Skip to main content

Module 0x2::tx_context

Struct TxContext​

Information about the transaction currently being executed. This cannot be constructed by a transaction--it is a privileged object created by the VM and passed in to the entrypoint of the transaction as &mut TxContext.

struct TxContext has drop
Fields
sender: address
The address of the user that signed the current transaction
tx_hash: vector<u8>
Hash of the current transaction
epoch: u64
The current epoch number
epoch_timestamp_ms: u64
Timestamp that the epoch started at
ids_created: u64
Counter recording the number of fresh id's created while executing this transaction. Always 0 at the start of a transaction

Function sender​

Return the address of the user that signed the current transaction

public fun sender(self: &tx_context::TxContext): address
Implementation
public fun sender(self: &TxContext): address {
    self.sender
}

Function digest​

Return the transaction digest (hash of transaction inputs). Please do not use as a source of randomness.

public fun digest(self: &tx_context::TxContext): &vector<u8>
Implementation
public fun digest(self: &TxContext): &vector<u8> {
    &self.tx_hash
}

Function epoch​

Return the current epoch

public fun epoch(self: &tx_context::TxContext): u64
Implementation
public fun epoch(self: &TxContext): u64 {
    self.epoch
}

Function epoch_timestamp_ms​

Return the epoch start time as a unix timestamp in milliseconds.

public fun epoch_timestamp_ms(self: &tx_context::TxContext): u64
Implementation
public fun epoch_timestamp_ms(self: &TxContext): u64 {
   self.epoch_timestamp_ms
}

Function fresh_object_address​

Create an address that has not been used. As it is an object address, it will never occur as the address for a user. In other words, the generated address is a globally unique object ID.

public fun fresh_object_address(ctx: &mut tx_context::TxContext): address
Implementation
public fun fresh_object_address(ctx: &mut TxContext): address {
    let ids_created = ctx.ids_created;
    let id = derive_id(*&ctx.tx_hash, ids_created);
    ctx.ids_created = ids_created + 1;
    id
}

Function ids_created​

Return the number of id's created by the current transaction. Hidden for now, but may expose later

fun ids_created(self: &tx_context::TxContext): u64
Implementation
fun ids_created(self: &TxContext): u64 {
    self.ids_created
}

Function derive_id​

Native function for deriving an ID via hash(tx_hash || ids_created)

fun derive_id(tx_hash: vector<u8>, ids_created: u64): address
Implementation
native fun derive_id(tx_hash: vector<u8>, ids_created: u64): address;