drain_buffer is removed (API Change):

* The drain_buffer dynamic buffer is no longer a public interface.

Actions Required:

* Replace code which uses drain_buffer. For websocket::stream,
  it is no longer necessary to manually drain the connection
  after closing.

CHANGELOG.md

@@ -21,11 +21,17 @@ API Changes:
 * Calls to stream::close and stream::async_close will
   automatically perform the required read operations
 
+* drain_buffer is removed
+
 Actions Required:
 
 * Remove calling code which drains the connection after
   calling stream::close or stream::async_close
 
+* Replace code which uses drain_buffer. For websocket::stream,
+  it is no longer necessary to manually drain the connection
+  after closing.
+
 --------------------------------------------------------------------------------
 
 Version 99:

doc/qbk/03_core/3_buffers.qbk

@@ -50,15 +50,6 @@ of scenarios:
     output areas equal to the size of the underlying mutable buffer sequence.
     The implementation does not perform heap allocations.
 ]]
-[[
-    [link beast.ref.boost__beast__drain_buffer `drain_buffer`]
-][
-    A drain buffer has a small internal buffer and maximum size that
-    uses no dynamic allocation. It always has a size of zero, and
-    silently discards its input. This buffer may be passed to functions
-    which store data in a dynamic buffer when the caller wishes to
-    efficiently discard the data.
-]]
 [[
     [link beast.ref.boost__beast__flat_buffer `flat_buffer`]
     [link beast.ref.boost__beast__basic_flat_buffer `basic_flat_buffer`]

doc/qbk/07_concepts/DynamicBuffer.qbk

@@ -126,7 +126,6 @@ implementation strategies:
 
 * [link beast.ref.boost__beast__basic_flat_buffer `basic_flat_buffer`]
 * [link beast.ref.boost__beast__basic_multi_buffer `basic_multi_buffer`]
-* [link beast.ref.boost__beast__drain_buffer `drain_buffer`]
 * [link beast.ref.boost__beast__flat_buffer `flat_buffer`]
 * [link beast.ref.boost__beast__flat_static_buffer `flat_static_buffer`]
 * [link beast.ref.boost__beast__flat_static_buffer_base `flat_static_buffer_base`]

doc/qbk/quickref.xml

@@ -183,7 +183,6 @@
             <member><link linkend="beast.ref.boost__beast__buffered_read_stream">buffered_read_stream</link></member>
             <member><link linkend="beast.ref.boost__beast__buffers_adapter">buffers_adapter</link></member>
             <member><link linkend="beast.ref.boost__beast__consuming_buffers">consuming_buffers</link></member>
-            <member><link linkend="beast.ref.boost__beast__drain_buffer">drain_buffer</link></member>
             <member><link linkend="beast.ref.boost__beast__file">file</link></member>
             <member><link linkend="beast.ref.boost__beast__file_mode">file_mode</link></member>
             <member><link linkend="beast.ref.boost__beast__file_posix">file_posix</link></member>

include/boost/beast/core.hpp

@@ -19,7 +19,6 @@
 #include <boost/beast/core/buffered_read_stream.hpp>
 #include <boost/beast/core/buffers_adapter.hpp>
 #include <boost/beast/core/consuming_buffers.hpp>
-#include <boost/beast/core/drain_buffer.hpp>
 #include <boost/beast/core/error.hpp>
 #include <boost/beast/core/file.hpp>
 #include <boost/beast/core/file_base.hpp>

include/boost/beast/core/drain_buffer.hpp

@@ -1,127 +0,0 @@
-//
-// Copyright (c) 2016-2017 Vinnie Falco (vinnie dot falco at gmail 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)
-//
-// Official repository: https://github.com/boostorg/beast
-//
-
-#ifndef BOOST_BEAST_DRAIN_BUFFER_HPP
-#define BOOST_BEAST_DRAIN_BUFFER_HPP
-
-#include <boost/beast/config.hpp>
-#include <boost/asio/buffer.hpp>
-#include <boost/throw_exception.hpp>
-
-namespace boost {
-namespace beast {
-
-/** A @b DynamicBuffer which does not retain its input sequence.
-
-    This object implements a dynamic buffer with a fixed size
-    output area, not dynamically allocated, and whose input
-    sequence is always length zero. Bytes committed from the
-    output area to the input area are always discarded. This
-    is useful for calling interfaces that require a dynamic
-    buffer for storage, but where the caller does not want
-    to retain the data.
-*/
-class drain_buffer
-{
-    char buf_[512];
-    std::size_t n_ = 0;
-
-public:
-    /// The type used to represent the input sequence as a list of buffers.
-    using const_buffers_type = boost::asio::null_buffers;
-
-    /// The type used to represent the output sequence as a list of buffers.
-    using mutable_buffers_type = boost::asio::mutable_buffers_1;
-
-    /// Constructor
-    drain_buffer() = default;
-
-    /// Copy constructor
-    drain_buffer(drain_buffer const&)
-    {
-        // Previously returned ranges are invalidated
-    }
-
-    /// Copy assignment
-    drain_buffer&
-    operator=(drain_buffer const&)
-    {
-        n_ = 0;
-        return *this;
-    }
-
-    /// Return the size of the input sequence.
-    std::size_t
-    size() const
-    {
-        return 0;
-    }
-
-    /// Return the maximum sum of the input and output sequence sizes.
-    std::size_t
-    max_size() const
-    {
-        return sizeof(buf_);
-    }
-
-    /// Return the maximum sum of input and output sizes that can be held without an allocation.
-    std::size_t
-    capacity() const
-    {
-        return max_size();
-    }
-
-    /** Get a list of buffers that represent the input sequence.
-
-        @note These buffers remain valid across subsequent calls to `prepare`.
-    */
-    const_buffers_type
-    data() const
-    {
-        return {};
-    }
-
-    /** Get a list of buffers that represent the output sequence, with the given size.
-
-        @throws std::length_error if the size would exceed the buffer limit
-    */
-    mutable_buffers_type
-    prepare(std::size_t n)
-    {
-        if(n > sizeof(buf_))
-            BOOST_THROW_EXCEPTION(std::length_error{
-                "buffer overflow"});
-        n_ = n;
-        return {buf_, n_};
-    }
-
-    /** Move bytes from the output sequence to the input sequence.
-
-        This call always discards the output sequence.
-        The size of the input sequence will remain at zero.
-    */
-    void
-    commit(std::size_t)
-    {
-    }
-
-    /** Remove bytes from the input sequence.
-
-        This call has no effect.
-    */
-    void
-    consume(std::size_t)
-    {
-    }
-};
-
-} // beast
-} // boost
-
-#endif

