feat: data tree and node

Signed-off-by: tison <[email protected]>

.editorconfig

@@ -0,0 +1,21 @@
+# Copyright 2023 Korandoru Contributors
+#
+# Licensed 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.
+
+root = true
+
+[*]
+end_of_line = lf
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true

pom.xml

@@ -14,8 +14,15 @@
         <maven.compiler.target>17</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 
+        <!-- lib dependencies -->
+        <assertj.version>3.24.2</assertj.version>
+        <junit.version>5.9.2</junit.version>
+        <lombok.version>1.18.26</lombok.version>
         <ratis.version>2.4.1</ratis.version>
         <slf4j.version>1.7.36</slf4j.version>
+
+        <!-- bundled maven plugins -->
+        <maven-surefire-plugin.version>3.0.0-M7</maven-surefire-plugin.version>
     </properties>
 
     <modules>

zeronos-bom/pom.xml

@@ -15,6 +15,11 @@
 
     <dependencyManagement>
         <dependencies>
+            <dependency>
+                <groupId>org.projectlombok</groupId>
+                <artifactId>lombok</artifactId>
+                <version>${lombok.version}</version>
+            </dependency>
             <dependency>
                 <groupId>org.slf4j</groupId>
                 <artifactId>slf4j-api</artifactId>

zeronos-parent/pom.xml

@@ -25,4 +25,51 @@
         </dependencies>
     </dependencyManagement>
 
+    <dependencies>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.ratis</groupId>
+            <artifactId>ratis-server-api</artifactId>
+        </dependency>
+
+        <!-- tests -->
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-params</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>${maven-surefire-plugin.version}</version>
+            </plugin>
+        </plugins>
+    </build>
 </project>

zeronos-server/src/main/java/io/korandoru/zeronos/server/DataNode.java

@@ -0,0 +1,33 @@
+package io.korandoru.zeronos.server;
+
+import java.util.Deque;
+import java.util.LinkedList;
+
+public class DataNode {
+
+    private final Deque<DataNodeEntry> revisions = new LinkedList<>();
+
+    public DataNode(DataNodeEntry entry) {
+        this.revisions.addLast(entry);
+    }
+
+    public DataNodeEntry readNodeLatest() {
+        // TODO - check if removed
+        return this.revisions.getLast();
+    }
+
+    public void createNode(DataNodeEntry entry) {
+        // TODO - check if exist
+        this.revisions.addLast(entry);
+    }
+
+    public void updateNode(DataNodeEntry entry) {
+        // TODO - check if exist
+        this.revisions.addLast(entry);
+    }
+
+    public void deleteNode(DataNodeEntry entry) {
+        // TODO - check if exist
+        this.revisions.addLast(entry);
+    }
+}

zeronos-server/src/main/java/io/korandoru/zeronos/server/DataNodeEntry.java

@@ -0,0 +1,9 @@
+package io.korandoru.zeronos.server;
+
+import lombok.Data;
+
+@Data
+public class DataNodeEntry {
+    private final long revision;
+    private final byte[] data;
+}

zeronos-server/src/main/java/io/korandoru/zeronos/server/DataTree.java

@@ -0,0 +1,38 @@
+package io.korandoru.zeronos.server;
+
+import java.util.SortedMap;
+import java.util.TreeMap;
+
+public class DataTree {
+
+    private final SortedMap<String, DataNode> nodes = new TreeMap<>();
+
+    public DataTree() {
+        this.nodes.put("", new DataNode(new DataNodeEntry(0, new byte[0])));
+    }
+
+    public void createNode(String path, byte[] data, long revision) {
+        final int slash = path.lastIndexOf('/');
+        final String parentPath = path.substring(0, slash);
+
+        final DataNode parent = nodes.get(parentPath);
+        if (parent == null) {
+            throw new RuntimeException("NoNode");
+        }
+
+        final DataNode child = nodes.get(path);
+        if (child == null) {
+            nodes.put(path, new DataNode(new DataNodeEntry(revision, data)));
+        } else {
+            child.createNode(new DataNodeEntry(revision, data));
+        }
+    }
+
+    public DataNodeEntry readNode(String path) {
+        final DataNode node = nodes.get(path);
+        if (node == null) {
+            throw new RuntimeException("NoNode");
+        }
+        return node.readNodeLatest();
+    }
+}

zeronos-server/src/test/java/io/korandoru/zeronos/server/DataTreeTest.java

@@ -0,0 +1,27 @@
+package io.korandoru.zeronos.server;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.atomic.AtomicLong;
+import org.junit.jupiter.api.Test;
+
+class DataTreeTest {
+
+    @Test
+    void testCreateNode() {
+        final DataTree tree = new DataTree();
+        final AtomicLong revision = new AtomicLong();
+        final byte[][] datas = new byte[][]{
+                "zero".getBytes(StandardCharsets.UTF_8),
+                "one".getBytes(StandardCharsets.UTF_8),
+                "two".getBytes(StandardCharsets.UTF_8),
+        };
+        tree.createNode("/zeronos", datas[0], revision.incrementAndGet());
+        tree.createNode("/zeronos/altair", datas[1], revision.incrementAndGet());
+        tree.createNode("/zeronos/vega", datas[2], revision.incrementAndGet());
+        assertThat(tree.readNode("/zeronos")).isEqualTo(new DataNodeEntry(1, datas[0]));
+        assertThat(tree.readNode("/zeronos/altair")).isEqualTo(new DataNodeEntry(2, datas[1]));
+        assertThat(tree.readNode("/zeronos/vega")).isEqualTo(new DataNodeEntry(3, datas[2]));
+    }
+
+}