<?php
/*
 * Copyright 2017 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
 *
 *     https://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.
 */

/*
 * GENERATED CODE WARNING
 * This file was generated from the file
 * https://github.com/google/googleapis/blob/master/google/spanner/v1/spanner.proto
 * and updates to that file get reflected here through a refresh process.
 *
 * @experimental
 */

namespace Google\Cloud\Spanner\V1\Gapic;

use Google\ApiCore\ApiException;
use Google\ApiCore\Call;
use Google\ApiCore\CredentialsWrapper;
use Google\ApiCore\GapicClientTrait;
use Google\ApiCore\PathTemplate;
use Google\ApiCore\RequestParamsHeaderDescriptor;
use Google\ApiCore\RetrySettings;
use Google\ApiCore\Transport\TransportInterface;
use Google\ApiCore\ValidationException;
use Google\Auth\FetchAuthTokenInterface;
use Google\Cloud\Spanner\V1\BatchCreateSessionsRequest;
use Google\Cloud\Spanner\V1\BatchCreateSessionsResponse;
use Google\Cloud\Spanner\V1\BeginTransactionRequest;
use Google\Cloud\Spanner\V1\CommitRequest;
use Google\Cloud\Spanner\V1\CommitResponse;
use Google\Cloud\Spanner\V1\CreateSessionRequest;
use Google\Cloud\Spanner\V1\DeleteSessionRequest;
use Google\Cloud\Spanner\V1\ExecuteBatchDmlRequest;
use Google\Cloud\Spanner\V1\ExecuteBatchDmlRequest\Statement;
use Google\Cloud\Spanner\V1\ExecuteBatchDmlResponse;
use Google\Cloud\Spanner\V1\ExecuteSqlRequest;
use Google\Cloud\Spanner\V1\ExecuteSqlRequest\QueryMode;
use Google\Cloud\Spanner\V1\ExecuteSqlRequest\QueryOptions;
use Google\Cloud\Spanner\V1\GetSessionRequest;
use Google\Cloud\Spanner\V1\KeySet;
use Google\Cloud\Spanner\V1\ListSessionsRequest;
use Google\Cloud\Spanner\V1\ListSessionsResponse;
use Google\Cloud\Spanner\V1\Mutation;
use Google\Cloud\Spanner\V1\PartialResultSet;
use Google\Cloud\Spanner\V1\PartitionOptions;
use Google\Cloud\Spanner\V1\PartitionQueryRequest;
use Google\Cloud\Spanner\V1\PartitionReadRequest;
use Google\Cloud\Spanner\V1\PartitionResponse;
use Google\Cloud\Spanner\V1\ReadRequest;
use Google\Cloud\Spanner\V1\ResultSet;
use Google\Cloud\Spanner\V1\RollbackRequest;
use Google\Cloud\Spanner\V1\Session;
use Google\Cloud\Spanner\V1\Transaction;
use Google\Cloud\Spanner\V1\TransactionOptions;
use Google\Cloud\Spanner\V1\TransactionSelector;
use Google\Protobuf\GPBEmpty;
use Google\Protobuf\Struct;

/**
 * Service Description: Cloud Spanner API.
 *
 * The Cloud Spanner API can be used to manage sessions and execute
 * transactions on data stored in Cloud Spanner databases.
 *
 * This class provides the ability to make remote calls to the backing service through method
 * calls that map to API methods. Sample code to get started:
 *
 * ```
 * $spannerClient = new SpannerClient();
 * try {
 *     $formattedDatabase = $spannerClient->databaseName('[PROJECT]', '[INSTANCE]', '[DATABASE]');
 *     $response = $spannerClient->createSession($formattedDatabase);
 * } finally {
 *     $spannerClient->close();
 * }
 * ```
 *
 * Many parameters require resource names to be formatted in a particular way. To assist
 * with these names, this class includes a format method for each type of name, and additionally
 * a parseName method to extract the individual identifiers contained within formatted names
 * that are returned by the API.
 *
 * @experimental
 */
class SpannerGapicClient
{
    use GapicClientTrait;

    /**
     * The name of the service.
     */
    const SERVICE_NAME = 'google.spanner.v1.Spanner';

    /**
     * The default address of the service.
     */
    const SERVICE_ADDRESS = 'spanner.googleapis.com';

    /**
     * The default port of the service.
     */
    const DEFAULT_SERVICE_PORT = 443;

    /**
     * The name of the code generator, to be included in the agent header.
     */
    const CODEGEN_NAME = 'gapic';

    /**
     * The default scopes required by the service.
     */
    public static $serviceScopes = [
        'https://www.googleapis.com/auth/cloud-platform',
        'https://www.googleapis.com/auth/spanner.data',
    ];
    private static $databaseNameTemplate;
    private static $sessionNameTemplate;
    private static $pathTemplateMap;

    private static function getClientDefaults()
    {
        return [
            'serviceName' => self::SERVICE_NAME,
            'apiEndpoint' => self::SERVICE_ADDRESS.':'.self::DEFAULT_SERVICE_PORT,
            'clientConfig' => __DIR__.'/../resources/spanner_client_config.json',
            'descriptorsConfigPath' => __DIR__.'/../resources/spanner_descriptor_config.php',
            'gcpApiConfigPath' => __DIR__.'/../resources/spanner_grpc_config.json',
            'credentialsConfig' => [
                'scopes' => self::$serviceScopes,
            ],
            'transportConfig' => [
                'rest' => [
                    'restClientConfigPath' => __DIR__.'/../resources/spanner_rest_client_config.php',
                ],
            ],
        ];
    }

    private static function getDatabaseNameTemplate()
    {
        if (null == self::$databaseNameTemplate) {
            self::$databaseNameTemplate = new PathTemplate('projects/{project}/instances/{instance}/databases/{database}');
        }

        return self::$databaseNameTemplate;
    }

    private static function getSessionNameTemplate()
    {
        if (null == self::$sessionNameTemplate) {
            self::$sessionNameTemplate = new PathTemplate('projects/{project}/instances/{instance}/databases/{database}/sessions/{session}');
        }

        return self::$sessionNameTemplate;
    }

    private static function getPathTemplateMap()
    {
        if (null == self::$pathTemplateMap) {
            self::$pathTemplateMap = [
                'database' => self::getDatabaseNameTemplate(),
                'session' => self::getSessionNameTemplate(),
            ];
        }

        return self::$pathTemplateMap;
    }

    /**
     * Formats a string containing the fully-qualified path to represent
     * a database resource.
     *
     * @param string $project
     * @param string $instance
     * @param string $database
     *
     * @return string The formatted database resource.
     * @experimental
     */
    public static function databaseName($project, $instance, $database)
    {
        return self::getDatabaseNameTemplate()->render([
            'project' => $project,
            'instance' => $instance,
            'database' => $database,
        ]);
    }

