mchades commented on code in PR #11926:
URL: https://github.com/apache/gravitino/pull/11926#discussion_r4120286778


##########
trino-connector/trino-connector/src/main/java/org/apache/gravitino/trino/connector/catalog/CatalogConnectorMetadata.java:
##########
@@ -454,4 +498,297 @@ public Function getFunction(String schemaName, String 
functionName) {
     }
     return functionCatalog.getFunction(NameIdentifier.of(schemaName, 
functionName));
   }
+
+  /**
+   * Checks whether the catalog supports view operations.
+   *
+   * @return true if the catalog supports view operations, false otherwise
+   */
+  public boolean supportsViews() {
+    return viewCatalog != null;
+  }
+
+  /**
+   * Retrieves the Gravitino view for the specified name, if it exists and has 
a Trino dialect SQL
+   * representation.
+   *
+   * @param schemaName the name of the schema
+   * @param viewName the name of the view
+   * @return an {@link Optional} containing the Gravitino view, or {@link 
Optional#empty()} if the
+   *     view does not exist or has no Trino dialect SQL representation
+   */
+  public Optional<GravitinoView> getViewIfPresent(String schemaName, String 
viewName) {
+    if (!supportsViews()) {
+      return Optional.empty();
+    }
+    try {
+      View view = viewCatalog.loadView(NameIdentifier.of(schemaName, 
viewName));
+      GravitinoView gravitinoView = new GravitinoView(schemaName, viewName, 
view);
+      if (gravitinoView.getSql() == null) {
+        // The view exists but has no Trino dialect SQL representation, so it 
is not visible to
+        // Trino.
+        LOG.debug(
+            "View {}.{} in catalog {} has no Trino dialect SQL representation, 
hiding it from"
+                + " Trino",
+            schemaName,
+            viewName,
+            catalogName);
+        return Optional.empty();
+      }
+      return Optional.of(gravitinoView);
+    } catch (NoSuchViewException e) {
+      return Optional.empty();
+    } catch (UnsupportedOperationException e) {
+      LOG.debug(
+          "Catalog {} does not support loading view {}.{}", catalogName, 
schemaName, viewName, e);
+      return Optional.empty();
+    }
+  }
+
+  /**
+   * Retrieves the Gravitino view for the specified name.
+   *
+   * @param schemaName the name of the schema
+   * @param viewName the name of the view
+   * @return the Gravitino view
+   * @throws TrinoException if the view does not exist or has no Trino dialect 
SQL representation
+   */
+  public GravitinoView getView(String schemaName, String viewName) {
+    return getViewIfPresent(schemaName, viewName)
+        .orElseThrow(
+            () ->
+                new TrinoException(
+                    GravitinoErrorCode.GRAVITINO_VIEW_NOT_EXISTS, "View does 
not exist"));
+  }
+
+  /**
+   * Lists the names of all views in the specified schema.
+   *
+   * @param schemaName the name of the schema
+   * @return a list of view names, or an empty list if the catalog does not 
support views
+   */
+  public List<String> listViews(String schemaName) {
+    if (!supportsViews()) {
+      return List.of();
+    }
+    try {
+      NameIdentifier[] views = viewCatalog.listViews(Namespace.of(schemaName));
+      return Arrays.stream(views)
+          .map(NameIdentifier::name)
+          .filter(viewName -> getViewIfPresent(schemaName, 
viewName).isPresent())
+          .toList();
+    } catch (UnsupportedOperationException e) {
+      LOG.debug(
+          "Catalog {} does not support listing views for schema {}", 
catalogName, schemaName, e);
+      return List.of();
+    } catch (NoSuchSchemaException e) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_SCHEMA_NOT_EXISTS, 
SCHEMA_DOES_NOT_EXIST_MSG, e);
+    }
+  }
+
+  /**
+   * Creates or replaces a view in the catalog.
+   *
+   * <p>Only views with a Trino dialect SQL representation are considered 
visible to Trino; if an
+   * entity with the same name already exists but has no Trino representation 
(e.g. a view created
+   * by another engine), it is never silently replaced.
