Struct InstanceCopyOnWrite 

pub struct InstanceCopyOnWrite<ITEM: Send + Debug> { /* private fields */ }

A base instance which is used to perform CoW and non-CoW operations on the inner value.

Borrow:

let val = 
    InstanceCopyOnWrite::new(TestStruct::new(1, 2));
 
let test_borrow = val.borrow().unwrap();

CoW copy-on-write

let val = 
    InstanceCopyOnWrite::new(TestStruct::new(1, 2));
 
let test_borrow = val.borrow().unwrap();

let val = 
    InstanceCopyOnWrite::new(TestStruct::new(1, 2));
 
let mut transaction = val.start_copying().unwrap();
 
transaction.start = 5;
transaction.stop = 6;
 
transaction.completed(false).unwrap();

Exclusive lock (non-CoW)

let val = 
    InstanceCopyOnWrite::new(TestStruct::new(1, 2));
 
let lock = val.lock();
 
drop(lock);

Implementations

impl<ITEM: Send + Debug> InstanceCopyOnWrite<ITEM>

pub fn new(item: ITEM) -> Self

Cretaes new instance with the pre-initialized item.

pub fn borrow(&self) -> Result<CowReadGuard<'_, ITEM>, CowGuardError>

Borrows the ITEM for read-only operations. The instance will remain unchaned even after the writing using copy-on-write. As long as the borrow exists, the exclusive lock is not possible.

Returns

Either a Result::Ok with CowReadGuard or Result::Err with CowGuardError is returned.

pub fn try_borrow(&self) -> Result<CowReadGuard<'_, ITEM>, CowGuardError>

Attempts to borrows the ITEM for read-only operations. If eclusive lock is pending, the error will be returned see CowReadGuard::new.

The instance will remain unchaned even after the writing using copy-on-write. As long as the borrow exists, the exclusive lock is not possible.

Returns

Either a Result::Ok with CowReadGuard or Result::Err with CowGuardError is returned.

pub fn lock(&self) -> Result<NoCowGuard<'_, ITEM>, NoCowGuardErr>

Makes the exclusive lock. See NoCowGuard for more information about pre-requests. See NoCowGuard::new for more info.

Returns

Either a Result::Ok with NoCowGuard or Result::Err with NoCowGuardErr is returned.

pub fn remove_poison_lock(&self) -> Result<NoCowGuard<'_, ITEM>, NoCowGuardErr>

Manually removes poison status by forcing the lock. (untested)

Does not check if any borrows.

See NoCowGuard for more info.

Returns

Either a Result::Ok with NoCowGuard or Result::Err with NoCowGuardErr is returned.

pub fn remove_poison_write(&self, new_inst: ITEM) -> Result<(), NoCowGuardErr>

Manually removes poison status by setting new_inst to the inner. (untested)

Is safer than Self::remove_poison_lock because active borrows would not be affected.

See NoCowGuard for more info.

Returns

Either a Result::Ok with () or Result::Err with NoCowGuardErr is returned.

• NoCowGuardErr::AlreadyLocked - if someone is already attempting to depoison.

• NoCowGuardErr::Poisoned - depoisoning have failed

impl<ITEM: Send + Debug + Copy> InstanceCopyOnWrite<ITEM>

pub fn start_copying( &self, ) -> Result<CowTransactionGuard<'_, ITEM>, CowGuardError>

Performing the copy-on-write by copying Copy the inner value ITEM.

See CowTransactionGuard for more info.

Either a Result::Ok with CowTransactionGuard or Result::Err with CowGuardError is returned.

pub fn try_start_copying( &self, ) -> Result<CowTransactionGuard<'_, ITEM>, CowGuardError>

Attempts to perform the copy-on-write by copying Copy the inner value ITEM.

See CowTransactionGuard for more info.

Either a Result::Ok with CowTransactionGuard or Result::Err with CowGuardError is returned.

impl<ITEM: Send + Debug + Clone> InstanceCopyOnWrite<ITEM>

pub fn start_cloning( &self, ) -> Result<CowTransactionGuard<'_, ITEM>, CowGuardError>

Performing the copy-on-write by cloning Clone the inner value ITEM.

See CowTransactionGuard for more info.

Either a Result::Ok with CowTransactionGuard or Result::Err with CowGuardError is returned.

pub fn try_start_cloning( &self, ) -> Result<CowTransactionGuard<'_, ITEM>, CowGuardError>

Attempts to perform the copy-on-write by copying Clone the inner value ITEM.

See CowTransactionGuard for more info.

Either a Result::Ok with CowTransactionGuard or Result::Err with CowGuardError is returned.

impl<ITEM: Send + Debug + Default> InstanceCopyOnWrite<ITEM>

pub fn start_default( &self, ) -> Result<CowTransactionGuard<'_, ITEM>, CowGuardError>

Performing the copy-on-write by creating the default Default of the inner value ITEM.

See CowTransactionGuard for more info.

Either a Result::Ok with CowTransactionGuard or Result::Err with CowGuardError is returned.

pub fn try_start_default( &self, ) -> Result<CowTransactionGuard<'_, ITEM>, CowGuardError>

Attempts to perform the copy-on-write by creating the default Default of the inner value ITEM.

See CowTransactionGuard for more info.

Either a Result::Ok with CowTransactionGuard or Result::Err with CowGuardError is returned.

impl<ITEM: Send + Debug> InstanceCopyOnWrite<ITEM>

pub fn start_new( &self, new_inst: ITEM, ) -> Result<CowTransactionGuard<'_, ITEM>, CowGuardError>

Performing the copy-on-write from the provided instance of the inner value ITEM.

See CowTransactionGuard for more info.

Either a Result::Ok with CowTransactionGuard or Result::Err with CowGuardError is returned.

pub fn try_start_new( &self, new_inst: ITEM, ) -> Result<CowTransactionGuard<'_, ITEM>, CowGuardError>

Attempting to perform the copy-on-write from the provided instance of the inner value ITEM.

See CowTransactionGuard for more info.

Either a Result::Ok with CowTransactionGuard or Result::Err with CowGuardError is returned.

Trait Implementations

impl<ITEM: Debug + Send + Debug> Debug for InstanceCopyOnWrite<ITEM>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<ITEM: Send + Debug> Drop for InstanceCopyOnWrite<ITEM>

fn drop(&mut self)

Executes the destructor for this type.