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https://issues.apache.org/jira/browse/NIFI-2851?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15582286#comment-15582286
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ASF GitHub Bot commented on NIFI-2851:
--------------------------------------
Github user olegz commented on a diff in the pull request:
https://github.com/apache/nifi/pull/1116#discussion_r83643595
--- Diff:
nifi-commons/nifi-utils/src/main/java/org/apache/nifi/stream/io/util/TextLineDemarcator.java
---
@@ -0,0 +1,227 @@
+/*
+ * 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.nifi.stream.io.util;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Implementation of demarcator of text lines in the provided
+ * {@link InputStream}. It works similar to the {@link BufferedReader} and
its
+ * {@link BufferedReader#readLine()} methods except that it does not
create a
+ * String representing the text line and instead returns the offset info
for the
+ * computed text line. See {@link #nextOffsetInfo()} and
+ * {@link #nextOffsetInfo(byte[])} for more details.
+ * <p>
+ * This class is NOT thread-safe.
+ * </p>
+ */
+public class TextLineDemarcator {
+
+ private final static int INIT_BUFFER_SIZE = 8192;
+
+ private final InputStream is;
+
+ private final int initialBufferSize;
+
+ private byte[] buffer;
+
+ private int index;
+
+ private int mark;
+
+ private long offset;
+
+ private int bufferLength;
+
+ /**
+ * Constructs an instance of demarcator with provided {@link
InputStream}
+ * and default buffer size.
+ */
+ public TextLineDemarcator(InputStream is) {
+ this(is, INIT_BUFFER_SIZE);
+ }
+
+ /**
+ * Constructs an instance of demarcator with provided {@link
InputStream}
+ * and initial buffer size.
+ */
+ public TextLineDemarcator(InputStream is, int initialBufferSize) {
+ if (is == null) {
+ throw new IllegalArgumentException("'is' must not be null.");
+ }
+ if (initialBufferSize < 1) {
+ throw new IllegalArgumentException("'initialBufferSize' must
be > 0.");
+ }
+ this.is = is;
+ this.initialBufferSize = initialBufferSize;
+ this.buffer = new byte[initialBufferSize];
+ }
+
+ /**
+ * Will compute the next <i>offset info</i> for a
+ * text line (line terminated by either '\r', '\n' or '\r\n').
+ * <br>
+ * The <i>offset info</i> computed and returned as <code>long[]</code>
consisting of
+ * 4 elements <code>{startOffset, length, crlfLength,
startsWithMatch}</code>.
+ * <ul>
+ * <li><i>startOffset</i> - the offset in the overall stream which
represents the beginning of the text line</li>
+ * <li><i>length</i> - length of the text line including CRLF
characters</li>
+ * <li><i>crlfLength</i> - the length of the CRLF. Could be either
1 (if line ends with '\n' or '\r')
+ * or 2 (if line ends with
'\r\n').</li>
+ * <li><i>startsWithMatch</i> - value is always 1. See {@link
#nextOffsetInfo(byte[])} for more info.</li>
+ * </ul>
+ *
+ * @return offset info as <code>long[]</code>
+ */
+ public long[] nextOffsetInfo() {
--- End diff --
Yes, it would be easier to read, but based on running some performance
tests there is also a price to pay for it although not very significant. Will
change
> Improve performance of SplitText
> --------------------------------
>
> Key: NIFI-2851
> URL: https://issues.apache.org/jira/browse/NIFI-2851
> Project: Apache NiFi
> Issue Type: Improvement
> Components: Core Framework
> Reporter: Mark Payne
> Assignee: Oleg Zhurakousky
> Fix For: 1.1.0
>
>
> SplitText is fairly CPU-intensive and quite slow. A simple flow that splits a
> 1.4 million line text file into 5k line chunks and then splits those 5k line
> chunks into 1 line chunks is only capable of pushing through about 10k lines
> per second. This equates to about 10 MB/sec. JVisualVM shows that the
> majority of the time is spent in the locateSplitPoint() method. Isolating
> this code and inspecting how it works, and using some micro-benchmarking, it
> appears that if we refactor the calls to InputStream.read() to instead read
> into a byte array, we can improve performance.
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