Updates in support of up-spec Issue: File Attachment Feature #114 #127
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Preliminary proposed uprotocol_options updates for notification support and for file transfer support.
Preliminary updates for publish support
Adding preliminary file publish sequence diagram with notification.
Updated to include file publish sequence diagram
Updated file publish sequence diagram
Updated notification and file streaming details.
Updating file transfer figure title
| // Delivery notification request for published messages | ||
| // Indication to uTransport-specific instance that a notification should be provided to the publisher of a message | ||
| // on completion/termination (with success/failure) | ||
| optional bool notify_publisher = 51302; |
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protobuf custom options are not passed in mesages that are sent/received, they are encoded in generated code.
| optional bool notify_publisher = 51302; | ||
| } | ||
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| // uPublish notification message, intended to deliver context-specific content known the publisher, and provided by the uTransport layer supporting the Notiication response |
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This documentation does not make any sense. and uprotocol_options does not make sense for what you are trying to do.
| // The following is used to identify files - to be transferred, or after transfer, to be accessed by the receiving uEs | ||
| // File Proto | ||
| message File { |
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There is already a file.proto and it needs to be added to UAttributes as it is a header attribute.
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| == File Publish Handling | ||
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| When a uStreamer instance dispatcher is supporting file transfer, the file details will generally be passed by reference, and the transfer will be queued for delivery. uP traffic priorities will affect when content can be delivered, and file size(s) along with available link bandwidth will also affect transfer duration. |
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We don't pass file details by reference, we pass file metadata in UAttributes (that is what we are suppose to do). The other text you wrote does not make sense (about priority etc...)
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| Sustained integrity of files queued for transfer is essential, and the providing uEs will need to prevent the files from being changed/deleted until such time as their transfer has been completed. | ||
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| The basic Publish, and uStreaming logic is a fire-and-forget approach, with content queued and delivered but no handshaking between the subscribing uEs. This works well for content passed by value, but cases where content is passed by reference and the transfer can take an indeterminate duration to complete necessitate communication with the Publishing uE. Dispatchers and uTransport instances are not exposed services and lack visible protobufs. Intent for Notification is for a "known" status response to be provided to the Publisher for the type of content being published, delivered as generic ".any" protobuf within a Notification message. The uProtocol_options.protobuf will provide an optional notification request field to trigger notifications to the publisher by applicable dispatcher(s) - in this case the File Streaming dispatcher, to indicate completion of transfer along with success/failure details. |
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Then files need to be attached to a request/response and NOT to a notification if you want to be notified when the upload is complete. That or both sides publish the file is being sent and then publish the file has been consumed. What you are doing with notification is fundamentally changing the design pattern.
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you're flows mean that dispatchers are generating notifications, that is ok but then it means that dispatchers need a uEntity_id, version, etc... This also means that dispatchers are visible to the uEs and part of the business logic. A publish does not generate a notification, we are mixing up design patterns.
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@urcorcoran what I recommend is to file an issue to describe the problem you're trying to solve and then we can discuss potential solutions. Furthermore the |
Added proposed updates to uprotocol_options.protobuf, and high level file streaming details with notification to L2 readme.doc.