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https://github.com/freebsd/freebsd-src
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String buffer API
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60ec413038
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svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=69990
271
sys/kern/subr_sbuf.c
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271
sys/kern/subr_sbuf.c
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/*-
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* Copyright (c) 2000 Poul-Henning Kamp and Dag-Erling Coïdan Smørgrav
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* All rights reserved.
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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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* in this position and unchanged.
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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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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <sys/sbuf.h>
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#include <sys/systm.h>
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#include <machine/stdarg.h>
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MALLOC_DEFINE(M_SBUF, "sbuf", "string buffers");
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#ifdef INVARIANTS
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static void
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assert_sbuf_integrity(struct sbuf *s)
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{
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KASSERT(s != NULL,
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(__FUNCTION__ " called with a NULL sbuf pointer"));
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KASSERT(s->s_buf != NULL,
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(__FUNCTION__ " called with unitialized or corrupt sbuf"));
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KASSERT(s->s_len < s->s_size,
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("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
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}
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static void
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assert_sbuf_state(struct sbuf *s, int state)
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{
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KASSERT((s->s_flags & SBUF_FINISHED) == state,
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(__FUNCTION__ " called with %sfinished or corrupt sbuf",
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(state ? "un" : "")));
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}
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#else
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#define assert_sbuf_integrity(s) do { } while (0)
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#define assert_sbuf_state(s, i) do { } while (0)
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#endif
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/*
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* Initialize an sbuf.
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* If buf is non-NULL, it points to a static or already-allocated string
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* big enough to hold at least length characters.
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*/
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int
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sbuf_new(struct sbuf *s, char *buf, size_t length, int flags)
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{
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KASSERT(flags == 0,
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(__FUNCTION__ " called with non-zero flags"));
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KASSERT(s != NULL,
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(__FUNCTION__ " called with a NULL sbuf pointer"));
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bzero(s, sizeof *s);
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s->s_size = length;
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if (buf) {
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s->s_buf = buf;
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return (0);
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}
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s->s_buf = malloc(s->s_size, M_SBUF, M_WAITOK);
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if (s->s_buf == NULL)
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return (-1);
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SBUF_SETFLAG(s, SBUF_DYNAMIC);
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return (0);
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}
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/*
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* Set the sbuf's position to an arbitrary value
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*/
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int
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sbuf_setpos(struct sbuf *s, size_t pos)
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{
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assert_sbuf_integrity(s);
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assert_sbuf_state(s, 0);
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KASSERT(pos >= 0,
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("attempt to seek to a negative position (%d)", pos));
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KASSERT(pos < s->s_size,
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("attempt to seek past end of sbuf (%d >= %d)", pos, s->s_size));
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if (pos < 0 || pos > s->s_len)
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return (-1);
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s->s_len = pos;
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return (0);
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}
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/*
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* Append a string to an sbuf.
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*/
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int
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sbuf_cat(struct sbuf *s, char *str)
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{
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assert_sbuf_integrity(s);
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assert_sbuf_state(s, 0);
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if (SBUF_HASOVERFLOWED(s))
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return (-1);
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while (*str && SBUF_HASROOM(s))
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s->s_buf[s->s_len++] = *str++;
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if (*str) {
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SBUF_SETFLAG(s, SBUF_OVERFLOWED);
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return (-1);
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}
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return (0);
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}
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/*
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* Copy a string into an sbuf.
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*/
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int
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sbuf_cpy(struct sbuf *s, char *str)
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{
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assert_sbuf_integrity(s);
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assert_sbuf_state(s, 0);
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s->s_len = 0;
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return (sbuf_cat(s, str));
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}
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/*
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* PCHAR function for sbuf_printf()
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*/
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static void
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_sbuf_pchar(int c, void *v)
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{
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struct sbuf *s = (struct sbuf *)v;
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assert_sbuf_integrity(s);
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assert_sbuf_state(s, 0);
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if (SBUF_HASOVERFLOWED(s))
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return;
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if (SBUF_HASROOM(s))
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s->s_buf[s->s_len++] = c;
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else
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SBUF_SETFLAG(s, SBUF_OVERFLOWED);
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}
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/*
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* Format the given arguments and append the resulting string to an sbuf.
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*/
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int
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sbuf_printf(struct sbuf *s, char *fmt, ...)
