Policy Store: Add PolicyEntity and PolicyTypes

polaris-core/src/main/java/org/apache/polaris/core/entity/PolarisEntityType.java

@@ -34,7 +34,8 @@ public enum PolarisEntityType {
   // generic table is either a view or a real table
   TABLE_LIKE(7, NAMESPACE, false, false),
   TASK(8, ROOT, false, false),
-  FILE(9, TABLE_LIKE, false, false);
+  FILE(9, TABLE_LIKE, false, false),
+  POLICY(10, NAMESPACE, false, false);
 
   // to efficiently map a code to its corresponding entity type, use a reverse array which
   // is initialized below

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

@@ -0,0 +1,128 @@
+/*
+ * 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 com.fasterxml.jackson.annotation.JsonIgnore;
+import com.google.common.base.Preconditions;
+import org.apache.iceberg.catalog.Namespace;
+import org.apache.iceberg.rest.RESTUtil;
+import org.apache.polaris.core.entity.NamespaceEntity;
+import org.apache.polaris.core.entity.PolarisBaseEntity;
+import org.apache.polaris.core.entity.PolarisEntity;
+import org.apache.polaris.core.entity.PolarisEntityType;
+
+public class PolicyEntity extends PolarisEntity {
+
+  public static final String POLICY_TYPE_CODE_KEY = "policy-type-code";
+  public static final String POLICY_DESCRIPTION_KEY = "policy-description";
+  public static final String POLICY_VERSION_KEY = "policy-version";
+  public static final String POLICY_CONTENT_KEY = "policy-content";
+
+  PolicyEntity(PolarisBaseEntity sourceEntity) {
+    super(sourceEntity);
+  }
+
+  public static PolicyEntity of(PolarisBaseEntity sourceEntity) {
+    if (sourceEntity != null) {
+      return new PolicyEntity(sourceEntity);
+    }
+
+    return null;
+  }
+
+  @JsonIgnore
+  public PolicyType getPolicyType() {
+    return PolicyType.fromCode(getPolicyTypeCode());
+  }
+
+  @JsonIgnore
+  public int getPolicyTypeCode() {
+    String policyTypeCode = getPropertiesAsMap().get(POLICY_TYPE_CODE_KEY);
+    if (policyTypeCode != null) {
+      return Integer.parseInt(policyTypeCode);
+    }
+
+    return -1;
+  }
+
+  @JsonIgnore
+  public String getDescription() {
+    return getPropertiesAsMap().get(POLICY_DESCRIPTION_KEY);
+  }
+
+  @JsonIgnore
+  public String getContent() {
+    return getPropertiesAsMap().get(POLICY_CONTENT_KEY);
+  }
+
+  @JsonIgnore
+  public String getPolicyVersion() {
+    return getPropertiesAsMap().get(POLICY_VERSION_KEY);
+  }
+
+  public static class Builder extends PolarisEntity.BaseBuilder<PolicyEntity, Builder> {
+    public Builder(Namespace namespace, String policyName) {
+      super();
+      setType(PolarisEntityType.POLICY);
+      setParentNamespace(namespace);
+      setName(policyName);
+      setPolicyVersion(0);
+    }
+
+    public Builder(PolicyEntity original) {
+      super(original);
+    }
+
+    @Override
+    public PolicyEntity build() {
+      Preconditions.checkArgument(
+          properties.get(POLICY_TYPE_CODE_KEY) != null, "Policy type must be specified");
+
+      return new PolicyEntity(buildBase());
+    }
+
+    public Builder setParentNamespace(Namespace namespace) {
+      if (namespace != null && !namespace.isEmpty()) {
+        internalProperties.put(
+            NamespaceEntity.PARENT_NAMESPACE_KEY, RESTUtil.encodeNamespace(namespace));
+      }
+      return this;
+    }
+
+    public Builder setPolicyType(PolicyType policyType) {
+      properties.put(POLICY_TYPE_CODE_KEY, Integer.toString(policyType.getCode()));
+      return this;
+    }
+
+    public Builder setDescription(String description) {
+      properties.put(POLICY_DESCRIPTION_KEY, description);
+      return this;
+    }
+
+    public Builder setPolicyVersion(long version) {
+      properties.put(POLICY_VERSION_KEY, Long.toString(version));
+      return this;
+    }
+
+    public Builder setContent(String content) {
+      properties.put(POLICY_CONTENT_KEY, content);
+      return this;
+    }
+  }
+}

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

@@ -0,0 +1,84 @@
+/*
+ * 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 com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
+import jakarta.annotation.Nullable;
+
+/**
+ * Represents a policy type in Polaris. A policy type defines a category of policies that may be
+ * either predefined or custom (user-defined).
+ *
+ * <p>A policy type can be either inheritable or non-inheritable. Inheritable policies are passed
+ * down to lower-level entities (e.g., from a namespace to a table).
+ */
+public interface PolicyType {
+
+  /**
+   * Retrieves the unique type code associated with this policy type.
+   *
+   * @return the type code of the policy type
+   */
+  @JsonValue
+  int getCode();
+
+  /**
+   * Retrieves the human-readable name of this policy type.
+   *
+   * @return the name of the policy type
+   */
+  String getName();
+
+  /**
+   * Determines whether this policy type is inheritable.
+   *
+   * @return {@code true} if the policy type is inheritable, otherwise {@code false}
+   */
+  boolean isInheritable();
+
+  /**
+   * Retrieves a {@link PolicyType} instance corresponding to the given type code.
+   *
+   * <p>This method searches for the policy type in predefined policy types. If a custom policy type
+   * storage mechanism is implemented in the future, it may also check registered custom policy
+   * types.
+   *
+   * @param code the type code of the policy type
+   * @return the corresponding {@link PolicyType}, or {@code null} if no matching type is found
+   */
+  @JsonCreator
+  static @Nullable PolicyType fromCode(int code) {
+    return PredefinedPolicyType.fromCode(code);
+  }
+
+  /**
+   * Retrieves a {@link PolicyType} instance corresponding to the given policy name.
+   *
+   * <p>This method searches for the policy type in predefined policy types. If a custom policy type
+   * storage mechanism is implemented in the future, it may also check registered custom policy
+   * types.
+   *
+   * @param name the name of the policy type
+   * @return the corresponding {@link PolicyType}, or {@code null} if no matching type is found
+   */
+  static @Nullable PolicyType fromName(String name) {
+    return PredefinedPolicyType.fromName(name);
+  }
+}

