You are viewing a plain text version of this content. The canonical link for it is here.
Posted to reviews@iotdb.apache.org by GitBox <gi...@apache.org> on 2021/05/18 08:54:30 UTC
[GitHub] [iotdb] liujiajun opened a new pull request #3218: [WIP] Dictionary encoding for TEXT
liujiajun opened a new pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218
## Description
This is still work-in-progress.
This PR has:
- [ ] been self-reviewed.
- [ ] concurrent read
- [ ] concurrent write
- [ ] concurrent read and write
- [ ] added documentation for new or modified features or behaviors.
- [ ] added Javadocs for most classes and all non-trivial methods.
- [ ] added or updated version, __license__, or notice information
- [ ] added comments explaining the "why" and the intent of the code wherever would not be obvious
for an unfamiliar reader.
- [ ] added unit tests or modified existing tests to cover new code paths, ensuring the threshold
for code coverage.
- [ ] added integration tests.
- [ ] been tested in a test IoTDB cluster.
<hr>
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] sonarcloud[bot] commented on pull request #3218: [IOTDB-1403] Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
sonarcloud[bot] commented on pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218#issuecomment-851879814
Kudos, SonarCloud Quality Gate passed!
[<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/common/bug.png' alt='Bug' width='16' height='16' />](https://sonarcloud.io/project/issues?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=BUG) [<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/checks/RatingBadge/A.png' alt='A' width='16' height='16' />](https://sonarcloud.io/project/issues?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=BUG) [0 Bugs](https://sonarcloud.io/project/issues?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=BUG)
[<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/common/vulnerability.png' alt='Vulnerability' width='16' height='16' />](https://sonarcloud.io/project/issues?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=VULNERABILITY) [<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/checks/RatingBadge/A.png' alt='A' width='16' height='16' />](https://sonarcloud.io/project/issues?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=VULNERABILITY) [0 Vulnerabilities](https://sonarcloud.io/project/issues?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=VULNERABILITY)
[<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/common/security_hotspot.png' alt='Security Hotspot' width='16' height='16' />](https://sonarcloud.io/project/security_hotspots?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=SECURITY_HOTSPOT) [<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/checks/RatingBadge/A.png' alt='A' width='16' height='16' />](https://sonarcloud.io/project/security_hotspots?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=SECURITY_HOTSPOT) [0 Security Hotspots](https://sonarcloud.io/project/security_hotspots?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=SECURITY_HOTSPOT)
[<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/common/code_smell.png' alt='Code Smell' width='16' height='16' />](https://sonarcloud.io/project/issues?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=CODE_SMELL) [<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/checks/RatingBadge/A.png' alt='A' width='16' height='16' />](https://sonarcloud.io/project/issues?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=CODE_SMELL) [0 Code Smells](https://sonarcloud.io/project/issues?id=apache_incubator-iotdb&pullRequest=3218&resolved=false&types=CODE_SMELL)
[<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/checks/CoverageChart/NoCoverageInfo.png' alt='No Coverage information' width='16' height='16' />](https://sonarcloud.io/component_measures?id=apache_incubator-iotdb&pullRequest=3218&metric=coverage&view=list) No Coverage information
[<img src='https://sonarsource.github.io/sonarcloud-github-static-resources/v2/checks/Duplications/NoDuplicationInfo.png' alt='No Duplication information' width='16' height='16' />](https://sonarcloud.io/component_measures?id=apache_incubator-iotdb&pullRequest=3218&metric=duplicated_lines_density&view=list) No Duplication information
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] liujiajun commented on a change in pull request #3218: [IOTDB-1403] Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
liujiajun commented on a change in pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218#discussion_r642034148
##########
File path: tsfile/src/main/java/org/apache/iotdb/tsfile/encoding/encoder/TSEncodingBuilder.java
##########
@@ -296,4 +298,22 @@ public void initFromProps(Map<String, String> props) {
// allowed do nothing
}
}
+
+ public static class Dictionary extends TSEncodingBuilder {
+
+ @Override
+ public Encoder getEncoder(TSDataType type) {
+ switch (type) {
+ case TEXT:
+ return new DictionaryEncoder();
+ default:
+ throw new UnSupportedDataTypeException("DICTIONARY doesn't support data type: " + type);
+ }
Review comment:
Updated
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] liujiajun commented on pull request #3218: [IOTDB-1403] Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
liujiajun commented on pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218#issuecomment-850807036
> Hi, thanks for you contribution. What an obviously good feature!
