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#[cfg_attr(feature = "wincode", derive(wincode::SchemaRead, wincode::SchemaWrite))]
25#[derive(Debug, Default, PartialEq, Eq, Clone)]
26pub struct AccountMeta {
27    /// An account's public key.
28    pub pubkey: Pubkey,
29    /// True if an `Instruction` requires a `Transaction` signature matching `pubkey`.
30    pub is_signer: bool,
31    /// True if the account data or metadata may be mutated during program execution.
32    pub is_writable: bool,
33}
34
35impl AccountMeta {
36    /// Construct metadata for a writable account.
37    ///
38    /// # Examples
39    ///
40    /// ```
41    /// # use solana_pubkey::Pubkey;
42    /// # use solana_instruction::{AccountMeta, Instruction};
43    /// # use borsh::{BorshSerialize, BorshDeserialize};
44    /// #
45    /// # #[derive(BorshSerialize, BorshDeserialize)]
46    /// # #[borsh(crate = "borsh")]
47    /// # pub struct MyInstruction;
48    /// #
49    /// # let instruction = MyInstruction;
50    /// # let from = Pubkey::new_unique();
51    /// # let to = Pubkey::new_unique();
52    /// # let program_id = Pubkey::new_unique();
53    /// let instr = Instruction::new_with_borsh(
54    ///     program_id,
55    ///     &instruction,
56    ///     vec![
57    ///         AccountMeta::new(from, true),
58    ///         AccountMeta::new(to, false),
59    ///     ],
60    /// );
61    /// ```
62    pub fn new(pubkey: Pubkey, is_signer: bool) -> Self {
63        Self {
64            pubkey,
65            is_signer,
66            is_writable: true,
67        }
68    }
69
70    /// Construct metadata for a read-only account.
71    ///
72    /// # Examples
73    ///
74    /// ```
75    /// # use solana_pubkey::Pubkey;
76    /// # use solana_instruction::{AccountMeta, Instruction};
77    /// # use borsh::{BorshSerialize, BorshDeserialize};
78    /// #
79    /// # #[derive(BorshSerialize, BorshDeserialize)]
80    /// # #[borsh(crate = "borsh")]
81    /// # pub struct MyInstruction;
82    /// #
83    /// # let instruction = MyInstruction;
84    /// # let from = Pubkey::new_unique();
85    /// # let to = Pubkey::new_unique();
86    /// # let from_account_storage = Pubkey::new_unique();
87    /// # let program_id = Pubkey::new_unique();
88    /// let instr = Instruction::new_with_borsh(
89    ///     program_id,
90    ///     &instruction,
91    ///     vec![
92    ///         AccountMeta::new(from, true),
93    ///         AccountMeta::new(to, false),
94    ///         AccountMeta::new_readonly(from_account_storage, false),
95    ///     ],
96    /// );
97    /// ```
98    pub fn new_readonly(pubkey: Pubkey, is_signer: bool) -> Self {
99        Self {
100            pubkey,
101            is_signer,
102            is_writable: false,
103        }
104    }
105}
solana_instruction/account_meta.rs

solana_instruction/
account_meta.rs