    /**
     * Formats a string containing the fully-qualified path to represent
     * a session resource.
     *
     * @param string $project
     * @param string $instance
     * @param string $database
     * @param string $session
     *
     * @return string The formatted session resource.
     * @experimental
     */
    public static function sessionName($project, $instance, $database, $session)
    {
        return self::getSessionNameTemplate()->render([
            'project' => $project,
            'instance' => $instance,
            'database' => $database,
            'session' => $session,
        ]);
    }

    /**
     * Parses a formatted name string and returns an associative array of the components in the name.
     * The following name formats are supported:
     * Template: Pattern
     * - database: projects/{project}/instances/{instance}/databases/{database}
     * - session: projects/{project}/instances/{instance}/databases/{database}/sessions/{session}.
     *
     * The optional $template argument can be supplied to specify a particular pattern, and must
     * match one of the templates listed above. If no $template argument is provided, or if the
     * $template argument does not match one of the templates listed, then parseName will check
     * each of the supported templates, and return the first match.
     *
     * @param string $formattedName The formatted name string
     * @param string $template      Optional name of template to match
     *
     * @return array An associative array from name component IDs to component values.
     *
     * @throws ValidationException If $formattedName could not be matched.
     * @experimental
     */
    public static function parseName($formattedName, $template = null)
    {
        $templateMap = self::getPathTemplateMap();

        if ($template) {
            if (!isset($templateMap[$template])) {
                throw new ValidationException("Template name $template does not exist");
            }

            return $templateMap[$template]->match($formattedName);
        }

        foreach ($templateMap as $templateName => $pathTemplate) {
            try {
                return $pathTemplate->match($formattedName);
            } catch (ValidationException $ex) {
                // Swallow the exception to continue trying other path templates
            }
        }
        throw new ValidationException("Input did not match any known format. Input: $formattedName");
    }

    /**
     * Constructor.
     *
     * @param array $options {
     *                       Optional. Options for configuring the service API wrapper.
     *
     *     @type string $serviceAddress
     *           **Deprecated**. This option will be removed in a future major release. Please
     *           utilize the `$apiEndpoint` option instead.
     *     @type string $apiEndpoint
     *           The address of the API remote host. May optionally include the port, formatted
     *           as "<uri>:<port>". Default 'spanner.googleapis.com:443'.
     *     @type string|array|FetchAuthTokenInterface|CredentialsWrapper $credentials
     *           The credentials to be used by the client to authorize API calls. This option
     *           accepts either a path to a credentials file, or a decoded credentials file as a
     *           PHP array.
     *           *Advanced usage*: In addition, this option can also accept a pre-constructed
     *           {@see \Google\Auth\FetchAuthTokenInterface} object or
     *           {@see \Google\ApiCore\CredentialsWrapper} object. Note that when one of these
     *           objects are provided, any settings in $credentialsConfig will be ignored.
     *     @type array $credentialsConfig
     *           Options used to configure credentials, including auth token caching, for the client.
     *           For a full list of supporting configuration options, see
     *           {@see \Google\ApiCore\CredentialsWrapper::build()}.
     *     @type bool $disableRetries
     *           Determines whether or not retries defined by the client configuration should be
     *           disabled. Defaults to `false`.
     *     @type string|array $clientConfig
     *           Client method configuration, including retry settings. This option can be either a
     *           path to a JSON file, or a PHP array containing the decoded JSON data.
     *           By default this settings points to the default client config file, which is provided
     *           in the resources folder.
     *     @type string|TransportInterface $transport
     *           The transport used for executing network requests. May be either the string `rest`
     *           or `grpc`. Defaults to `grpc` if gRPC support is detected on the system.
     *           *Advanced usage*: Additionally, it is possible to pass in an already instantiated
     *           {@see \Google\ApiCore\Transport\TransportInterface} object. Note that when this
     *           object is provided, any settings in $transportConfig, and any `$apiEndpoint`
     *           setting, will be ignored.
     *     @type array $transportConfig
     *           Configuration options that will be used to construct the transport. Options for
     *           each supported transport type should be passed in a key for that transport. For
     *           example:
     *           $transportConfig = [
     *               'grpc' => [...],
     *               'rest' => [...]
     *           ];
     *           See the {@see \Google\ApiCore\Transport\GrpcTransport::build()} and
     *           {@see \Google\ApiCore\Transport\RestTransport::build()} methods for the
     *           supported options.
     * }
     *
     * @throws ValidationException
     * @experimental
     */
    public function __construct(array $options = [])
    {
        $clientOptions = $this->buildClientOptions($options);
        $this->setClientOptions($clientOptions);
    }

    /**
     * Creates a new session. A session can be used to perform
     * transactions that read and/or modify data in a Cloud Spanner database.
     * Sessions are meant to be reused for many consecutive
     * transactions.
     *
     * Sessions can only execute one transaction at a time. To execute
     * multiple concurrent read-write/write-only transactions, create
     * multiple sessions. Note that standalone reads and queries use a
     * transaction internally, and count toward the one transaction
     * limit.
     *
     * Active sessions use additional server resources, so it is a good idea to
     * delete idle and unneeded sessions.
     * Aside from explicit deletes, Cloud Spanner may delete sessions for which no
     * operations are sent for more than an hour. If a session is deleted,
     * requests to it return `NOT_FOUND`.
     *
     * Idle sessions can be kept alive by sending a trivial SQL query
     * periodically, e.g., `"SELECT 1"`.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedDatabase = $spannerClient->databaseName('[PROJECT]', '[INSTANCE]', '[DATABASE]');
     *     $response = $spannerClient->createSession($formattedDatabase);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $database     Required. The database in which the new session is created.
     * @param array  $optionalArgs {
     *                             Optional.
     *
     *     @type Session $session
     *          The session to create.
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\Session
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function createSession($database, array $optionalArgs = [])
    {
        $request = new CreateSessionRequest();
        $request->setDatabase($database);
        if (isset($optionalArgs['session'])) {
            $request->setSession($optionalArgs['session']);
        }

