1 /* 2 * ***************************************************************************** 3 * 4 * SPDX-License-Identifier: BSD-2-Clause 5 * 6 * Copyright (c) 2018-2021 Gavin D. Howard and contributors. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions are met: 10 * 11 * * Redistributions of source code must retain the above copyright notice, this 12 * list of conditions and the following disclaimer. 13 * 14 * * Redistributions in binary form must reproduce the above copyright notice, 15 * this list of conditions and the following disclaimer in the documentation 16 * and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 * 30 * ***************************************************************************** 31 * 32 * Code for implementing buffered I/O on my own terms. 33 * 34 */ 35 36 #include <assert.h> 37 #include <errno.h> 38 #include <string.h> 39 40 #ifndef _WIN32 41 #include <unistd.h> 42 #endif // _WIN32 43 44 #include <file.h> 45 #include <vm.h> 46 47 /** 48 * Translates an integer into a string. 49 * @param val The value to translate. 50 * @param buf The return parameter. 51 */ 52 static void bc_file_ultoa(unsigned long long val, char buf[BC_FILE_ULL_LENGTH]) 53 { 54 char buf2[BC_FILE_ULL_LENGTH]; 55 size_t i, len; 56 57 // We need to make sure the entire thing is zeroed. 58 memset(buf2, 0, BC_FILE_ULL_LENGTH); 59 60 // The i = 1 is to ensure that there is a null byte at the end. 61 for (i = 1; val; ++i) { 62 63 unsigned long long mod = val % 10; 64 65 buf2[i] = ((char) mod) + '0'; 66 val /= 10; 67 } 68 69 len = i; 70 71 // Since buf2 is reversed, reverse it into buf. 72 for (i = 0; i < len; ++i) buf[i] = buf2[len - i - 1]; 73 } 74 75 /** 76 * Output to the file directly. 77 * @param fd The file descriptor. 78 * @param buf The buffer of data to output. 79 * @param n The number of bytes to output. 80 * @return A status indicating error or success. We could have a fatal I/O 81 * error or EOF. 82 */ 83 static BcStatus bc_file_output(int fd, const char *buf, size_t n) { 84 85 size_t bytes = 0; 86 sig_atomic_t lock; 87 88 BC_SIG_TRYLOCK(lock); 89 90 // While the number of bytes written is less than intended... 91 while (bytes < n) { 92 93 // Write. 94 ssize_t written = write(fd, buf + bytes, n - bytes); 95 96 // Check for error and return, if any. 97 if (BC_ERR(written == -1)) 98 return errno == EPIPE ? BC_STATUS_EOF : BC_STATUS_ERROR_FATAL; 99 100 bytes += (size_t) written; 101 } 102 103 BC_SIG_TRYUNLOCK(lock); 104 105 return BC_STATUS_SUCCESS; 106 } 107 108 BcStatus bc_file_flushErr(BcFile *restrict f, BcFlushType type) 109 { 110 BcStatus s; 111 112 // If there is stuff to output... 113 if (f->len) { 114 115 #if BC_ENABLE_HISTORY 116 117 // If history is enabled... 118 if (BC_TTY) { 119 120 // If we have been told to save the extras, and there *are* 121 // extras... 122 if (f->buf[f->len - 1] != '\n' && 123 (type == BC_FLUSH_SAVE_EXTRAS_CLEAR || 124 type == BC_FLUSH_SAVE_EXTRAS_NO_CLEAR)) 125 { 126 size_t i; 127 128 // Look for the last newline. 129 for (i = f->len - 2; i < f->len && f->buf[i] != '\n'; --i); 130 131 i += 1; 132 133 // Save the extras. 134 bc_vec_string(&vm.history.extras, f->len - i, f->buf + i); 135 } 136 // Else clear the extras if told to. 137 else if (type >= BC_FLUSH_NO_EXTRAS_CLEAR) { 138 bc_vec_popAll(&vm.history.extras); 139 } 140 } 141 #endif // BC_ENABLE_HISTORY 142 143 // Actually output. 144 s = bc_file_output(f->fd, f->buf, f->len); 145 f->len = 0; 146 } 147 else s = BC_STATUS_SUCCESS; 148 149 return s; 150 } 151 152 void bc_file_flush(BcFile *restrict f, BcFlushType type) { 153 154 BcStatus s = bc_file_flushErr(f, type); 155 156 // If we have an error... 