chore(spanner): add delayed transaction support for mux R/W

Author: harshachinta

google-cloud-spanner/src/main/java/com/google/cloud/spanner/DelayedTransactionManager.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * 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 com.google.cloud.spanner;
+
+import com.google.api.core.ApiFuture;
+import com.google.cloud.Timestamp;
+import java.util.concurrent.ExecutionException;
+
+class DelayedTransactionManager implements TransactionManager {
+
+  private final ApiFuture<TransactionManager> transactionManagerFuture;
+
+  DelayedTransactionManager(ApiFuture<TransactionManager> transactionManagerFuture) {
+    this.transactionManagerFuture = transactionManagerFuture;
+  }
+
+  TransactionManager getTransactionManager() {
+    try {
+      return this.transactionManagerFuture.get();
+    } catch (ExecutionException executionException) {
+      // Propagate the underlying exception as a RuntimeException (SpannerException is also a
+      // RuntimeException).
+      if (executionException.getCause() instanceof RuntimeException) {
+        throw (RuntimeException) executionException.getCause();
+      }
+      throw SpannerExceptionFactory.asSpannerException(executionException.getCause());
+    } catch (InterruptedException interruptedException) {
+      throw SpannerExceptionFactory.propagateInterrupt(interruptedException);
+    }
+  }
+
+  @Override
+  public TransactionContext begin() {
+    return getTransactionManager().begin();
+  }
+
+  @Override
+  public void commit() {
+    getTransactionManager().commit();
+  }
+
+  @Override
+  public void rollback() {
+    getTransactionManager().rollback();
+  }
+
+  @Override
+  public TransactionContext resetForRetry() {
+    return getTransactionManager().resetForRetry();
+  }
+
+  @Override
+  public Timestamp getCommitTimestamp() {
+    return getTransactionManager().getCommitTimestamp();
+  }
+
+  @Override
+  public CommitResponse getCommitResponse() {
+    return getTransactionManager().getCommitResponse();
+  }
+
+  @Override
+  public TransactionState getState() {
+    return getTransactionManager().getState();
+  }
+
+  @Override
+  public void close() {
+    getTransactionManager().close();
+  }
+}

google-cloud-spanner/src/main/java/com/google/cloud/spanner/DelayedTransactionRunner.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * 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 com.google.cloud.spanner;
+
+import com.google.api.core.ApiFuture;
+import com.google.cloud.Timestamp;
+import java.util.concurrent.ExecutionException;
+import javax.annotation.Nullable;
+
+/**
+ * Represents a {@link TransactionRunner} using a multiplexed session that is not yet ready. The
+ * execution will be delayed until the multiplexed session has been created and is ready. This class
+ * is only used during the startup of the client and the multiplexed session has not yet been
+ * created.
+ */
+class DelayedTransactionRunner implements TransactionRunner {
+  private final ApiFuture<TransactionRunner> transactionRunnerFuture;
+
+  DelayedTransactionRunner(ApiFuture<TransactionRunner> transactionRunnerFuture) {
+    this.transactionRunnerFuture = transactionRunnerFuture;
+  }
+
+  TransactionRunner getTransactionRunner() {
+    try {
+      return this.transactionRunnerFuture.get();
+    } catch (ExecutionException executionException) {
+      // Propagate the underlying exception as a RuntimeException (SpannerException is also a
+      // RuntimeException).
+      if (executionException.getCause() instanceof RuntimeException) {
+        throw (RuntimeException) executionException.getCause();
+      }
+      throw SpannerExceptionFactory.asSpannerException(executionException.getCause());
+    } catch (InterruptedException interruptedException) {
+      throw SpannerExceptionFactory.propagateInterrupt(interruptedException);
+    }
+  }
+
+  @Nullable
+  @Override
+  public <T> T run(TransactionCallable<T> callable) {
+    return getTransactionRunner().run(callable);
+  }
+
+  @Override
+  public Timestamp getCommitTimestamp() {
+    return getTransactionRunner().getCommitTimestamp();
+  }
+
+  @Override
+  public CommitResponse getCommitResponse() {
+    return getTransactionRunner().getCommitResponse();
+  }
+
+  @Override
+  public TransactionRunner allowNestedTransaction() {
+    return getTransactionRunner().allowNestedTransaction();
+  }
+}