huskies: merge 1061

server/src/db/shadow_write.rs

@@ -3,6 +3,10 @@
 //! `init` opens the database, runs migrations, loads existing content into the
 //! in-memory store, and spawns the write loop.  All subsequent writes are sent
 //! over an unbounded channel so callers never block on I/O.
+//!
+//! The opened pool is stored in [`SHARED_POOL`] so that other subsystems
+//! (event-trigger store, timer store, scheduled-timer store) can share the
+//! same database connection without re-opening the file.
 use crate::slog;
 use sqlx::SqlitePool;
 use sqlx::sqlite::SqliteConnectOptions;
@@ -11,6 +15,18 @@ use std::path::Path;
 use std::sync::OnceLock;
 use tokio::sync::mpsc;
 
+/// The process-global SQLite pool, set once by [`init`].
+///
+/// Other modules call [`get_shared_pool`] to access the pool without needing
+/// to pass it through every call-site.
+static SHARED_POOL: OnceLock<SqlitePool> = OnceLock::new();
+
+/// Return a reference to the shared pipeline database pool, if it has been
+/// initialised by a prior call to [`init`].
+pub fn get_shared_pool() -> Option<&'static SqlitePool> {
+    SHARED_POOL.get()
+}
+
 /// A pending shadow write for one pipeline item.
 pub(super) struct PipelineWriteMsg {
     pub(super) story_id: String,
@@ -47,6 +63,9 @@ pub async fn init(db_path: &Path) -> Result<(), sqlx::Error> {
     let pool = SqlitePool::connect_with(options).await?;
     sqlx::migrate!("./migrations").run(&pool).await?;
 
+    // Store pool in global static so other subsystems can reuse it.
+    let _ = SHARED_POOL.set(pool.clone());
+
     // Load existing content into the in-memory store.
     let rows: Vec<(String, Option<String>)> =
         sqlx::query_as("SELECT id, content FROM pipeline_items WHERE content IS NOT NULL")