| /* |
| * ***************************************************************************** |
| * |
| * SPDX-License-Identifier: BSD-2-Clause |
| * |
| * Copyright (c) 2018-2021 Gavin D. Howard and contributors. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * * Redistributions of source code must retain the above copyright notice, this |
| * list of conditions and the following disclaimer. |
| * |
| * * 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. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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. |
| * |
| * ***************************************************************************** |
| * |
| * Code for implementing buffered I/O on my own terms. |
| * |
| */ |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <string.h> |
| |
| #ifndef _WIN32 |
| #include <unistd.h> |
| #endif // _WIN32 |
| |
| #include <file.h> |
| #include <vm.h> |
| |
| /** |
| * Translates an integer into a string. |
| * @param val The value to translate. |
| * @param buf The return parameter. |
| */ |
| static void bc_file_ultoa(unsigned long long val, char buf[BC_FILE_ULL_LENGTH]) |
| { |
| char buf2[BC_FILE_ULL_LENGTH]; |
| size_t i, len; |
| |
| // We need to make sure the entire thing is zeroed. |
| memset(buf2, 0, BC_FILE_ULL_LENGTH); |
| |
| // The i = 1 is to ensure that there is a null byte at the end. |
| for (i = 1; val; ++i) { |
| |
| unsigned long long mod = val % 10; |
| |
| buf2[i] = ((char) mod) + '0'; |
| val /= 10; |
| } |
| |
| len = i; |
| |
| // Since buf2 is reversed, reverse it into buf. |
| for (i = 0; i < len; ++i) buf[i] = buf2[len - i - 1]; |
| } |
| |
| /** |
| * Output to the file directly. |
| * @param fd The file descriptor. |
| * @param buf The buffer of data to output. |
| * @param n The number of bytes to output. |
| * @return A status indicating error or success. We could have a fatal I/O |
| * error or EOF. |
| */ |
| static BcStatus bc_file_output(int fd, const char *buf, size_t n) { |
| |
| size_t bytes = 0; |
| sig_atomic_t lock; |
| |
| BC_SIG_TRYLOCK(lock); |
| |
| // While the number of bytes written is less than intended... |
| while (bytes < n) { |
| |
| // Write. |
| ssize_t written = write(fd, buf + bytes, n - bytes); |
| |
| // Check for error and return, if any. |
| if (BC_ERR(written == -1)) |
| return errno == EPIPE ? BC_STATUS_EOF : BC_STATUS_ERROR_FATAL; |
| |
| bytes += (size_t) written; |
| } |
| |
| BC_SIG_TRYUNLOCK(lock); |
| |
| return BC_STATUS_SUCCESS; |
| } |
| |
| BcStatus bc_file_flushErr(BcFile *restrict f, BcFlushType type) |
| { |
| BcStatus s; |
| |
| // If there is stuff to output... |
| if (f->len) { |
| |
| #if BC_ENABLE_HISTORY |
| |
| // If history is enabled... |
| if (BC_TTY) { |
| |
| // If we have been told to save the extras, and there *are* |
| // extras... |
| if (f->buf[f->len - 1] != '\n' && |
| (type == BC_FLUSH_SAVE_EXTRAS_CLEAR || |
| type == BC_FLUSH_SAVE_EXTRAS_NO_CLEAR)) |
| { |
| size_t i; |
| |
| // Look for the last newline. |
| for (i = f->len - 2; i < f->len && f->buf[i] != '\n'; --i); |
| |
| i += 1; |
| |
| // Save the extras. |
| bc_vec_string(&vm.history.extras, f->len - i, f->buf + i); |
| } |
| // Else clear the extras if told to. |
| else if (type >= BC_FLUSH_NO_EXTRAS_CLEAR) { |
| bc_vec_popAll(&vm.history.extras); |
| } |
| } |
| #endif // BC_ENABLE_HISTORY |
| |
| // Actually output. |
| s = bc_file_output(f->fd, f->buf, f->len); |
| f->len = 0; |
| } |
| else s = BC_STATUS_SUCCESS; |
| |
| return s; |
| } |
| |
| void bc_file_flush(BcFile *restrict f, BcFlushType type) { |
| |
| BcStatus s = bc_file_flushErr(f, type); |
| |
| // If we have an error... |
| if (BC_ERR(s)) { |
| |
| // For EOF, set it and jump. |
| if (s == BC_STATUS_EOF) { |
| vm.status = (sig_atomic_t) s; |
| BC_JMP; |
| } |
| // Blow up on fatal error. Okay, not blow up, just quit. |
