Core: View representation core implementation

api/src/main/java/org/apache/iceberg/view/SQLViewRepresentation.java

@@ -19,13 +19,15 @@
 package org.apache.iceberg.view;
 
 import java.util.List;
-import org.apache.iceberg.Schema;
+import javax.annotation.Nullable;
 import org.apache.iceberg.catalog.Namespace;
+import org.immutables.value.Value;
 
+@Value.Immutable
 public interface SQLViewRepresentation extends ViewRepresentation {
 
   @Override
-  default Type type() {
+  default String type() {
     return Type.SQL;
   }
 
@@ -36,13 +38,19 @@ default Type type() {
   String dialect();
 
   /** The default catalog when the view is created. */
+  @Nullable
   String defaultCatalog();
 
   /** The default namespace when the view is created. */
+  @Nullable
   Namespace defaultNamespace();
 
-  /** The query output schema at version create time, without aliases. */
-  Schema schema();
+  /**
+   * The query output schema ID at version create time, without aliases or null if no schema is
+   * defined
+   */
+  @Nullable
+  Integer schemaId();
 
   /** The view field comments. */
   List<String> fieldComments();

api/src/main/java/org/apache/iceberg/view/ViewRepresentation.java

@@ -18,21 +18,16 @@
  */
 package org.apache.iceberg.view;
 
-import java.util.Locale;
+import org.immutables.value.Value;
 
+@Value.Immutable
 public interface ViewRepresentation {
 
-  enum Type {
-    SQL;
+  class Type {
+    private Type() {}
 
-    public static Type fromString(String typeName) {
-      return valueOf(typeName.toUpperCase(Locale.ENGLISH));
-    }
-
-    public String typeName() {
-      return name().toLowerCase(Locale.ENGLISH);
-    }
+    public static final String SQL = "sql";
   }
 
-  Type type();
+  String type();
 }

build.gradle

@@ -245,6 +245,7 @@ project(':iceberg-api') {
   dependencies {
     implementation project(path: ':iceberg-bundled-guava', configuration: 'shadow')
     compileOnly "com.google.errorprone:error_prone_annotations"
+    compileOnly 'com.google.code.findbugs:jsr305'
     annotationProcessor "org.immutables:value"
     compileOnly "org.immutables:value"
     testImplementation "org.apache.avro:avro"

