aws-sdk-cpp调用时Aws::Client::ClientConfiguration创建对象耗时的问题处理

在使用aws-sdk-cpp时，都有一个初始化的过程，配置信息都由Aws::Client::ClientConfiguration创建对象配置服务器信息才能实现上传，下载文件，本篇记录在使用过程中Aws::Client::ClientConfiguration创建对象时耗时长的问题。

首先看示例代码：

void MainWindow::getBucketTest()
{
    // 初始化
    qDebug() << "getBucketTest===========1===========" << PRINTTIME;
    Aws::SDKOptions options;
    options.loggingOptions.logLevel = Aws::Utils::Logging::LogLevel::Debug;
    Aws::InitAPI(options);
    qDebug() << "getBucketTest===========2====start===sizeof(Aws::Client::ClientConfiguration)===="
             << sizeof(Aws::Client::ClientConfiguration) << PRINTTIME;
    Aws::Client::ClientConfiguration cfg;
    qDebug() << "getBucketTest===========2====end=====sizeof(Aws::Client::ClientConfiguration)===="
             << sizeof(Aws::Client::ClientConfiguration) << PRINTTIME;

    cfg.endpointOverride = "play.min.io";//官方测试服务器
    cfg.scheme = Aws::Http::Scheme::HTTPS; //https协议
    //cfg.scheme = Aws::Http::Scheme::HTTP;  //http协议
    //cfg.verifySSL = false;

    qDebug() << "getBucketTest==========3============" << PRINTTIME;
    Aws::Auth::AWSCredentials cred("Q3AM3UQ867SPQQA43P2F", "zuf+tfteSlswRu7BJ86wekitnifILbZam1KYY3TG");

    qDebug() << "getBucketTest==========4============" << PRINTTIME;
    Aws::S3::S3Client client(cred, cfg, Aws::Client::AWSAuthV4Signer::PayloadSigningPolicy::Always, false,
                             Aws::S3::US_EAST_1_REGIONAL_ENDPOINT_OPTION::NOT_SET);
    qDebug() << "getBucketTest==========5============" << PRINTTIME;
    auto response = client.ListBuckets();
    qDebug() << "getBucketTest==========6============" << PRINTTIME;
    if (response.IsSuccess()) {
        auto buckets = response.GetResult().GetBuckets();
        for (auto iter = buckets.begin(); iter != buckets.end(); ++iter) {
            cout << iter->GetName() << "\t" << iter->GetCreationDate().ToLocalTimeString(Aws::Utils::DateFormat::ISO_8601) << endl;
        }
    }
    qDebug() << "getBucketTest==========7============" << PRINTTIME;
    Aws::ShutdownAPI(options);
}

运行结果：

从上面可以看出Aws::Client::ClientConfiguration创建cfg对象时耗时24秒，这个类564个字节，这是32位环境，64位环境时这个类还到936个字节。

struct AWS_CORE_API ClientConfiguration
        {
            ClientConfiguration();

            /**
             * Create a configuration with default settings. By default IMDS calls are enabled.
             * @param ClientConfigurationInitValues ClientConfiguration initial customizable values
             */
            ClientConfiguration(const ClientConfigurationInitValues &configuration);

            /**
             * Create a configuration based on settings in the aws configuration file for the given profile name.
             * The configuration file location can be set via the environment variable AWS_CONFIG_FILE
             * @param profileName the aws profile name.
             * @param shouldDisableIMDS whether or not to disable IMDS calls.
             */
            ClientConfiguration(const char* profileName, bool shouldDisableIMDS = false);

            /**
             * Create a configuration with a predefined smart defaults
             * @param useSmartDefaults, required to differentiate c-tors
             * @param defaultMode, default mode to use
             * @param shouldDisableIMDS whether or not to disable IMDS calls.
             */
            explicit ClientConfiguration(bool useSmartDefaults, const char* defaultMode = "legacy", bool shouldDisableIMDS = false);

......
};

ClientConfiguration有4个构造函数，我们用的是默认的无参构造函数，后面几个函数还没使用过呢，其中第三个构造函数很特点，有一个参数shouldDisableIMDS whether or not to disable IMDS calls.是否禁用IMDS,这个才是耗时的关键，如果不禁用IMDS就会分析数据安全性，耗时。

因此，这里如果把这个IMDS禁用了，创建速度就很速度了，看示例：

void MainWindow::getBucketTest()
{
    // 初始化
    qDebug() << "getBucketTest===========1===========" << PRINTTIME;
    Aws::SDKOptions options;
    options.loggingOptions.logLevel = Aws::Utils::Logging::LogLevel::Debug;
    Aws::InitAPI(options);
    qDebug() << "getBucketTest===========2====start===sizeof(Aws::Client::ClientConfiguration)===="
             << sizeof(Aws::Client::ClientConfiguration) << PRINTTIME;
    Aws::Client::ClientConfiguration cfg("default", true);
    qDebug() << "getBucketTest===========2====end=====sizeof(Aws::Client::ClientConfiguration)===="
             << sizeof(Aws::Client::ClientConfiguration) << PRINTTIME;

    cfg.endpointOverride = "play.min.io"; //官方测试服务器
    cfg.scheme = Aws::Http::Scheme::HTTPS; //https协议
    //cfg.scheme = Aws::Http::Scheme::HTTP;  //http协议
    //cfg.verifySSL = false;

    qDebug() << "getBucketTest==========3============" << PRINTTIME;
    Aws::Auth::AWSCredentials cred("Q3AM3UQ867SPQQA43P2F", "zuf+tfteSlswRu7BJ86wekitnifILbZam1KYY3TG");
     

    qDebug() << "getBucketTest==========4============" << PRINTTIME;
    Aws::S3::S3Client client(cred, cfg, Aws::Client::AWSAuthV4Signer::PayloadSigningPolicy::Always, false,
                             Aws::S3::US_EAST_1_REGIONAL_ENDPOINT_OPTION::NOT_SET);
    qDebug() << "getBucketTest==========5============" << PRINTTIME;
    auto response = client.ListBuckets();
    qDebug() << "getBucketTest==========6============" << PRINTTIME;
    if (response.IsSuccess()) {
        auto buckets = response.GetResult().GetBuckets();
        for (auto iter = buckets.begin(); iter != buckets.end(); ++iter) {
            cout << iter->GetName() << "\t" << iter->GetCreationDate().ToLocalTimeString(Aws::Utils::DateFormat::ISO_8601) << endl;
        }
    }
    qDebug() << "getBucketTest==========7============" << PRINTTIME;
    Aws::ShutdownAPI(options);
}

运行结果：

Aws::Client::ClientConfiguration cfg("default", true);这样创建对象，基本就不耗时了。

参考：

Aws::Client::ClientConfiguration default construction is very slow · aws/aws-sdk-cpp · Discussion #2398 · GitHub