Colony » Colony Scout

/*-

 * Copyright (c) 1990, 1993

 *        The Regents of the University of California.  All rights reserved.

 *

 * This code is derived from software contributed to Berkeley by

 * Chris Torek.

 *

 * 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.

 * 3. Neither the name of the University nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.

 */

#include <stdio.h>

#include <string.h>

#include "local.h"

#include "fvwrite.h"

/*

 * Write some memory regions.  Return zero on success, EOF on error.

 *

 * This routine is large and unsightly, but most of the ugliness due

 * to the three different kinds of output buffering is handled here.

 */

int

__sfvwrite(fp, uio)

        FILE *fp;

        struct __suio *uio;

{

        size_t len;

        char *p;

        struct __siov *iov;

        int w, s;

        char *nl;

        int nlknown, nldist;

        if ((len = uio->uio_resid) == 0)

                return (0);

        /* make sure we can write */

        if (cantwrite(fp))

                return (EOF);

#define        MIN(a, b) ((a) < (b) ? (a) : (b))

#define        COPY(n)          (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n))

        iov = uio->uio_iov;

        p = iov->iov_base;

        len = iov->iov_len;

        iov++;

#define GETIOV(extra_work) \

        while (len == 0) { \

                extra_work; \

                p = iov->iov_base; \

                len = iov->iov_len; \

                iov++; \

        }

        if (fp->_flags & __SNBF) {

                /*

                 * Unbuffered: write up to BUFSIZ bytes at a time.

                 */

                do {

                        GETIOV(;);

                        w = __swrite(fp, p, MIN(len, BUFSIZ));

                        if (w <= 0)

                                goto err;

                        p += w;

                        len -= w;

                } while ((uio->uio_resid -= w) != 0);

        } else if ((fp->_flags & __SLBF) == 0) {

                /*

                 * Fully buffered: fill partially full buffer, if any,

                 * and then flush.  If there is no partial buffer, write

                 * one _bf._size byte chunk directly (without copying).

                 *

                 * String output is a special case: write as many bytes

                 * as fit, but pretend we wrote everything.  This makes

                 * snprintf() return the number of bytes needed, rather

                 * than the number used, and avoids its write function

                 * (so that the write function can be invalid).

                 */

                do {

                        GETIOV(;);

                        w = fp->_w;

                        if (fp->_flags & __SSTR) {

                                if (len < w)

                                        w = len;

                                COPY(w);        /* copy MIN(fp->_w,len), */

                                fp->_w -= w;

                                fp->_p += w;

                                w = len;        /* but pretend copied all */

                        } else if (fp->_p > fp->_bf._base && len > w) {

                                /* fill and flush */

                                COPY(w);

                                /* fp->_w -= w; */ /* unneeded */

                                fp->_p += w;

                                if (fflush(fp))

                                        goto err;

                        } else if (len >= (w = fp->_bf._size)) {

                                /* write directly */

                                w = __swrite(fp, p, w);

                                if (w <= 0)

                                        goto err;

                        } else {

                                /* fill and done */

                                w = len;

                                COPY(w);

                                fp->_w -= w;

                                fp->_p += w;

                        }

                        p += w;

                        len -= w;

                } while ((uio->uio_resid -= w) != 0);

        } else {

                /*

                 * Line buffered: like fully buffered, but we

                 * must check for newlines.  Compute the distance

                 * to the first newline (including the newline),

                 * or `infinity' if there is none, then pretend

                 * that the amount to write is MIN(len,nldist).

                 */

                nlknown = 0;

                nldist = 0;        /* XXX just to keep gcc happy */

                do {

                        GETIOV(nlknown = 0);

                        if (!nlknown) {

                                nl = memchr((void *)p, '\n', len);

                                nldist = nl ? nl + 1 - p : len + 1;

                                nlknown = 1;

                        }

                        s = MIN(len, nldist);

                        w = fp->_w + fp->_bf._size;

                        if (fp->_p > fp->_bf._base && s > w) {

                                COPY(w);

                                /* fp->_w -= w; */

                                fp->_p += w;

                                if (fflush(fp))

                                        goto err;

                        } else if (s >= (w = fp->_bf._size)) {

                                w = __swrite(fp, p, w);

                                if (w <= 0)

                                         goto err;

                        } else {

                                w = s;

                                COPY(w);

                                fp->_w -= w;

                                fp->_p += w;

                        }

                        if ((nldist -= w) == 0) {

                                /* copied the newline: flush and forget */

                                if (fflush(fp))

                                        goto err;

                                nlknown = 0;

                        }

                        p += w;

                        len -= w;

                } while ((uio->uio_resid -= w) != 0);

        }

        return (0);

err:

        fp->_flags |= __SERR;

        return (EOF);

}