Cocos2dx热更新遇到的那些坑

1、Cocos2dx热更新因为文件名含有空格，ios下载失败bug修改

问题描述：

　　项目中偶尔遇到美术图片命名时不规范，导致图片名字含有空格。导致ios热更新时，遇到下载失败。

解决方案：

1.从新改名字（以后命名一定要规范）

2.空格转义解决下载失败问题

url

web 开发中通过问号（？）方式在浏览器地址栏中传值时。浏览器是通过“&”来区分问号后的参数个数的。如果出现传值参数中带有“&”时，在接受页面就会出现错误，类似如下请求路径：/next.jsp?param1=hendhs89&furej & param2=sss

参数param1中含有转义字符“&” ，这样会导致被请求页的参数接收错误。

在传值前通过 java.net.URLEncoder.encode(param1) 编码处理后，可将转义字符转为16进制;

1. + URL 中+号表示空格 %2B

2. 空格 URL中的空格可以用+号或者编码 %20

4. ? 分隔实际的 URL 和参数 %3F

5. % 指定特殊字符 %25

6. # 表示书签 %23

7. & URL中指定的参数间的分隔符%26

8. = URL中指定参数的值 %3D

9. ! URL中指定参数的值 %2

具体解决方案

1、AssetsManagerEx::startUpdate()中，拼接地址时，将空格转义

void AssetsManagerEx::startUpdate()

{

    if (_updateState != State::NEED_UPDATE)

        return;

    _updateState = State::UPDATING;

    // Clean up before update

    _failedUnits.clear();

    _downloadUnits.clear();

    _compressedFiles.clear();

    _totalWaitToDownload = _totalToDownload = ;

    _percent = _percentByFile = _sizeCollected = _totalSize = ;

    _downloadedSize.clear();

    _totalEnabled = false;

    // Temporary manifest exists, resuming previous download

    if (_tempManifest->isLoaded() && _tempManifest->versionEquals(_remoteManifest))

    {

        _tempManifest->genResumeAssetsList(&_downloadUnits);

        _totalWaitToDownload = _totalToDownload = (int)_downloadUnits.size();

        this->batchDownload();

        std::string msg = StringUtils::format("Resuming from previous unfinished update, %d files remains to be finished.", _totalToDownload);

        dispatchUpdateEvent(EventAssetsManagerEx::EventCode::UPDATE_PROGRESSION, "", msg);

    }

    // Check difference

    else

    {

        // Temporary manifest not exists or out of date,

        // it will be used to register the download states of each asset,

        // in this case, it equals remote manifest.

        _tempManifest->release();

        _tempManifest = _remoteManifest;

        std::unordered_map<std::string, Manifest::AssetDiff> diff_map = _localManifest->genDiff(_remoteManifest);

        if (diff_map.size() == )

        {

            updateSucceed();

        }

        else

        {

            // Generate download units for all assets that need to be updated or added

            std::string packageUrl = _remoteManifest->getPackageUrl();

            for (auto it = diff_map.begin(); it != diff_map.end(); ++it)

            {

                Manifest::AssetDiff diff = it->second;

                if (diff.type == Manifest::DiffType::DELETED)

                {

                    _fileUtils->removeFile(_storagePath + diff.asset.path);

                }

                else

                {

                    std::string path = diff.asset.path;

                    // Create path

                    _fileUtils->createDirectory(basename(_storagePath + path));

                    DownloadUnit unit;

                    unit.customId = it->first;

                    std::string str(path),s2(" "),s3("%20");

                    std::string::size_type pos=0;

                    std::string::size_type a=s2.size();

                    std::string::size_type b=s3.size();

                    while((pos=str.find(s2,pos))!=std::string::npos)

                    {

                        str.replace(pos,a,s3);

                        pos+=b;

                    }

                    unit.srcUrl = packageUrl + str;

                    unit.storagePath = _storagePath + path;

                    _downloadUnits.emplace(unit.customId, unit);

                }

            }

            // Set other assets' downloadState to SUCCESSED

            auto &assets = _remoteManifest->getAssets();

            for (auto it = assets.cbegin(); it != assets.cend(); ++it)

            {

                const std::string &key = it->first;

                auto diffIt = diff_map.find(key);

                if (diffIt == diff_map.end())