        $requestParams = new RequestParamsHeaderDescriptor([
          'database' => $request->getDatabase(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'CreateSession',
            Session::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Creates multiple new sessions.
     *
     * This API can be used to initialize a session cache on the clients.
     * See https://goo.gl/TgSFN2 for best practices on session cache management.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedDatabase = $spannerClient->databaseName('[PROJECT]', '[INSTANCE]', '[DATABASE]');
     *     $sessionCount = 0;
     *     $response = $spannerClient->batchCreateSessions($formattedDatabase, $sessionCount);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $database     Required. The database in which the new sessions are created.
     * @param int    $sessionCount Required. The number of sessions to be created in this batch call.
     *                             The API may return fewer than the requested number of sessions. If a
     *                             specific number of sessions are desired, the client can make additional
     *                             calls to BatchCreateSessions (adjusting
     *                             [session_count][google.spanner.v1.BatchCreateSessionsRequest.session_count] as necessary).
     * @param array  $optionalArgs {
     *                             Optional.
     *
     *     @type Session $sessionTemplate
     *          Parameters to be applied to each created session.
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\BatchCreateSessionsResponse
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function batchCreateSessions($database, $sessionCount, array $optionalArgs = [])
    {
        $request = new BatchCreateSessionsRequest();
        $request->setDatabase($database);
        $request->setSessionCount($sessionCount);
        if (isset($optionalArgs['sessionTemplate'])) {
            $request->setSessionTemplate($optionalArgs['sessionTemplate']);
        }

        $requestParams = new RequestParamsHeaderDescriptor([
          'database' => $request->getDatabase(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'BatchCreateSessions',
            BatchCreateSessionsResponse::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Gets a session. Returns `NOT_FOUND` if the session does not exist.
     * This is mainly useful for determining whether a session is still
     * alive.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedName = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $response = $spannerClient->getSession($formattedName);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $name         Required. The name of the session to retrieve.
     * @param array  $optionalArgs {
     *                             Optional.
     *
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\Session
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function getSession($name, array $optionalArgs = [])
    {
        $request = new GetSessionRequest();
        $request->setName($name);

        $requestParams = new RequestParamsHeaderDescriptor([
          'name' => $request->getName(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'GetSession',
            Session::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Lists all sessions in a given database.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedDatabase = $spannerClient->databaseName('[PROJECT]', '[INSTANCE]', '[DATABASE]');
     *     // Iterate over pages of elements
     *     $pagedResponse = $spannerClient->listSessions($formattedDatabase);
     *     foreach ($pagedResponse->iteratePages() as $page) {
     *         foreach ($page as $element) {
     *             // doSomethingWith($element);
     *         }
     *     }
     *
     *
     *     // Alternatively:
     *
     *     // Iterate through all elements
     *     $pagedResponse = $spannerClient->listSessions($formattedDatabase);
     *     foreach ($pagedResponse->iterateAllElements() as $element) {
     *         // doSomethingWith($element);
     *     }
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $database     Required. The database in which to list sessions.
     * @param array  $optionalArgs {
     *                             Optional.
     *
     *     @type int $pageSize
     *          The maximum number of resources contained in the underlying API
     *          response. The API may return fewer values in a page, even if
     *          there are additional values to be retrieved.
     *     @type string $pageToken
     *          A page token is used to specify a page of values to be returned.
     *          If no page token is specified (the default), the first page
     *          of values will be returned. Any page token used here must have
     *          been generated by a previous call to the API.
     *     @type string $filter
     *          An expression for filtering the results of the request. Filter rules are
     *          case insensitive. The fields eligible for filtering are:
     *
     *            * `labels.key` where key is the name of a label
     *
     *          Some examples of using filters are:
     *
     *            * `labels.env:*` --> The session has the label "env".
     *            * `labels.env:dev` --> The session has the label "env" and the value of
     *                                 the label contains the string "dev".
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\ApiCore\PagedListResponse
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function listSessions($database, array $optionalArgs = [])
    {
        $request = new ListSessionsRequest();
        $request->setDatabase($database);
        if (isset($optionalArgs['pageSize'])) {
            $request->setPageSize($optionalArgs['pageSize']);
        }
        if (isset($optionalArgs['pageToken'])) {
            $request->setPageToken($optionalArgs['pageToken']);
        }
        if (isset($optionalArgs['filter'])) {
            $request->setFilter($optionalArgs['filter']);
        }

        $requestParams = new RequestParamsHeaderDescriptor([
          'database' => $request->getDatabase(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->getPagedListResponse(
            'ListSessions',
            $optionalArgs,
            ListSessionsResponse::class,
            $request
        );
    }

    /**
     * Ends a session, releasing server resources associated with it. This will
     * asynchronously trigger cancellation of any operations that are running with
     * this session.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedName = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $spannerClient->deleteSession($formattedName);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $name         Required. The name of the session to delete.
     * @param array  $optionalArgs {
     *                             Optional.
     *
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function deleteSession($name, array $optionalArgs = [])
    {
        $request = new DeleteSessionRequest();
        $request->setName($name);