> Would you like to create a jira issue and update the PR title with the issue number?
Thank you! Updated accordingly.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] liutaohua merged pull request #3218: [IOTDB-1403] Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
liutaohua merged pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] HTHou commented on a change in pull request #3218: [IOTDB-1403] Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
HTHou commented on a change in pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218#discussion_r642023156
##########
File path: tsfile/src/main/java/org/apache/iotdb/tsfile/encoding/encoder/TSEncodingBuilder.java
##########
@@ -296,4 +298,22 @@ public void initFromProps(Map<String, String> props) {
// allowed do nothing
}
}
+
+ public static class Dictionary extends TSEncodingBuilder {
+
+ @Override
+ public Encoder getEncoder(TSDataType type) {
+ switch (type) {
+ case TEXT:
+ return new DictionaryEncoder();
+ default:
+ throw new UnSupportedDataTypeException("DICTIONARY doesn't support data type: " + type);
+ }
Review comment:
How about using if-else here?
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] liutaohua commented on a change in pull request #3218: [WIP] Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
liutaohua commented on a change in pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218#discussion_r637868568
##########
File path: antlr/src/main/antlr4/org/apache/iotdb/db/qp/sql/SqlBase.g4
##########
@@ -695,7 +695,7 @@ dateExpression
;
encoding
- : PLAIN | PLAIN_DICTIONARY | RLE | DIFF | TS_2DIFF | GORILLA | REGULAR
+ : PLAIN | PLAIN_DICTIONARY | RLE | DIFF | TS_2DIFF | GORILLA | REGULAR | DICTIONARY
Review comment:
I suggest renaming the original `PLAIN_DICTIONARY` as `DICTIONARY`, and modify the relevant documents, including `Format.md` and so on...
##########
File path: client-cpp/src/main/Session.h
##########
@@ -112,7 +112,8 @@ namespace TSEncoding {
BITMAP = 5,
GORILLA_V1 = 6,
REGULAR = 7,
- GORILLA = 8
+ GORILLA = 8,
+ DICTIONARY = 9
Review comment:
reuse the number of `PLAIN_DICTIONARY`
##########
File path: client-py/iotdb/utils/IoTDBConstants.py
##########
@@ -40,6 +40,7 @@ class TSEncoding(Enum):
GORILLA_V1 = 6
REGULAR = 7
GORILLA = 8
+ DICTIONARY = 9
Review comment:
same
##########
File path: tsfile/src/main/java/org/apache/iotdb/tsfile/encoding/encoder/DictionaryEncoder.java
##########
@@ -0,0 +1,113 @@
+/*
+ * 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.iotdb.tsfile.encoding.encoder;
+
+import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
+import org.apache.iotdb.tsfile.utils.Binary;
+import org.apache.iotdb.tsfile.utils.ReadWriteForEncodingUtils;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * An encoder implementing dictionary encoding.
+ *
+ * <pre>Encoding format: {@code
+ * <map> <indexes>
+ * <map> := <map length> <map data>
+ * <map data> := [<entry size><entry data>]...
+ * <indexes> := [<index>]...