+   *
+   * @param view the Gravitino view, with the Trino dialect SQL definition set
+   * @param replace whether to replace the view if it already exists
+   */
+  public void createView(GravitinoView view, boolean replace) {
+    if (!supportsViews()) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_UNSUPPORTED_OPERATION, "Catalog does 
not support views");
+    }
+    Preconditions.checkArgument(
+        view.getSql() != null,
+        "View %s.%s has no Trino dialect SQL representation",
+        view.getSchemaName(),
+        view.getName());
+    NameIdentifier identifier = NameIdentifier.of(view.getSchemaName(), 
view.getName());
+    SQLRepresentation[] representations = {
+      
SQLRepresentation.builder().withDialect(Dialects.TRINO).withSql(view.getSql()).build()
+    };
+    try {
+      boolean exists = viewCatalog.viewExists(identifier);
+      if (exists) {
+        View existingView = viewCatalog.loadView(identifier);
+        if (!existingView.sqlFor(Dialects.TRINO).isPresent()) {
+          // An entity with this name already exists but is not visible to 
Trino (e.g. a view
+          // created by another engine), so it must not be treated as 
replaceable.
+          throw new TrinoException(
+              GravitinoErrorCode.GRAVITINO_VIEW_ALREADY_EXISTS, "View already 
exists");
+        }
+        if (!replace) {
+          throw new TrinoException(
+              GravitinoErrorCode.GRAVITINO_VIEW_ALREADY_EXISTS, "View already 
exists");
+        }
+        if (hasNonTrinoRepresentation(existingView.representations())) {
+          // Trino cannot regenerate SQL for other engines' dialects, so 
replacing here would
+          // leave those representations referring to a schema/body that no 
longer matches.
+          throw new TrinoException(
+              GravitinoErrorCode.GRAVITINO_UNSUPPORTED_OPERATION,
+              "Cannot replace view "
+                  + view.getSchemaName()
+                  + "."
+                  + view.getName()
+                  + " because it has SQL representations in other dialects");
+        }
+        List<ViewChange> changes = new ArrayList<>();
+        changes.add(
+            ViewChange.replaceView(
+                view.getRawColumns(),
+                representations,
+                view.getDefaultCatalog(),
+                view.getDefaultSchema(),
+                view.getComment()));
+        changes.addAll(computePropertyChanges(existingView.properties(), 
view.getProperties()));
+        viewCatalog.alterView(identifier, changes.toArray(new ViewChange[0]));
+      } else {
+        viewCatalog.createView(
+            identifier,
+            view.getComment(),
+            view.getRawColumns(),
+            representations,
+            view.getDefaultCatalog(),
+            view.getDefaultSchema(),
+            view.getProperties());
+      }
+    } catch (NoSuchSchemaException e) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_SCHEMA_NOT_EXISTS, 
SCHEMA_DOES_NOT_EXIST_MSG, e);
+    } catch (ViewAlreadyExistsException e) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_VIEW_ALREADY_EXISTS, "View already 
exists", e);
+    } catch (NoSuchViewException e) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_VIEW_NOT_EXISTS, "View does not exist", 
e);
+    } catch (UnsupportedOperationException e) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_UNSUPPORTED_OPERATION,
+          "Catalog does not support this view operation",
+          e);
+    }
+  }
+
+  /**
+   * Drops a view from the catalog.
+   *
+   * <p>Only views with a Trino dialect SQL representation are considered 
visible to Trino; views
+   * created by other engines without one are treated as not existing, so this 
method never drops
+   * them.
+   *
+   * @param schemaName the name of the schema
+   * @param viewName the name of the view
+   */
+  public void dropView(String schemaName, String viewName) {
+    if (!supportsViews()) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_UNSUPPORTED_OPERATION, "Catalog does 
not support views");
+    }
+    // Ensures the view is visible to Trino (exists and has a Trino dialect 
representation) before
+    // dropping it, so views created by other engines without a Trino 
representation are never
+    // silently dropped.
