xref: /illumos-gate/usr/src/lib/libc/port/stdio/fwrite.c (revision 581cede61ac9c14d8d4ea452562a567189eead78)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include "lint.h"
33 #include "file64.h"
34 #include "mtlib.h"
35 #include <sys/types.h>
36 #include <stdio.h>
37 #include <values.h>
38 #include <memory.h>
39 #include <thread.h>
40 #include <synch.h>
41 #include <unistd.h>
42 #include "stdiom.h"
43 #include "mse.h"
44 
45 size_t
46 _fwrite_unlocked(const void *ptr, size_t size, size_t count, FILE *iop);
47 
48 size_t
49 fwrite(const void *ptr, size_t size, size_t count, FILE *iop)
50 {
51 	rmutex_t	*lk;
52 	size_t	retval;
53 
54 	FLOCKFILE(lk, iop);
55 
56 	_SET_ORIENTATION_BYTE(iop);
57 
58 	retval = _fwrite_unlocked(ptr, size, count, iop);
59 	FUNLOCKFILE(lk);
60 
61 	return (retval);
62 }
63 
64 size_t
65 _fwrite_unlocked(const void *ptr, size_t size, size_t count, FILE *iop)
66 {
67 	ssize_t s, n;
68 	unsigned char *dptr = (unsigned char *)ptr;
69 	unsigned char *bufend;
70 
71 	if (_WRTCHK(iop))
72 		return (0);
73 
74 	/*
75 	 * This test is here to avoid the expensive multiply
76 	 */
77 	if (count == 1)
78 		s = size;
79 	else if (size == 1)
80 		s = count;
81 	else
82 		s = size * count;
83 
84 	if (iop->_flag & _IOLBF) {
85 		bufend = _bufend(iop);
86 		iop->_cnt = iop->_base - iop->_ptr;
87 		while (s > 0) {
88 			ssize_t buflen = bufend - iop->_base;
89 			if (--iop->_cnt >= (-buflen) && *dptr != '\n')
90 				*iop->_ptr++ = *dptr++;
91 			else if (__flsbuf(*dptr++, iop) == EOF)
92 				break;
93 			s--;
94 		}
95 	} else if (iop->_flag & _IONBF) {
96 		ssize_t bytes;
97 		ssize_t written = 0;
98 		char *data;
99 
100 		if (size < 1 || count < 1)
101 			return (0);
102 
103 		if (iop->_base != iop->_ptr) {
104 		/*
105 		 * Flush any existing data. Doesn't count towards return
106 		 * value.
107 		 */
108 			bytes = iop->_ptr - iop->_base;
109 			data = (char *)iop->_base;
110 
111 			while ((n = write(fileno(iop), data, (size_t)bytes))
112 			    != bytes) {
113 				if (n == -1) {
114 					if (!cancel_active())
115 						iop->_flag |= _IOERR;
116 					return (0);
117 				} else {
118 					data += n;
119 					bytes -= n;
120 				}
121 			}
122 			iop->_cnt = 0;
123 			iop->_ptr = iop->_base;
124 		}
125 		/*
126 		 * written is in bytes until the return.
127 		 * Then it is divided by size to produce items.
128 		 */
129 		while ((n = write(fileno(iop), dptr, s)) != s) {
130 			if (n == -1) {
131 				if (!cancel_active())
132 					iop->_flag |= _IOERR;
133 				return (written / size);
134 			} else {
135 				dptr += n;
136 				s -= n;
137 				written += n;
138 			}
139 		}
140 		written += n;
141 		return (written / size);
142 	} else while (s > 0) {
143 		if (iop->_cnt < s) {
144 			if (iop->_cnt > 0) {
145 				(void) memcpy(iop->_ptr, (void *)dptr,
146 				    iop->_cnt);
147 				dptr += iop->_cnt;
148 				iop->_ptr += iop->_cnt;
149 				s -= iop->_cnt;
150 			}
151 			if (_xflsbuf(iop) == EOF)
152 				break;
153 		}
154 		if (iop->_cnt >= s) {
155 			char *tmp = (char *)iop->_ptr;
156 
157 			switch (s) {
158 			case 8:
159 				*tmp++ = *dptr++;
160 				/*FALLTHRU*/
161 			case 7:
162 				*tmp++ = *dptr++;
163 				/*FALLTHRU*/
164 			case 6:
165 				*tmp++ = *dptr++;
166 				/*FALLTHRU*/
167 			case 5:
168 				*tmp++ = *dptr++;
169 				/*FALLTHRU*/
170 			case 4:
171 				*tmp++ = *dptr++;
172 				/*FALLTHRU*/
173 			case 3:
174 				*tmp++ = *dptr++;
175 				/*FALLTHRU*/
176 			case 2:
177 				*tmp++ = *dptr++;
178 				/*FALLTHRU*/
179 			case 1:
180 				*tmp++ = *dptr++;
181 				break;
182 			case 0:
183 				return (count);
184 			default:
185 				(void) memcpy(iop->_ptr, (void *)dptr, s);
186 			}
187 			iop->_ptr += s;
188 			iop->_cnt -= s;
189 
190 			return (count);
191 		}
192 	}
193 
194 	return (size != 0 ? count - ((s + size - 1) / size) : 0);
195 }
196