Initial Commit

include/asio/ssl/detail/buffered_handshake_op.hpp

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+//
+// ssl/detail/buffered_handshake_op.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2025 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_SSL_DETAIL_BUFFERED_HANDSHAKE_OP_HPP
+#define ASIO_SSL_DETAIL_BUFFERED_HANDSHAKE_OP_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#include "asio/ssl/detail/engine.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace ssl {
+namespace detail {
+
+template <typename ConstBufferSequence>
+class buffered_handshake_op
+{
+public:
+  static constexpr const char* tracking_name()
+  {
+    return "ssl::stream<>::async_buffered_handshake";
+  }
+
+  buffered_handshake_op(stream_base::handshake_type type,
+      const ConstBufferSequence& buffers)
+    : type_(type),
+      buffers_(buffers),
+      total_buffer_size_(asio::buffer_size(buffers_))
+  {
+  }
+
+  engine::want operator()(engine& eng,
+      asio::error_code& ec,
+      std::size_t& bytes_transferred) const
+  {
+    return this->process(eng, ec, bytes_transferred,
+        asio::buffer_sequence_begin(buffers_),
+        asio::buffer_sequence_end(buffers_));
+  }
+
+  template <typename Handler>
+  void call_handler(Handler& handler,
+      const asio::error_code& ec,
+      const std::size_t& bytes_transferred) const
+  {
+    static_cast<Handler&&>(handler)(ec, bytes_transferred);
+  }
+
+private:
+  template <typename Iterator>
+  engine::want process(engine& eng,
+      asio::error_code& ec,
+      std::size_t& bytes_transferred,
+      Iterator begin, Iterator end) const
+  {
+    Iterator iter = begin;
+    std::size_t accumulated_size = 0;
+
+    for (;;)
+    {
+      engine::want want = eng.handshake(type_, ec);
+      if (want != engine::want_input_and_retry
+          || bytes_transferred == total_buffer_size_)
+        return want;
+
+      // Find the next buffer piece to be fed to the engine.
+      while (iter != end)
+      {
+        const_buffer buffer(*iter);
+
+        // Skip over any buffers which have already been consumed by the engine.
+        if (bytes_transferred >= accumulated_size + buffer.size())
+        {
+          accumulated_size += buffer.size();
+          ++iter;
+          continue;
+        }
+
+        // The current buffer may have been partially consumed by the engine on
+        // a previous iteration. If so, adjust the buffer to point to the
+        // unused portion.
+        if (bytes_transferred > accumulated_size)
+          buffer = buffer + (bytes_transferred - accumulated_size);
+
+        // Pass the buffer to the engine, and update the bytes transferred to
+        // reflect the total number of bytes consumed so far.
+        bytes_transferred += buffer.size();
+        buffer = eng.put_input(buffer);
+        bytes_transferred -= buffer.size();
+        break;
+      }
+    }
+  }
+
+  stream_base::handshake_type type_;
+  ConstBufferSequence buffers_;
+  std::size_t total_buffer_size_;
+};
+
+} // namespace detail
+} // namespace ssl
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_SSL_DETAIL_BUFFERED_HANDSHAKE_OP_HPP