        $requestParams = new RequestParamsHeaderDescriptor([
          'name' => $request->getName(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'DeleteSession',
            GPBEmpty::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Executes an SQL statement, returning all results in a single reply. This
     * method cannot be used to return a result set larger than 10 MiB;
     * if the query yields more data than that, the query fails with
     * a `FAILED_PRECONDITION` error.
     *
     * Operations inside read-write transactions might return `ABORTED`. If
     * this occurs, the application should restart the transaction from
     * the beginning. See [Transaction][google.spanner.v1.Transaction] for more details.
     *
     * Larger result sets can be fetched in streaming fashion by calling
     * [ExecuteStreamingSql][google.spanner.v1.Spanner.ExecuteStreamingSql] instead.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $sql = '';
     *     $response = $spannerClient->executeSql($formattedSession, $sql);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $session      Required. The session in which the SQL query should be performed.
     * @param string $sql          Required. The SQL string.
     * @param array  $optionalArgs {
     *                             Optional.
     *
     *     @type TransactionSelector $transaction
     *          The transaction to use.
     *
     *          For queries, if none is provided, the default is a temporary read-only
     *          transaction with strong concurrency.
     *
     *          Standard DML statements require a read-write transaction. To protect
     *          against replays, single-use transactions are not supported.  The caller
     *          must either supply an existing transaction ID or begin a new transaction.
     *
     *          Partitioned DML requires an existing Partitioned DML transaction ID.
     *     @type Struct $params
     *          Parameter names and values that bind to placeholders in the SQL string.
     *
     *          A parameter placeholder consists of the `&#64;` character followed by the
     *          parameter name (for example, `&#64;firstName`). Parameter names can contain
     *          letters, numbers, and underscores.
     *
     *          Parameters can appear anywhere that a literal value is expected.  The same
     *          parameter name can be used more than once, for example:
     *
     *          `"WHERE id > &#64;msg_id AND id < &#64;msg_id + 100"`
     *
     *          It is an error to execute a SQL statement with unbound parameters.
     *     @type array $paramTypes
     *          It is not always possible for Cloud Spanner to infer the right SQL type
     *          from a JSON value.  For example, values of type `BYTES` and values
     *          of type `STRING` both appear in [params][google.spanner.v1.ExecuteSqlRequest.params] as JSON strings.
     *
     *          In these cases, `param_types` can be used to specify the exact
     *          SQL type for some or all of the SQL statement parameters. See the
     *          definition of [Type][google.spanner.v1.Type] for more information
     *          about SQL types.
     *     @type string $resumeToken
     *          If this request is resuming a previously interrupted SQL statement
     *          execution, `resume_token` should be copied from the last
     *          [PartialResultSet][google.spanner.v1.PartialResultSet] yielded before the interruption. Doing this
     *          enables the new SQL statement execution to resume where the last one left
     *          off. The rest of the request parameters must exactly match the
     *          request that yielded this token.
     *     @type int $queryMode
     *          Used to control the amount of debugging information returned in
     *          [ResultSetStats][google.spanner.v1.ResultSetStats]. If [partition_token][google.spanner.v1.ExecuteSqlRequest.partition_token] is set, [query_mode][google.spanner.v1.ExecuteSqlRequest.query_mode] can only
     *          be set to [QueryMode.NORMAL][google.spanner.v1.ExecuteSqlRequest.QueryMode.NORMAL].
     *          For allowed values, use constants defined on {@see \Google\Cloud\Spanner\V1\ExecuteSqlRequest\QueryMode}
     *     @type string $partitionToken
     *          If present, results will be restricted to the specified partition
     *          previously created using PartitionQuery().  There must be an exact
     *          match for the values of fields common to this message and the
     *          PartitionQueryRequest message used to create this partition_token.
     *     @type int $seqno
     *          A per-transaction sequence number used to identify this request. This field
     *          makes each request idempotent such that if the request is received multiple
     *          times, at most one will succeed.
     *
     *          The sequence number must be monotonically increasing within the
     *          transaction. If a request arrives for the first time with an out-of-order
     *          sequence number, the transaction may be aborted. Replays of previously
     *          handled requests will yield the same response as the first execution.
     *
     *          Required for DML statements. Ignored for queries.
     *     @type QueryOptions $queryOptions
     *          Query optimizer configuration to use for the given query.
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\ResultSet
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function executeSql($session, $sql, array $optionalArgs = [])
    {
        $request = new ExecuteSqlRequest();
        $request->setSession($session);
        $request->setSql($sql);
        if (isset($optionalArgs['transaction'])) {
            $request->setTransaction($optionalArgs['transaction']);
        }
        if (isset($optionalArgs['params'])) {
            $request->setParams($optionalArgs['params']);
        }
        if (isset($optionalArgs['paramTypes'])) {
            $request->setParamTypes($optionalArgs['paramTypes']);
        }
        if (isset($optionalArgs['resumeToken'])) {
            $request->setResumeToken($optionalArgs['resumeToken']);
        }
        if (isset($optionalArgs['queryMode'])) {
            $request->setQueryMode($optionalArgs['queryMode']);
        }
        if (isset($optionalArgs['partitionToken'])) {
            $request->setPartitionToken($optionalArgs['partitionToken']);
        }
        if (isset($optionalArgs['seqno'])) {
            $request->setSeqno($optionalArgs['seqno']);
        }
        if (isset($optionalArgs['queryOptions'])) {
            $request->setQueryOptions($optionalArgs['queryOptions']);
        }

