100 lines
2.6 KiB
C
100 lines
2.6 KiB
C
/* $NetBSD: buffer.h,v 1.4 2008/04/28 20:24:12 martin Exp $ */
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/*-
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* Copyright (c) 2005 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Christos Zoulas.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <err.h>
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#define BUF_SIZE BUFSIZ
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struct buffer {
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char *ptr;
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char *bptr;
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char *eptr;
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};
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static void
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buf_init(struct buffer *buf)
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{
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buf->ptr = buf->bptr = malloc(BUF_SIZE);
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if (buf->ptr == NULL)
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err(1, "Cannot allocate buffer");
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buf->eptr = buf->ptr + BUF_SIZE;
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}
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static void
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buf_end(struct buffer *buf)
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{
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free(buf->bptr);
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}
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static void
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buf_grow(struct buffer *buf, size_t minsize)
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{
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ptrdiff_t diff;
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size_t len = (buf->eptr - buf->bptr) +
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(minsize > BUF_SIZE ? minsize : BUF_SIZE);
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char *nptr = realloc(buf->bptr, len);
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if (nptr == NULL)
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err(1, "Cannot grow buffer");
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if (nptr == buf->bptr) {
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buf->eptr = buf->bptr + len;
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return;
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}
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diff = nptr - buf->bptr;
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buf->bptr += diff;
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buf->eptr = buf->bptr + len;
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buf->ptr += diff;
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}
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static inline void
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buf_putc(struct buffer *buf, char c)
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{
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if (buf->ptr >= buf->eptr)
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buf_grow(buf, 1);
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*buf->ptr++ = c;
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}
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static inline void
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buf_reset(struct buffer *buf)
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{
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buf->ptr = buf->bptr;
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}
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static inline char
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buf_unputc(struct buffer *buf)
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{
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return buf->ptr > buf->bptr ? *--buf->ptr : '\0';
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}
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