[java-info] Add basic architecture java-info into main (#481)

* Add basic architecture java-info into main

* Rename java-info to info

maven-projects/info/.scalafmt.conf

@@ -0,0 +1,8 @@
+version = "3.0.6"
+
+align.preset = some
+runner.dialect = scala212
+maxColumn = 80
+docstrings.style = Asterisk
+docstrings.removeEmpty = true
+project.git = true

maven-projects/info/README.md

@@ -0,0 +1 @@
+This module is under development

maven-projects/info/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    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">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.apache.graphar</groupId>
+        <artifactId>graphar-root</artifactId>
+        <version>${graphar.version}</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>info</artifactId>
+    <packaging>jar</packaging>
+
+    <name>info</name>
+
+    <properties>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.yaml</groupId>
+            <artifactId>snakeyaml</artifactId>
+            <version>2.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.hadoop</groupId>
+            <artifactId>hadoop-common</artifactId>
+            <version>3.4.0</version>
+        </dependency>
+    </dependencies>
+
+
+</project>

maven-projects/info/src/main/java/org/apache/graphar/info/type/AdjListType.java

@@ -0,0 +1,50 @@
+/*
+ * 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.graphar.info.type;
+
+public enum AdjListType {
+    /** collection of edges by source, but unordered, can represent COO format */
+    unordered_by_source,
+    /** collection of edges by destination, but unordered, can represent COO */
+    unordered_by_dest,
+    /** collection of edges by source, ordered by source, can represent CSR format */
+    ordered_by_source,
+    /** collection of edges by destination, ordered by destination, can represent CSC format */
+    ordered_by_dest;
+
+    public static AdjListType fromOrderedAndAlignedBy(boolean ordered, String alignedBy) {
+        switch (alignedBy) {
+            case "src":
+                return ordered ? ordered_by_source : unordered_by_source;
+            case "dst":
+                return ordered ? ordered_by_dest : unordered_by_dest;
+            default:
+                throw new IllegalArgumentException("Invalid alignedBy: " + alignedBy);
+        }
+    }
+
+    public boolean isOrdered() {
+        return this == ordered_by_source || this == ordered_by_dest;
+    }
+
+    public String getAlignedBy() {
+        return this == ordered_by_source || this == unordered_by_source ? "src" : "dst";
+    }
+}

maven-projects/info/src/main/java/org/apache/graphar/info/type/DataType.java

@@ -0,0 +1,69 @@
+/*
+ * 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.graphar.info.type;
+
+public enum DataType {
+    /** Boolean */
+    BOOL,
+
+    /** Signed 32-bit integer */
+    INT32,
+
+    /** Signed 64-bit integer */
+    INT64,
+
+    /** 4-byte floating point value */
+    FLOAT,
+
+    /** 8-byte floating point value */
+    DOUBLE,
+
+    /** UTF8 variable-length string */
+    STRING,
+
+    /** List of same type */
+    LIST;
+
+    public static DataType fromString(String s) {
+        switch (s) {
+            case "bool":
+                return BOOL;
+            case "int32":
+                return INT32;
+            case "int64":
+                return INT64;
+            case "float":
+                return FLOAT;
+            case "double":
+                return DOUBLE;
+            case "string":
+                return STRING;
+            case "list":
+                return LIST;
+            default:
+                throw new IllegalArgumentException("Unknown data type: " + s);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return name().toLowerCase();
+    }
+}

maven-projects/info/src/main/java/org/apache/graphar/info/type/FileType.java

@@ -0,0 +1,42 @@
+/*
+ * 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.graphar.info.type;
+
+public enum FileType {
+    CSV,
+    PARQUET,
+    ORC;
+
+    public static FileType fromString(String fileType) {
+        if (fileType == null) {
+            return null;
+        }
+        switch (fileType) {
+            case "csv":
+                return CSV;
+            case "parquet":
+                return PARQUET;
+            case "orc":
+                return ORC;
+            default:
+                throw new IllegalArgumentException("Unknown file type: " + fileType);
+        }
+    }
+}

maven-projects/info/src/main/java/org/apache/graphar/info/yaml/AdjacentListYamlParser.java

@@ -0,0 +1,75 @@
+/*
+ * 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.graphar.info.yaml;
+
+import org.apache.graphar.info.AdjacentList;
+
+public class AdjacentListYamlParser {
+    private boolean ordered;
+    private String aligned_by;
+    private String file_type;
+    private String prefix;
+
+    public AdjacentListYamlParser() {
+        this.ordered = false;
+        this.aligned_by = "";
+        this.file_type = "";
+        this.prefix = "";
+    }
+
+    public AdjacentListYamlParser(AdjacentList adjacentList) {
+        this.ordered = adjacentList.getType().isOrdered();
+        this.aligned_by = adjacentList.getType().getAlignedBy();
+        this.file_type = adjacentList.getFileType().toString();
+        this.prefix = adjacentList.getPrefix();
+    }
+
+    public boolean isOrdered() {
+        return ordered;
+    }
+
+    public void setOrdered(boolean ordered) {
+        this.ordered = ordered;
+    }
+
+    public String isAligned_by() {
+        return aligned_by;
+    }
+
+    public void setAligned_by(String aligned_by) {
+        this.aligned_by = aligned_by;
+    }
+
+    public String getFile_type() {
+        return file_type;
+    }
+
+    public void setFile_type(String file_type) {
+        this.file_type = file_type;
+    }
+
+    public String getPrefix() {
+        return prefix;
+    }
+
+    public void setPrefix(String prefix) {
+        this.prefix = prefix;
+    }
+}