feat: modify API to allow certain use cases; add ed25519/secp256k1 precompiles

[OliverNChalk]

Hi, feel free to let me know if you want certain commits dropped/reworked. I made these changes to my fork to enable:

• Passing AccountsDb to SanitizeTransaction::try_crate to get the account_keys iterable.
• Support LoaderV2 and LoaderV4.
• Return post account state when using simulate so test assertions can be run.
• Added support for transactions that use ed25519/secp256k1 precompiles.

[Aursen]

A bit hard to review as all code is on the same PR

[kevinheavey]

yeah can we split this up please?

[OliverNChalk]

Don't currently have the bandwidth to do this but if you wanna cherry pick the commits you want that's cool with me. Else I'll circle back to this when I'm looking to finalize my project that depends on it. For now im just building a fork

[kevinheavey]

ok i'll ask some questions here then. Firstly why does the precompiles commit need to add logic to check program IDs in process_transaction?

[OliverNChalk]

ok i'll ask some questions here then. Firstly why does the precompiles commit need to add logic to check program IDs in process_transaction?

When I was running TXs with precompiles I was getting a missing account error. To fix this I created dummy accounts, perhaps it would be more correct to avoid trying to load the account if it is a precompile?

I saw construct_instructions_account was doing a similar (though not dummy) operation.

[kevinheavey]

Hey coming back to this:

When I was running TXs with precompiles I was getting a missing account error.

What are these missing accounts supposed to be?

Support LoaderV2 and LoaderV4.

I think for users who want more control over what loader gets used we should just direct them to build the loader instructions and send the required transactions

Return post account state when using simulate so test assertions can be run.

This is useful, I will include it in a separate PR

Passing AccountsDb to SanitizeTransaction::try_crate to get the account_keys iterable.

Which commit is this?

[OliverNChalk]

Passing AccountsDb to SanitizeTransaction::try_crate to get the account_keys iterable.

Which commit is this?

https://github.com/LiteSVM/litesvm/pull/78/commits/f7dc4ad4c680c012599504fee7865c66402db437

Usage:

            let tx = SanitizedTransaction::try_create(
                tx,
                MessageHash::Compute,
                Some(false),
                &svm.accounts,
            )
            .unwrap();

[kevinheavey]

Passing AccountsDb to SanitizeTransaction::try_crate to get the account_keys iterable.

Which commit is this?

f7dc4ad

Usage:

            let tx = SanitizedTransaction::try_create(
                tx,
                MessageHash::Compute,
                Some(false),
                &svm.accounts,
            )
            .unwrap();

Coming back to this: what's the use case for passing all of svm.accounts in the reserved_account_keys arg?

[OliverNChalk]

Passing AccountsDb to SanitizeTransaction::try_crate to get the account_keys iterable.

Which commit is this?

f7dc4ad Usage:

            let tx = SanitizedTransaction::try_create(
                tx,
                MessageHash::Compute,
                Some(false),
                &svm.accounts,
            )
            .unwrap();

Coming back to this: what's the use case for passing all of svm.accounts in the reserved_account_keys arg?

Haha, this was pre 2.0 where that field did not exist. So it was my trying to communicate "pass the accounts db as an accounts loader". I have used this to make integration tests convenient to write (i just lazy load via RPC if network is enabled or from file if its not the first run/no network).

I think we can close this PR and I'll re-open individual PRs once 2.0 stabilizes. Then it will be easier to evaluate each proposed change's merit.

[kevinheavey]

Cool, the other thing I want to figure out is what's going on with precompiles. It sounds like there's some startup step we're missing?

[OliverNChalk]

I'm no expert on this (I try to avoid reading the upstream solana source code if I can). My intuition is:

• User creates a TX with precompile instruction.
• This declares the precompile as the program ID.
• Accounts DB loads the account, sees it is empty & thus returns an error due to CPI to non executable account.

I'll actually test this out when I open the new PRs, so for now the above is just my personal speculation