buf.c revision 1.12
1 /* $NetBSD: buf.c,v 1.12 1999/09/15 04:16:31 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California. 5 * Copyright (c) 1988, 1989 by Adam de Boor 6 * Copyright (c) 1989 by Berkeley Softworks 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Adam de Boor. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 */ 40 41 #ifdef MAKE_BOOTSTRAP 42 static char rcsid[] = "$NetBSD: buf.c,v 1.12 1999/09/15 04:16:31 mycroft Exp $"; 43 #else 44 #include <sys/cdefs.h> 45 #ifndef lint 46 #if 0 47 static char sccsid[] = "@(#)buf.c 8.1 (Berkeley) 6/6/93"; 48 #else 49 __RCSID("$NetBSD: buf.c,v 1.12 1999/09/15 04:16:31 mycroft Exp $"); 50 #endif 51 #endif /* not lint */ 52 #endif 53 54 /*- 55 * buf.c -- 56 * Functions for automatically-expanded buffers. 57 */ 58 59 #include "sprite.h" 60 #include "make.h" 61 #include "buf.h" 62 63 #ifndef max 64 #define max(a,b) ((a) > (b) ? (a) : (b)) 65 #endif 66 67 /* 68 * BufExpand -- 69 * Expand the given buffer to hold the given number of additional 70 * bytes. 71 * Makes sure there's room for an extra NULL byte at the end of the 72 * buffer in case it holds a string. 73 */ 74 #define BufExpand(bp,nb) \ 75 while (bp->left < (nb)+1) {\ 76 int newSize = (bp)->size * 2; \ 77 Byte *newBuf = (Byte *) erealloc((bp)->buffer, newSize); \ 78 \ 79 (bp)->inPtr = newBuf + ((bp)->inPtr - (bp)->buffer); \ 80 (bp)->outPtr = newBuf + ((bp)->outPtr - (bp)->buffer);\ 81 (bp)->buffer = newBuf;\ 82 (bp)->size = newSize;\ 83 (bp)->left = newSize - ((bp)->inPtr - (bp)->buffer);\ 84 } 85 86 #define BUF_DEF_SIZE 256 /* Default buffer size */ 87 88 /*- 89 *----------------------------------------------------------------------- 90 * Buf_OvAddByte -- 91 * Add a single byte to the buffer. left is zero or negative. 92 * 93 * Results: 94 * None. 95 * 96 * Side Effects: 97 * The buffer may be expanded. 98 * 99 *----------------------------------------------------------------------- 100 */ 101 void 102 Buf_OvAddByte (bp, byte) 103 register Buffer bp; 104 int byte; 105 { 106 int nbytes = 1; 107 bp->left = 0; 108 BufExpand (bp, nbytes); 109 110 *bp->inPtr++ = byte; 111 bp->left--; 112 113 /* 114 * Null-terminate 115 */ 116 *bp->inPtr = 0; 117 } 118 119 /*- 121 *----------------------------------------------------------------------- 122 * Buf_AddBytes -- 123 * Add a number of bytes to the buffer. 124 * 125 * Results: 126 * None. 127 * 128 * Side Effects: 129 * Guess what? 130 * 131 *----------------------------------------------------------------------- 132 */ 133 void 134 Buf_AddBytes (bp, numBytes, bytesPtr) 135 register Buffer bp; 136 int numBytes; 137 const Byte *bytesPtr; 138 { 139 140 BufExpand (bp, numBytes); 141 142 memcpy (bp->inPtr, bytesPtr, numBytes); 143 bp->inPtr += numBytes; 144 bp->left -= numBytes; 145 146 /* 147 * Null-terminate 148 */ 149 *bp->inPtr = 0; 150 } 151 152 /*- 154 *----------------------------------------------------------------------- 155 * Buf_GetAll -- 156 * Get all the available data at once. 157 * 158 * Results: 159 * A pointer to the data and the number of bytes available. 160 * 161 * Side Effects: 162 * None. 163 * 164 *----------------------------------------------------------------------- 165 */ 166 Byte * 167 Buf_GetAll (bp, numBytesPtr) 168 register Buffer bp; 169 int *numBytesPtr; 170 { 171 172 if (numBytesPtr != (int *)NULL) { 173 *numBytesPtr = bp->inPtr - bp->outPtr; 174 } 175 176 return (bp->outPtr); 177 } 178 179 /*- 181 *----------------------------------------------------------------------- 182 * Buf_Discard -- 183 * Throw away bytes in a buffer. 