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C++上传文件

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本文介绍如何在受版本控制的存储空间(Bucket)中上传文件(Object)。

注意事项

  • 本文以华东1(杭州)外网Endpoint为例。如果您希望通过与OSS同地域的其他阿里云产品访问OSS,请使用内网Endpoint。关于OSS支持的Region与Endpoint的对应关系,请参见访问域名和数据中心

  • 本文以OSS域名新建OSSClient为例。如果您希望通过自定义域名、STS等方式新建OSSClient,请参见新建OssClient

  • 要上传文件,您必须有oss:PutObject权限。具体操作,请参见为RAM用户授权自定义的权限策略

简单上传

在已开启版本控制的Bucket中,OSS会为新添加的Object自动生成唯一的版本ID,并在响应header中通过x-oss-version-id形式返回。在暂停了版本控制的Bucket中,新添加的Object的版本ID为“null”,上传同名Object,后一次会覆盖前一次上传的文件内容。OSS保证同一个Object只会有一个版本ID为“null”。

以下代码用于简单上传:

#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

int main(void)
{
    /* 初始化OSS账号信息。*/
            
    /* yourEndpoint填写Bucket所在地域对应的Endpoint。以华东1(杭州)为例,Endpoint填写为https://oss-cn-hangzhou.aliyuncs.com。*/
    std::string Endpoint = "yourEndpoint";
    /* 填写Bucket名称,例如examplebucket。*/
    std::string BucketName = "examplebucket";
    /* 填写Object完整路径,完整路径中不能包含Bucket名称,例如exampledir/exampleobject.txt。*/
    std::string ObjectName = "exampledir/exampleobject.txt";

    /* 初始化网络等资源。*/
    InitializeSdk();

    ClientConfiguration conf;
    /* 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。*/
    auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
    OssClient client(Endpoint, credentialsProvider, conf);
    std::shared_ptr<std::iostream> content = std::make_shared<std::stringstream>();
    *content << "test cpp sdk";
    PutObjectRequest request(BucketName, ObjectName, content);

    /* 上传文件。*/
    auto outcome = client.PutObject(request);

    if (outcome.isSuccess()) {
        std::cout << "versionid:" << outcome.result().VersionId() << std::endl;
    }
    else {
        /* 异常处理。*/
        std::cout << "PutObject fail" <<
        ",code:" << outcome.error().Code() <<
        ",message:" << outcome.error().Message() <<
        ",requestId:" << outcome.error().RequestId() << std::endl;
        return -1;
    }

    /* 释放网络等资源。*/
    ShutdownSdk();
    return 0;
}

追加上传

在受版本控制的Bucket中,仅支持对于当前版本为Appendable类型的Object执行追加(AppendObject)操作,不支持对于历史版本为Appendable类型的Object执行AppendObject操作。

说明
  • 对当前版本为Appendable类型的Object执行AppendObject操作时,OSS不会为该Appendable类型的Object生成历史版本。

  • 对当前版本为Appendable类型的Object执行PutObject或DeleteObject操作时,OSS会将该Appendable类型的Object保留为历史版本,且该Object不允许继续追加。

  • 不支持对当前版本为非Appendable类型的Object(包括Normal Object、Delete Marker等)执行AppendObject操作。

以下代码用于追加上传:

#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

int main(void)
{
    /* 初始化OSS账号信息。*/
            
    /* yourEndpoint填写Bucket所在地域对应的Endpoint。以华东1(杭州)为例,Endpoint填写为https://oss-cn-hangzhou.aliyuncs.com。*/
    std::string Endpoint = "yourEndpoint";
    /* 填写Bucket名称,例如examplebucket。*/
    std::string BucketName = "examplebucket";
    /* 填写Object完整路径,完整路径中不能包含Bucket名称,例如exampledir/exampleobject.txt。*/
    std::string ObjectName = "exampledir/exampleobject.txt";

    /* 初始化网络等资源。*/
    InitializeSdk();

    ClientConfiguration conf;
    /* 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。*/
    auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
    OssClient client(Endpoint, credentialsProvider, conf);

    auto meta = ObjectMetaData();
    meta.setContentType("text/plain");

    /* 第一次追加的位置是0,返回值为下一次追加的位置。后续追加的位置是追加前文件的长度。*/
    std::shared_ptr<std::iostream> content1 = std::make_shared<std::stringstream>();
    *content1 <<"Thank you for using Aliyun Object Storage Service!";
    AppendObjectRequest request(BucketName, ObjectName, content1, meta);
    request.setPosition(0L);

    /* 第一次追加文件。*/
    auto result = client.AppendObject(request);