157 if (BC_ERR(s)) { 158 159 // For EOF, set it and jump. 160 if (s == BC_STATUS_EOF) { 161 vm.status = (sig_atomic_t) s; 162 BC_JMP; 163 } 164 // Blow up on fatal error. Okay, not blow up, just quit. 165 else bc_vm_fatalError(BC_ERR_FATAL_IO_ERR); 166 } 167 } 168 169 void bc_file_write(BcFile *restrict f, BcFlushType type, 170 const char *buf, size_t n) 171 { 172 // If we have enough to flush, do it. 173 if (n > f->cap - f->len) { 174 bc_file_flush(f, type); 175 assert(!f->len); 176 } 177 178 // If the output is large enough to flush by itself, just output it. 179 // Otherwise, put it into the buffer. 180 if (BC_UNLIKELY(n > f->cap - f->len)) bc_file_output(f->fd, buf, n); 181 else { 182 memcpy(f->buf + f->len, buf, n); 183 f->len += n; 184 } 185 } 186 187 void bc_file_printf(BcFile *restrict f, const char *fmt, ...) 188 { 189 va_list args; 190 191 va_start(args, fmt); 192 bc_file_vprintf(f, fmt, args); 193 va_end(args); 194 } 195 196 void bc_file_vprintf(BcFile *restrict f, const char *fmt, va_list args) { 197 198 char *percent; 199 const char *ptr = fmt; 200 char buf[BC_FILE_ULL_LENGTH]; 201 202 // This is a poor man's printf(). While I could look up algorithms to make 203 // it as fast as possible, and should when I write the standard library for 204 // a new language, for bc, outputting is not the bottleneck. So we cheese it 205 // for now. 206 207 // Find each percent sign. 208 while ((percent = strchr(ptr, '%')) != NULL) { 209 210 char c; 211 212 // If the percent sign is not where we are, write what's inbetween to 213 // the buffer. 214 if (percent != ptr) { 215 size_t len = (size_t) (percent - ptr); 216 bc_file_write(f, bc_flush_none, ptr, len); 217 } 218 219 c = percent[1]; 220 221 // We only parse some format specifiers, the ones bc uses. If you add 222 // more, you need to make sure to add them here. 223 if (c == 'c') { 224 225 uchar uc = (uchar) va_arg(args, int); 226 227 bc_file_putchar(f, bc_flush_none, uc); 228 } 229 else if (c == 's') { 230 231 char *s = va_arg(args, char*); 232 233 bc_file_puts(f, bc_flush_none, s); 234 } 235 #if BC_DEBUG_CODE 236 // We only print signed integers in debug code. 237 else if (c == 'd') { 238 239 int d = va_arg(args, int); 240 241 // Take care of negative. Let's not worry about overflow. 242 if (d < 0) { 243 bc_file_putchar(f, bc_flush_none, '-'); 244 d = -d; 245 } 246 247 // Either print 0 or translate and print. 248 if (!d) bc_file_putchar(f, bc_flush_none, '0'); 249 else { 250 bc_file_ultoa((unsigned long long) d, buf); 251 bc_file_puts(f, bc_flush_none, buf); 252 } 253 } 254 #endif // BC_DEBUG_CODE 255 else { 256 257 unsigned long long ull; 258 259 // These are the ones that it expects from here. Fortunately, all of 260 // these are unsigned types, so they can use the same code, more or 261 // less. 262 assert((c == 'l' || c == 'z') && percent[2] == 'u'); 263 264 if (c == 'z') ull = (unsigned long long) va_arg(args, size_t); 265 else ull = (unsigned long long) va_arg(args, unsigned long); 266 267 // Either print 0 or translate and print. 268 if (!ull) bc_file_putchar(f, bc_flush_none, '0'); 269 else { 270 bc_file_ultoa(ull, buf); 271 bc_file_puts(f, bc_flush_none, buf); 272 } 273 } 274 275 // Increment to the next spot after the specifier. 276 ptr = percent + 2 + (c == 'l' || c == 'z'); 277 } 278 279 // If we get here, there are no more percent signs, so we just output 280 // whatever is left. 281 if (ptr[0]) bc_file_puts(f, bc_flush_none, ptr); 282 } 283 284 void bc_file_puts(BcFile *restrict f, BcFlushType type, const char *str) { 285 bc_file_write(f, type, str, strlen(str)); 286 } 287 288 void bc_file_putchar(BcFile *restrict f, BcFlushType type, uchar c) { 289 290 if (f->len == f->cap) bc_file_flush(f, type); 291 292 assert(f->len < f->cap); 293 294 f->buf[f->len] = (char) c; 295 f->len += 1; 296 } 297 298 void bc_file_init(BcFile *f, int fd, char *buf, size_t cap) { 299 300 BC_SIG_ASSERT_LOCKED; 301 302 f->fd = fd; 303 f->buf = buf; 304 f->len = 0; 305 f->cap = cap; 306 } 307 308 void bc_file_free(BcFile *f) { 309 BC_SIG_ASSERT_LOCKED; 310 bc_file_flush(f, bc_flush_none); 311 } 312