I'd like to build an algorithm that analyzes value creation, transfer and destruction on a blockchain (such as new ETH minted, ETH gas burned, ERC-20 tokens transferred, etc.).
Assuming I have a database of all Solidity function signatures and event signatures (such as https://4byte.directory), is it possible to identify any action on a blockchain that modifies value?
A simple use case is event signature
0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef (which is an ERC-20 token transfer). I could write code that analyzes that log event and see who sent however many of which tokens to whomever else.
But that's a simple use case since I know ahead of time that signature
0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef causes the movement of value between 2 addresses. For the hundreds of thousands of function and event signatures on a blockchain, I need to determine whether they modify value...and how.
While trying to uncover more actions which modify value, I'm curious...
- Are all value-modifying events required to emit log events, or is that up to the Solidity contract developers? If not, can this be discovered in the contract's functions?
- Are there a set of opcodes and/or data types which can reliably be used to see value being created, destroyed or transferred?
- Is there a simpler way (without digging into the opcodes and such) where the outcome of any blockchain transaction shows ALL deltas of what coin and token values were changed as a result of executing the contract function (i.e. before state and after state)?
I figure I can get some of this information (like ETH minted, gas used, ETH native coin transferred, etc.) from the
eth_getBlockByNumber RPC method (with full transaction details). But I know that doesn't cover token activity (which I hope to get from events/logs) and possibly other value-modifying actions from custom contracts (other than ERC-20, ERC-721, etc).
I appreciate any guidance you can offer.