Support PendingLogsSubscription in eth_subscribe

[deromik]

Describe the bug

i use the following request to subscribe

{ "id": 1, "jsonrpc": "2.0", "method": "eth_subscribe", "params": [ "logs", { "fromBlock": "pending", "toBlock": "pending", "topics": [], "address": [] } ] }

and it does not return logs during ongoing pending block, this subscription will send the logs back at once only when the block is mined and the data is from latest which is not exactly what i have subscribed on.

#3404 #3320 related

tried on alpha 11 and latest develop

Steps to reproduce

no specific steps to reproduce

Node logs

No response

Platform(s)

Linux (x86)

What version/commit are you on?

ae6f1e3

What database version are you on?

Current database version: 1
Local database version: 1

What type of node are you running?

Full via --full flag

What prune config do you use, if any?

No response

If you've built Reth from source, provide the full command you used

dockerfile from repo built on linux machine

Code of Conduct

• I agree to follow the Code of Conduct

[mattsse]

which pending block? locally built block or from CL?

[mattsse]

ref https://github.com/ethereum/go-ethereum/blob/0004c6b229b787281760b14fb9460ffd9c2496f1/eth/filters/filter_system.go#L315-L318

[deromik]

which pending block? locally built block or from CL?

from CL if i understood you correctly
im running prysmaticlabs/prysm-beacon-chain:v4.0.8

[mattsse]

makes sense, need to figure out how to do it

[mattsse]

@deromik do you know how this behaves exactly?

does this resend logs for the same block.number if there's an alternative pending block, or only one update per block.number?

[deromik]

@deromik do you know how this behaves exactly?

does this resend logs for the same block.number if there's an alternative pending block, or only one update per block.number?

one update with logs from latest block (at this moment it already became latest) in the beginning of the block

something like this

block #1
logs: 0 ->
...
subscribe <-
...
block #1
logs: 0 ->
...
-> new block
block #2
logs: 20 (all logs from block #1) ->
...
block #2
logs: 0 ->
...
block #2
logs: 0 ->

[mattsse]

one update with logs from latest block (at this moment it already became latest) in the beginning of the block

sorry I don't understand.

I'm also having trouble understanding the example.

the pending block might change throughout the 12s, so unclear how this is reflected in an active subscription that only targets the pending tag.

For example, let's say there's pending Block A that includes Tx_1 that emits a matching Log which we then send as a new subscription event.
what happens if there's an alternative Block B that includes the same Tx_1 and Log?

[allnil]

Take it