Add data compaction policy schema and its validator

polaris-core/build.gradle.kts

@@ -78,6 +78,8 @@ dependencies {
   implementation("software.amazon.awssdk:iam-policy-builder")
   implementation("software.amazon.awssdk:s3")
 
+  implementation("org.everit.json:org.everit.json.schema:1.5.1")
+
   implementation("org.apache.iceberg:iceberg-azure")
   implementation(platform(libs.azuresdk.bom))
   implementation("com.azure:azure-storage-blob")

polaris-core/src/main/java/org/apache/polaris/core/policy/BasePolicyValidator.java

@@ -0,0 +1,52 @@
+/*
+ * 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.polaris.core.policy;
+
+import java.io.InputStream;
+import org.everit.json.schema.Schema;
+import org.everit.json.schema.ValidationException;
+import org.everit.json.schema.loader.SchemaLoader;
+import org.json.JSONObject;
+import org.json.JSONTokener;
+
+public class BasePolicyValidator implements PolicyValidator {
+  @Override
+  public boolean validate(Policy policy) {
+    try {
+      InputStream schemaStream =
+          getResourceAsStream("schemas/policies/system/data-compaction/2025-02-03.json");
+      JSONObject rawSchema = new JSONObject(new JSONTokener(schemaStream));
+      Schema schema = SchemaLoader.load(rawSchema);
+
+      var jsonData = new JSONObject(new JSONTokener(policy.content));
+
+      schema.validate(jsonData);
+      return true;
+    } catch (ValidationException e) {
+      // The JSON failed validation; handle error information
+      System.out.println("JSON validation failed: " + e.getMessage());
+      // You can also inspect e.getCausingExceptions() for detail on multiple errors
+      return false;
+    }
+  }
+
+  private static InputStream getResourceAsStream(String fileName) {
+    return Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName);
+  }
+}

polaris-core/src/main/java/org/apache/polaris/core/policy/Policy.java

@@ -0,0 +1,31 @@
+/*
+ * 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.polaris.core.policy;
+
+public class Policy {
+  String content;
+
+  public Policy(String content) {
+    this.content = content;
+  }
+
+  public String getContent() {
+    return content;
+  }
+}

polaris-core/src/main/java/org/apache/polaris/core/policy/PolicyValidator.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.polaris.core.policy;
+
+public interface PolicyValidator {
+  boolean validate(Policy policy);
+}

polaris-core/src/main/resources/schemas/policies/system/data-compaction/2025-02-03.json

@@ -0,0 +1,40 @@
+{
+  "$id": "https://polaris.apache.org/schemas/policies/system/data-compaction/2025-02-03.json",
+  "title": "Data Compaction Policy",
+  "description": "Inheritable Polaris policy schema for Iceberg table data compaction.",
+  "type": "object",
+  "properties": {
+    "version": {
+      "type": "string",
+      "const": "2025-02-03",
+      "description": "Schema version."
+    },
+    "enable": {
+      "type": "boolean",
+      "description": "Enable or disable data compaction."
+    },
+    "target_file_size_bytes": {
+      "type": "number",
+      "description": "Target data file size in bytes."
+    },
+    "config": {
+      "type": "object",
+      "description": "A map containing custom configuration properties. Please note that interoperability is not guaranteed.",
+      "additionalProperties": {}
+    }
+  },
+  "required": ["enable"],
+  "additionalProperties": false,
+  "examples": [
+    {
+      "version": "2025-02-03",
+      "enable": true,
+      "target_file_size_bytes": 134217728,
+      "config": {
+        "compaction_strategy": "bin-pack",
+        "max-concurrent-file-group-rewrites": 5,
+        "my-key": "my-value"
+      }
+    }
+  ]
+}

polaris-core/src/test/java/org/apache/polaris/core/policy/BasePolicyValidatorTest.java

@@ -0,0 +1,65 @@
+/*
+ * 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.polaris.core.policy;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class BasePolicyValidatorTest {
+  private BasePolicyValidator validator;
+
+  @BeforeEach
+  public void setUp() {
+    validator = new BasePolicyValidator();
+  }
+
+  @Test
+  public void testValidateValidPolicy() {
+    var validJson = "{\"enable\": False}";
+    var result = validator.validate(new Policy(validJson));
+    assertThat(result).isTrue();
+
+    validJson = "{\"enable\": true, \"target_file_size_bytes\": 12342}";
+    result = validator.validate(new Policy(validJson));
+    assertThat(result).isTrue();
+
+    validJson = "{\"version\":\"2025-02-03\", \"enable\": true, \"target_file_size_bytes\": 12342}";
+    result = validator.validate(new Policy(validJson));
+    assertThat(result).isTrue();
+
+    validJson = "{\"enable\": true, \"config\": {\"key1\": \"value1\", \"key2\": true}}";
+    result = validator.validate(new Policy(validJson));
+    assertThat(result).isTrue();
+  }
+
+  @Test
+  public void testInValidateValidPolicy() {
+    // missing required key
+    var inValidJson = "{}";
+    var result = validator.validate(new Policy(inValidJson));
+    assertThat(result).isFalse();
+
+    // invalid keys
+    inValidJson = "{\"enable\": true, \"invalid_key\": 12342}";
+    result = validator.validate(new Policy(inValidJson));
+    assertThat(result).isFalse();
+  }
+}