core/src/main/java/org/apache/iceberg/view/SQLViewRepresentationParser.java

@@ -0,0 +1,119 @@
+/*
+ * 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.iceberg.view;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonNode;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import org.apache.iceberg.catalog.Namespace;
+import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
+import org.apache.iceberg.relocated.com.google.common.collect.Iterables;
+import org.apache.iceberg.util.JsonUtil;
+
+class SQLViewRepresentationParser {
+  private static final String SQL = "sql";
+  private static final String DIALECT = "dialect";
+  private static final String SCHEMA_ID = "schema-id";
+  private static final String DEFAULT_CATALOG = "default-catalog";
+  private static final String DEFAULT_NAMESPACE = "default-namespace";
+  private static final String FIELD_ALIASES = "field-aliases";
+  private static final String FIELD_COMMENTS = "field-comments";
+
+  private SQLViewRepresentationParser() {}
+
+  static String toJson(SQLViewRepresentation sqlViewRepresentation) {
+    return JsonUtil.generate(gen -> toJson(sqlViewRepresentation, gen), false);
+  }
+
+  static void toJson(SQLViewRepresentation view, JsonGenerator generator) throws IOException {
+    Preconditions.checkArgument(view != null, "Invalid SQL view representation: null");
+    generator.writeStartObject();
+    generator.writeStringField(ViewRepresentationParser.TYPE, view.type());
+    generator.writeStringField(SQL, view.sql());
+    generator.writeStringField(DIALECT, view.dialect());
+
+    if (view.schemaId() != null) {
+      generator.writeNumberField(SCHEMA_ID, view.schemaId());
+    }
+
+    if (view.defaultCatalog() != null) {
+      generator.writeStringField(DEFAULT_CATALOG, view.defaultCatalog());
+    }
+
+    if (view.defaultNamespace() != null) {
+      JsonUtil.writeStringArray(
+          DEFAULT_NAMESPACE, Arrays.asList(view.defaultNamespace().levels()), generator);
+    }
+
+    if (!view.fieldAliases().isEmpty()) {
+      JsonUtil.writeStringArray(
+          SQLViewRepresentationParser.FIELD_ALIASES, view.fieldAliases(), generator);
+    }
+
+    if (!view.fieldComments().isEmpty()) {
+      JsonUtil.writeStringArray(
+          SQLViewRepresentationParser.FIELD_COMMENTS, view.fieldComments(), generator);
+    }
+
+    generator.writeEndObject();
+  }
+
+  static SQLViewRepresentation fromJson(String json) {
+    return JsonUtil.parse(json, SQLViewRepresentationParser::fromJson);
+  }
+
+  static SQLViewRepresentation fromJson(JsonNode node) {
+    Preconditions.checkArgument(
+        node != null, "Cannot parse SQL view representation from null object");
+    Preconditions.checkArgument(
+        node.isObject(), "Cannot parse SQL view representation from non-object: %s", node);
+    ImmutableSQLViewRepresentation.Builder builder =
+        ImmutableSQLViewRepresentation.builder()
+            .sql(JsonUtil.getString(SQL, node))
+            .dialect(JsonUtil.getString(DIALECT, node));
+    String defaultCatalog = JsonUtil.getStringOrNull(DEFAULT_CATALOG, node);
+    if (defaultCatalog != null) {
+      builder.defaultCatalog(defaultCatalog);
+    }
+
+    Integer schemaId = JsonUtil.getIntOrNull(SCHEMA_ID, node);
+    if (schemaId != null) {
+      builder.schemaId(schemaId);
+    }
+
+    List<String> namespace = JsonUtil.getStringListOrNull(DEFAULT_NAMESPACE, node);
+    if (namespace != null && !namespace.isEmpty()) {
+      builder.defaultNamespace(Namespace.of(Iterables.toArray(namespace, String.class)));
+    }
+
+    List<String> fieldAliases = JsonUtil.getStringListOrNull(FIELD_ALIASES, node);
+    if (fieldAliases != null) {
+      builder.fieldAliases(fieldAliases);
+    }
+
+    List<String> fieldComments = JsonUtil.getStringListOrNull(FIELD_COMMENTS, node);
+    if (fieldComments != null) {
+      builder.fieldComments(fieldComments);
+    }
+
+    return builder.build();
+  }
+}

core/src/main/java/org/apache/iceberg/view/UnknownViewRepresentation.java

@@ -0,0 +1,24 @@
+/*
+ * 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.iceberg.view;
+
+import org.immutables.value.Value;
+
+@Value.Immutable
+public interface UnknownViewRepresentation extends ViewRepresentation {}

core/src/main/java/org/apache/iceberg/view/ViewRepresentationParser.java

@@ -0,0 +1,68 @@
+/*
+ * 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.iceberg.view;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonNode;
+import java.io.IOException;
+import java.util.Locale;
+import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
+import org.apache.iceberg.util.JsonUtil;
+
+class ViewRepresentationParser {
+  static final String TYPE = "type";
+
+  private ViewRepresentationParser() {}
+
+  static void toJson(ViewRepresentation representation, JsonGenerator generator)
+      throws IOException {
+    Preconditions.checkArgument(representation != null, "Invalid view representation: null");
+    switch (representation.type()) {
+      case ViewRepresentation.Type.SQL:
+        SQLViewRepresentationParser.toJson((SQLViewRepresentation) representation, generator);
+        break;
+
+      default:
+        throw new IllegalArgumentException(
+            String.format("Cannot serialize view representation type: %s", representation.type()));
+    }
+  }
+
+  static String toJson(ViewRepresentation entry) {
+    return JsonUtil.generate(gen -> toJson(entry, gen), false);
+  }
+
+  static ViewRepresentation fromJson(String json) {
+    return JsonUtil.parse(json, ViewRepresentationParser::fromJson);
+  }
+
+  static ViewRepresentation fromJson(JsonNode node) {
+    Preconditions.checkArgument(node != null, "Cannot parse view representation from null object");
+    Preconditions.checkArgument(
+        node.isObject(), "Cannot parse view representation from non-object: %s", node);
+    String type = JsonUtil.getString(TYPE, node).toLowerCase(Locale.ENGLISH);
+    switch (type) {
+      case ViewRepresentation.Type.SQL:
+        return SQLViewRepresentationParser.fromJson(node);
+
+      default:
+        return ImmutableUnknownViewRepresentation.builder().type(type).build();
+    }
+  }
+}