Struct MemoryBank

pub struct MemoryBank<T> { /* private fields */ }

A structure that reuses old data of type T to reduce the number of new allocations (useful for heap allocations).

Implementations

impl<T: Default> MemoryBank<T>

pub fn take_loan(&self) -> Loan<T>

Loans the user some memory to use. Will reuse an element from old memory if there are any, otherwise it will allocate on the heap.

If the loaned memory was previously used, it will be in the exact same state it was in right before the previous Loan got dropped.

impl<T> MemoryBank<T>

pub fn new() -> Self

Creates a new, empty MemoryBank<T>. The first loan is guaranteed to be a heap allocation.

pub fn deposit(&self, value: T) -> Loan<T>

Gives the bank ownership of value and returns it in a Loan.

Examples

use membank::MemoryBank;

let bank = MemoryBank::new();

let v = vec![2.1, 4.3, 1.0, 0.98];
let v_clone = v.clone();

let loan = bank.deposit(v);

assert_eq!(*loan, v_clone);

pub fn take_old_loan(&self) -> Option<Loan<T>>

Only take a loan if it’s from previously used memory, if there is no previously allocated memory, returns None.

Example

use membank::MemoryBank;

let bank: MemoryBank<Vec<i32>> = MemoryBank::new();
assert!(bank.take_old_loan().is_none());

let loan1 = bank.take_loan();

assert!(bank.take_old_loan().is_none());

drop(loan1);
assert!(bank.take_old_loan().is_some());

pub fn take_old_loan_timeout(&self, timeout: Duration) -> Option<Loan<T>>

Only take previously used memory. Will return None if it waits past timeout.

Example

use membank::MemoryBank;
use std::time::Duration;

let bank: MemoryBank<Vec<f64>> = MemoryBank::new();
assert!(bank.take_old_loan_timeout(Duration::from_millis(100)).is_none());

let mut loan1 = bank.take_loan();
loan1.push(3.21);
drop(loan1);

let loan2 = bank.take_old_loan_timeout(Duration::from_millis(100)).unwrap();
assert_eq!(*loan2, vec![3.21]);

Trait Implementations

impl<T: Clone> Clone for MemoryBank<T>

fn clone(&self) -> MemoryBank<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Default for MemoryBank<T>

fn default() -> Self

Returns the “default value” for a type.