SPARK-4365: Remove unnecessary filter call on records returned from parquet library

[saucam]

Since parquet library has been updated , we no longer need to filter the records returned from parquet library for null records , as now the library skips those :

from parquet-hadoop/src/main/java/parquet/hadoop/InternalParquetRecordReader.java

public boolean nextKeyValue() throws IOException, InterruptedException {
boolean recordFound = false;
while (!recordFound) {
// no more records left
if (current >= total)
{ return false; }
try {
checkRead();
currentValue = recordReader.read();
current ++;
if (recordReader.shouldSkipCurrentRecord())
{
// this record is being filtered via the filter2 package
if (DEBUG) LOG.debug("skipping record");
continue;
}
if (currentValue == null)
{
// only happens with FilteredRecordReader at end of block current = totalCountLoadedSoFar;
if (DEBUG) LOG.debug("filtered record reader reached end of block");
continue;
}

recordFound = true;
if (DEBUG) LOG.debug("read value: " + currentValue);
} catch (RuntimeException e)
{ throw new ParquetDecodingException(format("Can not read value at %d in block %d in file %s", current, currentBlock, file), e); }

}
return true;
}

[AmplabJenkins]

Can one of the admins verify this patch?

[liancheng]

test this please

[SparkQA]

Test build #23370 has started for PR 3229 at commit 8909ae9.

• This patch merges cleanly.

[SparkQA]

Test build #23370 has finished for PR 3229 at commit 8909ae9.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[AmplabJenkins]

Test PASSed.
Refer to this link for build results (access rights to CI server needed):
https://amplab.cs.berkeley.edu/jenkins//job/SparkPullRequestBuilder/23370/
Test PASSed.

[marmbrus]

Thanks! Merged to master and 1.2.

[saucam]

Thanks everyone!