Struct core::storage::StorageKey

pub struct StorageKey<T> {
    /// The assigned location in storage.
    slot: b256,
    /// The assigned offset based on the data structure `T`.
    offset: u64,
    /// A unique identifier.
    field_id: b256,
}

Expand description

Describes a location in storage.

Additional Information

The location in storage is specified by the b256 key of a particular storage slot and an
offset, in words, from the start of the storage slot at key. The parameter T is the type of
the data to be read from or written to at offset.
field_id is a unique identifier for the storage field being referred to, it is different even
for multiple zero sized fields that might live at the same location but
represent different storage constructs.

Fields

slot: b256

The assigned location in storage.

offset: u64

The assigned offset based on the data structure T.

field_id: b256

A unique identifier.

Trait Implementations

impl StorageKey for StorageKey<T>

pub fn new(slot: b256, offset: u64, field_id: b256) -> Self

Create a new StorageKey.

Arguments

slot: [b256] - The assigned location in storage for the new StorageKey.
offset: [u64] - The assigned offset based on the data structure T for the new StorageKey.
field_id: [b256] - A unique identifier for the new StorageKey.

Returns

[StorageKey] - The newly created StorageKey.

Examples

use std::hash::sha256;

fn foo() {
    let my_key = StorageKey::<u64>::new(b256::zero(), 0, sha256(b256::zero()));
    assert(my_key.slot() == b256::zero());
}

pub fn slot(self) -> b256

Returns the storage slot address.

Returns

[b256] - The address in storage that this storage slot points to.

Examples

use std::hash::sha256;

fn foo() {
    let my_key = StorageKey::<u64>::new(b256::zero(), 0, sha256(b256::zero()));
    assert(my_key.slot() == b256::zero());
}

pub fn offset(self) -> u64

Returns the offset on the storage slot.

Returns

[u64] - The offset in storage that this storage slot points to.

Examples

use std::hash::sha256;

fn foo() {
    let my_key = StorageKey::<u64>::new(b256::zero(), 0, sha256(b256::zero()));
    assert(my_key.offset() == 0);
}

pub fn field_id(self) -> b256

Returns the storage slot field id.

Additional Information

The field id is a unique identifier for the storage field being referred to, it is different even
for multiple zero sized fields that might live at the same location but
represent different storage constructs.

Returns

[b256] - The field id for this storage slot.

Examples

use std::hash::sha256;

fn foo() {
    let my_key = StorageKey::<u64>::new(b256::zero(), 0, sha256(b256::zero()));
    assert(my_key.field_id() == sha256(b256::zero()));
}