OpenSharing protocol: list schemas in granted shares

server/opensharing-server-core/src/main/java/io/opensharing/asset/SharedDataObjectStore.java

@@ -87,6 +87,21 @@ public List<SharedDataObjectEntity> list(ShareEntity share) {
                 .getResultList());
   }
 
+  /** One page of the schemas recipients see in {@code share}, ordered by name. */
+  public List<String> listSchemas(ShareEntity share, int offset, int limit) {
+    return tx.inTransaction(
+        true,
+        em ->
+            em.createQuery(
+                    "select distinct o.sharedAsSchema from SharedDataObjectEntity o"
+                        + " where o.share.id = :shareId order by o.sharedAsSchema",
+                    String.class)
+                .setParameter("shareId", share.getId())
+                .setFirstResult(offset)
+                .setMaxResults(limit)
+                .getResultList());
+  }
+
   /** Removes the object shared under the alias. Fails unless it exists with the given type. */
   public void removeByAlias(
       EntityManager em,

server/opensharing-server-core/src/main/java/io/opensharing/asset/schema/ProtocolSchemas.java

@@ -0,0 +1,34 @@
+package io.opensharing.asset.schema;
+
+import io.opensharing.asset.SharedDataObjectStore;
+import io.opensharing.asset.share.ProtocolShares;
+import io.opensharing.http.ListResponse;
+import io.opensharing.http.Pagination;
+import io.opensharing.recipient.RecipientPrincipal;
+import io.opensharing.share.ShareEntity;
+
+/**
+ * The schemas a recipient sees through the sharing protocol: the distinct schema aliases of the
+ * objects in a share it holds SELECT on.
+ */
+public class ProtocolSchemas {
+
+  private final ProtocolShares shares;
+  private final SharedDataObjectStore objects;
+
+  public ProtocolSchemas(ProtocolShares shares, SharedDataObjectStore objects) {
+    this.shares = shares;
+    this.objects = objects;
+  }
+
+  /** Lists one page of the share's schemas by name. */
+  public ListResponse<SchemaResponse> list(
+      RecipientPrincipal recipient, String share, Integer maxResults, String pageToken) {
+    ShareEntity granted = shares.requireGranted(recipient, share);
+    return Pagination.protocolPage(
+        maxResults,
+        pageToken,
+        (offset, limit) -> objects.listSchemas(granted, offset, limit),
+        name -> new SchemaResponse(name, granted.getName()));
+  }
+}

server/opensharing-server-core/src/main/java/io/opensharing/asset/schema/SchemaResponse.java

@@ -0,0 +1,10 @@
+package io.opensharing.asset.schema;
+
+/**
+ * Protocol schema listed under a share:
+ *
+ * <pre>{@code
+ * {"name": "<schema name>", "share": "<share name>"}
+ * }</pre>
+ */
+public record SchemaResponse(String name, String share) {}

server/opensharing-server-core/src/main/java/io/opensharing/asset/share/ProtocolShares.java

@@ -4,6 +4,7 @@
 import io.opensharing.http.ListResponse;
 import io.opensharing.http.Pagination;
 import io.opensharing.recipient.RecipientPrincipal;
+import io.opensharing.share.ShareEntity;
 import io.opensharing.share.ShareResponse;
 import io.opensharing.share.SharePermissionStore;
 import io.opensharing.share.ShareStore;
@@ -34,10 +35,16 @@ public ListResponse<ShareResponse> list(
 
   /** Gets one of the recipient's shares by name in any case. */
   public GetShareResponse get(RecipientPrincipal recipient, String share) {
+    return new GetShareResponse(ShareResponse.from(requireGranted(recipient, share)));
+  }
+
+  /**
+   * Looks up a share by name in any case. Fails with not-found unless the recipient holds SELECT.
+   */
+  public ShareEntity requireGranted(RecipientPrincipal recipient, String share) {
     return shares
         .find(share)
         .filter(candidate -> permissions.hasSelect(candidate, recipient.recipientId()))
-        .map(granted -> new GetShareResponse(ShareResponse.from(granted)))
         .orElseThrow(() -> ApiException.notFound("share '" + share + "' does not exist"));
   }
 }

server/opensharing-server-core/src/main/java/io/opensharing/protocol/OpenSharingProtocolService.java

@@ -6,6 +6,8 @@
 import com.linecorp.armeria.server.annotation.Get;
 import com.linecorp.armeria.server.annotation.Param;
 import com.linecorp.armeria.server.annotation.ProducesJson;
+import io.opensharing.asset.schema.ProtocolSchemas;
+import io.opensharing.asset.schema.SchemaResponse;
 import io.opensharing.asset.share.GetShareResponse;
 import io.opensharing.asset.share.ProtocolShares;
 import io.opensharing.http.ListResponse;
@@ -20,9 +22,11 @@
 public final class OpenSharingProtocolService {
 
   private final ProtocolShares shares;
+  private final ProtocolSchemas schemas;
 
