[Storage] Add UC Delta Rest Catalog API loadTable client APIs

storage/src/main/java/io/delta/storage/commit/uccommitcoordinator/UCTokenBasedApiClientProvider.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright (2021) The Delta Lake Project Authors.
+ *
+ * Licensed 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 io.delta.storage.commit.uccommitcoordinator;
+
+import io.unitycatalog.client.ApiClient;
+import io.unitycatalog.client.ApiClientBuilder;
+import io.unitycatalog.client.auth.TokenProvider;
+import io.unitycatalog.client.retry.JitterDelayRetryPolicy;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.Objects;
+
+abstract class UCTokenBasedApiClientProvider {
+  private ApiClient apiClient;
+
+  protected UCTokenBasedApiClientProvider(
+      String baseUri,
+      TokenProvider tokenProvider,
+      Map<String, String> appVersions) {
+    this.apiClient = buildApiClient(baseUri, tokenProvider, appVersions);
+  }
+
+  protected UCTokenBasedApiClientProvider(
+      String baseUri,
+      TokenProvider tokenProvider,
+      Map<String, String> appVersions,
+      String catalog) {
+    // The catalog is consumed by subclasses that probe catalog-scoped Delta API support.
+    this(baseUri, tokenProvider, appVersions);
+  }
+
+  private static ApiClient buildApiClient(
+      String baseUri,
+      TokenProvider tokenProvider,
+      Map<String, String> appVersions) {
+    Objects.requireNonNull(baseUri, "baseUri must not be null");
+    Objects.requireNonNull(tokenProvider, "tokenProvider must not be null");
+    Objects.requireNonNull(appVersions, "appVersions must not be null");
+
+    ApiClientBuilder builder = ApiClientBuilder.create()
+        .uri(baseUri)
+        .tokenProvider(tokenProvider)
+        .retryPolicy(JitterDelayRetryPolicy.builder().build());
+
+    appVersions.forEach((name, version) -> {
+      if (version != null) {
+        builder.addAppVersion(name, version);
+      }
+    });
+
+    return builder.build();
+  }
+
+  protected ApiClient getApiClient() {
+    return apiClient;
+  }
+
+  public void close() throws IOException {
+    apiClient = null;
+  }
+}

storage/src/main/java/io/delta/storage/commit/uccommitcoordinator/UCTokenBasedRestClient.java

@@ -26,7 +26,6 @@
 import io.delta.storage.commit.uniform.IcebergMetadata;
 import io.delta.storage.commit.uniform.UniformMetadata;
 import io.unitycatalog.client.ApiClient;
-import io.unitycatalog.client.ApiClientBuilder;
 import io.unitycatalog.client.ApiException;
 import io.unitycatalog.client.api.DeltaCommitsApi;
 import io.unitycatalog.client.api.MetastoresApi;
@@ -83,7 +82,7 @@
  * @see GetCommitsResponse
  * @see TokenProvider
  */
-public class UCTokenBasedRestClient implements UCClient {
+public class UCTokenBasedRestClient extends UCTokenBasedApiClientProvider implements UCClient {
 
   private DeltaCommitsApi deltaCommitsApi;
   private MetastoresApi metastoresApi;
@@ -109,21 +108,20 @@ public UCTokenBasedRestClient(
       String baseUri,
       TokenProvider tokenProvider,
       Map<String, String> appVersions) {
-    Objects.requireNonNull(baseUri, "baseUri must not be null");
-    Objects.requireNonNull(tokenProvider, "tokenProvider must not be null");
-    Objects.requireNonNull(appVersions, "appVersions must not be null");
-
-    ApiClientBuilder builder = ApiClientBuilder.create()
-        .uri(baseUri)
-        .tokenProvider(tokenProvider);
-
-    appVersions.forEach((name, version) -> {
-      if (version != null) {
-        builder.addAppVersion(name, version);
-      }
-    });
+    super(baseUri, tokenProvider, appVersions);
+    ApiClient apiClient = getApiClient();
+    this.deltaCommitsApi = new DeltaCommitsApi(apiClient);
+    this.metastoresApi = new MetastoresApi(apiClient);
+    this.tablesApi = new TablesApi(apiClient);
+  }
 
-    ApiClient apiClient = builder.build();
+  public UCTokenBasedRestClient(
+      String baseUri,
+      TokenProvider tokenProvider,
+      Map<String, String> appVersions,
+      String catalog) {
+    super(baseUri, tokenProvider, appVersions, catalog);
+    ApiClient apiClient = getApiClient();
     this.deltaCommitsApi = new DeltaCommitsApi(apiClient);
     this.metastoresApi = new MetastoresApi(apiClient);
     this.tablesApi = new TablesApi(apiClient);
@@ -233,6 +231,7 @@ public GetCommitsResponse getCommits(
 
   @Override
   public void close() throws IOException {
+    super.close();
     // Nulling out the API instances makes them eligible for GC. Once garbage collected,
     // the underlying connection pool is freed and destroyed.
     this.deltaCommitsApi = null;