// This file is part of the uSTL library, an STL implementation.
//
// Copyright (c) 2005 by Mike Sharov <msharov@users.sourceforge.net>
// This file is free software, distributed under the MIT License.

#include "cmemlink.h"
#include "ofstream.h"
#include "strmsize.h"
#include "ualgo.h"

namespace ustl {

/// \brief Attaches the object to pointer \p p of size \p n.
///
/// If \p p is NULL and \p n is non-zero, bad_alloc is thrown and current
/// state remains unchanged.
///
void cmemlink::link (const void* p, size_type n)
{
    if (!p && n)
	throw bad_alloc (n);
    unlink();
    relink (p, n);
}

void cmemlink::unlink (void) throw()
{
    m_Data = NULL; m_Size = 0;
}

/// Writes the object to stream \p os
void cmemlink::write (ostream& os) const
{
    const written_size_type sz (size());
    assert (sz == size() && "No support for writing memblocks larger than 4G");
    os << sz;
    os.write (cdata(), sz);
    os.align (alignof (sz));
}

/// Writes the object to stream \p os
void cmemlink::text_write (ostringstream& os) const
{
    os.write (begin(), readable_size());
}

/// Returns the number of bytes required to write this object to a stream.
cmemlink::size_type cmemlink::stream_size (void) const
{
    const written_size_type sz (size());
    return (Align (stream_size_of (sz) + sz, alignof(sz)));
}

/// Writes the data to file \p "filename".
void cmemlink::write_file (const char* filename, int mode) const
{
    fstream f;
    f.exceptions (fstream::allbadbits);
    f.open (filename, fstream::out | fstream::trunc, mode);
    f.write (cdata(), readable_size());
    f.close();
}

/// Compares to memory block pointed by l. Size is compared first.
bool cmemlink::operator== (const cmemlink& l) const
{
    return (l.m_Size == m_Size &&
	    (l.m_Data == m_Data || 0 == memcmp (l.m_Data, m_Data, m_Size)));
}

} // namespace ustl