-  public OpenSharingProtocolService(ProtocolShares shares) {
+  public OpenSharingProtocolService(ProtocolShares shares, ProtocolSchemas schemas) {
     this.shares = shares;
+    this.schemas = schemas;
   }
 
   /** {@code GET /shares}: lists one page of the shares the recipient holds SELECT on. */
@@ -39,4 +43,14 @@ public ListResponse<ShareResponse> listShares(
   public GetShareResponse getShare(ServiceRequestContext ctx, @Param String share) {
     return shares.get(RecipientTokenDecorator.recipient(ctx), share);
   }
+
+  /** {@code GET /shares/{share}/schemas}: lists one page of the schemas in a granted share. */
+  @Get("/shares/{share}/schemas")
+  public ListResponse<SchemaResponse> listSchemas(
+      ServiceRequestContext ctx,
+      @Param String share,
+      @Param @Nullable Integer maxResults,
+      @Param @Nullable String pageToken) {
+    return schemas.list(RecipientTokenDecorator.recipient(ctx), share, maxResults, pageToken);
+  }
 }

server/opensharing-server-core/src/main/java/io/opensharing/protocol/OpenSharingRecipientApi.java

@@ -39,7 +39,9 @@ public static void mount(
         .exceptionHandlers(errors)
         .decorator(new RecipientTokenDecorator(openSharing.recipients()))
         .decorator(errors)
-        .build(new OpenSharingProtocolService(openSharing.protocolShares()));
+        .build(
+            new OpenSharingProtocolService(
+                openSharing.protocolShares(), openSharing.protocolSchemas()));
     builder
         .annotatedService()
         .pathPrefix(activationBasePath)

server/opensharing-server-core/src/main/java/io/opensharing/runtime/OpenSharing.java

@@ -3,6 +3,7 @@
 import io.opensharing.Transactions;
 import io.opensharing.asset.SharedDataObjectEntity;
 import io.opensharing.asset.SharedDataObjectStore;
+import io.opensharing.asset.schema.ProtocolSchemas;
 import io.opensharing.asset.share.ProtocolShares;
 import io.opensharing.catalog.CatalogConnector;
 import io.opensharing.recipient.RecipientEntity;
@@ -27,22 +28,19 @@ public final class OpenSharing {
   private final ShareService shares;
   private final RecipientService recipients;
   private final ProtocolShares protocolShares;
+  private final ProtocolSchemas protocolSchemas;
 
   private OpenSharing(CatalogConnector catalog, Transactions tx) {
     this.catalog = catalog;
     ShareStore shareStore = new ShareStore(tx);
+    SharedDataObjectStore objectStore = new SharedDataObjectStore(tx);
     SharePermissionStore permissionStore = new SharePermissionStore(tx);
     RecipientStore recipientStore = new RecipientStore(tx);
     this.shares =
-        new ShareService(
-            catalog,
-            tx,
-            shareStore,
-            new SharedDataObjectStore(tx),
-            permissionStore,
-            recipientStore);
+        new ShareService(catalog, tx, shareStore, objectStore, permissionStore, recipientStore);
     this.recipients = new RecipientService(catalog, recipientStore);
     this.protocolShares = new ProtocolShares(shareStore, permissionStore);
+    this.protocolSchemas = new ProtocolSchemas(protocolShares, objectStore);
   }
 
   public static Builder builder() {
@@ -76,6 +74,11 @@ public ProtocolShares protocolShares() {
     return protocolShares;
   }
 
+  /** The schemas recipients see in their shares through the sharing protocol. */
+  public ProtocolSchemas protocolSchemas() {
+    return protocolSchemas;
+  }
+
   public static final class Builder {
 
     private CatalogConnector catalog;

server/opensharing-server/src/main/resources/local-catalog.yml

@@ -46,3 +46,13 @@ assets:
       subtype: MANAGED
     storageLocation: s3://test/main.sales.orders/
     format: delta
+
+  - identifier: main.hr
+    type: SCHEMA
+
+  - identifier: main.ops.people
+    type: TABLE
+    attributes:
+      subtype: MANAGED
+    storageLocation: s3://test/main.ops.people/
+    format: delta

server/opensharing-server/src/test/java/io/opensharing/protocol/ProtocolApiSupport.java

@@ -33,11 +33,26 @@ static void stopServer() {
     server.close();
   }
 
+  protected static void createShare(String name) {
+    String body = "{\"name\":\"%s\"}".formatted(name);
+    assertEquals(201, server.post(PROVIDER + "/shares", ALICE, body).status());
+  }
+
   protected static void createShare(String name, String displayName) {
     String body = "{\"name\":\"%s\",\"displayName\":\"%s\"}".formatted(name, displayName);
     assertEquals(201, server.post(PROVIDER + "/shares", ALICE, body).status());
   }
 