        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'ExecuteSql',
            ResultSet::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Like [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql], except returns the result
     * set as a stream. Unlike [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql], there
     * is no limit on the size of the returned result set. However, no
     * individual row in the result set can exceed 100 MiB, and no
     * column value can exceed 10 MiB.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $sql = '';
     *     // Read all responses until the stream is complete
     *     $stream = $spannerClient->executeStreamingSql($formattedSession, $sql);
     *     foreach ($stream->readAll() as $element) {
     *         // doSomethingWith($element);
     *     }
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $session      Required. The session in which the SQL query should be performed.
     * @param string $sql          Required. The SQL string.
     * @param array  $optionalArgs {
     *                             Optional.
     *
     *     @type TransactionSelector $transaction
     *          The transaction to use.
     *
     *          For queries, if none is provided, the default is a temporary read-only
     *          transaction with strong concurrency.
     *
     *          Standard DML statements require a read-write transaction. To protect
     *          against replays, single-use transactions are not supported.  The caller
     *          must either supply an existing transaction ID or begin a new transaction.
     *
     *          Partitioned DML requires an existing Partitioned DML transaction ID.
     *     @type Struct $params
     *          Parameter names and values that bind to placeholders in the SQL string.
     *
     *          A parameter placeholder consists of the `&#64;` character followed by the
     *          parameter name (for example, `&#64;firstName`). Parameter names can contain
     *          letters, numbers, and underscores.
     *
     *          Parameters can appear anywhere that a literal value is expected.  The same
     *          parameter name can be used more than once, for example:
     *
     *          `"WHERE id > &#64;msg_id AND id < &#64;msg_id + 100"`
     *
     *          It is an error to execute a SQL statement with unbound parameters.
     *     @type array $paramTypes
     *          It is not always possible for Cloud Spanner to infer the right SQL type
     *          from a JSON value.  For example, values of type `BYTES` and values
     *          of type `STRING` both appear in [params][google.spanner.v1.ExecuteSqlRequest.params] as JSON strings.
     *
     *          In these cases, `param_types` can be used to specify the exact
     *          SQL type for some or all of the SQL statement parameters. See the
     *          definition of [Type][google.spanner.v1.Type] for more information
     *          about SQL types.
     *     @type string $resumeToken
     *          If this request is resuming a previously interrupted SQL statement
     *          execution, `resume_token` should be copied from the last
     *          [PartialResultSet][google.spanner.v1.PartialResultSet] yielded before the interruption. Doing this
     *          enables the new SQL statement execution to resume where the last one left
     *          off. The rest of the request parameters must exactly match the
     *          request that yielded this token.
     *     @type int $queryMode
     *          Used to control the amount of debugging information returned in
     *          [ResultSetStats][google.spanner.v1.ResultSetStats]. If [partition_token][google.spanner.v1.ExecuteSqlRequest.partition_token] is set, [query_mode][google.spanner.v1.ExecuteSqlRequest.query_mode] can only
     *          be set to [QueryMode.NORMAL][google.spanner.v1.ExecuteSqlRequest.QueryMode.NORMAL].
     *          For allowed values, use constants defined on {@see \Google\Cloud\Spanner\V1\ExecuteSqlRequest\QueryMode}
     *     @type string $partitionToken
     *          If present, results will be restricted to the specified partition
     *          previously created using PartitionQuery().  There must be an exact
     *          match for the values of fields common to this message and the
     *          PartitionQueryRequest message used to create this partition_token.
     *     @type int $seqno
     *          A per-transaction sequence number used to identify this request. This field
     *          makes each request idempotent such that if the request is received multiple
     *          times, at most one will succeed.
     *
     *          The sequence number must be monotonically increasing within the
     *          transaction. If a request arrives for the first time with an out-of-order
     *          sequence number, the transaction may be aborted. Replays of previously
     *          handled requests will yield the same response as the first execution.
     *
     *          Required for DML statements. Ignored for queries.
     *     @type QueryOptions $queryOptions
     *          Query optimizer configuration to use for the given query.
     *     @type int $timeoutMillis
     *          Timeout to use for this call.
     * }
     *
     * @return \Google\ApiCore\ServerStream
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function executeStreamingSql($session, $sql, array $optionalArgs = [])
    {
        $request = new ExecuteSqlRequest();
        $request->setSession($session);
        $request->setSql($sql);
        if (isset($optionalArgs['transaction'])) {
            $request->setTransaction($optionalArgs['transaction']);
        }
        if (isset($optionalArgs['params'])) {
            $request->setParams($optionalArgs['params']);
        }
        if (isset($optionalArgs['paramTypes'])) {
            $request->setParamTypes($optionalArgs['paramTypes']);
        }
        if (isset($optionalArgs['resumeToken'])) {
            $request->setResumeToken($optionalArgs['resumeToken']);
        }
        if (isset($optionalArgs['queryMode'])) {
            $request->setQueryMode($optionalArgs['queryMode']);
        }
        if (isset($optionalArgs['partitionToken'])) {
            $request->setPartitionToken($optionalArgs['partitionToken']);
        }
        if (isset($optionalArgs['seqno'])) {
            $request->setSeqno($optionalArgs['seqno']);
        }
        if (isset($optionalArgs['queryOptions'])) {
            $request->setQueryOptions($optionalArgs['queryOptions']);
        }

        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'ExecuteStreamingSql',
            PartialResultSet::class,
            $optionalArgs,
            $request,
            Call::SERVER_STREAMING_CALL
        );
    }

    /**
     * Executes a batch of SQL DML statements. This method allows many statements
     * to be run with lower latency than submitting them sequentially with
     * [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql].
     *
     * Statements are executed in sequential order. A request can succeed even if
     * a statement fails. The [ExecuteBatchDmlResponse.status][google.spanner.v1.ExecuteBatchDmlResponse.status] field in the
     * response provides information about the statement that failed. Clients must
     * inspect this field to determine whether an error occurred.
     *
     * Execution stops after the first failed statement; the remaining statements
     * are not executed.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $transaction = new TransactionSelector();
     *     $statements = [];
     *     $seqno = 0;
     *     $response = $spannerClient->executeBatchDml($formattedSession, $transaction, $statements, $seqno);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string              $session     Required. The session in which the DML statements should be performed.
     * @param TransactionSelector $transaction Required. The transaction to use. Must be a read-write transaction.
     *
     * To protect against replays, single-use transactions are not supported. The
     * caller must either supply an existing transaction ID or begin a new
     * transaction.
     * @param Statement[] $statements Required. The list of statements to execute in this batch. Statements are executed
     *                                serially, such that the effects of statement `i` are visible to statement
     *                                `i+1`. Each statement must be a DML statement. Execution stops at the
     *                                first failed statement; the remaining statements are not executed.
     *
     * Callers must provide at least one statement.
     * @param int $seqno Required. A per-transaction sequence number used to identify this request. This field
     *                   makes each request idempotent such that if the request is received multiple
     *                   times, at most one will succeed.
     *
     * The sequence number must be monotonically increasing within the
     * transaction. If a request arrives for the first time with an out-of-order
     * sequence number, the transaction may be aborted. Replays of previously
     * handled requests will yield the same response as the first execution.
     * @param array $optionalArgs {
     *                            Optional.
     *
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\ExecuteBatchDmlResponse
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function executeBatchDml($session, $transaction, $statements, $seqno, array $optionalArgs = [])
    {
        $request = new ExecuteBatchDmlRequest();
        $request->setSession($session);
        $request->setTransaction($transaction);
        $request->setStatements($statements);
        $request->setSeqno($seqno);

