Struct Completion 

pub struct Completion { /* private fields */ }

A shared durability acknowledgement state used for issuing AckTicket’s

The completion state tracks following things:

• The latest assigned epoch
• The latest durable epoch
• Waiters blocked on durability advancement
• Durability errors (if any) blocking durability progress

Example

use frozen_core::ack::Completion;

let completion = Completion::default();

assert_eq!(completion.read_current_epoch(), 0);
assert_eq!(completion.read_durable_epoch(), 0);

Implementations

impl Completion

pub fn increment_current_epoch(&self) -> TEpoch

Advance current and return next durability epoch

NOTE: Epoch value is monotonically increasing and used to identify unique write operations.

Example

use frozen_core::ack::Completion;

let completion = Completion::default();

assert_eq!(completion.increment_current_epoch(), 1);
assert_eq!(completion.increment_current_epoch(), 2);
assert_eq!(completion.increment_current_epoch(), 3);

pub fn mark_epoch_as_durable(&self, epoch: TEpoch)

Mark given TEpoch as durable

NOTE: Once an epoch is marked durable, all earlier epochs are implicitly understood to be durable.

Example

use frozen_core::ack::Completion;

let completion = Completion::default();
completion.mark_epoch_as_durable(0x0A);

assert_eq!(completion.read_durable_epoch(), 0x0A);

pub fn get_err(&self) -> Option<FrozenError>

Fetch the acknowledgement error (if any)

Example

use frozen_core::ack::Completion;

let completion = Completion::default();
assert_eq!(completion.get_err(), None);

pub fn set_err(&self, new_error: FrozenError)

Update current acknowledgement error w/ a new FrozenError

Example

use frozen_core::{ack::Completion, error::{FrozenError, ErrCode}};

let completion = Completion::default();
let new_error = FrozenError::new(0x10, 0x20, ErrCode::new(0x30, "io"), "failed to read file");

completion.set_err(new_error.clone());
assert_eq!(completion.get_err(), Some(new_error));

pub fn del_err(&self)

Clear acknowledgement error by replacing the underying error w/ an empty pointer

Example

use frozen_core::{ack::Completion, error::{FrozenError, ErrCode}};

let completion = Completion::default();
let new_error = FrozenError::new(0x10, 0x20, ErrCode::new(0x30, "io"), "failed to read file");

completion.set_err(new_error.clone());
assert!(completion.get_err().is_some());

completion.del_err();
assert!(completion.get_err().is_none());

pub fn read_current_epoch(&self) -> TEpoch

Read the latest assigned epoch

Example

use frozen_core::ack::Completion;

let completion = Completion::default();
completion.increment_current_epoch();

assert_eq!(completion.read_current_epoch(), 1);

pub fn read_durable_epoch(&self) -> TEpoch

Read the latest durable epoch

Example

use frozen_core::ack::Completion;

let completion = Completion::default();
completion.mark_epoch_as_durable(0x3A);

assert_eq!(completion.read_durable_epoch(), 0x3A);

pub fn notify_all_listeners(&self)

Wake all the listeners currently waiting for durability progress

NOTE: Waking listeners does not modify any durable state and are typically called after advancing the durable epoch or after occurence of [AckError].

Example

use frozen_core::ack::Completion;

let completion = Completion::default();
completion.notify_all_listeners();

Trait Implementations

impl Debug for Completion

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

Formats the value using the given formatter.

impl Default for Completion

fn default() -> Self

Returns the “default value” for a type.