+ * }</pre>
+ */
+public class DictionaryEncoder extends Encoder {
+ private static final Logger logger = LoggerFactory.getLogger(DictionaryEncoder.class);
+
+ private HashMap<Binary, Integer> valueToCode;
Review comment:
rename to entryIndex
##########
File path: tsfile/src/main/java/org/apache/iotdb/tsfile/encoding/encoder/DictionaryEncoder.java
##########
@@ -0,0 +1,113 @@
+/*
+ * 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.iotdb.tsfile.encoding.encoder;
+
+import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
+import org.apache.iotdb.tsfile.utils.Binary;
+import org.apache.iotdb.tsfile.utils.ReadWriteForEncodingUtils;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * An encoder implementing dictionary encoding.
+ *
+ * <pre>Encoding format: {@code
+ * <map> <indexes>
+ * <map> := <map length> <map data>
+ * <map data> := [<entry size><entry data>]...
+ * <indexes> := [<index>]...
+ * }</pre>
+ */
+public class DictionaryEncoder extends Encoder {
+ private static final Logger logger = LoggerFactory.getLogger(DictionaryEncoder.class);
+
+ private HashMap<Binary, Integer> valueToCode;
+ private List<Binary> map;
Review comment:
rename to IndexEntry
##########
File path: tsfile/src/main/java/org/apache/iotdb/tsfile/encoding/decoder/DictionaryDecoder.java
##########
@@ -0,0 +1,86 @@
+/*
+ * 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.iotdb.tsfile.encoding.decoder;
+
+import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
+import org.apache.iotdb.tsfile.utils.Binary;
+import org.apache.iotdb.tsfile.utils.ReadWriteForEncodingUtils;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+
+public class DictionaryDecoder extends Decoder {
+ private static final Logger logger = LoggerFactory.getLogger(DictionaryDecoder.class);
+
+ private List<Binary> map;
Review comment:
rename to `indexEntry`
##########
File path: tsfile/src/main/java/org/apache/iotdb/tsfile/encoding/decoder/DictionaryDecoder.java
##########
@@ -0,0 +1,86 @@
+/*
+ * 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.iotdb.tsfile.encoding.decoder;
+
+import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
+import org.apache.iotdb.tsfile.utils.Binary;
+import org.apache.iotdb.tsfile.utils.ReadWriteForEncodingUtils;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+
+public class DictionaryDecoder extends Decoder {
+ private static final Logger logger = LoggerFactory.getLogger(DictionaryDecoder.class);
+
+ private List<Binary> map;
+ private IntRleDecoder valueDecoder;
+
+ public DictionaryDecoder() {
+ super(TSEncoding.DICTIONARY);
+
+ valueDecoder = new IntRleDecoder();
+ }
+
+ @Override
+ public boolean hasNext(ByteBuffer buffer) {
+ if (map == null) {
+ initMap(buffer);
+ }
+
+ try {
+ return valueDecoder.hasNext(buffer);
+ } catch (IOException e) {
+ logger.error("tsfile-decoding DictionaryDecoder: error occurs when decoding", e);
+ }
+
+ return false;
+ }
+
+ @Override
+ public Binary readBinary(ByteBuffer buffer) {
+ if (map == null) {
+ initMap(buffer);
+ }
+ int code = valueDecoder.readInt(buffer);
+ return map.get(code);
+ }
+
+ private void initMap(ByteBuffer buffer) {
+ map = new ArrayList<>();
+ int length = ReadWriteForEncodingUtils.readVarInt(buffer);
Review comment:
initialize the array with a fixed length to avoid redundant copies
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] HTHou commented on a change in pull request #3218: [IOTDB-1403] Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
HTHou commented on a change in pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218#discussion_r642023360
##########
File path: tsfile/src/main/java/org/apache/iotdb/tsfile/encoding/encoder/DictionaryEncoder.java
##########
@@ -0,0 +1,113 @@
+/*
+ * 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.iotdb.tsfile.encoding.encoder;
+
+import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
+import org.apache.iotdb.tsfile.utils.Binary;
+import org.apache.iotdb.tsfile.utils.ReadWriteForEncodingUtils;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * An encoder implementing dictionary encoding.
