130 lines
3.9 KiB
C
130 lines
3.9 KiB
C
/*
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* Copyright (c) 2000-2001
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* The Regents of the University of California. 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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* 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. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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*/
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#include <assert.h>
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#include <stdio.h>
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#include <string.h>
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#include "buffer.h"
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/* Invariant: buffer always null-terminated */
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struct growbuf
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{
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region r;
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unsigned int maxsize, cursize;
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char *buffer;
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};
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/* Make a new buffer with initial size */
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growbuf growbuf_new(region r, int size)
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{
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growbuf b = ralloc(r, struct growbuf);
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assert(size > 0);
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b->r = r;
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b->maxsize = size; /* Force some growth! */
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b->cursize = 1;
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b->buffer = rstralloc(r, size);
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b->buffer[0] = '\0';
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return b;
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}
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/* Empty a buffer */
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void growbuf_reset(growbuf b)
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{
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assert(b->maxsize > 0);
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b->cursize = 1;
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b->buffer[0] = '\0';
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}
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/* Print to a buffer */
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int gprintf(growbuf b, const char *fmt, ...)
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{
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va_list args;
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va_start(args, fmt);
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return gvprintf(b, fmt, args);
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}
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/* Print to a buffer */
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int gvprintf(growbuf b, const char *fmt, va_list args)
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{
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int nchars;
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if (!fmt) /* Bug (?)/feature of vnsprintf -- printing \0 returns -1,
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goes into infinite loop. */
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return 0;
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while (1)
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{
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char *bufStart;
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int sizeLeft;
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bufStart = b->buffer + b->cursize - 1; /* chop trailing \0 */
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sizeLeft = b->maxsize - b->cursize + 1; /* +1 size we're chooping
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the trailing \0 */
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assert(*bufStart == '\0');
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nchars = vsnprintf(bufStart, sizeLeft, fmt, args);
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if (nchars > -1 && nchars < sizeLeft)
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{
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b->cursize += nchars; /* nchars doesn't include \0,
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but we overwrote our \0 */
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break;
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}
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else
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{
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/* How much room do we need? In the new glibc, nchars
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tells us how much (not including the trailing null).
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So we need the current size, -1 since we'll remove the null,
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plus the new size, plus 1 for the new null. */
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int newSize = (nchars > -1) ? b->cursize - 1 + nchars + 1
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: b->maxsize * 2;
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char *newBuf;
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/* fprintf(stderr, "Reallocating buffer, newSize=%d\n", newSize); */
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newBuf = rstralloc(b->r, newSize);
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memcpy(newBuf, b->buffer, b->cursize);
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newBuf[b->cursize-1] = '\0'; /* vsnprintf has printed something! */
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b->buffer = newBuf;
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b->maxsize = newSize;
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/* b->cursize unchanged */
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}
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}
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return nchars;
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}
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/* Get the contents of a buffer */
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char *growbuf_contents(growbuf b)
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{
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return b->buffer;
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}
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bool growbuf_empty(growbuf b)
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{
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return b->cursize == 1; /* Buffer always null terminated */
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}
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