Struct concordium_std::ExternHost

pub struct ExternHost<State> {
    pub state: State,
    pub state_builder: StateBuilder<ExternStateApi>,
}

Operations backed by host functions for the high-level interface.

Typically referred to via the alias Host.

Fields

state: State

state_builder: StateBuilder<ExternStateApi>

Trait Implementations

impl<S> HasHost<S> for ExternHost<S>

where S: Serial + DeserialWithState<ExternStateApi>,

type ReturnValueType = ExternCallResponse

The type of return values this host provides. This is the raw return value. The intention is that it will be deserialized by the consumer, via the Read implementation.

type StateApiType = ExternStateApi

The type of low-level state that is associated with the host. This provides access to low-level state operations.

fn invoke_transfer( &self, receiver: &AccountAddress, amount: Amount ) -> TransferResult

Perform a transfer to the given account if the contract has sufficient balance.

fn invoke_contract_raw( &mut self, to: &ContractAddress, parameter: Parameter<'_>, method: EntrypointName<'_>, amount: Amount ) -> CallContractResult<Self::ReturnValueType>

Invoke a given method of a contract with the amount and parameter provided. If invocation succeeds then the return value is a pair of a boolean which indicates whether the state of the contract has changed or not, and a possible return value. The return value is present if and only if a V1 contract was invoked.

fn invoke_contract_raw_read_only( &self, to: &ContractAddress, parameter: Parameter<'_>, method: EntrypointName<'_>, amount: Amount ) -> ReadOnlyCallContractResult<Self::ReturnValueType>

Invoke a given method of a contract with the amount and parameter provided. If invocation succeeds and the state of the contract instance is not modified then the return value is the return value of the contract that was invoked. The return value is present (i.e., not None) if and only if a V1 contract was invoked. If the invocation succeeds but the state of the contract is modified then this method will panic.

fn account_balance(&self, address: AccountAddress) -> QueryAccountBalanceResult

Get the current public balance of an account. Here public means unencrypted or unshielded. See AccountBalance for more. This query will fail if the provided address does not exist on chain.

fn contract_balance( &self, address: ContractAddress ) -> QueryContractBalanceResult

Get the current balance of a contract instance.

fn exchange_rates(&self) -> ExchangeRates

Get the current exchange rates used by the chain. That is a Euro per Energy rate and micro CCD per Euro rate.

fn upgrade(&mut self, module: ModuleReference) -> UpgradeResult

Upgrade the module for this instance to a given module. The new module must contain a smart contract with a matching name. Invocations of this instance after the point of a successful upgrade, will use the new smart contract module. The remaining code after a successful upgrade in the same invokation is executed as normal.

fn account_public_keys( &self, address: AccountAddress ) -> QueryAccountPublicKeysResult

Get the account’s public keys.

fn check_account_signature( &self, address: AccountAddress, signatures: &AccountSignatures, data: &[u8] ) -> CheckAccountSignatureResult

Verify the signature with account’s public keys.

fn state(&self) -> &S

Get an immutable reference to the contract state.

fn state_mut(&mut self) -> &mut S

Get a mutable reference to the contract state.

fn commit_state(&mut self)

Make sure the contract state is fully written out, so that any changes that were done in-memory up to the point in contract execution are reflected in the actual contract state maintained by the node.

fn self_balance(&self) -> Amount

Get the contract’s own current balance. Upon entry to the entrypoint the balance that is returned is the sum of balance of the contract at the time of the invocation and the amount that is being transferred to the contract.

fn state_builder(&mut self) -> &mut StateBuilder<Self::StateApiType>

Get the state_builder for the contract state.

fn state_and_builder( &mut self ) -> (&mut S, &mut StateBuilder<Self::StateApiType>)

Get a mutable reference to both the state and the builder. This is required due to limitations of the Rust type system, since otherwise it is not possible to get the reference to the state and the state builder at the same time. Once some incarnation of “view types” is stable this will likely be possible to remove, and the types of state_builder and state_mut can be refined.

fn invoke_contract<P: Serial>( &mut self, to: &ContractAddress, parameter: &P, method: EntrypointName<'_>, amount: Amount ) -> CallContractResult<Self::ReturnValueType>

Like invoke_contract_raw, except that the parameter is automatically serialized. If the parameter already implements AsRef<[u8]> or can be equivalently cheaply converted to a byte array, then invoke_contract_raw should be used, since it avoids intermediate allocations.

fn invoke_contract_read_only<P: Serial>( &self, to: &ContractAddress, parameter: &P, method: EntrypointName<'_>, amount: Amount ) -> ReadOnlyCallContractResult<Self::ReturnValueType>

Like invoke_contract_raw_read_only, except that the parameter is automatically serialized. If the parameter already implements AsRef<[u8]> or can be equivalently cheaply converted to a byte array, then invoke_contract_raw should be used, since it avoids intermediate allocations.