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{
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va_list ap;
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size_t len;
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assert_sbuf_integrity(s);
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assert_sbuf_state(s, 0);
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KASSERT(fmt != NULL,
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(__FUNCTION__ " called with a NULL format string"));
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if (SBUF_HASOVERFLOWED(s))
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return (-1);
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va_start(ap, fmt);
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len = kvprintf(fmt, _sbuf_pchar, s, 10, ap);
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va_end(ap);
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KASSERT(s->s_len < s->s_size,
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("wrote past end of sbuf (%d >= %d)", s->s_len, s->s_size));
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if (SBUF_HASOVERFLOWED(s))
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return (-1);
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return (0);
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}
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/*
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* Append a character to an sbuf.
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*/
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int
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sbuf_putc(struct sbuf *s, int c)
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{
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assert_sbuf_integrity(s);
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assert_sbuf_state(s, 0);
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if (SBUF_HASOVERFLOWED(s))
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return (-1);
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if (!SBUF_HASROOM(s)) {
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SBUF_SETFLAG(s, SBUF_OVERFLOWED);
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return (-1);
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}
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s->s_buf[s->s_len++] = c;
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return (0);
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}
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/*
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* Finish off an sbuf.
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*/
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int
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sbuf_finish(struct sbuf *s)
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{
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assert_sbuf_integrity(s);
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assert_sbuf_state(s, 0);
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if (SBUF_HASOVERFLOWED(s))
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return (-1);
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s->s_buf[s->s_len++] = '\0';
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SBUF_SETFLAG(s, SBUF_FINISHED);
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return (0);
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}
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/*
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* Return a pointer to the sbuf data.
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*/
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char *
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sbuf_data(struct sbuf *s)
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{
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assert_sbuf_integrity(s);
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assert_sbuf_state(s, SBUF_FINISHED);
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if (SBUF_HASOVERFLOWED(s))
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return (NULL);
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return s->s_buf;
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}
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/*
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* Return the length of the sbuf data.
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*/
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size_t
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sbuf_len(struct sbuf *s)
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{
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assert_sbuf_integrity(s);
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assert_sbuf_state(s, SBUF_FINISHED);
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if (SBUF_HASOVERFLOWED(s))
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return (0);
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return s->s_len;
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}
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/*
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* Clear an sbuf, free its buffer if necessary.
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*/
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void
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sbuf_delete(struct sbuf *s)
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{
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assert_sbuf_integrity(s);
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/* don't care if it's finished or not */
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if (SBUF_ISDYNAMIC(s))
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free(s->s_buf, M_SBUF);
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bzero(s, sizeof *s);
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}
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76
sys/sys/sbuf.h
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76
sys/sys/sbuf.h
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@ -0,0 +1,76 @@
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/*-
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* Copyright (c) 2000 Poul-Henning Kamp and Dag-Erling Coïdan Smørgrav
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* All rights reserved.
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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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* in this position and unchanged.
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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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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _SYS_SBUF_H_
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#define _SYS_SBUF_H_
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/*
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* Structure definition
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*/
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struct sbuf {
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char *s_buf; /* storage buffer */
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struct sbuf *s_next; /* next in chain */
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size_t s_size; /* size of storage buffer */
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size_t s_len; /* current length of string */
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#define SBUF_AUTOEXTEND 0x00000001 /* automatically extend buffer */
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#define SBUF_DYNAMIC 0x00010000 /* s_buf must be freed */
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#define SBUF_FINISHED 0x00020000 /* set by sbuf_finish() */
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#define SBUF_OVERFLOWED 0x00040000 /* sbuf overflowed */
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int s_flags; /* flags */
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};
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/*
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* Predicates
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*/
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#define SBUF_ISDYNAMIC(s) ((s)->s_flags & SBUF_DYNAMIC)
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#define SBUF_ISFINISHED(s) ((s)->s_flags & SBUF_FINISHED)
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#define SBUF_HASOVERFLOWED(s) ((s)->s_flags & SBUF_OVERFLOWED)
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#define SBUF_HASROOM(s) ((s)->s_len < (s)->s_size - 1)
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/*
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* Other macros
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*/
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#define SBUF_SETFLAG(s, f) do { (s)->s_flags |= (f); } while (0)
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/*
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* API functions
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*/
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int sbuf_new(struct sbuf *s, char *buf, size_t length, int flags);
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int sbuf_setpos(struct sbuf *s, size_t pos);
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int sbuf_cat(struct sbuf *s, char *str);
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int sbuf_cpy(struct sbuf *s, char *str);
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int sbuf_printf(struct sbuf *s, char *fmt, ...);
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int sbuf_putc(struct sbuf *s, int c);
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int sbuf_finish(struct sbuf *s);
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char *sbuf_data(struct sbuf *s);
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size_t sbuf_len(struct sbuf *s);
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void sbuf_delete(struct sbuf *s);
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#endif
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