                {

                    _tempManifest->setAssetDownloadState(key, Manifest::DownloadState::SUCCESSED);

                }

            }

            _totalWaitToDownload = _totalToDownload = (int)_downloadUnits.size();

            this->batchDownload();

            std::string msg = StringUtils::format("Start to update %d files from remote package.", _totalToDownload);

            dispatchUpdateEvent(EventAssetsManagerEx::EventCode::UPDATE_PROGRESSION, "", msg);

        }

    }

}

2、Manifest.cpp

void Manifest::genResumeAssetsList(DownloadUnits *units) const

{

    for (auto it = _assets.begin(); it != _assets.end(); ++it)

    {

        Asset asset = it->second;

        if (asset.downloadState != DownloadState::SUCCESSED)

        {

            DownloadUnit unit;

            unit.customId = it->first;

            std::string str(asset.path),s2(" "),s3("%20");

            std::string::size_type pos=0;

            std::string::size_type a=s2.size();

            std::string::size_type b=s3.size();

            while((pos=str.find(s2,pos))!=std::string::npos)

            {

                str.replace(pos,a,s3);

                pos+=b;

            }

            unit.srcUrl = _packageUrl + str;

            unit.storagePath = _manifestRoot + asset.path;

            units->emplace(unit.customId, unit);

        }

    }

}

2、Cocos2dx热更新因为文件名含有空格，ios下载失败bug修改

问题描述：

AsstsManagerEx: project.manifest may be downloaded twice。

project.manifest下载两次，导致热更新失败。打印log提示解析project.manifest失败。

解决方案：

Cocos 3.14版本自己解决了这个问题，根据就该日志更新下载器。

3、更新过程强制退出，导致不能缓存下载。下载失败之后，不对比MD5所有文件都下载bug。

新版本不知道有没有。这个对应版本是 3.11

解决思路。

下载器一开始先判断有没有缓存文件，有缓存文件的话，直接读取缓存文件。由于上一次强退没有及时将下载进度写到缓存文件中

所以所有文件的状态都是1.这里由于是临时清单文件，没有做MD5对比。所有所有文件都被添加到下载清单，出现bug

如果正常出错，没有强退。下载器会正常调用，写临时清单，这个不会有bug。

void AssetsManagerEx::startUpdate()

{

    if (_updateState != State::NEED_UPDATE)

        return;

    _updateState = State::UPDATING;

    // Clean up before update

    _failedUnits.clear();

    _downloadUnits.clear();

    _compressedFiles.clear();

    _totalWaitToDownload = _totalToDownload = ;

    _percent = _percentByFile = _sizeCollected = _totalSize = ;

    _downloadedSize.clear();

    _totalEnabled = false;

    // Temporary manifest exists, resuming previous download

    if (_tempManifest->isLoaded() && _tempManifest->versionEquals(_remoteManifest))

    {

        std::unordered_map<std::string, Manifest::AssetDiff> diff_map = _localManifest->genDiff(_remoteManifest);

        if (diff_map.size() == 0)

        {

            updateSucceed();

        }

        else

        {

            // Set other assets' downloadState to SUCCESSED

            auto &assets = _remoteManifest->getAssets();

            for (auto it = assets.cbegin(); it != assets.cend(); ++it)

            {

                const std::string &key = it->first;

                auto diffIt = diff_map.find(key);

                if (diffIt == diff_map.end())

                {

                    _tempManifest->setAssetDownloadState(key, Manifest::DownloadState::SUCCESSED);

                }

            }

            _tempManifest->genResumeAssetsList(&_downloadUnits);

            _totalWaitToDownload = _totalToDownload = (int)_downloadUnits.size();

            this->batchDownload();

            std::string msg = StringUtils::format("Resuming from previous unfinished update, %d files remains to be finished.", _totalToDownload);

            dispatchUpdateEvent(EventAssetsManagerEx::EventCode::UPDATE_PROGRESSION, "", msg);

        }

    }

    // Check difference

    else

附

遇到问题不要着急，一步一步确定问题。经常看官网的coco动态，新版本的发布，以及bug的修改、

Cocos2dx git

Cocos2dx 官网