+  /** Adds the catalog asset {@code name} of {@code type} to the share as {@code sharedAs}. */
+  protected static void addObject(String share, String type, String name, String sharedAs) {
+    String body =
+        "{\"updates\":[{\"action\":\"ADD\",\"dataObject\":"
+            + "{\"name\":\"%s\",\"type\":\"%s\",\"sharedAs\":\"%s\"}}]}";
+    Response added =
+        server.patch(PROVIDER + "/shares/" + share, ALICE, body.formatted(name, type, sharedAs));
+    assertEquals(200, added.status());
+  }
+
   /** Creates a TOKEN recipient, redeems its activation URL, and returns the bearer token. */
   protected static String createAndActivateRecipient(String name) {
     Response created =

server/opensharing-server/src/test/java/io/opensharing/protocol/ProtocolSchemasTest.java

@@ -0,0 +1,85 @@
+package io.opensharing.protocol;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.linecorp.armeria.common.MediaType;
+import io.opensharing.TestServer.Response;
+import io.opensharing.http.ErrorCodes;
+import java.nio.charset.StandardCharsets;
+import org.junit.jupiter.api.Test;
+
+class ProtocolSchemasTest extends ProtocolApiSupport {
+
+  @Test
+  void listsDistinctSchemasInAGrantedShare() {
+    createShare("schema-share");
+    addObject("schema-share", "TABLE", "main.sales.table1", "alpha.t1");
+    addObject("schema-share", "TABLE", "main.sales.orders", "alpha.t2");
+    addObject("schema-share", "SCHEMA", "main.hr", "beta");
+    addObject("schema-share", "TABLE", "main.ops.people", "gamma.t3");
+    createShare("hidden-share");
+    addObject("hidden-share", "TABLE", "main.sales.table1", "hidden.t");
+    String bearer = createAndActivateRecipient("schema-partner");
+    grant("schema-share", "schema-partner");
+
+    // Distinct shared-as schemas, ordered by name; the share lookup is case-insensitive.
+    Response list = server.get(PROTOCOL + "/shares/SCHEMA-SHARE/schemas", bearer);
+    assertEquals(200, list.status());
+    MediaType contentType = list.headers().contentType();
+    assertTrue(contentType.is(MediaType.JSON), contentType.toString());
+    assertEquals(StandardCharsets.UTF_8, contentType.charset());
+    JsonNode items = list.body().path("items");
+    assertEquals(3, items.size());
+    assertEquals("alpha", items.path(0).path("name").asText());
+    assertEquals("schema-share", items.path(0).path("share").asText());
+    assertEquals("beta", items.path(1).path("name").asText());
+    assertEquals("gamma", items.path(2).path("name").asText());
+    assertTrue(list.body().path("nextPageToken").isMissingNode());
+
+    // Ungranted and missing shares are both reported as missing.
+    Response hidden = server.get(PROTOCOL + "/shares/hidden-share/schemas", bearer);
+    assertEquals(404, hidden.status());
+    assertEquals(ErrorCodes.RESOURCE_DOES_NOT_EXIST, hidden.errorCode());
+    Response missing = server.get(PROTOCOL + "/shares/missing/schemas", bearer);
+    assertEquals(404, missing.status());
+    assertEquals(ErrorCodes.RESOURCE_DOES_NOT_EXIST, missing.errorCode());
+  }
+
+  @Test
+  void paginatesSchemasAndAllowsAnEmptyGrantedShare() {
+    createShare("paged-schemas");
+    addObject("paged-schemas", "TABLE", "main.sales.table1", "alpha.t");
+    addObject("paged-schemas", "TABLE", "main.sales.orders", "beta.t");
+    createShare("empty-share");
+    String bearer = createAndActivateRecipient("schema-paged");
+    grant("paged-schemas", "schema-paged");
+    grant("empty-share", "schema-paged");
+
+    String schemas = PROTOCOL + "/shares/paged-schemas/schemas";
+    Response first = server.get(page(schemas, 1, null), bearer);
+    assertEquals(200, first.status());
+    assertEquals(1, first.body().path("items").size());
+    assertEquals("alpha", first.body().path("items").path(0).path("name").asText());
+    String pageToken = first.body().path("nextPageToken").asText();
+    assertFalse(pageToken.isEmpty());
+    Response second = server.get(page(schemas, 1, pageToken), bearer);
+    assertEquals(200, second.status());
+    assertEquals(1, second.body().path("items").size());
+    assertEquals("beta", second.body().path("items").path(0).path("name").asText());
+    assertTrue(second.body().path("nextPageToken").isMissingNode());
+
+    // A page size of 0 returns no schemas, but a token to resume from.
+    Response zero = server.get(page(schemas, 0, null), bearer);
+    assertEquals(0, zero.body().path("items").size());
+    assertFalse(zero.body().path("nextPageToken").isMissingNode());
+
+    // A granted share with no objects lists no schemas.
+    Response empty = server.get(PROTOCOL + "/shares/empty-share/schemas", bearer);
+    assertEquals(200, empty.status());
+    assertEquals(0, empty.body().path("items").size());
+    assertTrue(empty.body().path("nextPageToken").isMissingNode());
+  }
+}