github.com/dim4egster/coreth@v0.10.2/plugin/evm/README.md (about)

     1  # EVM Package
     2  
     3  The EVM package implements the AvalancheGo VM interface.
     4  
     5  ## VM
     6  
     7  The VM creates the Ethereum backend and provides basic block building, parsing, and retrieval logic to the consensus engine.
     8  
     9  ## APIs
    10  
    11  The VM creates APIs for the node through the function `CreateHandlers()`. CreateHandlers returns the `Service` struct to serve Coreth specific APIs. Additionally, the Ethereum backend APIs are also returned at the `/rpc` extension.
    12  
    13  ## Block Handling
    14  
    15  The VM implements `buildBlock`, `parseBlock`, and `getBlock` and uses the `chain` package from AvalancheGo to construct a metered state, which uses these functions to implement an efficient caching layer and maintain the required invariants for blocks that get returned to the consensus engine.
    16  
    17  To do this, the VM uses a modified version of the Ethereum RLP block type [here](../../core/types/block.go) and uses the core package's BlockChain type [here](../../core/blockchain.go) to handle the insertion and storage of blocks into the chain.
    18  
    19  ## Block
    20  
    21  The Block type implements the AvalancheGo ChainVM Block interface. The key functions for this interface are `Verify()`, `Accept()`, `Reject()`, and `Status()`.
    22  
    23  The Block type wraps the stateless block type [here](../../core/types/block.go) and implements these functions to allow the consensus engine to verify blocks as valid, perform consensus, and mark them as accepted or rejected. See the documentation in AvalancheGo for the more detailed VM invariants that are maintained here.
    24  
    25  ## Atomic Transactions
    26  
    27  Atomic transactions utilize Shared Memory (documented [here](https://github.com/dim4egster/qmallgo/blob/master/chains/atomic/README.md)) to send assets to the P-Chain and X-Chain.
    28  
    29  Operations on shared memory cannot be reverted, so atomic transactions must separate their verification and processing into two stages: verifying the transaction as valid to be performed within its block and actually performing the operation. For example, once an export transaction is accepted, there is no way for the C-Chain to take that asset back and it can be imported immediately by the recipient chain.
    30  
    31  The C-Chain uses the account model for its own state, but atomic transactions must be compatible with the P-Chain and X-Chain, such that C-Chain atomic transactions must transform between the account model and the UTXO model.