ICallSolana Interface

Introduction

To use the Composability feature of Solana, let us learn about the interface and the functions included in the interface that will be used to interact with the Solana programs via the precompile 0xFF00000000000000000000000000000000000006.

The interface contract ICallSolana.sol can be found in this Github Repository.

Struct Variables

1. AccountMeta : For each account needed by an instruction, the following details must be provided -
   • account: The account's on-chain address in bytes32.
   • is_writable: Indicates if the account's data will be modified in boolean.
   • is_signer: Indicates if the account needs to sign the transaction in boolean.
2. Instruction : Instruction struct variable includes the following -
   • program_id: The address of the program that contains the execution logic for the invoked instruction.
   • accounts: Contains the AccountMeta for each account required by an instruction.
   • instruction_data: The instruction data as a buffer of bytes.

Functions

getNeonAddress(address) -> bytes32
This function returns the Solana address in bytes32 format for a Neon EVM address.

getResourceAddress(bytes32 salt) -> bytes32
This function returns the Solana address in bytes32 format of a resource represented by the salt for contracts.

createResource(bytes32 salt, uint64 space, uint64 lamports, bytes32 owner) -> bytes32
This function creates a resource with the specified salt and returns the Solana address of the created resource in bytes32 format.

getSolanaPDA(bytes32 program_id, bytes memory seeds) -> bytes32
This function returns the Solana PDA in bytes32 format generated from the specified program_id and seeds.

getExtAuthority(bytes32 salt) -> bytes32
This function returns the Solana address in bytes32 format of the external authority represented by the salt.

getPayer() -> bytes32
This function returns the Solana address of the payer account in bytes32 format. Payer account is required if an instruction needs an account to fund newly created accounts.

execute(uint64 lamports, Instruction memory instruction) -> bytes

This function executes the instruction with a call to the Solana program and returns the data of the executed instruction in bytes format. The lamports parameter specifies the amount of lamports that will be required to create new accounts during execution. These lamports are transferred to the payer account. The instruction parameter is the struct variable with the values of program_id, accounts and instruction_data.

executeWithSeed(uint64 lamports, bytes32 salt, Instruction memory instruction) -> bytes

This function executes the instruction with a call to the Solana program and returns the data of the executed instruction in bytes format. The lamports parameter specifies the amount of lamports that will be required to create new accounts during execution. These lamports are transferred to the payer account. The salt parameter is to generate an address of external authority. The instruction parameter is the struct variable with the values of program_id, accounts and instruction_data.

execute(uint64 lamports, bytes memory instruction) -> bytes

This function executes the instruction with a call to the Solana program and returns the data of the executed instruction in bytes format. The lamports parameter specifies the amount of lamports that will be required to create new accounts during execution. These lamports are transferred to the payer account. The instruction is the bincode serialized instruction which needs to be executed. This method uses PDA of the sender to authorize the operation.

executeWithSeed(uint64 lamports, bytes32 salt, bytes memory instruction) -> bytes

This function executes the instruction with a call to the Solana program and returns the data of the executed instruction in bytes format. The lamports parameter specifies the amount of lamports that will be required to create new accounts during execution. These lamports are transferred to the payer account. The salt parameter is to generate an address of external authority. The instruction is the bincode serialized instruction which needs to be executed. This method uses external authority to authorize the operation.

getReturnData() -> bytes32, bytes
This function returns the program_id and returned data of the last executed instruction. Note: This method should be called after execute / executeWithSeed methods.