1 /* $NetBSD: buffer.h,v 1.5 2017/10/13 00:11:56 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2005 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <stddef.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <wchar.h> 36 #include <err.h> 37 38 #define BUF_SIZE BUFSIZ 39 struct buffer { 40 wchar_t *ptr; 41 wchar_t *bptr; 42 wchar_t *eptr; 43 }; 44 45 static void 46 buf_init(struct buffer *buf) 47 { 48 buf->ptr = buf->bptr = calloc(BUF_SIZE, sizeof(*buf->ptr)); 49 if (buf->ptr == NULL) 50 err(1, "Cannot allocate buffer"); 51 buf->eptr = buf->ptr + BUF_SIZE; 52 } 53 54 static void 55 buf_end(struct buffer *buf) 56 { 57 free(buf->bptr); 58 } 59 60 static void 61 buf_grow(struct buffer *buf, size_t minsize) 62 { 63 ptrdiff_t diff; 64 size_t len = (buf->eptr - buf->bptr) + 65 (minsize > BUF_SIZE ? minsize : BUF_SIZE); 66 wchar_t *nptr = realloc(buf->bptr, len * sizeof(*buf->ptr)); 67 68 if (nptr == NULL) 69 err(1, "Cannot grow buffer"); 70 71 if (nptr == buf->bptr) { 72 buf->eptr = buf->bptr + len; 73 return; 74 } 75 76 diff = nptr - buf->bptr; 77 buf->bptr += diff; 78 buf->eptr = buf->bptr + len; 79 buf->ptr += diff; 80 } 81 82 static inline void 83 buf_putc(struct buffer *buf, wchar_t c) 84 { 85 if (buf->ptr >= buf->eptr) 86 buf_grow(buf, 1); 87 *buf->ptr++ = c; 88 } 89 90 static inline void 91 buf_reset(struct buffer *buf) 92 { 93 buf->ptr = buf->bptr; 94 } 95 96 static inline wchar_t 97 buf_unputc(struct buffer *buf) 98 { 99 return buf->ptr > buf->bptr ? *--buf->ptr : '\0'; 100 } 101