alloc
- , torrent_handle const& h)
- : torrent_alert(alloc, h) {}
+ , torrent_handle const& h, client_data_t u)
+ : torrent_alert(alloc, h)
+ , userdata(u) {}
 
 #if TORRENT_ABI_VERSION == 1
  anonymous_mode_alert::anonymous_mode_alert(aux::stack_allocator& alloc

src/torrent.cpp

@@ -18,7 +18,7 @@ Copyright (c) 2018, airium
 Copyright (c) 2018, d-komarov
 Copyright (c) 2020, Paul-Louis Ageneau
 Copyright (c) 2021, AdvenT
-Copyright (c) 2021, Joris CARRIER
+Copyright (c) 2021, 2023, Joris CARRIER
 Copyright (c) 2021, thrnz
 All rights reserved.
 
@@ -8397,7 +8397,7 @@ namespace {
  {
  // we need to keep the object alive during this operation
  m_ses.disk_thread().async_release_files(m_storage
- , std::bind(&torrent::on_cache_flushed, shared_from_this(), false));
+ , std::bind(&torrent::on_cache_flushed, shared_from_this(), false, client_data_t()));
  m_ses.deferred_submit_jobs();
  }
 
@@ -9462,7 +9462,7 @@ namespace {
  && !m_session_paused;
  }
 
- void torrent::flush_cache()
+ void torrent::flush_cache(client_data_t userdata)
  {
  TORRENT_ASSERT(is_single_thread());
 
@@ -9473,18 +9473,18 @@ namespace {
  return;
  }
  m_ses.disk_thread().async_release_files(m_storage
- , std::bind(&torrent::on_cache_flushed, shared_from_this(), true));
+ , std::bind(&torrent::on_cache_flushed, shared_from_this(), true, userdata));
  m_ses.deferred_submit_jobs();
  }
 
- void torrent::on_cache_flushed(bool const manually_triggered) try
+ void torrent::on_cache_flushed(bool const manually_triggered, client_data_t userdata) try
  {
  TORRENT_ASSERT(is_single_thread());
 
  if (m_ses.is_aborted()) return;
 
  if (manually_triggered || alerts().should_post<cache_flushed_alert>())
- alerts().emplace_alert<cache_flushed_alert>(get_handle());
+ alerts().emplace_alert<cache_flushed_alert>(get_handle(), userdata);
  }
  catch (...) { handle_exception(); }
 

src/torrent_handle.cpp

@@ -8,6 +8,7 @@ Copyright (c) 2017, Falcosc
 Copyright (c) 2018, Steven Siloti
 Copyright (c) 2019, Andrei Kurushin
 Copyright (c) 2019, ghbplayer
+Copyright (c) 2023, Joris Carrier
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -356,9 +357,9 @@ namespace libtorrent {
  { async_call(&torrent::set_sequential_download, sd); }
 #endif
 
- void torrent_handle::flush_cache() const
+ void torrent_handle::flush_cache(client_data_t userdata) const
  {
- async_call(&torrent::flush_cache);
+ async_call(&torrent::flush_cache, userdata);
  }
 
  void torrent_handle::set_ssl_certificate(