Refactor net buffers classes

beast/net/DynamicBuffer.h

@@ -0,0 +1,125 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_NET_DYNAMICBUFFER_H_INCLUDED
+#define BEAST_NET_DYNAMICBUFFER_H_INCLUDED
+
+#include <vector>
+
+namespace beast {
+
+/** Disjoint, but efficient buffer storage for network operations.
+    This is designed to not require asio in order to compile.
+*/
+class DynamicBuffer
+{
+public:
+    enum
+    {
+        defaultBlocksize = 32 * 1024
+    };
+
+    typedef std::size_t             size_type;
+
+    /** Create the dynamic buffer with the specified block size. */
+    explicit DynamicBuffer (size_type blocksize = defaultBlocksize);
+    
+    DynamicBuffer (DynamicBuffer const& other);
+
+    ~DynamicBuffer ();
+
+    DynamicBuffer& operator= (DynamicBuffer const& other);
+
+    /** Swap the contents of this buffer with another.
+        This is the preferred way to transfer ownership.
+    */
+    void swapWith (DynamicBuffer& other);
+
+    /** Returns the size of the input sequence. */
+    size_type size () const;
+
+    /** Returns a buffer to the input sequence.
+        ConstBufferType must be constructible with this signature:
+            ConstBufferType (void const* buffer, size_type bytes);
+    */
+    template <typename ConstBufferType>
+    std::vector <ConstBufferType> data () const
+    {
+        std::vector <ConstBufferType> buffers;
+        buffers.reserve (m_buffers.size());
+        size_type amount (m_size);
+        for (typename Buffers::const_iterator iter (m_buffers.begin());
+            amount > 0 && iter != m_buffers.end(); ++iter)
+        {
+            size_type const n (std::min (amount, m_blocksize));
+            buffers.push_back (ConstBufferType (*iter, n));
+            amount -= n;
+        }
+        return buffers;
+    }
+
+    /** Reserve space in the output sequence.
+        This also returns a buffer suitable for writing.
+        MutableBufferType must be constructible with this signature:
+            MutableBufferType (void* buffer, size_type bytes);
+    */
+    template <typename MutableBufferType>
+    std::vector <MutableBufferType> prepare (size_type amount)
+    {
+        std::vector <MutableBufferType> buffers;
+        buffers.reserve (m_buffers.size());
+        reserve (amount);
+        size_type offset (m_size % m_blocksize);
+        for (Buffers::iterator iter = m_buffers.begin () + (m_size / m_blocksize);
+            amount > 0 && iter != m_buffers.end (); ++iter)
+        {
+            size_type const n (std::min (amount, m_blocksize - offset));
+            buffers.push_back (MutableBufferType (
+                ((static_cast <char*> (*iter)) + offset), n));
+            amount -= n;
+            offset = 0;
+        }
+        return buffers;
+    }
+
+    /** Reserve space in the output sequence. */
+    void reserve (size_type n);
+
+    /** Move bytes from the output to the input sequence. */
+    void commit (size_type n);
+
+    /** Release memory while preserving the input sequence. */
+    void shrink_to_fit ();
+
+    /** Convert the entire buffer into a single string.
+        This is mostly for diagnostics, it defeats the purpose of the class!
+    */
+    std::string to_string () const;
+
+private:
+    typedef std::vector <void*> Buffers;
+
+    size_type m_blocksize;
+    size_type m_size;
+    Buffers m_buffers;
+};
+
+}
+
+#endif