Hello,
As part of some custom filter building I took the source
of SingleColumnValueFilter (HBase 0.92.1) [1] and wanted to tweak it to NOT
return the matched column - thus essentially make it
equivalent SingleColumnValueExcludeFilter. I thought it must be trivial but
for some reason I cannot get it to work. The filter always includes the
matched KV pair.
The only change I made is in the filterKeyValue(<KeyValue>) method by
editing the last statement (see below):
public ReturnCode filterKeyValue(KeyValue keyValue) {
if (this.matchedColumn) {
// We already found and matched the single column, all keys now pass
return ReturnCode.INCLUDE;
} else if (this.latestVersionOnly && this.foundColumn) {
// We found but did not match the single column, skip to next row
return ReturnCode.NEXT_ROW;
}
if (!keyValue.matchingColumn(this.columnFamily, this.columnQualifier)) {
return ReturnCode.INCLUDE;
}
foundColumn = true;
if (filterColumnValue(keyValue.getBuffer(),
keyValue.getValueOffset(), keyValue.getValueLength())) {
return this.latestVersionOnly? ReturnCode.NEXT_ROW:
ReturnCode.INCLUDE;
}
this.matchedColumn = true;
// Commented line below to NOT include matched column
// return ReturnCode.INCLUDE;
return ReturnCode.SKIP;
}
Is this expected behavior? What am I overlooking here? By the way - how can
I sensibly debug filters. I tried using the Log instance but the output
does not show up in the region server's output.
Thank you,
/David
[1]
http://grepcode.com/file_/repo1.maven.org/maven2/org.apache.hbase/hbase/0.92.1/org/apache/hadoop/hbase/filter/SingleColumnValueFilter.java/?v=source
