[GitHub] [arrow] aucahuasi commented on a diff in pull request #14226: ARROW-17599: [C++] Change the way how arrow reads parquet buffered files

[GitBox]

aucahuasi commented on code in PR #14226:
URL: https://github.com/apache/arrow/pull/14226#discussion_r996424739


##########
cpp/src/parquet/arrow/reader.cc:
##########
@@ -1107,8 +1112,13 @@ class RowGroupGenerator {
     if (!reader->properties().pre_buffer()) {
       row_group_read = SubmitRead(cpu_executor_, reader, row_group, 
column_indices);
     } else {
+      reader->parquet_reader()->PreBuffer({row_group}, column_indices_,
+                                          reader_properties_.io_context(),
+                                          reader_properties_.cache_options());
       auto ready = reader->parquet_reader()->WhenBuffered({row_group}, 
column_indices);
       if (cpu_executor_) ready = cpu_executor_->TransferAlways(ready);
+      // wait for buffering the rowgroup before read it
+      ready.Wait();

Review Comment:
   Thanks David, I got this error when I don't use wait:
   `ReadRangeCache did not find matching cache entry`
   It's like the `parquet_reader()->WhenBuffered` call is not really waiting to 
have the buffer ready before read the rowgroup.
   I'll investigate more what could be the issue here.



-- 
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