StdLib/LibC/Stdio/fvwrite.c

   1 /*
   2     Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>
   3     This program and the accompanying materials are licensed and made available
   4     under the terms and conditions of the BSD License that accompanies this
   5     distribution.  The full text of the license may be found at
   6     http://opensource.org/licenses/bsd-license.
   7
   8     THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   9     WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  10
  11  * Copyright (c) 1990, 1993
  12  *  The Regents of the University of California.  All rights reserved.
  13  *
  14  * This code is derived from software contributed to Berkeley by
  15  * Chris Torek.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions
  19  * are met:
  20  * 1. Redistributions of source code must retain the above copyright
  21  *    notice, this list of conditions and the following disclaimer.
  22  * 2. Redistributions in binary form must reproduce the above copyright
  23  *    notice, this list of conditions and the following disclaimer in the
  24  *    documentation and/or other materials provided with the distribution.
  25  * 3. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40
  41     NetBSD: fvwrite.c,v 1.16.2.1 2007/05/07 19:49:09 pavel Exp
  42     fvwrite.c 8.1 (Berkeley) 6/4/93
  43 */
  44 #include  <LibConfig.h>
  45 #include <sys/EfiCdefs.h>
  46
  47 #include <assert.h>
  48 #include <errno.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include "reentrant.h"
  53 #include "local.h"
  54 #include "fvwrite.h"
  55
  56 /*
  57  * Write some memory regions.  Return zero on success, EOF on error.
  58  *
  59  * This routine is large and unsightly, but most of the ugliness due
  60  * to the three different kinds of output buffering is handled here.
  61  */
  62 int
  63 __sfvwrite(FILE *fp, struct __suio *uio)
  64 {
  65   size_t len;
  66   char *p;
  67   struct __siov *iov;
  68   int w, s;
  69   char *nl;
  70   int nlknown, nldist;
  71
  72   _DIAGASSERT(fp != NULL);
  73   _DIAGASSERT(uio != NULL);
  74   if(fp == NULL) {
  75     errno = EINVAL;
  76     return (EOF);
  77   }
  78
  79   if ((len = uio->uio_resid) == 0)
  80     return (0);
  81   /* make sure we can write */
  82   if (cantwrite(fp)) {
  83     errno = EBADF;
  84     return (EOF);
  85   }
  86
  87 //#define MIN(a, b) ((a) < (b) ? (a) : (b))
  88 #define COPY(n)   (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n))
  89
  90   iov = uio->uio_iov;
  91   p = iov->iov_base;
  92   len = iov->iov_len;
  93   iov++;
  94 #define GETIOV(extra_work) \
  95   while (len == 0) { \
  96     extra_work; \
  97     p = iov->iov_base; \
  98     len = iov->iov_len; \
  99     iov++; \
 100   }
 101   if (fp->_flags & __SNBF) {
 102     /*
 103      * Unbuffered: write up to BUFSIZ bytes at a time.
 104      */
 105     do {
 106       GETIOV(;);
 107       w = (*fp->_write)(fp->_cookie, p,
 108           (int)MIN(len, BUFSIZ));
 109       if (w < 0)
 110         goto err;
 111       p += w;
 112       len -= w;
 113     } while ((uio->uio_resid -= w) > 0);
 114     uio->uio_resid = 0;   // Just in case it went negative such as when NL is expanded to CR NL
 115   } else if ((fp->_flags & __SLBF) == 0) {
 116     /*
 117      * Fully buffered: fill partially full buffer, if any,
 118      * and then flush.  If there is no partial buffer, write
 119      * one _bf._size byte chunk directly (without copying).
 120      *
 121      * String output is a special case: write as many bytes
 122      * as fit, but pretend we wrote everything.  This makes
 123      * snprintf() return the number of bytes needed, rather
 124      * than the number used, and avoids its write function
 125      * (so that the write function can be invalid).
 126      */
 127     do {
 128       GETIOV(;);
 129       if ((fp->_flags & (__SALC | __SSTR)) ==
 130           (__SALC | __SSTR) && fp->_w < (int)len) {
 131         size_t blen = fp->_p - fp->_bf._base;
 132         unsigned char *_base;
 133         int _size;
 134
 135         /* Allocate space exponentially. */
 136         _size = fp->_bf._size;
 137         do {
 138           _size = (_size << 1) + 1;
 139         } while (_size < (int)(blen + len));
 140         _base = realloc(fp->_bf._base,
 141             (size_t)(_size + 1));
 142         if (_base == NULL)
 143           goto err;
 144         fp->_w += _size - fp->_bf._size;
 145         fp->_bf._base = _base;
 146         fp->_bf._size = _size;
 147         fp->_p = _base + blen;
 148       }
 149       w = fp->_w;
 150       if (fp->_flags & __SSTR) {
 151         if (len < (size_t)w)
 152           w = (int)len;
 153         COPY(w);  /* copy MIN(fp->_w,len), */
 154         fp->_w -= w;
 155         fp->_p += w;
 156         w = (int)len;  /* but pretend copied all */
 157       } else if (fp->_p > fp->_bf._base && len > (size_t)w) {
 158         /* fill and flush */
 159         COPY(w);
 160         /* fp->_w -= w; */ /* unneeded */
 161         fp->_p += w;
 162         if (fflush(fp))
 163           goto err;
 164       } else if (len >= (size_t)(w = fp->_bf._size)) {
 165         /* write directly */
 166         w = (*fp->_write)(fp->_cookie, p, w);
 167         if (w <= 0)
 168           goto err;
 169       } else {
 170         /* fill and done */
 171         w = (int)len;
 172         COPY(w);
 173         fp->_w -= w;
 174         fp->_p += w;
 175       }
 176       p += w;
 177       len -= w;
 178     } while ((uio->uio_resid -= w) != 0);
 179   } else {
 180     /*
 181      * Line buffered: like fully buffered, but we
 182      * must check for newlines.  Compute the distance
 183      * to the first newline (including the newline),
 184      * or `infinity' if there is none, then pretend
 185      * that the amount to write is MIN(len,nldist).
 186      */
 187     nlknown = 0;
 188     nldist = 0; /* XXX just to keep gcc happy */
 189     do {
 190       GETIOV(nlknown = 0);
 191       if (!nlknown) {
 192         nl = memchr((void *)p, '\n', len);          // Divide the string at the first '\n'
 193         nldist = (int)(nl ? nl + 1 - p : len + 1);
 194         nlknown = 1;
 195       }
 196       s = (int)(MIN((int)len, nldist));
 197       w = fp->_w + fp->_bf._size;
 198       if (fp->_p > fp->_bf._base && s > w) {
 199         COPY(w);
 200         /* fp->_w -= w; */
 201         fp->_p += w;
 202         if (fflush(fp))
 203           goto err;
 204       } else if (s >= (w = fp->_bf._size)) {
 205         w = (*fp->_write)(fp->_cookie, p, w);
 206         if (w <= 0)
 207           goto err;
 208       } else {
 209         w = s;
 210         COPY(w);
 211         fp->_w -= w;
 212         fp->_p += w;
 213       }
 214       if ((nldist -= w) == 0) {
 215         /* copied the newline: flush and forget */
 216         if (fflush(fp))
 217           goto err;
 218         nlknown = 0;
 219       }
 220       p += w;
 221       len -= w;
 222     } while ((uio->uio_resid -= w) != 0);
 223   }
 224   return (0);
 225
 226 err:
 227   fp->_flags |= __SERR;
 228   return (EOF);
 229 }