Support per channel transport config

[hannahhoward]

Goals

This aims to import transport configuration by allowing a configuration when opening a channel.

You can now pass WithTransportOptions, and then use options provided by your chose transport.

Implementation

• track transport options in a simple mutex protected array
• BREAKING (but hey, it's go-data-transfer v2 which is still RC) - change the signature of RegisterTransportConfigurer, which was super weird, to return TransportOptions -- this reduces what the calling library has to do.
• Transports themselves now provide options which makes for MUCH cleaner usage.

For Discussion

This implementation is... not quite perfect, but I think good enough for Lassie + go-fil-markets, the consumers.

The interaction between the old mechanism and the new mechanism is somewhat conflicting, and once I tried to replace the old mechanism completely, I ran into many of the perpetual design problems I struggle with in this library:

• how to support restarts after a reboot (i.e. from disk)
• how to support configure transfers for the receiver of an incoming request
• rather than go down yet another design hole like I did with the transport refactor that never got finished, I decided to call this good enough.

Companion PR for go-fil-markets: https://github.com/filecoin-project/go-fil-markets/pull/780

[codecov-commenter]

Codecov Report

Merging #362 (ad4a627) into master (f936292) will decrease coverage by 0.51%. The diff coverage is 0.00%.

Additional details and impacted files

[](https://codecov.io/gh/filecoin-project/go-data-transfer/pull/362?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=filecoin-project) ```diff @@ Coverage Diff @@ ## master #362 +/- ## ========================================== - Coverage 67.81% 67.30% -0.52% ========================================== Files 23 23 Lines 2865 2887 +22 ========================================== Hits 1943 1943 - Misses 701 721 +20 - Partials 221 223 +2 ``` | [Impacted Files](https://codecov.io/gh/filecoin-project/go-data-transfer/pull/362?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=filecoin-project) | Coverage Δ | | |---|---|---| | [impl/impl.go](https://codecov.io/gh/filecoin-project/go-data-transfer/pull/362?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=filecoin-project#diff-aW1wbC9pbXBsLmdv) | `50.52% <0.00%> (-2.23%)` | :arrow_down: | | [transport/graphsync/graphsync.go](https://codecov.io/gh/filecoin-project/go-data-transfer/pull/362?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=filecoin-project#diff-dHJhbnNwb3J0L2dyYXBoc3luYy9ncmFwaHN5bmMuZ28=) | `76.66% <0.00%> (-0.80%)` | :arrow_down: |