[coro_rpc][feature] support complete handler

[poor-circle]

Why

What is changing

1. fix example
2. add more document
3. add support for coro_rpc_server to set complete callback, When the server successfully writes the RPC response data to the socket, the complete callback function is invoked. Users can set this callback function for logging, statistics, etc. Moreover, when the return value of the RPC function includes types like std::string_view or std::span, this callback function can be used to destruct objects at an appropriate time.

Example

void foo() {
  auto ctx = coro_rpc::get_context();
  ctx->set_response_handler([](const std::error_code& ec, std::size_t length) {
    if (ec) {
      std::cout << "error: " << ec.message() << std::endl;
    } else {
      std::cout << "ok: wrote " << length << " bytes" << std::endl;
    }
  });
  return;
}

std::string_view hello() {
  auto ctx = coro_rpc::get_context();
  auto str = std::make_unique<std::string>("Hello");
  ctx->set_response_handler([str = std::move(str)](const std::error_code& ec, std::size_t length) {
    if (ec) {
      std::cout << "error: " << ec.message() << std::endl;
    } else {
      std::cout << "ok: write " << length << " bytes" << std::endl;
    }
  });
  return *str; /*this is safe*/
}

[github-actions]

Code Coverage Report
for detail, goto summary download Artifacts

Filename                                          Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
coro_io/channel.hpp                                      14                 0   100.00%         105                 3    97.14%          30                 2    93.33%
coro_io/client_pool.hpp                                  28                 0   100.00%         352                48    86.36%         106                32    69.81%
coro_io/coro_file.hpp                                    24                 4    83.33%         216                46    78.70%          56                21    62.50%
coro_io/coro_io.hpp                                      53                 4    92.45%         371                63    83.02%           6                 1    83.33%
coro_io/detail/client_queue.hpp                          10                 1    90.00%          47                 1    97.87%          10                 1    90.00%
coro_io/io_context_pool.hpp                              37                 5    86.49%         215                26    87.91%          28                 8    71.43%
coro_io/rate_limiter.hpp                                 13                 1    92.31%          85                 9    89.41%           8                 3    62.50%
coro_rpc/impl/common_service.hpp                          3                 0   100.00%          55                 0   100.00%          26                 7    73.08%
coro_rpc/impl/context.hpp                                 8                 0   100.00%         103                 6    94.17%          16                 6    62.50%
coro_rpc/impl/coro_connection.hpp                        45                10    77.78%         454                74    83.70%         112                38    66.07%
coro_rpc/impl/coro_rpc_client.hpp                        64                11    82.81%         706               117    83.43%         162                56    65.43%
coro_rpc/impl/coro_rpc_server.hpp                        21                 1    95.24%         237                29    87.76%          82                36    56.10%
coro_rpc/impl/errno.h                                    18                 4    77.78%          64                40    37.50%          36                16    55.56%
coro_rpc/impl/protocol/coro_rpc_protocol.hpp              9                 1    88.89%         101                32    68.32%          24                 9    62.50%
coro_rpc/impl/protocol/struct_pack_protocol.hpp           3                 0   100.00%          14                 0   100.00%           0                 0         -
coro_rpc/impl/router.hpp                                 22                 0   100.00%         221                13    94.12%          26                13    50.00%
coro_rpc/impl/rpc_execute.hpp                             3                 0   100.00%         172                 0   100.00%           4                 1    75.00%
easylog.hpp                                              17                 0   100.00%          73                 3    95.89%          14                 5    64.29%
easylog/appender.hpp                                     23                 0   100.00%         275                16    94.18%          90                25    72.22%
easylog/record.hpp                                       17                 0   100.00%         121                14    88.43%          16                 2    87.50%