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

@@ -0,0 +1,108 @@
+/*
+ * 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 com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.google.common.collect.ImmutableMap;
+import jakarta.annotation.Nullable;
+
+/* Represents all predefined policy types in Polaris */
+public enum PredefinedPolicyType implements PolicyType {
+  DATA_COMPACTION(0, "system.data-compaction", true),
+  METADATA_COMPACTION(1, "system.metadata-compaction", true),
+  ORPHAN_FILE_REMOVAL(2, "system.orphan-file-removal", true),
+  SNAPSHOT_RETENTION(3, "system.snapshot-retention", true);
+
+  private final int code;
+  private final String name;
+  private final boolean isInheritable;
+  private static final PredefinedPolicyType[] REVERSE_CODE_MAPPING_ARRAY;
+  private static final ImmutableMap<String, PredefinedPolicyType> REVERSE_NAME_MAPPING_ARRAY;
+
+  static {
+    int maxId = 0;
+    for (PredefinedPolicyType policyType : PredefinedPolicyType.values()) {
+      if (maxId < policyType.code) {
+        maxId = policyType.code;
+      }
+    }
+
+    REVERSE_CODE_MAPPING_ARRAY = new PredefinedPolicyType[maxId + 1];
+    ImmutableMap.Builder<String, PredefinedPolicyType> builder = ImmutableMap.builder();
+    // populate both
+    for (PredefinedPolicyType policyType : PredefinedPolicyType.values()) {
+      REVERSE_CODE_MAPPING_ARRAY[policyType.code] = policyType;
+      builder.put(policyType.name, policyType);
+    }
+    REVERSE_NAME_MAPPING_ARRAY = builder.build();
+  }
+
+  PredefinedPolicyType(int code, String name, boolean isInheritable) {
+    this.code = code;
+    this.name = name;
+    this.isInheritable = isInheritable;
+  }
+
+  /** {@inheritDoc} */
+  @Override
+  @JsonValue
+  public int getCode() {
+    return code;
+  }
+
+  /** {@inheritDoc} */
+  @Override
+  public String getName() {
+    return name;
+  }
+
+  /** {@inheritDoc} */
+  @Override
+  public boolean isInheritable() {
+    return isInheritable;
+  }
+
+  /**
+   * Retrieves a {@link PredefinedPolicyType} instance corresponding to the given type code.
+   *
+   * @param code the type code of the predefined policy type
+   * @return the corresponding {@link PredefinedPolicyType}, or {@code null} if no matching type is
+   *     found
+   */
+  @JsonCreator
+  public static @Nullable PredefinedPolicyType fromCode(int code) {
+    if (code >= REVERSE_CODE_MAPPING_ARRAY.length) {
+      return null;
+    }
+
+    return REVERSE_CODE_MAPPING_ARRAY[code];
+  }
+
+  /**
+   * Retrieves a {@link PredefinedPolicyType} instance corresponding to the given policy name.
+   *
+   * @param name the name of the predefined policy type
+   * @return the corresponding {@link PredefinedPolicyType}, or {@code null} if no matching type is
+   *     found
+   */
+  public static @Nullable PredefinedPolicyType fromName(String name) {
+    return REVERSE_NAME_MAPPING_ARRAY.get(name);
+  }
+}

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

@@ -0,0 +1,53 @@
+/*
+ * 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.util.stream.Stream;
+import org.apache.iceberg.catalog.Namespace;
+import org.apache.polaris.core.entity.PolarisEntityType;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+public class PolicyEntityTest {
+
+  static Stream<Arguments> policyTypes() {
+    return Stream.of(
+        Arguments.of(PredefinedPolicyType.DATA_COMPACTION),
+        Arguments.of(PredefinedPolicyType.METADATA_COMPACTION),
+        Arguments.of(PredefinedPolicyType.ORPHAN_FILE_REMOVAL),
+        Arguments.of(PredefinedPolicyType.METADATA_COMPACTION));
+  }
+
+  @ParameterizedTest
+  @MethodSource("policyTypes")
+  public void testPolicyEntity(PolicyType policyType) {
+    PolicyEntity entity =
+        new PolicyEntity.Builder(Namespace.of("NS1"), "testPolicy")
+            .setPolicyType(policyType)
+            .setContent("test_content")
+            .setPolicyVersion(0)
+            .build();
+    Assertions.assertThat(entity.getType()).isEqualTo(PolarisEntityType.POLICY);
+    Assertions.assertThat(entity.getPolicyType()).isEqualTo(policyType);
+    Assertions.assertThat(entity.getPolicyTypeCode()).isEqualTo(policyType.getCode());
+    Assertions.assertThat(entity.getContent()).isEqualTo("test_content");
+  }
+}