Add getLogs by blockHash

[charles-cooper]

What was wrong?

getLogs did not accept the blockHash parameter.

Related to Issue #1236

How was it fixed?

Added blockHash as a parameter in contract.getLogs. Marked WIP because I was not sure if my approach was in line with the style of the rest of the code base, but I did not want to touch construct_event_filter_params because that can also be used to create a filter (for which blockHash is not a valid parameter). Feedback/guidance on my approach would be appreciated!

Cute Animal Picture

[kclowes]

This style/approach looks to be in line with the rest of the codebase, @charles-cooper. Thanks for taking it on!

[charles-cooper]

Great! The next step I wanted to take was to change the defaults for fromBlock and toBlock in contract.getLogs to be None. That way we can a) enforce that only fromBlock/toBlock or blockHash is set (following the semantics of eth_getLogs) and b) 'pass through' the default semantics of eth_getLogs. Would that be OK? (paging @miohtama for input)

fromBlock: QUANTITY|TAG - (optional, default: "latest") Integer block number, or "latest" for the last mined block or "pending", "earliest" for not yet mined transactions.
toBlock: QUANTITY|TAG - (optional, default: "latest") Integer block number, or "latest" for the last mined block or "pending", "earliest" for not yet mined transactions.
...
blockhash: DATA, 32 Bytes - (optional) With the addition of EIP-234 (Geth >= v1.8.13 or Parity >= v2.1.0), blockHash is a new filter option which restricts the logs returned to the single block with the 32-byte hash blockHash. Using blockHash is equivalent to fromBlock = toBlock = the block number with hash blockHash. If blockHash is present in the filter criteria, then neither fromBlock nor toBlock are allowed.

[kclowes]

That makes sense to me. @pipermerriam do you see issues with that approach?

[pipermerriam]

👍 apart from the test and lint failures.

[kclowes]

I didn't forget about this @charles-cooper. I should be able to get to it early next week! Thanks!

[kclowes]

Looks good to me @charles-cooper! Thanks!