EtherscanProvider getLogs optimization (blockhash)

[timaiv]

EtherscanProvider has specific logic for downloading blockHash for all logs.
In my case i downloaded 1000 logs (etherscan limit) with different blocks, after which ethers.js executed 1000 requests

this.getBlock(log.blockNumber);

Also etherscan getLogs returns block timestamp in response.
So.

1. I think is good to have option disable loading blockHashes. (Actually i always want from logs only log data, block number, address)
2. Looks like we can use multicall, and just call

   blockhash(uint blockNumber) returns (bytes32)
   

   with 1 request to node (not tested and i dont know etherscan eth_call gas limit).
3. I think we can pass log.timestamp further, its useful in indexers.
4. Also we cant use etherscan without any apiKey (even without default community key, that always returns 429, etherscan has 1 request/5 sec for missed api key)

I did it all (without multicall) in my EtherscanProviderEx, i think it will be also useful in ethers.js.

[ricmoo]

Keep in mind blockhash in EVM only has access to the last 1023 blocks.

I keep meaning to contact Etherscan and see if I can get them to include the blockhash in their response.

I’ll move this to on-deck to remind me.

I could also provide an alternate _getLogs that doesn’t do the necessary fetch to keep the API stable.