Provide a resume point to bridge clients from state snapshots to the event sequence.

1 files changed, 37 insertions, 15 deletions

diff --git a/src/repo/sequence.rs b/src/repo/sequence.rs
index 8fe9dab..c47b41c 100644
--- a/src/repo/sequence.rs
+++ b/src/repo/sequence.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use sqlx::{sqlite::Sqlite, SqliteConnection, Transaction};
 
 pub trait Provider {
@@ -10,6 +12,37 @@ impl<'c> Provider for Transaction<'c, Sqlite> {
     }
 }
 
+pub struct Sequences<'t>(&'t mut SqliteConnection);
+
+impl<'c> Sequences<'c> {
+    pub async fn next(&mut self) -> Result<Sequence, sqlx::Error> {
+        let next = sqlx::query_scalar!(
+            r#"
+                update event_sequence
+                set last_value = last_value + 1
+                returning last_value as "next_value: Sequence"
+            "#,
+        )
+        .fetch_one(&mut *self.0)
+        .await?;
+
+        Ok(next)
+    }
+
+    pub async fn current(&mut self) -> Result<Sequence, sqlx::Error> {
+        let next = sqlx::query_scalar!(
+            r#"
+                select last_value as "last_value: Sequence"
+                from event_sequence
+            "#,
+        )
+        .fetch_one(&mut *self.0)
+        .await?;
+
+        Ok(next)
+    }
+}
+
 #[derive(
     Clone,
     Copy,
@@ -26,20 +59,9 @@ impl<'c> Provider for Transaction<'c, Sqlite> {
 #[sqlx(transparent)]
 pub struct Sequence(i64);
 
-pub struct Sequences<'t>(&'t mut SqliteConnection);
-
-impl<'c> Sequences<'c> {
-    pub async fn next(&mut self) -> Result<Sequence, sqlx::Error> {
-        let next = sqlx::query_scalar!(
-            r#"
-                update event_sequence
-                set last_value = last_value + 1
-                returning last_value as "next_value: Sequence"
-            "#,
-        )
-        .fetch_one(&mut *self.0)
-        .await?;
-
-        Ok(next)
+impl fmt::Display for Sequence {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Self(value) = self;
+        value.fmt(f)
     }
 }