view packages/language/c/libc/stdio/current/src/input/fread.cxx @ 163:0d2b193a635f

Merge from eCos master repository on 2001-06-22-17:38:39-BST
author jlarmour
date Fri, 22 Jun 2001 18:18:44 +0000
parents 6ed91473a1cd
children e0c0827131d1
line wrap: on
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//========================================================================
//
//      fread.cxx
//
//      ANSI Stdio fread() function
//
//========================================================================
//####COPYRIGHTBEGIN####
//                                                                          
// -------------------------------------------                              
// The contents of this file are subject to the Red Hat eCos Public License 
// Version 1.1 (the "License"); you may not use this file except in         
// compliance with the License.  You may obtain a copy of the License at    
// http://www.redhat.com/                                                   
//                                                                          
// Software distributed under the License is distributed on an "AS IS"      
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
// License for the specific language governing rights and limitations under 
// the License.                                                             
//                                                                          
// The Original Code is eCos - Embedded Configurable Operating System,      
// released September 30, 1998.                                             
//                                                                          
// The Initial Developer of the Original Code is Red Hat.                   
// Portions created by Red Hat are                                          
// Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             
// All Rights Reserved.                                                     
// -------------------------------------------                              
//                                                                          
//####COPYRIGHTEND####
//========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):     jlarmour
// Contributors:  
// Date:          2000-04-20
// Purpose:     
// Description: 
// Usage:       
//
//####DESCRIPTIONEND####
//
//=======================================================================

// CONFIGURATION

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

// INCLUDES

#include <cyg/infra/cyg_type.h>     // Common project-wide type definitions
#include <cyg/infra/cyg_ass.h>      // Assertion support
#include <cyg/infra/cyg_trac.h>     // Tracing support
#include <stddef.h>                 // NULL and size_t from compiler
#include <stdio.h>                  // header for this file
#include <errno.h>                  // error codes
#include <cyg/libc/stdio/stream.hxx>// Cyg_StdioStream

// FUNCTIONS

externC size_t
fread( void *ptr, size_t object_size, size_t num_objects, FILE *stream )
{
    Cyg_StdioStream *real_stream = (Cyg_StdioStream *)stream;
    cyg_ucount32 bytes_read;
    cyg_ucount32 bytes_to_read;
    cyg_ucount32 total_read;
    Cyg_ErrNo err;
    cyg_uint8 *ptrc = (cyg_uint8 *)ptr;
    

    CYG_REPORT_FUNCNAMETYPE( "fread", "read %d objects" );
    CYG_REPORT_FUNCARG4( "ptr=%08x, object_size=%d, num_objects=%d, "
                         "stream=%08x", ptr, object_size, num_objects,
                         stream );

    bytes_to_read = object_size*num_objects;
    total_read = 0;

    if ( !bytes_to_read ) {
        CYG_REPORT_RETVAL(0);
        return 0;
    } // if

    err = real_stream->read( (cyg_uint8 *)ptr, bytes_to_read,
                             &bytes_read );
    bytes_to_read -= bytes_read;
    total_read += bytes_read;
    ptrc += bytes_read;

    while (!err && bytes_to_read) { // if no err, but not finished - get next
        err = real_stream->refill_read_buffer();
        if ( !err ) {
            err = real_stream->read( (cyg_uint8 *)ptr, bytes_to_read,
                                     &bytes_read );
            bytes_to_read -= bytes_read;
            total_read += bytes_read;
            ptrc += bytes_read;
        } // if
    } // while

    if (err) {
        real_stream->set_error( err );
        errno = err;
    } // if
    
    // we return the number of _objects_ read. Simple division is
    // sufficient as this returns the quotient rather than rounding
    CYG_REPORT_RETVAL( bytes_read/object_size );
    return total_read/object_size;

} // fread()

// EOF fread.cxx