rust/syn/bigint.rs

Source file repositories/reference/linux-study-clean/rust/syn/bigint.rs

File Facts

System
Linux kernel
Corpus path
rust/syn/bigint.rs
Extension
.rs
Size
1657 bytes
Lines
69
Domain
Rust Kernel Layer
Bucket
Rust API Membrane
Inferred role
Rust Kernel Layer: implementation source
Status
source implementation candidate

Why This File Exists

Rust-side wrappers and abstractions around kernel C APIs, ownership contracts, allocation, synchronization, and module integration.

Dependency Surface

Detected Declarations

Annotated Snippet

fn reserve_two_digits(&mut self) {
        let len = self.digits.len();
        let desired =
            len + !self.digits.ends_with(&[0, 0]) as usize + !self.digits.ends_with(&[0]) as usize;
        self.digits.resize(desired, 0);
    }
}

impl AddAssign<u8> for BigInt {
    // Assumes increment <16.
    fn add_assign(&mut self, mut increment: u8) {
        self.reserve_two_digits();

        let mut i = 0;
        while increment > 0 {
            let sum = self.digits[i] + increment;
            self.digits[i] = sum % 10;
            increment = sum / 10;
            i += 1;
        }
    }
}

impl MulAssign<u8> for BigInt {
    // Assumes base <=16.
    fn mul_assign(&mut self, base: u8) {
        self.reserve_two_digits();

        let mut carry = 0;
        for digit in &mut self.digits {
            let prod = *digit * base + carry;
            *digit = prod % 10;
            carry = prod / 10;
        }
    }
}

Annotation

Implementation Notes