Struct AccountMeta

#[repr(C)]
pub struct AccountMeta {
    pub pubkey: Pubkey,
    pub is_signer: bool,
    pub is_writable: bool,
}

Describes a single account read or written by a program during instruction execution.

When constructing an Instruction, a list of all accounts that may be read or written during the execution of that instruction must be supplied. Any account that may be mutated by the program during execution, either its data or metadata such as held lamports, must be writable.

Note that because the Solana runtime schedules parallel transaction execution around which accounts are writable, care should be taken that only accounts which actually may be mutated are specified as writable. As the default AccountMeta::new constructor creates writable accounts, this is a minor hazard: use AccountMeta::new_readonly to specify that an account is not writable.

Fields

pubkey: Pubkey

An account’s public key.

is_signer: bool

True if an Instruction requires a Transaction signature matching pubkey.

is_writable: bool

True if the account data or metadata may be mutated during program execution.

Implementations

impl AccountMeta

pub fn new(pubkey: Pubkey, is_signer: bool) -> AccountMeta

Construct metadata for a writable account.

Examples

let instr = Instruction::new_with_borsh(
    program_id,
    &instruction,
    vec![
        AccountMeta::new(from, true),
        AccountMeta::new(to, false),
    ],
);

pub fn new_readonly(pubkey: Pubkey, is_signer: bool) -> AccountMeta

Construct metadata for a read-only account.

Examples

let instr = Instruction::new_with_borsh(
    program_id,
    &instruction,
    vec![
        AccountMeta::new(from, true),
        AccountMeta::new(to, false),
        AccountMeta::new_readonly(from_account_storage, false),
    ],
);

Trait Implementations

impl Clone for AccountMeta

fn clone(&self) -> AccountMeta

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AccountMeta

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for AccountMeta

fn default() -> AccountMeta

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for AccountMeta

fn deserialize<__D>( __deserializer: __D, ) -> Result<AccountMeta, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for AccountMeta

fn eq(&self, other: &AccountMeta) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for AccountMeta

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl ToAccountMetas for AccountMeta

fn to_account_metas(&self, _is_signer: Option<bool>) -> Vec<AccountMeta>

is_signer is given as an optional override for the signer meta field. This covers the edge case when a program-derived-address needs to relay a transaction from a client to another program but sign the transaction before the relay. The client cannot mark the field as a signer, and so we have to override the is_signer meta field given by the client.

impl Eq for AccountMeta

impl StructuralPartialEq for AccountMeta