solana_instruction/
account_meta.rs

1use solana_pubkey::Pubkey;
2
3/// Describes a single account read or written by a program during instruction
4/// execution.
5///
6/// When constructing an [`Instruction`], a list of all accounts that may be
7/// read or written during the execution of that instruction must be supplied.
8/// Any account that may be mutated by the program during execution, either its
9/// data or metadata such as held lamports, must be writable.
10///
11/// Note that because the Solana runtime schedules parallel transaction
12/// execution around which accounts are writable, care should be taken that only
13/// accounts which actually may be mutated are specified as writable. As the
14/// default [`AccountMeta::new`] constructor creates writable accounts, this is
15/// a minor hazard: use [`AccountMeta::new_readonly`] to specify that an account
16/// is not writable.
17///
18/// [`Instruction`]: crate::Instruction
19#[repr(C)]
20#[cfg_attr(
21    feature = "serde",
22    derive(serde_derive::Serialize, serde_derive::Deserialize)
23)]
24#[derive(Debug, Default, PartialEq, Eq, Clone)]
25pub struct AccountMeta {
26    /// An account's public key.
27    pub pubkey: Pubkey,
28    /// True if an `Instruction` requires a `Transaction` signature matching `pubkey`.
29    pub is_signer: bool,
30    /// True if the account data or metadata may be mutated during program execution.
31    pub is_writable: bool,
32}
33
34impl AccountMeta {
35    /// Construct metadata for a writable account.
36    ///
37    /// # Examples
38    ///
39    /// ```
40    /// # use solana_pubkey::Pubkey;
41    /// # use solana_instruction::{AccountMeta, Instruction};
42    /// # use borsh::{BorshSerialize, BorshDeserialize};
43    /// #
44    /// # #[derive(BorshSerialize, BorshDeserialize)]
45    /// # #[borsh(crate = "borsh")]
46    /// # pub struct MyInstruction;
47    /// #
48    /// # let instruction = MyInstruction;
49    /// # let from = Pubkey::new_unique();
50    /// # let to = Pubkey::new_unique();
51    /// # let program_id = Pubkey::new_unique();
52    /// let instr = Instruction::new_with_borsh(
53    ///     program_id,
54    ///     &instruction,
55    ///     vec![
56    ///         AccountMeta::new(from, true),
57    ///         AccountMeta::new(to, false),
58    ///     ],
59    /// );
60    /// ```
61    pub fn new(pubkey: Pubkey, is_signer: bool) -> Self {
62        Self {
63            pubkey,
64            is_signer,
65            is_writable: true,
66        }
67    }
68
69    /// Construct metadata for a read-only account.
70    ///
71    /// # Examples
72    ///
73    /// ```
74    /// # use solana_pubkey::Pubkey;
75    /// # use solana_instruction::{AccountMeta, Instruction};
76    /// # use borsh::{BorshSerialize, BorshDeserialize};
77    /// #
78    /// # #[derive(BorshSerialize, BorshDeserialize)]
79    /// # #[borsh(crate = "borsh")]
80    /// # pub struct MyInstruction;
81    /// #
82    /// # let instruction = MyInstruction;
83    /// # let from = Pubkey::new_unique();
84    /// # let to = Pubkey::new_unique();
85    /// # let from_account_storage = Pubkey::new_unique();
86    /// # let program_id = Pubkey::new_unique();
87    /// let instr = Instruction::new_with_borsh(
88    ///     program_id,
89    ///     &instruction,
90    ///     vec![
91    ///         AccountMeta::new(from, true),
92    ///         AccountMeta::new(to, false),
93    ///         AccountMeta::new_readonly(from_account_storage, false),
94    ///     ],
95    /// );
96    /// ```
97    pub fn new_readonly(pubkey: Pubkey, is_signer: bool) -> Self {
98        Self {
99            pubkey,
100            is_signer,
101            is_writable: false,
102        }
103    }
104}
solana_instruction/account_meta.rs

solana_instruction/
account_meta.rs
