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JournalWriter

Struct JournalWriter 

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pub struct JournalWriter { /* private fields */ }
Expand description

The background actor that owns the write path to a LocalBackend’s durable.db.

Construct it with JournalWriter::new (which also returns the handle), then drive it with JournalWriter::run on a supervised task.

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impl JournalWriter

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pub fn new( backend: Arc<LocalBackend>, config: &DurableConfig, ) -> (Self, JournalWriterHandle)

Build the writer and its cloneable handle from a backend and the durable configuration.

The flush interval and ACK timeout are taken from config; the channel is bounded at the spec capacity. Spawn JournalWriter::run to start processing.

§Examples
use std::sync::Arc;
use zeph_durable::{DurableConfig, LocalBackend, JournalWriter};

let backend = Arc::new(LocalBackend::open("durable.db", 1_048_576).await?);
backend.init().await?;
let (writer, handle) = JournalWriter::new(backend, &DurableConfig::default());
let task = tokio::spawn(writer.run());
// ... use `handle` to append; drop all handles to stop the writer ...
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pub async fn run(self)

Run the actor loop until every JournalWriterHandle is dropped.

On entry the writer reads MAX(seq) to resume from the last committed entry (FR-DE-12). It then group-commits buffered entries on each flush tick (or when the batch fills), flushes before every acked commit (INV-4), and emits a durable.journal.writer.queue_depth gauge per commit cycle. When the channel closes it drains any remaining buffered entries and returns, so the supervisor can restart it cleanly.

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impl Debug for JournalWriter

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

Formats the value using the given formatter. Read more

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