/**
 * @license
 * Copyright 2020 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.
 */
import { Transaction as InternalTransaction } from '../core/transaction';
import { DocumentData, DocumentReference } from '../lite-api/reference';
import { Transaction as LiteTransaction } from '../lite-api/transaction';
import { Firestore } from './database';
import { DocumentSnapshot } from './snapshot';
import { TransactionOptions } from './transaction_options';
/**
 * A reference to a transaction.
 *
 * The `Transaction` object passed to a transaction's `updateFunction` provides
 * the methods to read and write data within the transaction context. See
 * {@link runTransaction}.
 */
export declare class Transaction extends LiteTransaction {
    protected readonly _firestore: Firestore;
    /** @hideconstructor */
    constructor(_firestore: Firestore, _transaction: InternalTransaction);
    /**
     * Reads the document referenced by the provided {@link DocumentReference}.
     *
     * @param documentRef - A reference to the document to be read.
     * @returns A `DocumentSnapshot` with the read data.
     */
    get<AppModelType, DbModelType extends DocumentData>(documentRef: DocumentReference<AppModelType, DbModelType>): Promise<DocumentSnapshot<AppModelType, DbModelType>>;
}
/**
 * Executes the given `updateFunction` and then attempts to commit the changes
 * applied within the transaction. If any document read within the transaction
 * has changed, Cloud Firestore retries the `updateFunction`. If it fails to
 * commit after 5 attempts, the transaction fails.
 *
 * The maximum number of writes allowed in a single transaction is 500.
 *
 * @param firestore - A reference to the Firestore database to run this
 * transaction against.
 * @param updateFunction - The function to execute within the transaction
 * context.
 * @param options - An options object to configure maximum number of attempts to
 * commit.
 * @returns If the transaction completed successfully or was explicitly aborted
 * (the `updateFunction` returned a failed promise), the promise returned by the
 * `updateFunction `is returned here. Otherwise, if the transaction failed, a
 * rejected promise with the corresponding failure error is returned.
 */
export declare function runTransaction<T>(firestore: Firestore, updateFunction: (transaction: Transaction) => Promise<T>, options?: TransactionOptions): Promise<T>;