string buf;
buf.resize(buf_size);
size_t ret = ZDICT_trainFromBuffer(&buf[0], buf_size, dictionary_buf.data(), lengths.data(), lengths.size());
+ if (ret == size_t(-1)) {
+ return "";
+ }
dprintf("Sampled %zu bytes in %zu blocks, built a dictionary of size %zu\n", dictionary_buf.size(), lengths.size(), ret);
buf.resize(ret);