        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'ExecuteBatchDml',
            ExecuteBatchDmlResponse::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Reads rows from the database using key lookups and scans, as a
     * simple key/value style alternative to
     * [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql].  This method cannot be used to
     * return a result set larger than 10 MiB; if the read matches more
     * data than that, the read fails with a `FAILED_PRECONDITION`
     * error.
     *
     * Reads inside read-write transactions might return `ABORTED`. If
     * this occurs, the application should restart the transaction from
     * the beginning. See [Transaction][google.spanner.v1.Transaction] for more details.
     *
     * Larger result sets can be yielded in streaming fashion by calling
     * [StreamingRead][google.spanner.v1.Spanner.StreamingRead] instead.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $table = '';
     *     $columns = [];
     *     $keySet = new KeySet();
     *     $response = $spannerClient->read($formattedSession, $table, $columns, $keySet);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string   $session Required. The session in which the read should be performed.
     * @param string   $table   Required. The name of the table in the database to be read.
     * @param string[] $columns Required. The columns of [table][google.spanner.v1.ReadRequest.table] to be returned for each row matching
     *                          this request.
     * @param KeySet   $keySet  Required. `key_set` identifies the rows to be yielded. `key_set` names the
     *                          primary keys of the rows in [table][google.spanner.v1.ReadRequest.table] to be yielded, unless [index][google.spanner.v1.ReadRequest.index]
     *                          is present. If [index][google.spanner.v1.ReadRequest.index] is present, then [key_set][google.spanner.v1.ReadRequest.key_set] instead names
     *                          index keys in [index][google.spanner.v1.ReadRequest.index].
     *
     * If the [partition_token][google.spanner.v1.ReadRequest.partition_token] field is empty, rows are yielded
     * in table primary key order (if [index][google.spanner.v1.ReadRequest.index] is empty) or index key order
     * (if [index][google.spanner.v1.ReadRequest.index] is non-empty).  If the [partition_token][google.spanner.v1.ReadRequest.partition_token] field is not
     * empty, rows will be yielded in an unspecified order.
     *
     * It is not an error for the `key_set` to name rows that do not
     * exist in the database. Read yields nothing for nonexistent rows.
     * @param array $optionalArgs {
     *                            Optional.
     *
     *     @type TransactionSelector $transaction
     *          The transaction to use. If none is provided, the default is a
     *          temporary read-only transaction with strong concurrency.
     *     @type string $index
     *          If non-empty, the name of an index on [table][google.spanner.v1.ReadRequest.table]. This index is
     *          used instead of the table primary key when interpreting [key_set][google.spanner.v1.ReadRequest.key_set]
     *          and sorting result rows. See [key_set][google.spanner.v1.ReadRequest.key_set] for further information.
     *     @type int $limit
     *          If greater than zero, only the first `limit` rows are yielded. If `limit`
     *          is zero, the default is no limit. A limit cannot be specified if
     *          `partition_token` is set.
     *     @type string $resumeToken
     *          If this request is resuming a previously interrupted read,
     *          `resume_token` should be copied from the last
     *          [PartialResultSet][google.spanner.v1.PartialResultSet] yielded before the interruption. Doing this
     *          enables the new read to resume where the last read left off. The
     *          rest of the request parameters must exactly match the request
     *          that yielded this token.
     *     @type string $partitionToken
     *          If present, results will be restricted to the specified partition
     *          previously created using PartitionRead().    There must be an exact
     *          match for the values of fields common to this message and the
     *          PartitionReadRequest message used to create this partition_token.
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\ResultSet
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function read($session, $table, $columns, $keySet, array $optionalArgs = [])
    {
        $request = new ReadRequest();
        $request->setSession($session);
        $request->setTable($table);
        $request->setColumns($columns);
        $request->setKeySet($keySet);
        if (isset($optionalArgs['transaction'])) {
            $request->setTransaction($optionalArgs['transaction']);
        }
        if (isset($optionalArgs['index'])) {
            $request->setIndex($optionalArgs['index']);
        }
        if (isset($optionalArgs['limit'])) {
            $request->setLimit($optionalArgs['limit']);
        }
        if (isset($optionalArgs['resumeToken'])) {
            $request->setResumeToken($optionalArgs['resumeToken']);
        }
        if (isset($optionalArgs['partitionToken'])) {
            $request->setPartitionToken($optionalArgs['partitionToken']);
        }

        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'Read',
            ResultSet::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Like [Read][google.spanner.v1.Spanner.Read], except returns the result set as a
     * stream. Unlike [Read][google.spanner.v1.Spanner.Read], there is no limit on the
     * size of the returned result set. However, no individual row in
     * the result set can exceed 100 MiB, and no column value can exceed
     * 10 MiB.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $table = '';
     *     $columns = [];
     *     $keySet = new KeySet();
     *     // Read all responses until the stream is complete
     *     $stream = $spannerClient->streamingRead($formattedSession, $table, $columns, $keySet);
     *     foreach ($stream->readAll() as $element) {
     *         // doSomethingWith($element);
     *     }
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string   $session Required. The session in which the read should be performed.
     * @param string   $table   Required. The name of the table in the database to be read.
     * @param string[] $columns Required. The columns of [table][google.spanner.v1.ReadRequest.table] to be returned for each row matching
     *                          this request.
     * @param KeySet   $keySet  Required. `key_set` identifies the rows to be yielded. `key_set` names the
     *                          primary keys of the rows in [table][google.spanner.v1.ReadRequest.table] to be yielded, unless [index][google.spanner.v1.ReadRequest.index]
     *                          is present. If [index][google.spanner.v1.ReadRequest.index] is present, then [key_set][google.spanner.v1.ReadRequest.key_set] instead names
     *                          index keys in [index][google.spanner.v1.ReadRequest.index].
     *
     * If the [partition_token][google.spanner.v1.ReadRequest.partition_token] field is empty, rows are yielded
     * in table primary key order (if [index][google.spanner.v1.ReadRequest.index] is empty) or index key order
     * (if [index][google.spanner.v1.ReadRequest.index] is non-empty).  If the [partition_token][google.spanner.v1.ReadRequest.partition_token] field is not
     * empty, rows will be yielded in an unspecified order.
     *
     * It is not an error for the `key_set` to name rows that do not
     * exist in the database. Read yields nothing for nonexistent rows.
     * @param array $optionalArgs {
     *                            Optional.
     *
     *     @type TransactionSelector $transaction
     *          The transaction to use. If none is provided, the default is a
     *          temporary read-only transaction with strong concurrency.
     *     @type string $index
     *          If non-empty, the name of an index on [table][google.spanner.v1.ReadRequest.table]. This index is
     *          used instead of the table primary key when interpreting [key_set][google.spanner.v1.ReadRequest.key_set]
     *          and sorting result rows. See [key_set][google.spanner.v1.ReadRequest.key_set] for further information.
     *     @type int $limit
     *          If greater than zero, only the first `limit` rows are yielded. If `limit`
     *          is zero, the default is no limit. A limit cannot be specified if
     *          `partition_token` is set.
     *     @type string $resumeToken
     *          If this request is resuming a previously interrupted read,
     *          `resume_token` should be copied from the last
     *          [PartialResultSet][google.spanner.v1.PartialResultSet] yielded before the interruption. Doing this
     *          enables the new read to resume where the last read left off. The
     *          rest of the request parameters must exactly match the request
     *          that yielded this token.
     *     @type string $partitionToken
     *          If present, results will be restricted to the specified partition
     *          previously created using PartitionRead().    There must be an exact
     *          match for the values of fields common to this message and the
     *          PartitionReadRequest message used to create this partition_token.
     *     @type int $timeoutMillis
     *          Timeout to use for this call.
     * }
     *
     * @return \Google\ApiCore\ServerStream
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function streamingRead($session, $table, $columns, $keySet, array $optionalArgs = [])
    {
        $request = new ReadRequest();
        $request->setSession($session);
        $request->setTable($table);
        $request->setColumns($columns);
        $request->setKeySet($keySet);
        if (isset($optionalArgs['transaction'])) {
            $request->setTransaction($optionalArgs['transaction']);
        }
        if (isset($optionalArgs['index'])) {
            $request->setIndex($optionalArgs['index']);
        }
        if (isset($optionalArgs['limit'])) {
            $request->setLimit($optionalArgs['limit']);
        }
        if (isset($optionalArgs['resumeToken'])) {
            $request->setResumeToken($optionalArgs['resumeToken']);
        }
        if (isset($optionalArgs['partitionToken'])) {
            $request->setPartitionToken($optionalArgs['partitionToken']);
        }