struct_pack.hpp                                          35                 2    94.29%         320                28    91.25%          34                14    58.82%
struct_pack/alignment.hpp                                 9                 9     0.00%         136               136     0.00%           0                 0         -
struct_pack/calculate_size.hpp                           21                 5    76.19%         405                81    80.00%          32                 7    78.12%
struct_pack/compatible.hpp                                6                 0   100.00%           9                 0   100.00%           6                 2    66.67%
struct_pack/derived_helper.hpp                           14                 7    50.00%         127                61    51.97%           6                 3    50.00%
struct_pack/endian_wrapper.hpp                            9                 3    66.67%         152                28    81.58%           2                 1    50.00%
struct_pack/error_code.hpp                               11                 6    45.45%          38                30    21.05%           0                 0         -
struct_pack/foreach_macro.h                               1                 0   100.00%           1                 0   100.00%           0                 0         -
struct_pack/md5_constexpr.hpp                            27                 3    88.89%         174                18    89.66%          32                 1    96.88%
struct_pack/packer.hpp                                   23                 2    91.30%         495                20    95.96%          48                 9    81.25%
struct_pack/reflection.hpp                               17                10    41.18%        8605              5158    40.06%         514               251    51.17%
struct_pack/size_info.hpp                                 2                 0   100.00%          10                 0   100.00%           0                 0         -
struct_pack/trivial_view.hpp                              4                 0   100.00%          10                 0   100.00%           0                 0         -
struct_pack/tuple.hpp                                    21                 2    90.48%          54                 4    92.59%           6                 3    50.00%
struct_pack/type_calculate.hpp                           37                30    18.92%         753               576    23.51%           0                 0         -
struct_pack/type_id.hpp                                   4                 4     0.00%         277               277     0.00%           0                 0         -
struct_pack/unpacker.hpp                                 50                 5    90.00%        1296               141    89.12%         212                89    58.02%
struct_pack/user_helper.hpp                               6                 0   100.00%          63                 2    96.83%           2                 1    50.00%
struct_pack/util.h                                       12                 7    41.67%         105                61    41.90%           2                 0   100.00%
struct_pack/varint.hpp                                   23                 3    86.96%         147                14    90.48%          12                 3    75.00%
util/concurrentqueue.h                                   79                19    75.95%        1256               554    55.89%         292               151    48.29%
util/dragonbox.h                                         90                50    44.44%         735               388    47.21%          38                34    10.53%
util/dragonbox_to_chars.h                                 6                 1    83.33%         440               365    17.05%          54                43    20.37%
util/expected.hpp                                        93                 8    91.40%         248                38    84.68%          44                17    61.36%
util/function_name.h                                      2                 1    50.00%          22                 7    68.18%           0                 0         -
util/magic_names.hpp                                      1                 1     0.00%          56                56     0.00%           0                 0         -
util/meta_string.hpp                                     10                 3    70.00%          46                23    50.00%           8                 0   100.00%
util/time_util.h                                         21                12    42.86%         184               119    35.33%          26                 5    80.77%
util/type_traits.h                                        1                 0   100.00%           9                 0   100.00%           0                 0         -

