[
https://issues.apache.org/jira/browse/ARROW-2411?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16429793#comment-16429793
]
ASF GitHub Bot commented on ARROW-2411:
---------------------------------------
pitrou commented on a change in pull request #1852: ARROW-2411: [C++] Add
StringBuilder::Append(const char **values)
URL: https://github.com/apache/arrow/pull/1852#discussion_r179952045
##########
File path: cpp/src/arrow/builder.cc
##########
@@ -1413,6 +1413,41 @@ Status StringBuilder::Append(const
std::vector<std::string>& values,
return Status::OK();
}
+Status StringBuilder::Append(const char** values,
+ int64_t length,
+ const uint8_t* valid_bytes) {
+ std::size_t total_length = 0;
+ std::vector<std::size_t> value_lengths(length);
+ for (int64_t i = 0; i < length; ++i) {
+ if (values[i]) {
+ auto value_length = strlen(values[i]);
+ value_lengths[i] = value_length;
+ total_length += value_length;
+ }
+ }
+ RETURN_NOT_OK(Reserve(length));
+ RETURN_NOT_OK(value_data_builder_.Reserve(total_length));
+ RETURN_NOT_OK(offsets_builder_.Reserve(length));
+
+ if (valid_bytes) {
+ for (int64_t i = 0; i < length; ++i) {
+ RETURN_NOT_OK(AppendNextOffset());
+ if (valid_bytes[i]) {
+ RETURN_NOT_OK(value_data_builder_.Append(
+ reinterpret_cast<const uint8_t*>(values[i]), value_lengths[i]));
+ }
+ }
+ } else {
+ for (int64_t i = 0; i < length; ++i) {
+ RETURN_NOT_OK(AppendNextOffset());
+ RETURN_NOT_OK(value_data_builder_.Append(
+ reinterpret_cast<const uint8_t*>(values[i]), value_lengths[i]));
Review comment:
Hmm, yes, I think it's a bad idea. If we accept `NULL` value pointers, it
should IMHO *always* mean a null item in the array (regardless of
`valid_bytes`). If we don't accept `NULL` value pointers, we should at least
add a DCHECK against them.
I think it's a good idea to accept them, that way people don't have to
allocate a separate `valid_bytes` array.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
> [C++] Add method to append batches of null-terminated strings to StringBuilder
> ------------------------------------------------------------------------------
>
> Key: ARROW-2411
> URL: https://issues.apache.org/jira/browse/ARROW-2411
> Project: Apache Arrow
> Issue Type: Improvement
> Components: C++, GLib
> Reporter: Uwe L. Korn
> Priority: Major
> Labels: pull-request-available
> Fix For: 0.10.0
>
>
> We should add a method {{StringBuilder::AppendCStrings(const char** values,
> const uint8_t* valid_bytes = NULLPTR)}} to the {{StringBuilder}} class to
> have fast inserts for these strings. See
> https://github.com/apache/arrow/pull/1845/files for a use case.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