        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'StreamingRead',
            PartialResultSet::class,
            $optionalArgs,
            $request,
            Call::SERVER_STREAMING_CALL
        );
    }

    /**
     * Begins a new transaction. This step can often be skipped:
     * [Read][google.spanner.v1.Spanner.Read], [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql] and
     * [Commit][google.spanner.v1.Spanner.Commit] can begin a new transaction as a
     * side-effect.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $options = new TransactionOptions();
     *     $response = $spannerClient->beginTransaction($formattedSession, $options);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string             $session      Required. The session in which the transaction runs.
     * @param TransactionOptions $options      Required. Options for the new transaction.
     * @param array              $optionalArgs {
     *                                         Optional.
     *
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\Transaction
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function beginTransaction($session, $options, array $optionalArgs = [])
    {
        $request = new BeginTransactionRequest();
        $request->setSession($session);
        $request->setOptions($options);

        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'BeginTransaction',
            Transaction::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Commits a transaction. The request includes the mutations to be
     * applied to rows in the database.
     *
     * `Commit` might return an `ABORTED` error. This can occur at any time;
     * commonly, the cause is conflicts with concurrent
     * transactions. However, it can also happen for a variety of other
     * reasons. If `Commit` returns `ABORTED`, the caller should re-attempt
     * the transaction from the beginning, re-using the same session.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $mutation = new \Google\Cloud\Spanner\V1\Mutation();
     *     $response = $spannerClient->commit($formattedSession, [$mutation]);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string     $session      Required. The session in which the transaction to be committed is running.
     * @param Mutation[] $mutations    The mutations to be executed when this transaction commits. All
     *                                 mutations are applied atomically, in the order they appear in
     *                                 this list.
     * @param array      $optionalArgs {
     *                             Optional.
     *
     *     @type string $transactionId
     *          Commit a previously-started transaction.
     *     @type TransactionOptions $singleUseTransaction
     *          Execute mutations in a temporary transaction. Note that unlike
     *          commit of a previously-started transaction, commit with a
     *          temporary transaction is non-idempotent. That is, if the
     *          `CommitRequest` is sent to Cloud Spanner more than once (for
     *          instance, due to retries in the application, or in the
     *          transport library), it is possible that the mutations are
     *          executed more than once. If this is undesirable, use
     *          [BeginTransaction][google.spanner.v1.Spanner.BeginTransaction] and
     *          [Commit][google.spanner.v1.Spanner.Commit] instead.
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\CommitResponse
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function commit($session, $mutations, array $optionalArgs = [])
    {
        $request = new CommitRequest();
        $request->setSession($session);
        if (isset($optionalArgs['transactionId'])) {
            $request->setTransactionId($optionalArgs['transactionId']);
        }
        if (isset($optionalArgs['singleUseTransaction'])) {
            $request->setSingleUseTransaction($optionalArgs['singleUseTransaction']);
        }
        $request->setMutations($mutations);
        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'Commit',
            CommitResponse::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Rolls back a transaction, releasing any locks it holds. It is a good
     * idea to call this for any transaction that includes one or more
     * [Read][google.spanner.v1.Spanner.Read] or [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql] requests and
     * ultimately decides not to commit.
     *
     * `Rollback` returns `OK` if it successfully aborts the transaction, the
     * transaction was already aborted, or the transaction is not
     * found. `Rollback` never returns `ABORTED`.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $transactionId = '';
     *     $spannerClient->rollback($formattedSession, $transactionId);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $session       Required. The session in which the transaction to roll back is running.
     * @param string $transactionId Required. The transaction to roll back.
     * @param array  $optionalArgs  {
     *                              Optional.
     *
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function rollback($session, $transactionId, array $optionalArgs = [])
    {
        $request = new RollbackRequest();
        $request->setSession($session);
        $request->setTransactionId($transactionId);

