diff options
Diffstat (limited to 'sum_fd.c')
| -rw-r--r-- | sum_fd.c | 32 |
1 files changed, 32 insertions, 0 deletions
@@ -16,17 +16,42 @@ libsha1_sum_fd(int fd, enum libsha1_algorithm algorithm, void *restrict hashsum) { struct libsha1_state state; ssize_t r; +#ifndef _WIN32 struct stat attr; +#endif size_t blksize = 4096; char *restrict chunk; if (libsha1_init(&state, algorithm) < 0) return -1; +#ifndef _WIN32 if (fstat(fd, &attr) == 0 && attr.st_blksize > 0) blksize = (size_t)(attr.st_blksize); +#endif +#if ALLOCA_LIMIT > 0 + if (blksize > (size_t)ALLOCA_LIMIT) { + blksize = (size_t)ALLOCA_LIMIT; + blksize -= blksize % sizeof(((struct libsha1_state)NULL)->chunk); + if (!blksize) + blksize = sizeof(((struct libsha1_state)NULL)->chunk); + } +# if defined(__clang__) + /* We are using a limit so it's just like declaring an array + * in a function, except we might use less of the stack. */ +# pragma clang diagnostic push +# pragma clang diagnostic ignored "-Walloca" +# endif chunk = alloca(blksize); +# if defined(__clang__) +# pragma clang diagnostic pop +# endif +#else + chunk = malloc(blksize); + if (!chunk) + return -1; +#endif for (;;) { r = read(fd, chunk, blksize); @@ -35,11 +60,18 @@ libsha1_sum_fd(int fd, enum libsha1_algorithm algorithm, void *restrict hashsum) break; if (errno == EINTR) continue; +#if ALLOCA_LIMIT <= 0 + free(chunk); +#endif return -1; } libsha1_update(&state, chunk, (size_t)r * 8); } libsha1_digest(&state, NULL, 0, hashsum); + +#if ALLOCA_LIMIT <= 0 + free(chunk); +#endif return 0; } |