Buffer.h

// Copyright (c) 2013 by István Váradi
 
// This file is part of VSCPL, a simple cross-platform utility library
 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
 
// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.
 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
// The views and conclusions contained in the software and documentation are those
// of the authors and should not be interpreted as representing official policies,
// either expressed or implied, of the FreeBSD Project.
 
#ifndef HU_VARADIISTVAN_SCPL_IO_BUFFER_H
#define HU_VARADIISTVAN_SCPL_IO_BUFFER_H
//------------------------------------------------------------------------------
 
#include <algorithm>
 
#include <cstdlib>
#include <cstring>
 
//------------------------------------------------------------------------------
 
namespace hu { namespace varadiistvan { namespace scpl { namespace io {
 
//------------------------------------------------------------------------------
 
class Buffer
{
private:
    unsigned char* data;
 
    size_t capacity;
 
    size_t length;
 
public:
    Buffer(size_t capacity);
 
    ~Buffer();
 
    size_t getCapacity() const;
 
    const unsigned char* getData() const;
 
    unsigned char* getData();
 
    size_t getLength() const;
 
    bool isEmpty() const;
 
    size_t getAvailable() const;
 
    void reset();
 
    size_t addLength(size_t n);
 
    size_t append(const void* src, size_t size);
 
    size_t extract(void* dest, size_t size, size_t offset = 0) const;
};
 
//------------------------------------------------------------------------------
// Inline definitions
//------------------------------------------------------------------------------
 
inline Buffer::Buffer(size_t capacity) :
    data(new unsigned char[capacity]),
    capacity(capacity),
    length(0)
{
}
 
//------------------------------------------------------------------------------
 
inline Buffer::~Buffer()
{
    delete[] data;
}
 
//------------------------------------------------------------------------------
 
inline size_t Buffer::getCapacity() const
{
    return capacity;
}
 
//------------------------------------------------------------------------------
 
inline const unsigned char* Buffer::getData() const
{
    return data;
}
 
//------------------------------------------------------------------------------
 
inline unsigned char* Buffer::getData()
{
    return data;
}
 
//------------------------------------------------------------------------------
 
inline size_t Buffer::getLength() const
{
    return length;
}
 
//------------------------------------------------------------------------------
 
inline bool Buffer::isEmpty() const
{
    return length==0;
}
 
//------------------------------------------------------------------------------
 
inline size_t Buffer::getAvailable() const
{
    return capacity - length;
}
 
//------------------------------------------------------------------------------
 
inline void Buffer::reset()
{
    length = 0;
}
 
//------------------------------------------------------------------------------
 
inline size_t Buffer::addLength(size_t n)
{
    size_t toAdd = std::min(n, getAvailable());
    length += toAdd;
    return toAdd;
}
 
//------------------------------------------------------------------------------
 
inline size_t Buffer::append(const void* src, size_t size)
{
    size_t toCopy = std::min(size, getAvailable());
    memcpy(data + length, src, toCopy);
    length += toCopy;
    return toCopy;
}
 
//------------------------------------------------------------------------------
 
inline size_t Buffer::extract(void* dest, size_t size, size_t offset) const
{
    size_t toCopy = (offset>=length) ? 0 : std::min(size, length - offset);
    memcpy(dest, data + offset, toCopy);
    return toCopy;
}
 
//------------------------------------------------------------------------------
 
} /* namespace hu::varadiistvan::scpl::io */ } /* namespace hu::varadiistvan::scpl */ } /* namespace hu::varadiistvan */ } /* namespace hu */
 
//------------------------------------------------------------------------------
#endif // HU_VARADIISTVAN_SCPL_IO_BUFFER_H
 
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