Add span_body

include/beast/core/span.hpp

@@ -190,7 +190,7 @@ public:
     {
         return data_;
     }
-        
+       
     /// Returns an iterator to one past the end of the span
     const_iterator
     end() const

include/beast/http.hpp

@@ -23,6 +23,7 @@
 #include <beast/http/read.hpp>
 #include <beast/http/rfc7230.hpp>
 #include <beast/http/serializer.hpp>
+#include <beast/http/span_body.hpp>
 #include <beast/http/status.hpp>
 #include <beast/http/string_body.hpp>
 #include <beast/http/string_view_body.hpp>

include/beast/http/span_body.hpp

@@ -0,0 +1,167 @@
+//
+// Copyright (c) 2013-2017 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)
+//
+
+#ifndef BEAST_HTTP_SPAN_BODY_HPP
+#define BEAST_HTTP_SPAN_BODY_HPP
+
+#include <beast/config.hpp>
+#include <beast/core/span.hpp>
+#include <beast/http/error.hpp>
+#include <beast/http/message.hpp>
+#include <boost/optional.hpp>
+
+namespace beast {
+namespace http {
+
+/** A @b Body using @ref span
+
+    This body uses @ref span as a memory-based container for
+    holding message payloads. The container represents a
+    non-owning reference to a continguous area of memory.
+    Messages using this body type may be serialized and
+    parsed.
+
+    Unlike @ref buffer_body, only one buffer may be provided
+    during a parse or serialize operation.
+*/
+template<class T>
+struct span_body
+{
+private:
+    static_assert(std::is_pod<T>::value,
+        "POD requirements not met");
+
+public:
+    /** The type of container used for the body
+
+        This determines the type of @ref message::body
+        when this body type is used with a message container.
+    */
+    using value_type = span<T>;
+
+    /** Returns the payload size of the body
+
+        When this body is used with @ref message::prepare_payload,
+        the Content-Length will be set to the payload size, and
+        any chunked Transfer-Encoding will be removed.
+    */
+    static
+    std::uint64_t
+    size(value_type const& body)
+    {
+        return body.size();
+    }
+
+    /** The algorithm for serializing the body
+
+        Meets the requirements of @b BodyReader.
+    */
+#if BEAST_DOXYGEN
+    using reader = implementation_defined;
+#else
+    class reader
+    {
+        value_type const& body_;
+
+    public:
+        using const_buffers_type =
+            boost::asio::const_buffers_1;
+
+        template<bool isRequest, class Fields>
+        explicit
+        reader(message<isRequest,
+                span_body, Fields> const& msg)
+            : body_(msg.body)
+        {
+        }
+
+        void
+        init(error_code& ec)
+        {
+            ec.assign(0, ec.category());
+        }
+
+        boost::optional<std::pair<const_buffers_type, bool>>
+        get(error_code& ec)
+        {
+            ec.assign(0, ec.category());
+            return {{
+                { body_.data(),
+                  body_.size() * sizeof(typename
+                    value_type::value_type)},
+                false}};
+        }
+    };
+#endif
+
+    /** The algorithm for parsing the body
+
+        Meets the requirements of @b BodyReader.
+    */
+#if BEAST_DOXYGEN
+    using writer = implementation_defined;
+#else
+    class writer
+    {
+        value_type& body_;
+
+    public:
+        template<bool isRequest, class Fields>
+        explicit
+        writer(message<isRequest,
+                span_body, Fields>& m)
+            : body_(m.body)
+        {
+        }
+
+        void
+        init(boost::optional<
+            std::uint64_t> const& length, error_code& ec)
+        {
+            if(length && *length > body_.size())
+            {
+                ec = error::buffer_overflow;
+                return;
+            }
+            ec.assign(0, ec.category());
+        }
+
+        template<class ConstBufferSequence>
+        std::size_t
+        put(ConstBufferSequence const& buffers,
+            error_code& ec)
+        {
+            using boost::asio::buffer_size;
+            using boost::asio::buffer_copy;
+            auto const n = buffer_size(buffers);
+            auto const len = body_.size();
+            if(n > len)
+            {
+                ec = error::buffer_overflow;
+                return 0;
+            }
+            ec.assign(0, ec.category());
+            buffer_copy(boost::asio::buffer(
+                body_.data(), n), buffers);
+            body_ = value_type{
+                body_.data() + n, body_.size() - n};
+            return n;
+        }
+
+        void
+        finish(error_code& ec)
+        {
+            ec.assign(0, ec.category());
+        }
+    };
+#endif
+};
+
+} // http
+} // beast
+
+#endif