Make bridge descriptor sanitization more maintainable and more modular

[iwakeh]

SanitizedBridgeServerDescriptor should extend BridgeServerDescriptor.
It receives a BridgeServerDescriptor at construction time and sanitizes the descriptor.
All getters should only supply sanitized data; this explicitely includes method from the Descriptor interface like getRawDescriptorBytes.

In addition, a SanitizedBridgeServerDescriptorTest should be created that verifies the sanitation and data integrity.

[karsten]

Try to make the summary slightly more useful.

[iwakeh]

Also pay attention to the issues mentioned in #23981's comments.

Shouldn't this be moved to metrics-2017?

[karsten]

Replying to iwakeh:

Also pay attention to the issues mentioned in #23981's comments.

Right. In particular, I'd like to try out the following change that I suggested on that ticket:

"While working on this patch I considered taking a different approach where we'd include placeholders for parts that we cannot sanitize yet and fill them in after finishing to read the original descriptor. This could be a List<StringBuilder> to retain order of original lines and where we'd keep references to some StringBuilders that we need to sanitize after reading. Still something to think about. Let's do that after fixing this ugly bug."

Shouldn't this be moved to metrics-2017?

Sure. Worth trying.

[karsten]

Replying to karsten:

"While working on this patch I considered taking a different approach where we'd include placeholders for parts that we cannot sanitize yet and fill them in after finishing to read the original descriptor. This could be a List<StringBuilder> to retain order of original lines and where we'd keep references to some StringBuilders that we need to sanitize after reading. Still something to think about. Let's do that after fixing this ugly bug."

I started an implementation in ​my task-20549 branch that doesn't get us all the way to implementing this ticket yet, but which may be a start. Feedback welcome!

[iwakeh]

Adding these to my reviewing list.

[iwakeh]

Will be completed in 2018.

[karsten]

Raising priority, as this may soon become more relevant when reprocessing bridge descriptors.

[iwakeh]

This s a different approach from the tickets description. But, I really like this idea and added seven more commits. The commit comments should describe the details, if necessary. The general changes are some name changes, like introducing DescriptorBuilder as builder, which we might reuse elsewhere.
The new DescriptorBuilder also accepts appending DescriptorBuilder now.

Please review ​seven commits on the task-20549 branch.

Maybe, we should change the title and summary to a more general "Make bridge descriptor sanitization more maintainable and more modular"?

[iwakeh]

Changing to needs_information also meaning needs_review.

[karsten]

Great! Your additional changes look good to me. I made two tiny changes in ​my task-20549 branch (this. and a whitespace change), squashed, rebased, and pushed to master. Setting status to merge_ready.

Do we want to make further changes as part of this ticket? If so, can you start a list of next steps here? If not, can you close this ticket? Thanks!

[iwakeh]

Changes look ok, thanks!

Well, there'll always be more steps, but let's call this ticket finished.

I created #25307 as I'm now aware that this should be quite easy (just a question to clarify on that ticket).

Closing.
Thanks!