forked from cerc-io/laconicd-deprecated
70 lines
2.3 KiB
Markdown
70 lines
2.3 KiB
Markdown
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order: 1
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# Encoding
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Learn about the encoding formats used on Ethermint. {synopsis}
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## Pre-requisite Readings
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- [Cosmos SDK Encoding](https://docs.cosmos.network/master/core/encoding.html) {prereq}
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- [Ethereum RLP](https://eth.wiki/en/fundamentals/rlp) {prereq}
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## Encoding Formats
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### Protocol Buffers
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The Cosmos [Stargate](https://stargate.cosmos.network/) release introduces
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[protobuf](https://developers.google.com/protocol-buffers) as the main encoding format for both
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client and state serialization. All the EVM module types that are used for state and clients
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(transaction messages, genesis, query services, etc) will be implemented as protocol buffer messages.
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### Amino
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The Cosmos SDK also supports the legacy Amino encoding format for backwards compatibility with
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previous versions, specially for client encoding and signing with Ledger devices. Ethermint does not
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support Amino in the EVM module, but it is supported for all other Cosmos SDK modules that enable it.
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### RLP
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Recursive Length Prefix ([RLP](https://eth.wiki/en/fundamentals/rlp)), is an encoding/decoding algorithm that serializes a message and
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allows for quick reconstruction of encoded data. Ethermint uses RLP to encode/decode Ethereum
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messages for JSON-RPC handling to conform messages to the proper Ethereum format. This allows
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messages to be encoded and decoded in the exact format as Ethereum's.
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The `x/evm` transactions (`MsgEthereumTx`) encoding is performed by casting the message to a go-ethereum's `Transaction` and then marshaling the transaction data using RLP:
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```go
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// TxEncoder overwrites sdk.TxEncoder to support MsgEthereumTx
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func (g txConfig) TxEncoder() sdk.TxEncoder {
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return func(tx sdk.Tx) ([]byte, error) {
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msg, ok := tx.(*evmtypes.MsgEthereumTx)
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if ok {
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return msg.AsTransaction().MarshalBinary()
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}
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return g.TxConfig.TxEncoder()(tx)
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}
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}
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// TxDecoder overwrites sdk.TxDecoder to support MsgEthereumTx
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func (g txConfig) TxDecoder() sdk.TxDecoder {
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return func(txBytes []byte) (sdk.Tx, error) {
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tx := ðtypes.Transaction{}
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err := tx.UnmarshalBinary(txBytes)
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if err == nil {
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msg := &evmtypes.MsgEthereumTx{}
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msg.FromEthereumTx(tx)
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return msg, nil
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}
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return g.TxConfig.TxDecoder()(txBytes)
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}
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}
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```
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## Next {hide}
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Learn how [pending state](./pending_state.md) is handled on Ethermint. {hide}
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