For some reason, when using HttpWebRequest.GetRequestStreamAsync, the
Amazon Cloud Drive and Box backends would fail when attempting to upload
larger amounts of data (these are the only backends that use the
PostMultipartAsync method).
This fixes issue #3756.
The previous implementations resulted in an overload being hidden by one
without a default parameter, making it unclear which method was being
called. For example, consider the following signatures:
public MultipartItem(string content, string contenttype = null, string name = null, string filename = null)
public MultipartItem(string contenttype, string name = null, string filename = null)
From https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/named-and-optional-arguments,
> If two candidates are judged to be equally good, preference goes to a
> candidate that does not have optional parameters for which arguments
> were omitted in the call. This is a consequence of a general preference
> in overload resolution for candidates that have fewer parameters.
By changing to IEnumerable, it is possible to iterate only a portion of the list, which is useful when not all entries are needed (e.g., when testing a connection).
All existing backends have been updated, and any which were able to be changed to yield return results in a straightforward way now do.
Many backends had a try/catch in the List() method. Due to the fact that yield returns can't be placed within a try/catch block, these have been refactored to either scope the try/catch to the parts that (should) be the only places throwing exceptions, so that exceptions are still caught and handled.
Note that lazy evaluation may cause some changes in behavior - exceptions that were previously thrown at the point of invokation of List() may now be thrown while it is being enumerated.
I believe this will not be problematic though, as the only well-known exception seems to be FolderMissingException, which should be thrown by Test(), but TestList() attempts to enumerate the list to force this exception.
Any places that require the legacy behavior can get it by simply converting the lazy enumerable to a List()
InvariantCulture is useful when comparing / sorting human language strings in a culturely correct way. It handles things like accented letters in a way that makes sense to humans (e.g., 'a' should be sorted next to 'á', rather than after 'z').
Ordinal looks just at the raw code points of the characters. As such, it is recommended for use in cases when comparing system strings (file paths, command line parameters, config settings, etc.). Since it doesn't need to use the culture specific sorting rules, this method can often be faster.
For more information, see https://stackoverflow.com/questions/492799/difference-between-invariantculture-and-ordinal-string-comparison (and other related questions)
Use delay for Delete, Rename, GetCurrentDirectory and Get. Calculate the
delay from the completion of the operations instead of the start. I have
no idea if this is correct or not, but it seems to fix my issues with
consistency.
For filtering parameters, prepend \ to special characters + - & | ! ( ) { } [ ] ^ ' " ~ * ? : \ and space according to Amazon Cloud Drive API documentation, and encode space as %20 instead of + to avoid mistaking space as plus sign in filtering parameter.
Amazon Cloud Drive API documentation on escaping special characters of filtering parameters:
https://developer.amazon.com/public/apis/experience/cloud-drive/content/nodes#Filtering
Actually files cannot be deleted on Amazon Cloud Drive, but now they are put into trash instead of being put into the root folder.
This improves issue #1546