Files which contain no functions:
struct_pack/marco.h                                       0                 0         -           0                 0         -           0                 0         -
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                  1067               235    77.98%       20160              8725    56.72%        2222               916    58.78%

[github-actions]

Code Coverage Report
for detail, goto summary download Artifacts

Filename                                          Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
coro_io/channel.hpp                                      14                 0   100.00%         105                 3    97.14%          30                 2    93.33%
coro_io/client_pool.hpp                                  28                 0   100.00%         352                48    86.36%         106                34    67.92%
coro_io/coro_file.hpp                                    24                 4    83.33%         216                46    78.70%          56                21    62.50%
coro_io/coro_io.hpp                                      53                 4    92.45%         371                63    83.02%           6                 1    83.33%
coro_io/detail/client_queue.hpp                          10                 1    90.00%          47                 5    89.36%          10                 1    90.00%
coro_io/io_context_pool.hpp                              37                 5    86.49%         215                26    87.91%          28                 8    71.43%
coro_io/rate_limiter.hpp                                 13                 1    92.31%          85                 9    89.41%           8                 3    62.50%
coro_rpc/impl/common_service.hpp                          3                 0   100.00%          55                 0   100.00%          26                 7    73.08%
coro_rpc/impl/context.hpp                                 8                 0   100.00%         103                 6    94.17%          16                 6    62.50%
coro_rpc/impl/coro_connection.hpp                        45                10    77.78%         454                74    83.70%         112                38    66.07%
coro_rpc/impl/coro_rpc_client.hpp                        64                11    82.81%         706               117    83.43%         162                56    65.43%
coro_rpc/impl/coro_rpc_server.hpp                        21                 1    95.24%         237                29    87.76%          82                36    56.10%
coro_rpc/impl/errno.h                                    18                 4    77.78%          64                40    37.50%          36                16    55.56%
coro_rpc/impl/protocol/coro_rpc_protocol.hpp              9                 1    88.89%         101                32    68.32%          24                 9    62.50%
coro_rpc/impl/protocol/struct_pack_protocol.hpp           3                 0   100.00%          14                 0   100.00%           0                 0         -
coro_rpc/impl/router.hpp                                 22                 0   100.00%         221                13    94.12%          26                13    50.00%
coro_rpc/impl/rpc_execute.hpp                             3                 0   100.00%         172                 0   100.00%           4                 1    75.00%
easylog.hpp                                              17                 0   100.00%          73                 3    95.89%          14                 5    64.29%
easylog/appender.hpp                                     23                 0   100.00%         275                16    94.18%          90                25    72.22%
easylog/record.hpp                                       17                 0   100.00%         121                14    88.43%          16                 2    87.50%
struct_pack.hpp                                          35                 2    94.29%         320                28    91.25%          34                14    58.82%
struct_pack/alignment.hpp                                 9                 9     0.00%         136               136     0.00%           0                 0         -
struct_pack/calculate_size.hpp                           21                 5    76.19%         405                81    80.00%          32                 7    78.12%
struct_pack/compatible.hpp                                6                 0   100.00%           9                 0   100.00%           6                 2    66.67%
struct_pack/derived_helper.hpp                           14                 7    50.00%         127                61    51.97%           6                 3    50.00%
struct_pack/endian_wrapper.hpp                            9                 3    66.67%         152                28    81.58%           2                 1    50.00%
struct_pack/error_code.hpp                               11                 6    45.45%          38                30    21.05%           0                 0         -
struct_pack/foreach_macro.h                               1                 0   100.00%           1                 0   100.00%           0                 0         -
struct_pack/md5_constexpr.hpp                            27                 3    88.89%         174                18    89.66%          32                 1    96.88%
struct_pack/packer.hpp                                   23                 2    91.30%         495                20    95.96%          48                 9    81.25%
struct_pack/reflection.hpp                               17                10    41.18%        8605              5158    40.06%         514               251    51.17%
struct_pack/size_info.hpp                                 2                 0   100.00%          10                 0   100.00%           0                 0         -
struct_pack/trivial_view.hpp                              4                 0   100.00%          10                 0   100.00%           0                 0         -
struct_pack/tuple.hpp                                    21                 2    90.48%          54                 4    92.59%           6                 3    50.00%
struct_pack/type_calculate.hpp                           37                30    18.92%         753               576    23.51%           0                 0         -
struct_pack/type_id.hpp                                   4                 4     0.00%         277               277     0.00%           0                 0         -
struct_pack/unpacker.hpp                                 50                 5    90.00%        1296               141    89.12%         212                89    58.02%
struct_pack/user_helper.hpp                               6                 0   100.00%          63                 2    96.83%           2                 1    50.00%
struct_pack/util.h                                       12                 7    41.67%         105                61    41.90%           2                 0   100.00%
struct_pack/varint.hpp                                   23                 3    86.96%         147                14    90.48%          12                 3    75.00%
util/concurrentqueue.h                                   79                19    75.95%        1256               565    55.02%         292               150    48.63%
util/dragonbox.h                                         90                50    44.44%         735               388    47.21%          38                34    10.53%
util/dragonbox_to_chars.h                                 6                 1    83.33%         440               365    17.05%          54                43    20.37%
util/expected.hpp                                        93                 8    91.40%         248                38    84.68%          44                17    61.36%
util/function_name.h                                      2                 1    50.00%          22                 7    68.18%           0                 0         -
util/magic_names.hpp                                      1                 1     0.00%          56                56     0.00%           0                 0         -
util/meta_string.hpp                                     10                 3    70.00%          46                23    50.00%           8                 0   100.00%
util/time_util.h                                         21                12    42.86%         184               119    35.33%          26                 5    80.77%
util/type_traits.h                                        1                 0   100.00%           9                 0   100.00%           0                 0         -

Files which contain no functions:
struct_pack/marco.h                                       0                 0         -           0                 0         -           0                 0         -
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                  1067               235    77.98%       20160              8740    56.65%        2222               917    58.73%