augustoasilva commented on a change in pull request #11551: URL: https://github.com/apache/arrow/pull/11551#discussion_r745739442
########## File path: cpp/src/gandiva/gdv_function_stubs.cc ########## @@ -794,6 +795,94 @@ const char* gdv_fn_initcap_utf8(int64_t context, const char* data, int32_t data_ *out_len = out_idx; return out; } + +GANDIVA_EXPORT +const char* gdv_fn_mask_first_n(int64_t context, const char* data, int32_t data_len, + int32_t n_to_mask, int32_t* out_len) { + if (data_len <= 0) { + *out_len = 0; + return nullptr; + } + + int32_t end_idx = data_len < n_to_mask ? data_len : n_to_mask; + + *out_len = data_len; + + char* out = reinterpret_cast<char*>(gdv_fn_context_arena_malloc(context, *out_len)); + if (out == nullptr) { + gdv_fn_context_set_error_msg(context, "Could not allocate memory for output string"); + *out_len = 0; + return nullptr; + } + + static char mask_array[] = { + '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', + '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', + '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0', + '\0', '\0', '\0', '\0', '\0', '\0', 'n', 'n', 'n', 'n', 'n', 'n', 'n', 'n', + 'n', 'n', '\0', '\0', '\0', '\0', '\0', '\0', '\0', 'X', 'X', 'X', 'X', 'X', + 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', + 'X', 'X', 'X', 'X', 'X', 'X', 'X', '\0', '\0', '\0', '\0', '\0', '\0', 'x', + 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', + 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', 'x', '\0'}; + + // do the masking + for (int i = 0; i < end_idx; ++i) { + if (mask_array[(unsigned char)data[i]] != '\0') { Review comment: Removed -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org