test/beast/core/CMakeLists.txt

@@ -26,7 +26,6 @@ add_executable (tests-beast-core
     buffers_adapter.cpp
     clamp.cpp
     consuming_buffers.cpp
-    drain_buffer.cpp
     error.cpp
     file.cpp
     file_posix.cpp

test/beast/core/Jamfile

@@ -16,7 +16,6 @@ local SOURCES =
     buffers_adapter.cpp
     clamp.cpp
     consuming_buffers.cpp
-    drain_buffer.cpp
     error.cpp
     file.cpp
     file_posix.cpp

test/beast/core/drain_buffer.cpp

@@ -1,55 +0,0 @@
-//
-// Copyright (c) 2016-2017 Vinnie Falco (vinnie dot falco at gmail 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)
-//
-// Official repository: https://github.com/boostorg/beast
-//
-
-// Test that header file is self-contained.
-#include <boost/beast/core/drain_buffer.hpp>
-
-#include <boost/beast/core/type_traits.hpp>
-#include <boost/beast/unit_test/suite.hpp>
-
-namespace boost {
-namespace beast {
-
-static_assert(is_dynamic_buffer<drain_buffer>::value,
-    "DynamicBuffer requirements not met");
-
-class drain_buffer_test : public beast::unit_test::suite
-{
-public:
-    void
-    run() override
-    {
-        using boost::asio::buffer_size;
-        drain_buffer b;
-        BEAST_EXPECT(buffer_size(b.prepare(0)) == 0);
-        BEAST_EXPECT(buffer_size(b.prepare(100)) == 100);
-        try
-        {
-            b.prepare(b.max_size() + 1);
-            fail("", __FILE__, __LINE__);
-        }
-        catch(std::length_error const&)
-        {
-            pass();
-        }
-        b.prepare(10);
-        BEAST_EXPECT(b.size() == 0);
-        b.commit(10);
-        BEAST_EXPECT(b.size() == 0);
-        b.consume(10);
-        BEAST_EXPECT(b.size() == 0);
-        b.consume(1000);
-        BEAST_EXPECT(b.size() == 0);
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(beast,core,drain_buffer);
-
-} // beast
-} // boost

test/beast/core/read_size.cpp

@@ -10,7 +10,6 @@
 // Test that header file is self-contained.
 #include <boost/beast/core/read_size.hpp>
 
-#include <boost/beast/core/drain_buffer.hpp>
 #include <boost/beast/core/flat_buffer.hpp>
 #include <boost/beast/core/flat_static_buffer.hpp>
 #include <boost/beast/core/multi_buffer.hpp>
@@ -37,7 +36,6 @@ public:
     void
     run() override
     {
-        check<drain_buffer>();
         check<flat_buffer>();
         check<flat_static_buffer<1024>>();
         check<multi_buffer>();

test/example/server/tests.cpp

@@ -20,7 +20,6 @@
 # include "example/server-framework/wss_ports.hpp"
 #endif
 
-#include <boost/beast/core/drain_buffer.hpp>
 #include <boost/beast/websocket.hpp>
 #include <boost/beast/test/yield_to.hpp>
 #include <boost/beast/unit_test/suite.hpp>
@@ -107,16 +106,6 @@ public:
         ws.close(beast::websocket::close_code::normal, ec);
         if(! BEAST_EXPECTS(! ec, ec.message()))
             return;
-        // VFALCO Verify the buffer's contents
-        drain_buffer drain; 
-        for(;;)
-        {
-            ws.read(drain, ec);
-            if(ec == beast::websocket::error::closed)
-                break;
-            if(! BEAST_EXPECTS(! ec, ec.message()))
-                return;
-        }
     }
 
     void