Examples with MongoRecordReader com.mongodb.hadoop.mapred.input.MongoRecordReader used on opensource projects

Example 1 with MongoRecordReader

use of com.mongodb.hadoop.mapred.input.MongoRecordReader in project mongo-hadoop by mongodb.

the class HiveMongoInputFormat method getRecordReader.

@Override
public RecordReader<BSONWritable, BSONWritable> getRecordReader(final InputSplit split, final JobConf conf, final Reporter reporter) throws IOException {
    // split is of type 'MongoHiveInputSplit'
    MongoHiveInputSplit mhis = (MongoHiveInputSplit) split;
    // Get column name mapping.
    Map<String, String> colToMongoNames = columnMapping(conf);
    // Add projection from Hive.
    DBObject mongoProjection = getProjection(conf, colToMongoNames);
    MongoInputSplit delegate = (MongoInputSplit) mhis.getDelegate();
    if (mongoProjection != null) {
        if (LOG.isDebugEnabled()) {
            LOG.debug("Adding MongoDB projection : " + mongoProjection);
        }
        delegate.setFields(mongoProjection);
    }
    // Filter from Hive.
    DBObject filter = getFilter(conf, colToMongoNames);
    // Combine with filter from table, if there is one.
    if (conf.get(MongoConfigUtil.INPUT_QUERY) != null) {
        DBObject tableFilter = MongoConfigUtil.getQuery(conf);
        if (null == filter) {
            filter = tableFilter;
        } else {
            BasicDBList conditions = new BasicDBList();
            conditions.add(filter);
            conditions.add(tableFilter);
            // Use $and clause so we don't overwrite any of the table
            // filter.
            filter = new BasicDBObject("$and", conditions);
        }
    }
    if (filter != null) {
        if (LOG.isDebugEnabled()) {
            LOG.debug("Adding MongoDB query: " + filter);
        }
        delegate.setQuery(filter);
    }
    // return MongoRecordReader. Delegate is of type 'MongoInputSplit'
    return new MongoRecordReader(delegate);
}