+ *
+ * <pre>Encoding format: {@code
+ * <map> <indexes>
+ * <map> := <map length> <map data>
+ * <map data> := [<entry size><entry data>]...
+ * <indexes> := [<index>]...
+ * }</pre>
+ */
+public class DictionaryEncoder extends Encoder {
+ private static final Logger logger = LoggerFactory.getLogger(DictionaryEncoder.class);
+
+ private HashMap<Binary, Integer> entryIndex;
+ private List<Binary> indexEntry;
+ private IntRleEncoder valuesEncoder;
+ private long mapSize;
+
+ public DictionaryEncoder() {
+ super(TSEncoding.DICTIONARY);
+
+ entryIndex = new HashMap<>();
+ indexEntry = new ArrayList<>();
+ valuesEncoder = new IntRleEncoder();
+ mapSize = 0;
+ }
+
+ @Override
+ public void encode(Binary value, ByteArrayOutputStream out) {
+ if (!entryIndex.containsKey(value)) {
+ entryIndex.put(value, entryIndex.size());
+ indexEntry.add(value);
+ mapSize += value.getLength();
+ }
Review comment:
How about using `entryIndex.computeIfAbsent()`?
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] coveralls commented on pull request #3218: [IOTDB-1403] Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
coveralls commented on pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218#issuecomment-851876475
[](https://coveralls.io/builds/40191622)
Coverage increased (+0.03%) to 67.898% when pulling **38cfb74c41d38924acc88d51fe7085a4ac1fd6fd on liujiajun:master** into **d381f9796692055dcd37d0268f9d3600fba9afaa on apache:master**.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] HTHou commented on pull request #3218: Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
HTHou commented on pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218#issuecomment-850784685
Hi, thanks for you contribution. What an obviously good feature!
Would you like to create a jira issue and update the PR title with the issue number?
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
[GitHub] [iotdb] liujiajun commented on a change in pull request #3218: [IOTDB-1403] Dictionary encoding for TEXT
Posted by GitBox <gi...@apache.org>.
liujiajun commented on a change in pull request #3218:
URL: https://github.com/apache/iotdb/pull/3218#discussion_r642034173
##########
File path: tsfile/src/main/java/org/apache/iotdb/tsfile/encoding/encoder/DictionaryEncoder.java
##########
@@ -0,0 +1,113 @@
+/*
+ * 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.iotdb.tsfile.encoding.encoder;
+
+import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
+import org.apache.iotdb.tsfile.utils.Binary;
+import org.apache.iotdb.tsfile.utils.ReadWriteForEncodingUtils;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * An encoder implementing dictionary encoding.
+ *
+ * <pre>Encoding format: {@code
+ * <map> <indexes>
+ * <map> := <map length> <map data>
+ * <map data> := [<entry size><entry data>]...
+ * <indexes> := [<index>]...
+ * }</pre>
+ */
+public class DictionaryEncoder extends Encoder {
+ private static final Logger logger = LoggerFactory.getLogger(DictionaryEncoder.class);
+
+ private HashMap<Binary, Integer> entryIndex;
+ private List<Binary> indexEntry;
+ private IntRleEncoder valuesEncoder;
+ private long mapSize;
+
+ public DictionaryEncoder() {
+ super(TSEncoding.DICTIONARY);
+
+ entryIndex = new HashMap<>();
+ indexEntry = new ArrayList<>();
+ valuesEncoder = new IntRleEncoder();
+ mapSize = 0;
+ }
+
+ @Override
+ public void encode(Binary value, ByteArrayOutputStream out) {
+ if (!entryIndex.containsKey(value)) {
+ entryIndex.put(value, entryIndex.size());
+ indexEntry.add(value);
+ mapSize += value.getLength();
+ }
Review comment:
Updated
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org