Struct mz_persist_client::fetch::LeasedBatchPart

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

A token representing one fetch-able batch part.

It is tradeable via crate::fetch::fetch_batch for the resulting data stored in the part.

Exchange

You can exchange LeasedBatchPart:

• If leased_seqno.is_none()
• By converting it to SerdeLeasedBatchPart through Self::into_exchangeable_part. SerdeLeasedBatchPart is exchangeable, including over the network.

n.b. Self::into_exchangeable_part is known to be equivalent to SerdeLeasedBatchPart::from(self), but we want the additional warning message to be visible and sufficiently scary.

Panics

LeasedBatchPart panics when dropped unless a very strict set of invariants are held:

LeasedBatchPart may only be dropped if it:

• Does not have a leased SeqNo (i.e. self.leased_seqno.is_none()`)

In any other circumstance, dropping LeasedBatchPart panics.

Implementations

impl<T> LeasedBatchPart<T>

where T: Timestamp + Codec64,

pub fn into_exchangeable_part(self) -> SerdeLeasedBatchPart

Takes self into a SerdeLeasedBatchPart, which allows self to be exchanged (potentially across the network).

!!!WARNING!!!

This semantically transfers the lease to the returned SerdeLeasedBatchPart. If self has a leased_seqno, failing to take the returned SerdeLeasedBatchPart back into a LeasedBatchPart will leak SeqNos and prevent persist GC.

pub fn encoded_size_bytes(&self) -> usize

The encoded size of this part in bytes

pub fn request_filter_pushdown_audit(&mut self)

The filter has indicated we don’t need this part, we can verify the ongoing end-to-end correctness of corner cases via “audit”. This means we fetch the part like normal and if the MFP keeps anything from it, then something has gone horribly wrong.

pub fn stats(&self) -> Option<PartStats>

Returns the pushdown stats for this part.

Trait Implementations

impl<T: Debug> Debug for LeasedBatchPart<T>

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

Formats the value using the given formatter.

impl<T> Drop for LeasedBatchPart<T>

fn drop(&mut self)

For details, see LeasedBatchPart.

impl<T: Timestamp + Codec64> RustType<(ProtoLeasedBatchPart, Arc<Metrics>)> for LeasedBatchPart<T>

fn into_proto(&self) -> (ProtoLeasedBatchPart, Arc<Metrics>)

Convert a Self into a Proto value.

fn from_proto( proto: (ProtoLeasedBatchPart, Arc<Metrics>) ) -> Result<Self, TryFromProtoError>

Consume and convert a Proto back into a Self value.