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https://issues.apache.org/jira/browse/DRILL-7293?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16862969#comment-16862969
]
ASF GitHub Bot commented on DRILL-7293:
---------------------------------------
arina-ielchiieva commented on pull request #1807: DRILL-7293: Convert the regex
("log") plugin to use EVF
URL: https://github.com/apache/drill/pull/1807#discussion_r293326805
##########
File path:
exec/java-exec/src/main/java/org/apache/drill/exec/store/log/LogBatchReader.java
##########
@@ -0,0 +1,210 @@
+/*
+ * 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.drill.exec.store.log;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+import org.apache.drill.common.exceptions.UserException;
+import
org.apache.drill.exec.physical.impl.scan.file.FileScanFramework.FileSchemaNegotiator;
+import org.apache.drill.exec.physical.impl.scan.framework.ManagedReader;
+import org.apache.drill.exec.physical.rowSet.ResultSetLoader;
+import org.apache.drill.exec.physical.rowSet.RowSetLoader;
+import org.apache.drill.exec.record.metadata.TupleMetadata;
+import org.apache.drill.exec.vector.accessor.ScalarWriter;
+import org.apache.drill.shaded.guava.com.google.common.base.Charsets;
+import org.apache.hadoop.mapred.FileSplit;
+
+public class LogBatchReader implements ManagedReader<FileSchemaNegotiator> {
+
+ private static final org.slf4j.Logger logger =
org.slf4j.LoggerFactory.getLogger(LogBatchReader.class);
+ public static final String RAW_LINE_COL_NAME = "_raw";
+ public static final String UNMATCHED_LINE_COL_NAME = "_unmatched_rows";
+
+ private FileSplit split;
+ private final LogFormatConfig formatConfig;
+ private final Pattern pattern;
+ private final TupleMetadata schema;
+ private BufferedReader reader;
+ private int capturingGroups;
+ private ResultSetLoader loader;
+ private ScalarWriter rawColWriter;
+ private ScalarWriter unmatchedColWriter;
+ private boolean saveMatchedRows;
+ private int maxErrors;
+ private int lineNumber;
+ private int errorCount;
+
+ public LogBatchReader(LogFormatConfig formatConfig, Pattern pattern,
TupleMetadata schema) {
+ this.formatConfig = formatConfig;
+ this.maxErrors = Math.max(0, formatConfig.getMaxErrors());
+ this.pattern = pattern;
+ this.schema = schema;
+ }
+
+ @Override
+ public boolean open(FileSchemaNegotiator negotiator) {
+ split = negotiator.split();
+ setupPattern();
+ negotiator.setTableSchema(schema, true);
+ loader = negotiator.build();
+ bindColumns(loader.writer());
+ openFile(negotiator);
+ return true;
+ }
+
+ private void setupPattern() {
+ try {
+ Matcher m = pattern.matcher("test");
+ capturingGroups = m.groupCount();
+ } catch (PatternSyntaxException e) {
+ throw UserException
+ .validationError(e)
+ .message("Failed to parse regex: \"%s\"", formatConfig.getRegex())
+ .build(logger);
+ }
+ }
+
+ private void bindColumns(RowSetLoader writer) {
+ for (int i = 0; i < capturingGroups; i++) {
+ saveMatchedRows |= writer.scalar(i).isProjected();
+ }
+ rawColWriter = writer.scalar(RAW_LINE_COL_NAME);
+ saveMatchedRows |= rawColWriter.isProjected();
+ unmatchedColWriter = writer.scalar(UNMATCHED_LINE_COL_NAME);
+
+ // If no match-case columns are projected, and the unmatched
+ // columns is unprojected, then we want to count (matched)
+ // rows.
+
+ saveMatchedRows |= !unmatchedColWriter.isProjected();
+ }
+
+ private void openFile(FileSchemaNegotiator negotiator) {
+ InputStream in;
+ try {
+ in = negotiator.fileSystem().open(split.getPath());
+ } catch (Exception e) {
+ throw UserException
+ .dataReadError(e)
+ .message("Failed to open open input file: %s", split.getPath())
+ .addContext("User name", negotiator.userName())
+ .build(logger);
+ }
+ reader = new BufferedReader(new InputStreamReader(in, Charsets.UTF_8));
+ }
+
+ @Override
+ public boolean next() {
+ RowSetLoader rowWriter = loader.writer();
+ while (! rowWriter.isFull()) {
+ if (! nextLine(rowWriter)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ private boolean nextLine(RowSetLoader rowWriter) {
+ String line;
+ try {
+ line = reader.readLine();
+ } catch (IOException e) {
+ throw UserException
+ .dataReadError(e)
+ .message("Error reading file:")
Review comment:
```suggestion
.message("Error reading file")
```
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> Convert the regex ("log") plugin to use EVF
> -------------------------------------------
>
> Key: DRILL-7293
> URL: https://issues.apache.org/jira/browse/DRILL-7293
> Project: Apache Drill
> Issue Type: Improvement
> Affects Versions: 1.16.0
> Reporter: Paul Rogers
> Assignee: Paul Rogers
> Priority: Major
> Fix For: 1.17.0
>
>
> The "log" plugin (which uses a regex to define the row format) is the subject
> of Chapter 12 of the Learning Apache Drill book (though the version in the
> book is simpler than the one in the master branch.)
> The recently-completed "Enhanced Vector Framework" (EVF, AKA the "row set
> framework") gives Drill control over the size of batches created by readers,
> and allows readers to use the recently-added provided schema mechanism.
> We wish to use the log reader as an example for how to convert a Drill format
> plugin to use the EVF so that other developers can convert their own plugins.
> This PR provides the first set of log plugin changes to enable us to publish
> a tutorial on the EVF.
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