纯C ringbuf源码和示例

/* * test-ringbuf.c - unit tests for C ring buffer implementation. * * Written in 2011 by Drew Hess <dhess-src@bothan.net>. * * To the extent possible under law, the author(s) have dedicated all * copyright and related and neighboring rights to this software to * the public domain worldwide. This software is distributed without * any warranty. * * You should have received a copy of the CC0 Public Domain Dedication * along with this software. If not, see * <http://creativecommons.org/publicdomain/zero/1.0/>. */ #include <string.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <signal.h> #include <assert.h> #include "ringbuf.h" /* * Fill a buffer with a test pattern. */ void * fill_buffer(void *buf, size_t buf_size, const char *test_pattern) { size_t pattern_size = strlen(test_pattern); size_t nblocks = buf_size / pattern_size; uint8_t *p = buf; size_t n; for (n = 0; n != nblocks; ++n, p += pattern_size) memcpy(p, (const void *) test_pattern, pattern_size); memcpy(p, (const void *) test_pattern, buf_size % pattern_size); return buf; } int rdfd = -1; int wrfd = -1; char rd_template[] = "/tmp/tmpXXXXXXringbuf"; char wr_template[] = "/tmp/tmpXXXXXXringbuf-wr"; void cleanup() { if (rdfd != -1) { close(rdfd); unlink(rd_template); } if (wrfd != -1) { close(wrfd); unlink(wr_template); } } void sigabort(int unused) { cleanup(); exit(1); } #define START_NEW_TEST(test_num) \ fprintf(stderr, "Test %d...", (++test_num)); #define END_TEST(test_num) \ fprintf(stderr, "pass.\n"); /* Default size for these tests. */ #define RINGBUF_SIZE 4096 int main(int argc, char **argv) { if (atexit(cleanup) == -1) { fprintf(stderr, "Can't install atexit handler, exiting.\n"); exit(98); } /* * catch SIGABRT when asserts fail for proper test file * cleanup. */ struct sigaction sa, osa; sa.sa_handler = sigabort; sigemptyset(&sa.sa_mask); sa.sa_flags = 0; if (sigaction(SIGABRT, &sa, &osa) == -1) { fprintf(stderr, "Can't install SIGABRT handler, exiting.\n"); exit(99); } ringbuf_t rb1 = ringbuf_new(RINGBUF_SIZE - 1); int test_num = 0; /* * N.B.: these tests check both the ringbuf_t interface *and* a * particular implementation. They are not black-box tests. If you * make changes to the ringbuf_t implementation, some of these * tests may break. */ /* We use the base pointer for some implementation testing. */ const uint8_t *rb1_base = ringbuf_head(rb1); /* Initial conditions */ START_NEW_TEST(test_num); assert(ringbuf_buffer_size(rb1) == RINGBUF_SIZE); assert(ringbuf_capacity(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_bytes_free(rb1) == ringbuf_capacity(rb1)); assert(ringbuf_bytes_used(rb1) == 0); assert(!ringbuf_is_full(rb1)); assert(ringbuf_is_empty(rb1)); assert(ringbuf_tail(rb1) == ringbuf_head(rb1)); assert(ringbuf_tail(rb1) == rb1_base); END_TEST(test_num); /* freeing a ring buffer sets the pointer to 0 */ START_NEW_TEST(test_num); ringbuf_free(&rb1); assert(!rb1); END_TEST(test_num); /* Different sizes */ rb1 = ringbuf_new(24); rb1_base = ringbuf_head(rb1); START_NEW_TEST(test_num); assert(ringbuf_buffer_size(rb1) == 25); assert(ringbuf_capacity(rb1) == 24); assert(ringbuf_bytes_free(rb1) == ringbuf_capacity(rb1)); assert(ringbuf_bytes_used(rb1) == 0); assert(!ringbuf_is_full(rb1)); assert(ringbuf_is_empty(rb1)); assert(ringbuf_tail(rb1) == ringbuf_head(rb1)); assert(ringbuf_tail(rb1) == rb1_base); ringbuf_free(&rb1); assert(!rb1); END_TEST(test_num); rb1 = ringbuf_new(RINGBUF_SIZE - 1); rb1_base = ringbuf_head(rb1); /* ringbuf_reset tests */ START_NEW_TEST(test_num); ringbuf_memset(rb1, 1, 