/// <summary>
/// Binds the object based on the given <see cref="BindingContext"/> in a manner that is aware of the presence of <see cref="IFunctionDataCache"/>.
/// This means that before reading an object, it will be attempted to be read from the cache. When writing, it will be attempted to be written to the cache.
/// In case of a read access (i.e., <see cref="FileAccess.Read"/>), the binding may be delayed as the object could be read either from the cache or storage.
/// The actual conversion is thus delayed to <see cref="RpcSharedMemoryDataExtension"/>.
/// </summary>
internal static async Task BindCacheAwareAsync(BindingContext context, FileAccess access)
{
if (access == FileAccess.Write)
{
ICacheAwareWriteObject obj = await context.Binder.BindAsync <ICacheAwareWriteObject>(context.Attributes);
if (context.Value is SharedMemoryObject sharedMemoryObj)
{
using (Stream sharedMemoryStream = sharedMemoryObj.Content)
using (Stream blobStream = obj.BlobStream)
{
await sharedMemoryStream.CopyToAsync(blobStream);
await blobStream.FlushAsync();
}
}
else
{
throw new NotSupportedException($"Cannot perform cache-aware binding of write object with type: {context.Value.GetType()}");
}
context.Value = obj;
}
else if (access == FileAccess.Read)
{
ICacheAwareReadObject obj = await context.Binder.BindAsync <ICacheAwareReadObject>(context.Attributes);
// We get a binding to the object. It could either be read from the cache or from storage.
// Therefore, we delay the conversion into the actual object to the RpcSharedMemoryDataExtension.
// The extension will check if the object was already in the cache, then no conversion is necessary.
// If the object was not in the cache then it will be read directly into shared memory without creating extra
// intermediate copies.
context.Value = obj;
}
else
{
throw new NotSupportedException($"FileAccess: {access} not supported in CacheAware mode");
}
}
public static void ByteArrayBindingWriteToCacheAsync(
[Blob(ContainerName + "/" + OutputBlobName, FileAccess.Write)] ICacheAwareWriteObject blob)
{
Assert.NotNull(blob.BlobStream);
}
