AWS CPP S3访问COS

# yum install -y gcc-c++ cmake zlib-devel openssl-devel curl-devel

# git clone --recurse-submodules https://github.com/aws/aws-sdk-cpp

# mkdir build_dir
# cd build_dir
# cmake -DCMAKE_BUILD_TYPE=Release ../aws-sdk-cpp

# make -j `nproc` -C aws-cpp-sdk-core
# make -j `nproc` -C aws-cpp-sdk-s3-crt
# make -j `nproc` -C crt/aws-crt-cpp
# make -j `nproc` -C aws-cpp-sdk-s3
​
# make install -C aws-cpp-sdk-core
# make install -C aws-cpp-sdk-s3-crt
# make install -C crt/aws-crt-cpp
# make install -C aws-cpp-sdk-s3

#include <iostream>
#include <fstream>
#include <sys/stat.h>
#include <unistd.h>

#include <aws/s3/S3Client.h>
#include <aws/core/Aws.h>
#include <aws/s3/model/GetObjectRequest.h>
#include <aws/core/auth/AWSCredentialsProvider.h>

using namespace Aws::S3;
using namespace Aws::S3::Model;
using namespace std;

bool get_s3_object(const S3Client &s3_client,
        const Aws::String& s3_bucket_name,
        const Aws::String& s3_object_name,
        const string& file_name)
{
    GetObjectRequest object_request;
    object_request.SetBucket(s3_bucket_name);
    object_request.SetKey(s3_object_name);

    time_t time1 = time(nullptr);
    Aws::S3::Model::GetObjectOutcome outcome = s3_client.GetObject(object_request);
    if(!outcome.IsSuccess()) {
        cout << "GetObject error: " <<
            outcome.GetError().GetExceptionName() << " - " <<
            outcome.GetError().GetMessage() << endl;
        return -1;
    }

    time_t time2 = time(nullptr);
    Aws::OFStream local_file;
    local_file.open(file_name.c_str(), std::fstream::in | std::fstream::out | std::fstream::trunc);
    assert(local_file.good());

    Aws::S3::Model::GetObjectResult read_result = outcome.GetResultWithOwnership();
    time_t time3 = time(nullptr);
    local_file << read_result.GetBody().rdbuf();
    //local_file << outcome.GetResult().GetBody().rdbuf();
    local_file.close();
    time_t time4 = time(nullptr);

    double time_diff = difftime(time4, time1);
    cout << "start getobject: " << ctime(&time1)<< endl;
    cout << "done getobject: " << ctime(&time2)<< endl;
    cout << "start writefile: " << ctime(&time3)<< endl;
    cout << "done writefile: " << ctime(&time4)<< endl;
    cout << "time_diff: " << time_diff << "s" << endl;

    return true;
}

int main(int argc, char** argv)
{
    if (argc < 2)
    {
        cout << "getobject <loops>" << endl;
        exit(1);
    }
    int loops = atoi(argv[1]);

    Aws::SDKOptions options;
    Aws::InitAPI(options);
    {
        Aws::Client::ClientConfiguration cfg;
        cfg.scheme = Aws::Http::Scheme::HTTP;
        cfg.region = "ap-shanghai";
        cfg.endpointOverride = "cos.ap-shanghai.myqcloud.com";
        //cfg.verifySSL = false;
        //cfg.connectTimeoutMs = 100000;
        //cfg.requestTimeoutMs = 100000;

        Aws::Auth::AWSCredentials cred("xxxxxxxxxx", "xxxxxxxxxx");
        S3Client s3_client(cred, cfg);

        const Aws::String bucket_name = "bruins-1253766168";
        const string file_name = "localfile";
        const Aws::String object_name = "testfile";

        cout << "从存储桶 " << bucket_name
             << "下载对象 " << object_name
             << "存为 " << file_name << endl;
        for (int i = 1; i <= loops; ++i) {
            cout << "loop-" << i << endl;
            get_s3_object(s3_client, bucket_name, object_name, file_name);
        }
    }
    Aws::ShutdownAPI(options);
}

编译命令如下：
# g++ -std=c++11 -I/usr/local/include -L/usr/local/lib64 -laws-cpp-sdk-core -laws-cpp-sdk-s3 s3getobject.cpp -o s3getobject

运行如下：
# export LD_LIBRARY_PATH=/usr/local/lib64
# ./s3getobject