Struct Env

pub struct Env {

    pub blockchain: BlockchainOverlayPtr,
    pub db_handles: RefCell<Vec<DbHandle>>,
    pub contract_id: ContractId,
    pub contract_bincode: Vec<u8>,
    pub contract_section: ContractSection,
    pub contract_return_data: Cell<Option<Vec<u8>>>,
    pub logs: RefCell<Vec<String>>,
    pub memory: Option<Memory>,
    pub objects: RefCell<Vec<Vec<u8>>>,
    pub verifying_block_height: u32,
    pub block_target: u32,
    pub tx_hash: TransactionHash,
    pub call_idx: u8,
    pub instance: Option<Arc<Instance>>,
}

The WASM VM runtime environment instantiated for every smart contract that runs.

Fields

blockchain: BlockchainOverlayPtr

Blockchain overlay access

db_handles: RefCell<Vec<DbHandle>>

Overlay tree handles used with db_*

contract_id: ContractId

The contract ID being executed

contract_bincode: Vec<u8>

The compiled wasm bincode being executed,

contract_section: ContractSection

The contract section being executed

contract_return_data: Cell<Option<Vec<u8>>>

State update produced by a smart contract function call

logs: RefCell<Vec<String>>

Logs produced by the contract

memory: Option<Memory>

Direct memory access to the VM

objects: RefCell<Vec<Vec<u8>>>

Object store for transferring memory from the host to VM

verifying_block_height: u32

Block height number runtime verifies against. For unconfirmed txs, this will be the current max height in the chain.

block_target: u32

Currently configured block time target, in seconds

tx_hash: TransactionHash

The hash for this transaction the runtime is being run against.

call_idx: u8

The index for this call in the transaction

instance: Option<Arc<Instance>>

Parent Instance

Implementations

impl Env

pub fn memory_view<'a>(&'a self, store: &'a impl AsStoreRef) -> MemoryView<'a>

Provide safe access to the memory (it must be initialized before it can be used)

// ctx: FunctionEnvMut<Env>
let env = ctx.data();
let memory = env.memory_view(&ctx);

pub fn memory(&self) -> &Memory

Get memory, that needs to have been set fist

pub fn subtract_gas(&mut self, ctx: &mut impl AsStoreMut, gas: u64)

Subtract given gas cost from remaining gas in the current runtime