Struct Completion 

pub struct Completion { /* private fields */ }

A shared durability acknowledgement state used for issuing AckTicket

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

let completion = frozen_core::ack::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

Epoch

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

Example

let completion = frozen_core::ack::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

Monotonic Epoch

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 (i.e. replace) 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 underlying error w/ None

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 listeners currently waiting for durability progress

Waking listeners does not modify any durable state and is typically called after advancing the durable epoch or setting an error

Example

use frozen_core::ack::Completion;

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

pub fn set_sync_trigger(&self, trigger: Weak<dyn SyncTrigger>)

Register a SyncTrigger implementation for triggering syncs

pub fn trigger_sync(&self) -> FrozenResult<()>

Trigger synchronization using the registered SyncTrigger

pub fn wait_for_epoch(&self, epoch: TEpoch) -> FrozenResult<TEpoch>

Blocks the current thread until the specified epoch becomes durable or an error is reported

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.