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//===========================================================================

//

//      streambuf.cxx

//

//      C library stdio stream buffer functions

//

//===========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under

// the terms of the GNU General Public License as published by the Free

// Software Foundation; either version 2 or (at your option) any later version.

//

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// WARRANTY; without even the implied warranty of MERCHANTABILITY or

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

// for more details.

//

// You should have received a copy of the GNU General Public License along

// with eCos; if not, write to the Free Software Foundation, Inc.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

// As a special exception, if other files instantiate templates or use macros

// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

// by itself cause the resulting work to be covered by the GNU General Public

// License. However the source code for this file must still be made available

// in accordance with section (3) of the GNU General Public License.

//

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// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//===========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):    jlarmour

// Contributors: 

// Date:         2000-04-20

// Purpose:     

// Description: 

// Usage:       

//

//####DESCRIPTIONEND####

//

//===========================================================================

// CONFIGURATION

#include <pkgconf/libc_stdio.h>   // Configuration header

// Include buffered I/O?

#if defined(CYGSEM_LIBC_STDIO_WANT_BUFFERED_IO)

// INCLUDES

#include <cyg/infra/cyg_type.h>   // Common project-wide type definitions

#include <cyg/infra/cyg_ass.h>    // Assertion support

#include <errno.h>                // Cyg_ErrNo

#include <stdlib.h>               // malloc() and free()

#include <cyg/libc/stdio/streambuf.hxx> // header for this file, just in case

// FUNCTIONS

Cyg_ErrNo

Cyg_StdioStreamBuffer::set_buffer( cyg_ucount32 size,

                                   cyg_uint8 *new_buffer )

{

#ifdef CYGSEM_LIBC_STDIO_DYNAMIC_SETVBUF

    // user-supplied buffer?

    if (new_buffer != NULL) {

        CYG_CHECK_DATA_PTR(new_buffer, "new_buffer not valid");

#ifdef CYGSEM_LIBC_STDIO_SETVBUF_MALLOC

        // first check if we were responsible for the old buffer

        if (call_free) {

            free(buffer_bottom);

            call_free = false;

        }

#endif        

        buffer_bottom = new_buffer;

    }

#ifdef CYGSEM_LIBC_STDIO_SETVBUF_MALLOC    

    else if ( size != buffer_size ) { // as long as its different from

                                      // what we've got now

        cyg_uint8 *malloced_buf;

        malloced_buf = (cyg_uint8 * )malloc( size );

        if (malloced_buf == NULL)

            return ENOMEM;

        // should the old buffer be freed? This waits till after we know

        // whether the malloc succeeded

        if (call_free)

            free( buffer_bottom );

        buffer_bottom = malloced_buf;

        call_free=true;

    } // else if

#else

    // Here we have not been given a new buffer, but have been given

    // a new buffer size. If possible, we just shrink what we already

    // have.

    else if( size > buffer_size )

        return EINVAL;

#endif    

#else // ifdef CYGSEM_LIBC_STDIO_DYNAMIC_SETVBUF

    // In this config we can't use a different buffer, or set a

    // size greater than now. We can pretend to shrink it though

    // Note on the next line we compare it with the size of static_buffer

    // and not the current size, as that's what is the limiting factor

    if ( (new_buffer != NULL) || (size > sizeof(static_buffer)) )

        return EINVAL;

#endif // ifdef CYGSEM_LIBC_STDIO_DYNAMIC_SETVBUF

    buffer_top = current_buffer_position = &buffer_bottom[0];

    buffer_size = size;

    return ENOERR;

} // set_buffer()

#endif // if defined(CYGSEM_LIBC_STDIO_WANT_BUFFERED_IO)

// EOF streambuf.cxx