seek.c

Apache V2.0.15 Alpha For Linuxhttpd-2_0_15-alpha.tar.Z

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2001 The Apache Software Foundation.  All rights
 * reserved.
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 * 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.
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 *    distribution.
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 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

#include "fileio.h"
#include "apr_file_io.h"
#include "apr_lib.h"
#include <string.h>
#include <io.h>


static apr_status_t setptr(apr_file_t *thefile, unsigned long pos )
{
    long newbufpos;
    ULONG rc;

    if (thefile->direction == 1) {
        apr_file_flush(thefile);
        thefile->bufpos = thefile->direction = thefile->dataRead = 0;
    }

    newbufpos = pos - (thefile->filePtr - thefile->dataRead);
    if (newbufpos >= 0 && newbufpos <= thefile->dataRead) {
        thefile->bufpos = newbufpos;
        rc = 0;
    } else {
        rc = DosSetFilePtr(thefile->filedes, pos, FILE_BEGIN, &thefile->filePtr );

        if ( !rc )
            thefile->bufpos = thefile->dataRead = 0;
    }

    return APR_OS2_STATUS(rc);
}



apr_status_t apr_file_seek(apr_file_t *thefile, apr_seek_where_t where, apr_off_t *offset)
{
    if (!thefile->isopen) {
        return APR_EBADF;
    }

    if (thefile->buffered) {
        int rc = EINVAL;
        apr_finfo_t finfo;

        switch (where) {
        case APR_SET:
            rc = setptr(thefile, *offset);
            break;

        case APR_CUR:
            rc = setptr(thefile, thefile->filePtr - thefile->dataRead + thefile->bufpos + *offset);
            break;

        case APR_END:
            rc = apr_file_info_get(&finfo, APR_FINFO_NORM, thefile);
            if (rc == APR_SUCCESS)
                rc = setptr(thefile, finfo.size - *offset);
            break;
        }

        *offset = thefile->filePtr + thefile->bufpos;
        return rc;
    } else {
        switch (where) {
        case APR_SET:
            where = FILE_BEGIN;
            break;

        case APR_CUR:
            where = FILE_CURRENT;
            break;

        case APR_END:
            where = FILE_END;
            break;
        }

        return APR_OS2_STATUS(DosSetFilePtr(thefile->filedes, *offset, where, (ULONG *)&offset));
    }
}