GH-3116: Implement the Variant binary encoding

parquet-variant/pom.xml

@@ -0,0 +1,88 @@
+<!--
+  ~ 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.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <parent>
+    <groupId>org.apache.parquet</groupId>
+    <artifactId>parquet</artifactId>
+    <relativePath>../pom.xml</relativePath>
+    <version>1.16.0-SNAPSHOT</version>
+  </parent>
+
+  <modelVersion>4.0.0</modelVersion>
+
+  <artifactId>parquet-variant</artifactId>
+  <packaging>jar</packaging>
+
+  <name>Apache Parquet Variant</name>
+  <url>https://parquet.apache.org</url>
+
+  <properties>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.parquet</groupId>
+      <artifactId>parquet-jackson</artifactId>
+      <version>${project.version}</version>
+      <scope>runtime</scope>
+    </dependency>
+    <dependency>
+      <groupId>${jackson.groupId}</groupId>
+      <artifactId>jackson-core</artifactId>
+      <version>${jackson.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>${jackson.groupId}</groupId>
+      <artifactId>jackson-databind</artifactId>
+      <version>${jackson-databind.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
+      <version>${guava.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-log4j12</artifactId>
+      <version>${slf4j.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+      <version>${slf4j.version}</version>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-jar-plugin</artifactId>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-shade-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>

parquet-variant/src/main/java/org/apache/parquet/variant/MalformedVariantException.java

@@ -0,0 +1,23 @@
+/*
+ * 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.parquet.variant;
+
+/**
+ * An exception indicating that the Variant is malformed.
+ */
+public class MalformedVariantException extends RuntimeException {
+}

parquet-variant/src/main/java/org/apache/parquet/variant/UnknownVariantTypeException.java

@@ -0,0 +1,39 @@
+/*
+ * 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.parquet.variant;
+
+/**
+ * An exception indicating that the Variant contains an unknown type.
+ */
+public class UnknownVariantTypeException extends RuntimeException {
+  public final int typeId;
+
+  /**
+   * @param typeId the type id that was unknown
+   */
+  public UnknownVariantTypeException(int typeId) {
+    super("Unknown type in Variant. id: " + typeId);
+    this.typeId = typeId;
+  }
+
+  /**
+   * @return the type id that was unknown
+   */
+  public int getTypeId() {
+    return typeId;
+  }
+}