        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'Rollback',
            GPBEmpty::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Creates a set of partition tokens that can be used to execute a query
     * operation in parallel.  Each of the returned partition tokens can be used
     * by [ExecuteStreamingSql][google.spanner.v1.Spanner.ExecuteStreamingSql] to specify a subset
     * of the query result to read.  The same session and read-only transaction
     * must be used by the PartitionQueryRequest used to create the
     * partition tokens and the ExecuteSqlRequests that use the partition tokens.
     *
     * Partition tokens become invalid when the session used to create them
     * is deleted, is idle for too long, begins a new transaction, or becomes too
     * old.  When any of these happen, it is not possible to resume the query, and
     * the whole operation must be restarted from the beginning.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $sql = '';
     *     $response = $spannerClient->partitionQuery($formattedSession, $sql);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $session Required. The session used to create the partitions.
     * @param string $sql     Required. The query request to generate partitions for. The request will fail if
     *                        the query is not root partitionable. The query plan of a root
     *                        partitionable query has a single distributed union operator. A distributed
     *                        union operator conceptually divides one or more tables into multiple
     *                        splits, remotely evaluates a subquery independently on each split, and
     *                        then unions all results.
     *
     * This must not contain DML commands, such as INSERT, UPDATE, or
     * DELETE. Use [ExecuteStreamingSql][google.spanner.v1.Spanner.ExecuteStreamingSql] with a
     * PartitionedDml transaction for large, partition-friendly DML operations.
     * @param array $optionalArgs {
     *                            Optional.
     *
     *     @type TransactionSelector $transaction
     *          Read only snapshot transactions are supported, read/write and single use
     *          transactions are not.
     *     @type Struct $params
     *          Parameter names and values that bind to placeholders in the SQL string.
     *
     *          A parameter placeholder consists of the `&#64;` character followed by the
     *          parameter name (for example, `&#64;firstName`). Parameter names can contain
     *          letters, numbers, and underscores.
     *
     *          Parameters can appear anywhere that a literal value is expected.  The same
     *          parameter name can be used more than once, for example:
     *
     *          `"WHERE id > &#64;msg_id AND id < &#64;msg_id + 100"`
     *
     *          It is an error to execute a SQL statement with unbound parameters.
     *     @type array $paramTypes
     *          It is not always possible for Cloud Spanner to infer the right SQL type
     *          from a JSON value.  For example, values of type `BYTES` and values
     *          of type `STRING` both appear in [params][google.spanner.v1.PartitionQueryRequest.params] as JSON strings.
     *
     *          In these cases, `param_types` can be used to specify the exact
     *          SQL type for some or all of the SQL query parameters. See the
     *          definition of [Type][google.spanner.v1.Type] for more information
     *          about SQL types.
     *     @type PartitionOptions $partitionOptions
     *          Additional options that affect how many partitions are created.
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\PartitionResponse
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function partitionQuery($session, $sql, array $optionalArgs = [])
    {
        $request = new PartitionQueryRequest();
        $request->setSession($session);
        $request->setSql($sql);
        if (isset($optionalArgs['transaction'])) {
            $request->setTransaction($optionalArgs['transaction']);
        }
        if (isset($optionalArgs['params'])) {
            $request->setParams($optionalArgs['params']);
        }
        if (isset($optionalArgs['paramTypes'])) {
            $request->setParamTypes($optionalArgs['paramTypes']);
        }
        if (isset($optionalArgs['partitionOptions'])) {
            $request->setPartitionOptions($optionalArgs['partitionOptions']);
        }

        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'PartitionQuery',
            PartitionResponse::class,
            $optionalArgs,
            $request
        )->wait();
    }

    /**
     * Creates a set of partition tokens that can be used to execute a read
     * operation in parallel.  Each of the returned partition tokens can be used
     * by [StreamingRead][google.spanner.v1.Spanner.StreamingRead] to specify a subset of the read
     * result to read.  The same session and read-only transaction must be used by
     * the PartitionReadRequest used to create the partition tokens and the
     * ReadRequests that use the partition tokens.  There are no ordering
     * guarantees on rows returned among the returned partition tokens, or even
     * within each individual StreamingRead call issued with a partition_token.
     *
     * Partition tokens become invalid when the session used to create them
     * is deleted, is idle for too long, begins a new transaction, or becomes too
     * old.  When any of these happen, it is not possible to resume the read, and
     * the whole operation must be restarted from the beginning.
     *
     * Sample code:
     * ```
     * $spannerClient = new SpannerClient();
     * try {
     *     $formattedSession = $spannerClient->sessionName('[PROJECT]', '[INSTANCE]', '[DATABASE]', '[SESSION]');
     *     $table = '';
     *     $keySet = new KeySet();
     *     $response = $spannerClient->partitionRead($formattedSession, $table, $keySet);
     * } finally {
     *     $spannerClient->close();
     * }
     * ```
     *
     * @param string $session Required. The session used to create the partitions.
     * @param string $table   Required. The name of the table in the database to be read.
     * @param KeySet $keySet  Required. `key_set` identifies the rows to be yielded. `key_set` names the
     *                        primary keys of the rows in [table][google.spanner.v1.PartitionReadRequest.table] to be yielded, unless [index][google.spanner.v1.PartitionReadRequest.index]
     *                        is present. If [index][google.spanner.v1.PartitionReadRequest.index] is present, then [key_set][google.spanner.v1.PartitionReadRequest.key_set] instead names
     *                        index keys in [index][google.spanner.v1.PartitionReadRequest.index].
     *
     * It is not an error for the `key_set` to name rows that do not
     * exist in the database. Read yields nothing for nonexistent rows.
     * @param array $optionalArgs {
     *                            Optional.
     *
     *     @type TransactionSelector $transaction
     *          Read only snapshot transactions are supported, read/write and single use
     *          transactions are not.
     *     @type string $index
     *          If non-empty, the name of an index on [table][google.spanner.v1.PartitionReadRequest.table]. This index is
     *          used instead of the table primary key when interpreting [key_set][google.spanner.v1.PartitionReadRequest.key_set]
     *          and sorting result rows. See [key_set][google.spanner.v1.PartitionReadRequest.key_set] for further information.
     *     @type string[] $columns
     *          The columns of [table][google.spanner.v1.PartitionReadRequest.table] to be returned for each row matching
     *          this request.
     *     @type PartitionOptions $partitionOptions
     *          Additional options that affect how many partitions are created.
     *     @type RetrySettings|array $retrySettings
     *          Retry settings to use for this call. Can be a
     *          {@see Google\ApiCore\RetrySettings} object, or an associative array
     *          of retry settings parameters. See the documentation on
     *          {@see Google\ApiCore\RetrySettings} for example usage.
     * }
     *
     * @return \Google\Cloud\Spanner\V1\PartitionResponse
     *
     * @throws ApiException if the remote call fails
     * @experimental
     */
    public function partitionRead($session, $table, $keySet, array $optionalArgs = [])
    {
        $request = new PartitionReadRequest();
        $request->setSession($session);
        $request->setTable($table);
        $request->setKeySet($keySet);
        if (isset($optionalArgs['transaction'])) {
            $request->setTransaction($optionalArgs['transaction']);
        }
        if (isset($optionalArgs['index'])) {
            $request->setIndex($optionalArgs['index']);
        }
        if (isset($optionalArgs['columns'])) {
            $request->setColumns($optionalArgs['columns']);
        }
        if (isset($optionalArgs['partitionOptions'])) {
            $request->setPartitionOptions($optionalArgs['partitionOptions']);
        }

        $requestParams = new RequestParamsHeaderDescriptor([
          'session' => $request->getSession(),
        ]);
        $optionalArgs['headers'] = isset($optionalArgs['headers'])
            ? array_merge($requestParams->getHeader(), $optionalArgs['headers'])
            : $requestParams->getHeader();

        return $this->startCall(
            'PartitionRead',
            PartitionResponse::class,
            $optionalArgs,
            $request
        )->wait();
    }
}