+    getView(schemaName, viewName);
+    boolean dropped;
+    try {
+      dropped = viewCatalog.dropView(NameIdentifier.of(schemaName, viewName));
+    } catch (UnsupportedOperationException e) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_UNSUPPORTED_OPERATION,
+          "Catalog does not support this view operation",
+          e);
+    }
+    if (!dropped) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_OPERATION_FAILED,
+          "Failed to drop view " + schemaName + "." + viewName);
+    }
+  }
+
+  /**
+   * Renames a view in the catalog.
+   *
+   * <p>Only views with a Trino dialect SQL representation are considered 
visible to Trino; views
+   * created by other engines without one are treated as not existing, so this 
method never renames
+   * them.
+   *
+   * @param oldViewName the old name of the view
+   * @param newViewName the new name of the view
+   */
+  public void renameView(SchemaTableName oldViewName, SchemaTableName 
newViewName) {
+    if (!supportsViews()) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_UNSUPPORTED_OPERATION, "Catalog does 
not support views");
+    }
+    if (!oldViewName.getSchemaName().equals(newViewName.getSchemaName())) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_UNSUPPORTED_OPERATION, "Cannot rename 
view across schemas");
+    }
+    // Ensures the view is visible to Trino before renaming it, for the same 
reason as dropView.
+    getView(oldViewName.getSchemaName(), oldViewName.getTableName());
+    if (oldViewName.getTableName().equals(newViewName.getTableName())) {
+      return;
+    }
+    try {
+      viewCatalog.alterView(
+          NameIdentifier.of(oldViewName.getSchemaName(), 
oldViewName.getTableName()),
+          ViewChange.rename(newViewName.getTableName()));
+    } catch (NoSuchViewException e) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_VIEW_NOT_EXISTS, "View does not exist", 
e);
+    } catch (ViewAlreadyExistsException e) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_VIEW_ALREADY_EXISTS, "View already 
exists", e);
+    } catch (UnsupportedOperationException e) {
+      throw new TrinoException(
+          GravitinoErrorCode.GRAVITINO_UNSUPPORTED_OPERATION,
+          "Catalog does not support this view operation",
+          e);
+    }
+  }
+
+  /**
+   * Checks whether any of the given representations belongs to a dialect 
other than {@link
+   * Dialects#TRINO}.
+   *
+   * @param representations the representations to check
+   * @return true if a non-Trino dialect representation is present
+   */
+  private static boolean hasNonTrinoRepresentation(Representation[] 
representations) {
+    return Arrays.stream(representations)
+        .anyMatch(
+            representation ->
+                representation instanceof SQLRepresentation
+                    && !Dialects.TRINO.equalsIgnoreCase(
+                        ((SQLRepresentation) representation).dialect()));
+  }
+
+  /**
+   * Computes the {@link ViewChange} operations needed to apply {@code 
desired} on top of a view's
+   * current properties, so that {@code CREATE OR REPLACE VIEW ... WITH (...)} 
applies the new
+   * properties instead of silently leaving them unset ({@link 
ViewChange#replaceView} does not
+   * affect properties).
+   *
+   * <p>Only additions/updates are applied, never removals: {@code current} is 
the view's full

Review Comment:
   **[P1] This also prevents switching an existing DEFINER view to INVOKER.** 
With `CREATE OR REPLACE VIEW ... SECURITY INVOKER`, the new definition has no 
owner, but this merge retains the old `trino.internal.view.owner`. Reload then 
returns the old owner with `runAsInvoker=false`; I reproduced this through the 
current conversion/property-diff methods.
   
   Native Trino [clears the execution owner for 
INVOKER](https://github.com/trinodb/trino/blob/440/core/trino-main/src/main/java/io/trino/execution/CreateViewTask.java#L103),
 including replacement. Please remove this connector-managed property when 
switching to INVOKER, preserve unrelated backend properties, and add a 
DEFINER-to-INVOKER replacement test.



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to