/* * Copyright (c) 2000-2001 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * */ #include #include #include #include "buffer.h" /* Invariant: buffer always null-terminated */ struct growbuf { region r; unsigned int maxsize, cursize; char *buffer; }; /* Make a new buffer with initial size */ growbuf growbuf_new(region r, int size) { growbuf b = ralloc(r, struct growbuf); assert(size > 0); b->r = r; b->maxsize = size; /* Force some growth! */ b->cursize = 1; b->buffer = rstralloc(r, size); b->buffer[0] = '\0'; return b; } /* Empty a buffer */ void growbuf_reset(growbuf b) { assert(b->maxsize > 0); b->cursize = 1; b->buffer[0] = '\0'; } /* Print to a buffer */ int gprintf(growbuf b, const char *fmt, ...) { va_list args; va_start(args, fmt); return gvprintf(b, fmt, args); } /* Print to a buffer */ int gvprintf(growbuf b, const char *fmt, va_list args) { int nchars; if (!fmt) /* Bug (?)/feature of vnsprintf -- printing \0 returns -1, goes into infinite loop. */ return 0; while (1) { char *bufStart; int sizeLeft; bufStart = b->buffer + b->cursize - 1; /* chop trailing \0 */ sizeLeft = b->maxsize - b->cursize + 1; /* +1 size we're chooping the trailing \0 */ assert(*bufStart == '\0'); nchars = vsnprintf(bufStart, sizeLeft, fmt, args); if (nchars > -1 && nchars < sizeLeft) { b->cursize += nchars; /* nchars doesn't include \0, but we overwrote our \0 */ break; } else { /* How much room do we need? In the new glibc, nchars tells us how much (not including the trailing null). So we need the current size, -1 since we'll remove the null, plus the new size, plus 1 for the new null. */ int newSize = (nchars > -1) ? b->cursize - 1 + nchars + 1 : b->maxsize * 2; char *newBuf; /* fprintf(stderr, "Reallocating buffer, newSize=%d\n", newSize); */ newBuf = rstralloc(b->r, newSize); memcpy(newBuf, b->buffer, b->cursize); newBuf[b->cursize-1] = '\0'; /* vsnprintf has printed something! */ b->buffer = newBuf; b->maxsize = newSize; /* b->cursize unchanged */ } } return nchars; } /* Get the contents of a buffer */ char *growbuf_contents(growbuf b) { return b->buffer; } bool growbuf_empty(growbuf b) { return b->cursize == 1; /* Buffer always null terminated */ }