| else bc_vm_fatalError(BC_ERR_FATAL_IO_ERR); |
| } |
| } |
| |
| void bc_file_write(BcFile *restrict f, BcFlushType type, |
| const char *buf, size_t n) |
| { |
| // If we have enough to flush, do it. |
| if (n > f->cap - f->len) { |
| bc_file_flush(f, type); |
| assert(!f->len); |
| } |
| |
| // If the output is large enough to flush by itself, just output it. |
| // Otherwise, put it into the buffer. |
| if (BC_UNLIKELY(n > f->cap - f->len)) bc_file_output(f->fd, buf, n); |
| else { |
| memcpy(f->buf + f->len, buf, n); |
| f->len += n; |
| } |
| } |
| |
| void bc_file_printf(BcFile *restrict f, const char *fmt, ...) |
| { |
| va_list args; |
| |
| va_start(args, fmt); |
| bc_file_vprintf(f, fmt, args); |
| va_end(args); |
| } |
| |
| void bc_file_vprintf(BcFile *restrict f, const char *fmt, va_list args) { |
| |
| char *percent; |
| const char *ptr = fmt; |
| char buf[BC_FILE_ULL_LENGTH]; |
| |
| // This is a poor man's printf(). While I could look up algorithms to make |
| // it as fast as possible, and should when I write the standard library for |
| // a new language, for bc, outputting is not the bottleneck. So we cheese it |
| // for now. |
| |
| // Find each percent sign. |
| while ((percent = strchr(ptr, '%')) != NULL) { |
| |
| char c; |
| |
| // If the percent sign is not where we are, write what's inbetween to |
| // the buffer. |
| if (percent != ptr) { |
| size_t len = (size_t) (percent - ptr); |
| bc_file_write(f, bc_flush_none, ptr, len); |
| } |
| |
| c = percent[1]; |
| |
| // We only parse some format specifiers, the ones bc uses. If you add |
| // more, you need to make sure to add them here. |
| if (c == 'c') { |
| |
| uchar uc = (uchar) va_arg(args, int); |
| |
| bc_file_putchar(f, bc_flush_none, uc); |
| } |
| else if (c == 's') { |
| |
| char *s = va_arg(args, char*); |
| |
| bc_file_puts(f, bc_flush_none, s); |
| } |
| #if BC_DEBUG_CODE |
| // We only print signed integers in debug code. |
| else if (c == 'd') { |
| |
| int d = va_arg(args, int); |
| |
| // Take care of negative. Let's not worry about overflow. |
| if (d < 0) { |
| bc_file_putchar(f, bc_flush_none, '-'); |
| d = -d; |
| } |
| |
| // Either print 0 or translate and print. |
| if (!d) bc_file_putchar(f, bc_flush_none, '0'); |
| else { |
| bc_file_ultoa((unsigned long long) d, buf); |
| bc_file_puts(f, bc_flush_none, buf); |
| } |
| } |
| #endif // BC_DEBUG_CODE |
| else { |
| |
| unsigned long long ull; |
| |
| // These are the ones that it expects from here. Fortunately, all of |
| // these are unsigned types, so they can use the same code, more or |
| // less. |
| assert((c == 'l' || c == 'z') && percent[2] == 'u'); |
| |
| if (c == 'z') ull = (unsigned long long) va_arg(args, size_t); |
| else ull = (unsigned long long) va_arg(args, unsigned long); |
| |
| // Either print 0 or translate and print. |
| if (!ull) bc_file_putchar(f, bc_flush_none, '0'); |
| else { |
| bc_file_ultoa(ull, buf); |
| bc_file_puts(f, bc_flush_none, buf); |
| } |
| } |
| |
| // Increment to the next spot after the specifier. |
| ptr = percent + 2 + (c == 'l' || c == 'z'); |
| } |
| |
| // If we get here, there are no more percent signs, so we just output |
| // whatever is left. |
| if (ptr[0]) bc_file_puts(f, bc_flush_none, ptr); |
| } |
| |
| void bc_file_puts(BcFile *restrict f, BcFlushType type, const char *str) { |
| bc_file_write(f, type, str, strlen(str)); |
| } |
| |
| void bc_file_putchar(BcFile *restrict f, BcFlushType type, uchar c) { |
| |
| if (f->len == f->cap) bc_file_flush(f, type); |
| |
| assert(f->len < f->cap); |
| |
| f->buf[f->len] = (char) c; |
| f->len += 1; |
| } |
| |
| void bc_file_init(BcFile *f, int fd, char *buf, size_t cap) { |
| |
| BC_SIG_ASSERT_LOCKED; |
| |
| f->fd = fd; |
| f->buf = buf; |
| f->len = 0; |
| f->cap = cap; |
| } |
| |
| void bc_file_free(BcFile *f) { |
| BC_SIG_ASSERT_LOCKED; |
| bc_file_flush(f, bc_flush_none); |
| } |