sbuffer.hpp

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//
// MessagePack for C++ simple buffer implementation
//
// Copyright (C) 2008-2016 FURUHASHI Sadayuki and KONDO Takatoshi
//
//    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 MSGPACK_V1_SBUFFER_HPP
#define MSGPACK_V1_SBUFFER_HPP
 
#include "msgpack/v1/cpp_config_decl.hpp"
#include "msgpack/v1/sbuffer_decl.hpp"
#include "msgpack/assert.hpp"
 
#include <stdexcept>
#include <cstring>
 
namespace msgpack {

MSGPACK_API_VERSION_NAMESPACE(v1) {
 
class sbuffer {
public:
    sbuffer(size_t initsz = MSGPACK_SBUFFER_INIT_SIZE):m_size(0), m_alloc(initsz)
    {
        if(initsz == 0) {
            m_data = MSGPACK_NULLPTR;
        } else {
            m_data = (char*)::malloc(initsz);
            if(!m_data) {
                throw std::bad_alloc();
            }
        }
    }
 
    ~sbuffer()
    {
        ::free(m_data);
    }
 
#if !defined(MSGPACK_USE_CPP03)
    sbuffer(const sbuffer&) = delete;
    sbuffer& operator=(const sbuffer&) = delete;
 
    sbuffer(sbuffer&& other) :
        m_size(other.m_size), m_data(other.m_data), m_alloc(other.m_alloc)
    {
        other.m_size = other.m_alloc = 0;
        other.m_data = MSGPACK_NULLPTR;
    }
 
    sbuffer& operator=(sbuffer&& other)
    {
        ::free(m_data);
 
        m_size = other.m_size;
        m_alloc = other.m_alloc;
        m_data = other.m_data;
 
        other.m_size = other.m_alloc = 0;
        other.m_data = MSGPACK_NULLPTR;
 
        return *this;
    }
#endif // !defined(MSGPACK_USE_CPP03)
 
    void write(const char* buf, size_t len)
    {
        MSGPACK_ASSERT(buf || len == 0);
 
        if (!buf) return;
 
        if(m_alloc - m_size < len) {
            expand_buffer(len);
        }
        std::memcpy(m_data + m_size, buf, len);
        m_size += len;
    }
 
    char* data()
    {
        return m_data;
    }
 
    const char* data() const
    {
        return m_data;
    }
 
    size_t size() const
    {
        return m_size;
    }
 
    char* release()
    {
        char* tmp = m_data;
        m_size = 0;
        m_data = MSGPACK_NULLPTR;
        m_alloc = 0;
        return tmp;
    }
 
    void clear()
    {
        m_size = 0;
    }
 
private:
    void expand_buffer(size_t len)
    {
        size_t nsize = (m_alloc > 0) ?
                m_alloc * 2 : MSGPACK_SBUFFER_INIT_SIZE;
 
        while(nsize < m_size + len) {
            size_t tmp_nsize = nsize * 2;
            if (tmp_nsize <= nsize) {
                nsize = m_size + len;
                break;
            }
            nsize = tmp_nsize;
        }
 
        void* tmp = ::realloc(m_data, nsize);
        if(!tmp) {
            throw std::bad_alloc();
        }
 
        m_data = static_cast<char*>(tmp);
        m_alloc = nsize;
    }
 
#if defined(MSGPACK_USE_CPP03)
private:
    sbuffer(const sbuffer&);
    sbuffer& operator=(const sbuffer&);
#endif  // defined(MSGPACK_USE_CPP03)
 
private:
    size_t m_size;
    char* m_data;
    size_t m_alloc;
};

}  // MSGPACK_API_VERSION_NAMESPACE(v1)
 
}  // namespace msgpack
 
#endif // MSGPACK_V1_SBUFFER_HPP