private async Task <IRandomAccessStream> LoadImageStreamFromCacheInternal(Uri imageUri)
{
var imageUrl = imageUri.AbsoluteUri;
//获取不到内存缓存
if (ImageConfig.Default.CacheMode == CacheMode.OnlyStorageCache)
{
//网络uri且缓存可用
if (imageUri.IsWebScheme() && await ImageConfig.Default.StorageCacheImpl.IsCacheExistsAndAlive(imageUrl))
{
ImageLog.Log("[storage] " + imageUrl);
var storageStream = await ImageConfig.Default.StorageCacheImpl.LoadCacheStreamAsync(imageUrl);
return(storageStream);
}
}
return(null);
}
private async Task <IRandomAccessStream> LoadImageStreamFromCacheInternal(Uri imageUri)
{
var imageUrl = imageUri.AbsoluteUri;
if (_ImageConfig.CacheMode == CacheMode.MemoryAndStorageCache ||
_ImageConfig.CacheMode == CacheMode.OnlyMemoryCache)
{
IRandomAccessStream memoryStream;
//尝试获取内存缓存
if (_ImageConfig.MemoryCacheImpl.TryGetValue(imageUrl, out memoryStream))
{
ImageLog.Log("[memory] " + imageUrl);
//SaveStream(memoryStream, imageUri.LocalPath);
return(memoryStream);
}
}
//获取不到内存缓存
if (_ImageConfig.CacheMode == CacheMode.MemoryAndStorageCache ||
_ImageConfig.CacheMode == CacheMode.OnlyStorageCache)
{
//网络uri且缓存可用
if (imageUri.IsWebScheme() && await _ImageConfig.StorageCacheImpl.IsCacheExistsAndAlive(imageUrl))
{
ImageLog.Log("[storage] " + imageUrl);
var storageStream = await _ImageConfig.StorageCacheImpl.LoadCacheStreamAsync(imageUrl);
// Moving cache to the memory
if (_ImageConfig.CacheMode == CacheMode.MemoryAndStorageCache &&
storageStream != null)
{
_ImageConfig.MemoryCacheImpl.Put(imageUrl, storageStream);
}
//SaveStream(storageStream, imageUri.LocalPath);
return(storageStream);
}
}
return(null);
}
/// <summary>
/// Async loading image stream from cache or network
/// </summary>
/// <param name="imageUri">Uri of the image to load</param>
/// <returns>Stream of the image if load was successfull, null otherwise</returns>
public virtual async Task <IRandomAccessStream> LoadImageStream(Uri imageUri,
CancellationTokenSource cancellationTokenSource)
{
CheckConfig();
if (imageUri == null)
{
return(null);
}
var imageUrl = imageUri.AbsoluteUri;
//有Cache情况，先加载Cache
if (_ImageConfig.CacheMode != CacheMode.NoCache)
{
//加载Cache
var resultFromCache = await this.LoadImageStreamFromCache(imageUri);
if (resultFromCache != null)
{
return(resultFromCache);
}
}
try
{
ImageLog.Log("[network] loading " + imageUrl);
IRandomAccessStream randStream = null;
//如果有自定义UriParser,使用自定义,反之使用默认方式.
if (_ImageConfig.UriParser != null)
{
randStream = await _ImageConfig.
UriParser.GetStreamFromUri(imageUri, cancellationTokenSource.Token);
}
else
{
randStream = await imageUri.GetStreamFromUri(cancellationTokenSource.Token);
}
if (randStream == null)
{
ImageLog.Log("[error] failed to download: " + imageUrl);
return(null);
}
var inMemoryStream = new InMemoryRandomAccessStream();
using (randStream)
{
var copyAction = RandomAccessStream.CopyAndCloseAsync(
randStream.GetInputStreamAt(0L),
inMemoryStream.GetOutputStreamAt(0L));
await copyAction.AsTask(cancellationTokenSource.Token);
}
randStream = inMemoryStream;
ImageLog.Log("[network] loaded " + imageUrl);
if (_ImageConfig.CacheMode != CacheMode.NoCache)
{
if (_ImageConfig.CacheMode == CacheMode.MemoryAndStorageCache ||
_ImageConfig.CacheMode == CacheMode.OnlyMemoryCache)
{
if (randStream != null)
{
_ImageConfig.MemoryCacheImpl.Put(imageUrl, randStream);
}
}
if (_ImageConfig.CacheMode == CacheMode.MemoryAndStorageCache ||
_ImageConfig.CacheMode == CacheMode.OnlyStorageCache)
{
//是http or https 才加入本地缓存
if (imageUri.IsWebScheme())
{
await Task.Factory.StartNew(() =>
{
ImageLog.Log(string.Format("{0} in task t-{1}", imageUri, Task.CurrentId));
// Async saving to the storage cache without await
var saveAsync = _ImageConfig.StorageCacheImpl.SaveAsync(imageUrl, randStream)
.ContinueWith(task =>
{
ImageLog.Log(string.Format("{0} in task t1-{1}", imageUri, Task.CurrentId));
if (task.IsFaulted || !task.Result)
{
ImageLog.Log("[error] failed to save in storage: " + imageUri);
}
}
);
}, default(CancellationToken), TaskCreationOptions.AttachedToParent, this._sequentialScheduler);
}
}
}
return(randStream);
}
catch (Exception ex)
{
ImageLog.Log("[error] failed to save loaded image: " + imageUrl);
}
//var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
// May be another thread has saved image to the cache
// It is real working case
if (_ImageConfig.CacheMode != CacheMode.NoCache)
{
var resultFromCache = await this.LoadImageStreamFromCache(imageUri);
if (resultFromCache != null)
{
return(resultFromCache);
}
}
ImageLog.Log("[error] failed to load image stream from cache and network: " + imageUrl);
return(null);
}