/// <summary>
/// 写入下载缓存信息，用于断点续传
/// </summary>
void SaveDownloadCacheData()
{
if (CurrentState < EmState.UpdateAssetBundle)
{
return;
}
if (!Directory.Exists(DownLoadCommon.CACHE_PATH))
{
return;
}
//载入新的Manifest
string new_manifest_name = DownLoadCommon.GetCacheFileFullName(DownLoadCommon.MAIN_MANIFEST_FILE_NAME);
AssetBundleManifest new_manifest = DownLoadCommon.LoadMainManifestByPath(new_manifest_name);
if (new_manifest == null)
{
return;
}
//先尝试读取旧的缓存信息，再保存现在已经下载的数据
//PS:由于只有版本完整更新完才会移动Cache目录，且玩家可能多次尝试下载更新，所以必须保留旧的缓存信息
DownloadCache cache = new DownloadCache();
cache.Load(DownLoadCommon.DOWNLOADCACHE_FILE_PATH);
if (_ab_download != null &&
_ab_download.CompleteDownloads != null &&
_ab_download.CompleteDownloads.Count > 0)
{
for (int i = 0; i < _ab_download.CompleteDownloads.Count; ++i)
{
string assetbundle_name = _ab_download.CompleteDownloads[i];
Hash128 hash_code = new_manifest.GetAssetBundleHash(assetbundle_name);
if (hash_code.isValid && !cache.Data.AssetBundles.ContainsKey(assetbundle_name))
{
DownloadCacheData.AssetBundle elem = new DownloadCacheData.AssetBundle()
{
AssetBundleName = assetbundle_name,
Hash = hash_code.ToString(),
};
Debug.Log(cache.Data.AssetBundles.Count + " - Cache Add:" + assetbundle_name);
cache.Data.AssetBundles.Add(assetbundle_name, elem);
}
}
}
if (cache.HasData())
{
cache.Save(DownLoadCommon.DOWNLOADCACHE_FILE_PATH);
}
}
//<summary>
// 比较AssetBundle差异，获得下载列表与删除列表
//</summary>
static void CompareAssetBundleDifference(ref List <string> download_files
, ref List <string> delete_files
, AssetBundleManifest old_manifest
, AssetBundleManifest new_manifest
)
{
if (download_files != null)
{
download_files.Clear();
}
if (delete_files != null)
{
delete_files.Clear();
}
if (old_manifest == null)
{
return;
}
if (new_manifest == null)
{
return;
}
//采用位标记的方式判断资源
//位标记： 0： 存在旧资源中 1： 存在新资源中 2：本地资源标记
int old_version_bit = 0x1; // 存在旧资源中
int new_version_bit = 0x2; // 存在新资源中
Dictionary <string, int> temp_dic = new Dictionary <string, int>();
//标记旧资源
string[] all_assetbundle = old_manifest.GetAllAssetBundles();
for (int i = 0; i < all_assetbundle.Length; ++i)
{
string name = all_assetbundle[i];
_SetDictionaryBit(ref temp_dic, name, old_version_bit);
}
//标记新资源
string[] new_all_assetbundle = new_manifest.GetAllAssetBundles();
for (int i = 0; i < new_all_assetbundle.Length; ++i)
{
string name = new_all_assetbundle[i];
_SetDictionaryBit(ref temp_dic, name, new_version_bit);
}
//获得对应需操作的文件名， 优先级： both > add > delete
//both: 第0位与第1位都被标记的
//delete: 仅第0位被标记的
//add: 第2位未标记，且第3位被标记的
int both_bit = old_version_bit | new_version_bit; // 二个版本资源都存在
List <string> add_files = new List <string>();
List <string> both_files = new List <string>();
var itr = temp_dic.GetEnumerator();
while (itr.MoveNext())
{
string name = itr.Current.Key;
int mask = itr.Current.Value;
if ((mask & new_version_bit) == new_version_bit &&
(mask & old_version_bit) == 0)
{
add_files.Add(name);
}
else if ((mask & both_bit) == both_bit)
{
both_files.Add(name);
}
else if ((mask & old_version_bit) == old_version_bit)
{
delete_files.Add(name);
}
}
itr.Dispose();
//载入下载缓存数据
DownloadCache download_cache = new DownloadCache();
download_cache.Load(DownLoadCommon.DOWNLOADCACHE_FILE_PATH);
if (!download_cache.HasData())
{
download_cache = null;
}
//记录需下载的文件
{
//加入新增的文件
download_files.AddRange(add_files);
//比较所有同时存在的文件，判断哪些需要更新
for (int i = 0; i < both_files.Count; ++i)
{
string name = both_files[i];
string full_name = DownLoadCommon.GetFileFullName(name);
if (File.Exists(full_name))
{
//判断哈希值是否相等
string old_hash = old_manifest.GetAssetBundleHash(name).ToString();
string new_hash = new_manifest.GetAssetBundleHash(name).ToString();
if (old_hash.CompareTo(new_hash) == 0)
{
continue;
}
download_files.Add(name);
}
else
{
download_files.Add(name);
}
}
//过滤缓存中已下载的文件
if (download_cache != null)
{
var cache_itr = download_cache.Data.AssetBundles.GetEnumerator();
while (cache_itr.MoveNext())
{
DownloadCacheData.AssetBundle elem = cache_itr.Current.Value;
string name = elem.AssetBundleName;
string full_name = DownLoadCommon.GetFileFullName(name);
if (File.Exists(full_name))
{
string cache_hash = elem.Hash;
string new_hash = new_manifest.GetAssetBundleHash(name).ToString();
if (!string.IsNullOrEmpty(cache_hash) &&
cache_hash.CompareTo(new_hash) == 0)
{
download_files.Remove(name);
}
}
}
}
}
}