2023 Feb 08

• Pretty cool, Iter<Option<_>>::map will map to another Option, so you don’t have to handle unwrapping in order to convert the inner type.

• Updated my followup PR.

• Probably going to do some review and cryptopals today.

• Considering switching to NeoVim…Vim is just more universal and I imagine everything I do in helix can be done in NeoVim. Then again, it is really nice how small the config is, and it’s not like I’m working on remote servers all that often…

• Feeling like I’m getting a better foundation for how to write good PRs/just be a better open-source contributor/software developer. Getting better at manipulating commits, understanding better when it makes sense to separate commits and whether to squash fixups and how to lookover my changes before pushing.

• Realized payment_secret doesn’t really need to tie together MPP HTLCs because they also all use the same payment_hash.

• Reviewing

  • Why is it necessary to move payment retrying for trampoline?

    • Saw in preceding PRs that moving payment retrying into ChannelManager is to be able to support trampoline payments. Is this to support retrying payments when a node built with LDK is acting as a trampoline node (did automated retrying not exist in LDK before)?

  • Dang so, you don’t need a mutable reference to an object if its behind a mutex (outbound_payment::abandon_payment, check_retry_payments, etc.)

    • So apparently there’s “interior mutability” which basically breaks the core laws of Rust wtf!! Sometimes you want to have a shared reference that’s mutable by multiple parties (Mutex, doesn’t differentiate between readers and writers), and sometimes you do want to have a shared reference where different parties are reading or writing (RwLock, one writer many readers), along with other instances where you need to employ mutability where Rust typically wouldn’t let you.

    • What is the reason for changing abandon_payment and check_retry_payments to take in pending_events as opposed to how it was before. Is it mainly just because it’s a bit cleaner or is there other significance?

• I love Bitcoin Optech: great summary on trampoline.

  • Question: to conceal whether a trampoline node is sending to the final destination, the recipient must also be a trampoline node right (which definitely wouldn’t always be the case)? Because in order for it to be ambiguous, a trampoline would have to not be able to tell if it was sending to another trampoline or not, but whether nodes support trampoline is public or easily discovered right?