Implemented read piece callbacks in torrent handling.

include/libtorrent/alert_types.hpp

@@ -306,13 +306,13 @@ TORRENT_VERSION_NAMESPACE_3
  // number of bytes that was read.
  //
  // If the operation fails, ``error`` will indicate what went wrong.
- struct TORRENT_EXPORT read_piece_alert final : torrent_alert
+ struct TORRENT_EXPORT read_piece_alert final : torrent_alert, callback_t<read_piece_alert>
  {
  // internal
  TORRENT_UNEXPORT read_piece_alert(aux::stack_allocator& alloc, torrent_handle const& h
- , piece_index_t p, boost::shared_array<char> d, int s);
+ , piece_index_t p, boost::shared_array<char> d, int s, callback_t<read_piece_alert>::type callback = {});
  TORRENT_UNEXPORT read_piece_alert(aux::stack_allocator& alloc, torrent_handle h
- , piece_index_t p, error_code e);
+ , piece_index_t p, error_code e, callback_t<read_piece_alert>::type callback = {});
 
  TORRENT_DEFINE_ALERT_PRIO(read_piece_alert, 5, alert_priority::critical)
 

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
@@ -485,8 +486,9 @@ namespace libtorrent {
  int blocks_left;
  bool fail;
  error_code error;
+ callback_t<read_piece_alert>::type callback;
  };
- void read_piece(piece_index_t);
+ void read_piece(piece_index_t, callback_t<read_piece_alert>::type callback = {});
  void on_disk_read_complete(disk_buffer_holder, storage_error const&
  , peer_request const&, std::shared_ptr<read_piece_struct>);
 

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
@@ -69,6 +70,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/pex_flags.hpp"
 #include "libtorrent/client_data.hpp"
 #include "libtorrent/address.hpp" // for address_v4 and address_v6
+#include "libtorrent/alert.hpp" // for callback_t
 
 namespace libtorrent {
 namespace aux {
@@ -85,6 +87,8 @@ namespace aux {
  [[noreturn]] void throw_invalid_handle();
 #endif
 
+ struct read_piece_alert;
+
  using status_flags_t = flags::bitfield_flag<std::uint32_t, struct status_flags_tag>;
  using add_piece_flags_t = flags::bitfield_flag<std::uint8_t, struct add_piece_flags_tag>;
  using pause_flags_t = flags::bitfield_flag<std::uint8_t, struct pause_flags_tag>;
@@ -309,7 +313,7 @@ namespace aux {
  //
  // Note that if you read multiple pieces, the read operations are not
  // guaranteed to finish in the same order as you initiated them.
- void read_piece(piece_index_t piece) const;
+ void read_piece(piece_index_t piece, callback_t<read_piece_alert>::type callback = {}) const;
 
  // Returns true if this piece has been completely downloaded and written
  // to disk, and false otherwise.

src/alert.cpp

@@ -200,19 +200,23 @@ namespace libtorrent {
 
  read_piece_alert::read_piece_alert(aux::stack_allocator& alloc
  , torrent_handle const& h
- , piece_index_t p, boost::shared_array<char> d, int s)
+ , piece_index_t p, boost::shared_array<char> d, int s
+ , callback_t<read_piece_alert>::type c)
  : torrent_alert(alloc, h)
  , buffer(std::move(d))
  , piece(p)
  , size(s)
+ , callback_t<read_piece_alert>(std::move(c))
  {}
 
  read_piece_alert::read_piece_alert(aux::stack_allocator& alloc
- , torrent_handle h, piece_index_t p, error_code e)
+ , torrent_handle h, piece_index_t p, error_code e
+ , callback_t<read_piece_alert>::type c)
  : torrent_alert(alloc, h)
  , error(e)
  , piece(p)
  , size(0)
+ , callback_t<read_piece_alert>(std::move(c))
 #if TORRENT_ABI_VERSION == 1
  , ec(e)
 #endif

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.
 
@@ -743,7 +743,7 @@ bool is_downloading_state(int const st)
  m_ses.close_connection(p);
  }
 
- void torrent::read_piece(piece_index_t const piece)
+ void torrent::read_piece(piece_index_t const piece, callback_t<read_piece_alert>::type callback)
  {
  error_code ec;
  if (m_abort || m_deleted)
@@ -761,7 +761,7 @@ bool is_downloading_state(int const st)
 
  if (ec)
  {
- m_ses.alerts().emplace_alert<read_piece_alert>(get_handle(), piece, ec);
+ m_ses.alerts().emplace_alert<read_piece_alert>(get_handle(), piece, ec, callback);
  return;
  }
 
@@ -776,7 +776,7 @@ bool is_downloading_state(int const st)
  // this shouldn't actually happen
  boost::shared_array<char> buf;
  m_ses.alerts().emplace_alert<read_piece_alert>(
- get_handle(), piece, buf, 0);
+ get_handle(), piece, buf, 0, callback);
  return;
  }
 
@@ -785,11 +785,12 @@ bool is_downloading_state(int const st)
  if (!rp->piece_data)
  {
  m_ses.alerts().emplace_alert<read_piece_alert>(
- get_handle(), piece, error_code(boost::system::errc::not_enough_memory, generic_category()));
+ get_handle(), piece, error_code(boost::system::errc::not_enough_memory, generic_category()), callback);
  return;
  }
  rp->blocks_left = blocks_in_piece;
  rp->fail = false;
+ rp->callback = callback;
 
  disk_job_flags_t flags{};
  auto const read_mode = settings().get_int(settings_pack::disk_io_read_mode);
@@ -1216,12 +1217,12 @@ bool is_downloading_state(int const st)
  if (rp->fail)
  {
  m_ses.alerts().emplace_alert<read_piece_alert>(
- get_handle(), r.piece, rp->error);
+ get_handle(), r.piece, rp->error, rp->callback);
  }
  else
  {
  m_ses.alerts().emplace_alert<read_piece_alert>(
- get_handle(), r.piece, rp->piece_data, size);
+ get_handle(), r.piece, rp->piece_data, size, rp->callback);
  }
  }
  }

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
@@ -742,9 +743,9 @@ namespace libtorrent {
  async_call(&torrent::add_piece_async, piece, std::move(data), flags);
  }
 
- void torrent_handle::read_piece(piece_index_t piece) const
+ void torrent_handle::read_piece(piece_index_t piece, callback_t<read_piece_alert>::type callback) const
  {
- async_call(&torrent::read_piece, piece);
+ async_call(&torrent::read_piece, piece, callback);
  }
 
  bool torrent_handle::have_piece(piece_index_t piece) const