Function posix_log_append

src/daemon/service.c:591–656

}

static bool posix_log_append(const char *log_path, const char *record, size_t record_length,
                             size_t cap_bytes) {
    posix_log_path_t path;
    if (!posix_log_path_open(log_path, &path)) {
        return false;
    }
    bool lock_created = false;
    int lock_fd = posix_lock_file_open(&path, &lock_created);
    if (lock_fd >= 0) {
        conflict_log_test_hook(CBM_DAEMON_CONFLICT_LOG_BEFORE_SERIALIZATION_LOCK);
    }
    bool ok = lock_fd >= 0 && posix_lock_exclusive(lock_fd);
    if (ok) {
        conflict_log_test_hook(CBM_DAEMON_CONFLICT_LOG_AFTER_SERIALIZATION_LOCK);
    }
    struct stat status;
    bool created = false;
    int fd = ok ? posix_log_file_open(&path, &status, &created) : -1;
    ok = ok && fd >= 0 && posix_log_refresh_locked(&path, fd, &status);
    bool directory_changed = lock_created || created;
    bool rotate = false;
    if (ok && status.st_size > 0) {
        uintmax_t size = (uintmax_t)status.st_size;
        rotate = size > cap_bytes || record_length > cap_bytes - (size_t)size;
    }
    if (ok && rotate) {
        ok = renameat(path.dir_fd, path.base, path.dir_fd, path.rotated) == 0;
        ok = close(fd) == 0 && ok;
        fd = -1;
        directory_changed = directory_changed || ok;
        if (ok) {
            fd = posix_log_file_open(&path, &status, &created);
            ok = fd >= 0 && posix_log_refresh_locked(&path, fd, &status);
            directory_changed = directory_changed || created;
        }
    }
    if (ok) {
        char last = '\n';
        if (status.st_size > 0) {
            ssize_t count;
            do {
                count = pread(fd, &last, 1, status.st_size - 1);
            } while (count < 0 && errno == EINTR);
            ok = count == 1 && last == '\n';
        }
        if (ok) {
            ok = posix_complete_write(fd, record, record_length, status.st_size);
        }
    }
    if (fd >= 0) {
        if (close(fd) != 0) {
            ok = false;
        }
    }
    if (lock_fd >= 0) {
        (void)flock(lock_fd, LOCK_UN);
        if (close(lock_fd) != 0) {
            ok = false;