    /* 查看本次执行追加文件的object的版本ID。*/
    if (result.isSuccess()) {
        std::cout << "versionid:" << result.result().VersionId() << std::endl;
    }
    else {
        /* 异常处理。*/
        std::cout << "AppendObject fail" <<
        ",code:" << result.error().Code() <<
        ",message:" << result.error().Message() <<
        ",requestId:" << result.error().RequestId() << std::endl;
        return -1;
    }

    std::shared_ptr<std::iostream> content2 = std::make_shared<std::stringstream>();
    *content2 <<"Thank you for using Aliyun Object Storage Service!";
    auto position = result.result().Length();
    AppendObjectRequest appendObjectRequest(BucketName, ObjectName, content2);
    appendObjectRequest.setPosition(position);

    /* 第二次追加文件。*/
    auto outcome = client.AppendObject(appendObjectRequest);

    if (outcome.isSuccess()) {
        std::cout << "versionid:" << outcome.result().VersionId() << std::endl;
    }
    else {
        /* 异常处理。*/
        std::cout << "AppendObject fail" <<
        ",code:" << outcome.error().Code() <<
        ",message:" << outcome.error().Message() <<
        ",requestId:" << outcome.error().RequestId() << std::endl;
        return -1;
    }

    /* 释放网络等资源。*/
    ShutdownSdk();
    return 0;
}

分片上传

在受版本控制的Bucket中,调用CompleteMultipartUpload接口来完成整个文件的分片上传,OSS会为整个文件生成唯一的版本ID,并在响应header中以x-oss-version-id的形式返回。

以下代码用于分片上传:

#include <alibabacloud/oss/OssClient.h>
#include <fstream>

int64_t getFileSize(const std::string& file)
{
    std::fstream f(file, std::ios::in | std::ios::binary);
    f.seekg(0, f.end);
    int64_t size = f.tellg();
    f.close();
    return size;
}

using namespace AlibabaCloud::OSS;

int main(void)
{
    /* 初始化OSS账号信息。*/
            
    /* yourEndpoint填写Bucket所在地域对应的Endpoint。以华东1(杭州)为例,Endpoint填写为https://oss-cn-hangzhou.aliyuncs.com。*/
    std::string Endpoint = "yourEndpoint";
    /* 填写Bucket名称,例如examplebucket。*/
    std::string BucketName = "examplebucket";
    /* 填写Object完整路径,完整路径中不能包含Bucket名称,例如exampledir/exampleobject.txt。*/
    std::string ObjectName = "exampledir/exampleobject.txt";

    /* 初始化网络等资源。*/
    InitializeSdk();

    ClientConfiguration conf;
    /* 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。*/
    auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
    OssClient client(Endpoint, credentialsProvider, conf);
    InitiateMultipartUploadRequest initUploadRequest(BucketName, ObjectName);

    /* 初始化分片上传事件。*/
    auto uploadIdResult = client.InitiateMultipartUpload(initUploadRequest);
    auto uploadId = uploadIdResult.result().UploadId();
    std::string fileToUpload = "yourLocalFilename";
    int64_t partSize = 100 * 1024;
    PartList partETagList;
    auto fileSize = getFileSize(fileToUpload);
    int partCount = static_cast<int>(fileSize / partSize);
    /* 计算分片个数。*/
    if (fileSize % partSize != 0) {
        partCount++;
    }

    /* 对每一个分片进行上传。*/
    for (int i = 1; i <= partCount; i++) {
        auto skipBytes = partSize * (i - 1);
        auto size = (partSize < fileSize - skipBytes) ? partSize : (fileSize - skipBytes);
        std::shared_ptr<std::iostream> content = std::make_shared<std::fstream>(fileToUpload, std::ios::in|std::ios::binary);
        content->seekg(skipBytes, std::ios::beg);

        UploadPartRequest uploadPartRequest(BucketName, ObjectName, content);
        uploadPartRequest.setContentLength(size);
        uploadPartRequest.setUploadId(uploadId);
        uploadPartRequest.setPartNumber(i);
        auto uploadPartOutcome = client.UploadPart(uploadPartRequest);
        if (uploadPartOutcome.isSuccess()) {
                Part part(i, uploadPartOutcome.result().ETag());
                partETagList.push_back(part);
        }
        else {
                std::cout << "uploadPart fail" <<
            ",code:" << uploadPartOutcome.error().Code() <<
            ",message:" << uploadPartOutcome.error().Message() <<
            ",requestId:" << uploadPartOutcome.error().RequestId() << std::endl;
        }
    }

    /* 完成分片上传。*/
    CompleteMultipartUploadRequest request(BucketName, ObjectName);
    request.setUploadId(uploadId);
    request.setPartList(partETagList);
    auto outcome = client.CompleteMultipartUpload(request);

    if (outcome.isSuccess()) {
        std::cout << "versionid:" << outcome.result().VersionId() << std::endl;
    }
    else {
        /* 异常处理。*/
        std::cout << "CompleteMultipartUpload fail" <<
        ",code:" << outcome.error().Code() <<
        ",message:" << outcome.error().Message() <<
        ",requestId:" << outcome.error().RequestId() << std::endl;
        return -1;
    }

    /* 释放网络等资源。*/
    ShutdownSdk();
    return 0;
}

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