184 * 185 * Results: 186 * None. 187 * 188 * Side Effects: 189 * The bytes are discarded. 190 * 191 *----------------------------------------------------------------------- 192 */ 193 void 194 Buf_Discard (bp, numBytes) 195 register Buffer bp; 196 int numBytes; 197 { 198 199 if (bp->inPtr - bp->outPtr <= numBytes) { 200 bp->inPtr = bp->outPtr = bp->buffer; 201 bp->left = bp->size; 202 *bp->inPtr = 0; 203 } else { 204 bp->outPtr += numBytes; 205 } 206 } 207 208 /*- 210 *----------------------------------------------------------------------- 211 * Buf_Size -- 212 * Returns the number of bytes in the given buffer. Doesn't include 213 * the null-terminating byte. 214 * 215 * Results: 216 * The number of bytes. 217 * 218 * Side Effects: 219 * None. 220 * 221 *----------------------------------------------------------------------- 222 */ 223 int 224 Buf_Size (buf) 225 Buffer buf; 226 { 227 return (buf->inPtr - buf->outPtr); 228 } 229 230 /*- 232 *----------------------------------------------------------------------- 233 * Buf_Init -- 234 * Initialize a buffer. If no initial size is given, a reasonable 235 * default is used. 236 * 237 * Results: 238 * A buffer to be given to other functions in this library. 239 * 240 * Side Effects: 241 * The buffer is created, the space allocated and pointers 242 * initialized. 243 * 244 *----------------------------------------------------------------------- 245 */ 246 Buffer 247 Buf_Init (size) 248 int size; /* Initial size for the buffer */ 249 { 250 Buffer bp; /* New Buffer */ 251 252 bp = (Buffer)emalloc(sizeof(*bp)); 253 254 if (size <= 0) { 255 size = BUF_DEF_SIZE; 256 } 257 bp->left = bp->size = size; 258 bp->buffer = (Byte *)emalloc(size); 259 bp->inPtr = bp->outPtr = bp->buffer; 260 *bp->inPtr = 0; 261 262 return (bp); 263 } 264 265 /*- 267 *----------------------------------------------------------------------- 268 * Buf_Destroy -- 269 * Nuke a buffer and all its resources. 270 * 271 * Results: 272 * None. 273 * 274 * Side Effects: 275 * The buffer is freed. 276 * 277 *----------------------------------------------------------------------- 278 */ 279 void 280 Buf_Destroy (buf, freeData) 281 Buffer buf; /* Buffer to destroy */ 282 Boolean freeData; /* TRUE if the data should be destroyed as well */ 283 { 284 285 if (freeData) { 286 free ((char *)buf->buffer); 287 } 288 free ((char *)buf); 289 } 290 291 /*- 293 *----------------------------------------------------------------------- 294 * Buf_ReplaceLastByte -- 295 * Replace the last byte in a buffer. 296 * 297 * Results: 298 * None. 299 * 300 * Side Effects: 301 * If the buffer was empty intially, then a new byte will be added. 302 * Otherwise, the last byte is overwritten. 303 * 304 *----------------------------------------------------------------------- 305 */ 306 void 307 Buf_ReplaceLastByte (buf, byte) 308 Buffer buf; /* buffer to augment */ 309 int byte; /* byte to be written */ 310 { 311 if (buf->inPtr == buf->outPtr) 312 Buf_AddByte(buf, byte); 313 else 314 *(buf->inPtr - 1) = byte; 315 } 316
Indexes created Mon Sep 22 13:09:51 GMT 2025