8); ringbuf_reset(rb1); assert(ringbuf_buffer_size(rb1) == RINGBUF_SIZE); assert(ringbuf_capacity(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_bytes_free(rb1) == ringbuf_capacity(rb1)); assert(ringbuf_bytes_used(rb1) == 0); assert(!ringbuf_is_full(rb1)); assert(ringbuf_is_empty(rb1)); assert(ringbuf_tail(rb1) == ringbuf_head(rb1)); assert(ringbuf_tail(rb1) == rb1_base); END_TEST(test_num); START_NEW_TEST(test_num); ringbuf_memset(rb1, 1, ringbuf_buffer_size(rb1)); /* overflow */ ringbuf_reset(rb1); assert(ringbuf_buffer_size(rb1) == RINGBUF_SIZE); assert(ringbuf_capacity(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_bytes_free(rb1) == ringbuf_capacity(rb1)); assert(ringbuf_bytes_used(rb1) == 0); assert(!ringbuf_is_full(rb1)); assert(ringbuf_is_empty(rb1)); assert(ringbuf_tail(rb1) == ringbuf_head(rb1)); assert(ringbuf_tail(rb1) == rb1_base); END_TEST(test_num); /* ringbuf_memset with zero count */ START_NEW_TEST(test_num); ringbuf_reset(rb1); assert(ringbuf_memset(rb1, 1, 0) == 0); assert(ringbuf_capacity(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_bytes_free(rb1) == ringbuf_capacity(rb1)); assert(ringbuf_bytes_used(rb1) == 0); assert(!ringbuf_is_full(rb1)); assert(ringbuf_is_empty(rb1)); assert(ringbuf_tail(rb1) == ringbuf_head(rb1)); END_TEST(test_num); uint8_t *buf = malloc(RINGBUF_SIZE * 2); memset(buf, 57, RINGBUF_SIZE); memset(buf + RINGBUF_SIZE, 58, RINGBUF_SIZE); /* ringbuf_memset a few bytes of data */ START_NEW_TEST(test_num); ringbuf_reset(rb1); assert(ringbuf_memset(rb1, 57, 7) == 7); assert(ringbuf_capacity(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_bytes_free(rb1) == ringbuf_capacity(rb1) - 7); assert(ringbuf_bytes_used(rb1) == 7); assert(!ringbuf_is_full(rb1)); assert(!ringbuf_is_empty(rb1)); assert(strncmp((const char *) buf, ringbuf_tail(rb1), 7) == 0); END_TEST(test_num); /* ringbuf_memset full capacity */ START_NEW_TEST(test_num); ringbuf_reset(rb1); assert(ringbuf_memset(rb1, 57, RINGBUF_SIZE - 1) == RINGBUF_SIZE - 1); assert(ringbuf_capacity(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_bytes_free(rb1) == 0); assert(ringbuf_bytes_used(rb1) == ringbuf_capacity(rb1)); assert(ringbuf_is_full(rb1)); assert(!ringbuf_is_empty(rb1)); assert(strncmp(ringbuf_tail(rb1), (const char *) buf, RINGBUF_SIZE - 1) == 0); END_TEST(test_num); /* ringbuf_memset, twice */ START_NEW_TEST(test_num); ringbuf_reset(rb1); assert(ringbuf_memset(rb1, 57, 7) == 7); assert(ringbuf_memset(rb1, 57, 15) == 15); assert(ringbuf_capacity(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_bytes_used(rb1) == 7 + 15); assert(ringbuf_bytes_free(rb1) == ringbuf_capacity(rb1) - (7 + 15)); assert(!ringbuf_is_full(rb1)); assert(!ringbuf_is_empty(rb1)); assert(strncmp((const char *) buf, ringbuf_tail(rb1), 7 + 15) == 0); END_TEST(test_num); /* ringbuf_memset, twice (to full capacity) */ START_NEW_TEST(test_num); ringbuf_reset(rb1); assert(ringbuf_memset(rb1, 57, RINGBUF_SIZE - 2) == RINGBUF_SIZE - 2); assert(ringbuf_memset(rb1, 57, 1) == 1); assert(ringbuf_capacity(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_bytes_free(rb1) == 0); assert(ringbuf_bytes_used(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_is_full(rb1)); assert(!ringbuf_is_empty(rb1)); assert(strncmp((const char *) buf, ringbuf_tail(rb1), RINGBUF_SIZE - 1) == 0); END_TEST(test_num); /* ringbuf_memset, overflow by 1 byte */ START_NEW_TEST(test_num); ringbuf_reset(rb1); assert(ringbuf_memset(rb1, 57, RINGBUF_SIZE) == RINGBUF_SIZE); assert(ringbuf_capacity(rb1) == RINGBUF_SIZE - 1); assert(ringbuf_bytes_free(rb1) == 0); assert(ringbuf_bytes_used(rb1) == ringbuf_capacity(rb1)); assert(ringbuf_is_full(rb1)); assert(!ringbuf_is_empty(rb1)); /* head sho