solana/sdk/src/commitment_config.rs

#[derive(Serialize, Deserialize, Default, Clone, Copy, Debug, PartialEq)]
#[serde(rename_all = "camelCase")]
pub struct CommitmentConfig {
    pub commitment: CommitmentLevel,
}

impl CommitmentConfig {
    pub fn recent() -> Self {
        Self {
            commitment: CommitmentLevel::Recent,
        }
    }

    pub fn max() -> Self {
        Self {
            commitment: CommitmentLevel::Max,
        }
    }

    pub fn root() -> Self {
        Self {
            commitment: CommitmentLevel::Root,
        }
    }

    pub fn single() -> Self {
        Self {
            commitment: CommitmentLevel::Single,
        }
    }

    pub fn single_gossip() -> Self {
        Self {
            commitment: CommitmentLevel::SingleGossip,
        }
    }

    pub fn ok(self) -> Option<Self> {
        if self == Self::default() {
            None
        } else {
            Some(self)
        }
    }
}

#[derive(Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq, Hash)]
#[serde(rename_all = "camelCase")]
/// An attribute of a slot. It describes how finalized a block is at some point in time. For example, a slot
/// is said to be at the max level immediately after the cluster recognizes the block at that slot as
/// finalized. When querying the ledger state, use lower levels of commitment to report progress and higher
/// levels to ensure state changes will not be rolled back.
pub enum CommitmentLevel {
    /// The highest slot having reached max vote lockout, as recognized by a supermajority of the cluster.
    Max,

    /// The highest slot of the heaviest fork. Ledger state at this slot is not derived from a finalized
    /// block, but if multiple forks are present, is from the fork the validator believes is most likely
    /// to finalize.
    Recent,

    /// The highest slot having reached max vote lockout.
    Root,

    /// (DEPRECATED) The highest slot having reached 1 confirmation by supermajority of the cluster.
    Single,

    /// The highest slot that has been voted on by supermajority of the cluster
    /// This differs from `single` in that:
    /// 1) It incorporates votes from gossip and replay.
    /// 2) It does not count votes on descendants of a block, only direct votes on that block.
    /// 3) This confirmation level also upholds "optimistic confirmation" guarantees in
    /// release 1.3 and onwards.
    SingleGossip,
}

impl Default for CommitmentLevel {
    fn default() -> Self {
        Self::Max
    }
}