Struct CheckpointState 

pub struct CheckpointState {
    pub id: CheckpointId,
    pub operator_states: HashMap<String, Vec<u8>>,
    pub source_offsets: HashMap<String, u64>,
    pub watermark_ns: u64,
    pub event_count: u64,
    pub metadata: HashMap<String, String>,
}

Serialisable snapshot captured at a checkpoint.

Binary format

[8 bytes]  sequence          (little-endian u64)
[8 bytes]  watermark_ns      (little-endian u64)
[8 bytes]  event_count       (little-endian u64)
[4 bytes]  n_operators       (little-endian u32)
for each operator:
  [4 bytes] name_len         (little-endian u32)
  [name_len bytes] name      (UTF-8)
  [4 bytes] state_len        (little-endian u32)
  [state_len bytes] state    (opaque bytes)
[4 bytes]  n_sources         (little-endian u32)
for each source:
  [4 bytes] name_len         (little-endian u32)
  [name_len bytes] name      (UTF-8)
  [8 bytes] offset           (little-endian u64)

Fields

id: CheckpointId

Identity of this checkpoint.

operator_states: HashMap<String, Vec<u8>>

Per-operator opaque state blobs. Key: operator name.

source_offsets: HashMap<String, u64>

Per-source byte/record offsets. Key: source identifier.

watermark_ns: u64

Maximum processed event time expressed as nanoseconds since the Unix epoch.

event_count: u64

Number of events processed up to and including this checkpoint.

metadata: HashMap<String, String>

Arbitrary key→value metadata.

Implementations

impl CheckpointState

pub fn new(id: CheckpointId) -> Self

Create an empty state for the given checkpoint ID.

pub fn set_operator_state( &mut self, operator: impl Into<String>, state: Vec<u8>, )

Store an operator’s serialised state.

pub fn set_source_offset(&mut self, source: impl Into<String>, offset: u64)

Record the byte/record offset for a source.

pub fn serialize(&self) -> Vec<u8>

Serialise this state to a compact binary representation.

pub fn deserialize(stream_id: &str, data: &[u8]) -> Result<Self, StreamingError>

Deserialise a CheckpointState from bytes previously produced by Self::serialize.

Returns StreamingError::DeserializationError if the data is truncated or otherwise malformed.

Trait Implementations

impl Clone for CheckpointState

fn clone(&self) -> CheckpointState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CheckpointState

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

Formats the value using the given formatter.