Github user ravipesala commented on a diff in the pull request:
https://github.com/apache/carbondata/pull/2374#discussion_r197016816
--- Diff:
hadoop/src/main/java/org/apache/carbondata/hadoop/CsvRecordReader.java ---
@@ -0,0 +1,506 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.carbondata.hadoop;
+
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.io.UnsupportedEncodingException;
+import java.math.BigDecimal;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.carbondata.common.annotations.InterfaceAudience;
+import org.apache.carbondata.common.annotations.InterfaceStability;
+import org.apache.carbondata.common.logging.LogService;
+import org.apache.carbondata.common.logging.LogServiceFactory;
+import org.apache.carbondata.core.constants.CarbonCommonConstants;
+import org.apache.carbondata.core.constants.CarbonV3DataFormatConstants;
+import org.apache.carbondata.core.datastore.block.SegmentProperties;
+import org.apache.carbondata.core.metadata.schema.table.CarbonTable;
+import
org.apache.carbondata.core.metadata.schema.table.column.CarbonColumn;
+import
org.apache.carbondata.core.metadata.schema.table.column.CarbonDimension;
+import
org.apache.carbondata.core.metadata.schema.table.column.CarbonMeasure;
+import
org.apache.carbondata.core.metadata.schema.table.column.ColumnSchema;
+import
org.apache.carbondata.core.scan.expression.exception.FilterUnsupportedException;
+import org.apache.carbondata.core.scan.filter.FilterUtil;
+import org.apache.carbondata.core.scan.filter.GenericQueryType;
+import org.apache.carbondata.core.scan.filter.executer.FilterExecuter;
+import org.apache.carbondata.core.scan.filter.intf.RowImpl;
+import org.apache.carbondata.core.scan.filter.intf.RowIntf;
+import org.apache.carbondata.core.scan.filter.resolver.FilterResolverIntf;
+import org.apache.carbondata.core.scan.model.QueryModel;
+import org.apache.carbondata.core.statusmanager.FileFormatProperties;
+import org.apache.carbondata.core.util.CarbonUtil;
+import org.apache.carbondata.core.util.DataTypeUtil;
+import org.apache.carbondata.hadoop.api.CarbonTableInputFormat;
+import org.apache.carbondata.hadoop.readsupport.CarbonReadSupport;
+import org.apache.carbondata.processing.loading.csvinput.CSVInputFormat;
+
+import com.univocity.parsers.csv.CsvParser;
+import com.univocity.parsers.csv.CsvParserSettings;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.mapreduce.InputSplit;
+import org.apache.hadoop.mapreduce.TaskAttemptContext;
+import org.apache.hadoop.mapreduce.lib.input.FileSplit;
+
+/**
+ * scan csv file and filter on it
+ */
[email protected]
[email protected]
+public class CsvRecordReader<T> extends AbstractRecordReader<T> {
+ private static final LogService LOGGER = LogServiceFactory.getLogService(
+ CsvRecordReader.class.getName());
+ private static final int MAX_BATCH_SIZE =
+
CarbonV3DataFormatConstants.NUMBER_OF_ROWS_PER_BLOCKLET_COLUMN_PAGE_DEFAULT;
+ // vector reader
+ private boolean isVectorReader;
+ private T columnarBatch;
+
+ // metadata
+ private CarbonTable carbonTable;
+ private CarbonColumn[] carbonColumns;
+ // input
+ private QueryModel queryModel;
+ private CarbonReadSupport<T> readSupport;
+ private FileSplit fileSplit;
+ private Configuration hadoopConf;
+ // the index is schema ordinal, the value is the csv ordinal
+ private int[] schema2csvIdx;
+
+ // filter
+ private FilterExecuter filter;
--- End diff --
And also there should be an option whether we should push down filters or
execution should handle this and default let execution handle it. Here we are
supporting filters in a crude way, so the performance will not be good. If
execution engine like spark handles it in a better way using code generation.
---
