feat(ext/kv) add backoffSchedule to enqueue

cli/tests/unit/kv_queue_undelivered_test.ts

@@ -43,8 +43,9 @@ queueTest("queue with undelivered", async (db) => {
   try {
     await db.enqueue("test", {
       keysIfUndelivered: [["queue_failed", "a"], ["queue_failed", "b"]],
+      backoffSchedule: [10, 20],
     });
-    await sleep(100000);
+    await sleep(3000);
     const undelivered = await collect(db.list({ prefix: ["queue_failed"] }));
     assertEquals(undelivered.length, 2);
     assertEquals(undelivered[0].key, ["queue_failed", "a"]);

cli/tests/unit/kv_test.ts

@@ -1600,6 +1600,24 @@ queueTest("queue retries", async (db) => {
   assertEquals(4, count);
 });
 
+queueTest("queue retries with backoffSchedule", async (db) => {
+  let count = 0;
+  const listener = db.listenQueue((_msg) => {
+    count += 1;
+    throw new TypeError("dequeue error");
+  });
+  try {
+    await db.enqueue("test", { backoffSchedule: [1] });
+    await sleep(2000);
+  } finally {
+    db.close();
+    await listener;
+  }
+
+  // There should have been 1 attempt + 1 retry
+  assertEquals(2, count);
+});
+
 queueTest("multiple listenQueues", async (db) => {
   const numListens = 10;
   let count = 0;
@@ -1876,6 +1894,23 @@ Deno.test({
   },
 });
 
+dbTest("invalid backoffSchedule", async (db) => {
+  await assertRejects(
+    async () => {
+      await db.enqueue("foo", { backoffSchedule: [1, 1, 1, 1, 1, 1] });
+    },
+    TypeError,
+    "invalid backoffSchedule",
+  );
+  await assertRejects(
+    async () => {
+      await db.enqueue("foo", { backoffSchedule: [3600001] });
+    },
+    TypeError,
+    "invalid backoffSchedule",
+  );
+});
+
 dbTest("atomic operation is exposed", (db) => {
   assert(Deno.AtomicOperation);
   const ao = db.atomic();

cli/tsc/dts/lib.deno.unstable.d.ts

@@ -1786,7 +1786,11 @@ declare namespace Deno {
      */
     enqueue(
       value: unknown,
-      options?: { delay?: number; keysIfUndelivered?: Deno.KvKey[] },
+      options?: {
+        delay?: number;
+        keysIfUndelivered?: Deno.KvKey[];
+        backoffSchedule?: number[];
+      },
     ): this;
     /**
      * Commit the operation to the KV store. Returns a value indicating whether
@@ -1995,14 +1999,28 @@ declare namespace Deno {
      * listener after several attempts. The values are set to the value of
      * the queued message.
      *
+     * The `backoffSchedule` option can be used to specify the retry policy for
+     * failed message delivery. Each element in the array represents the number of
+     * milliseconds to wait before retrying the delivery. For example,
+     * `[1000, 5000, 10000]` means that a failed delivery will be retried
+     * at most 3 times, with 1 second, 5 seconds, and 10 seconds delay
+     * between each retry.
+     *
      * ```ts
      * const db = await Deno.openKv();
-     * await db.enqueue("bar", { keysIfUndelivered: [["foo", "bar"]] });
+     * await db.enqueue("bar", {
+     *   keysIfUndelivered: [["foo", "bar"]],
+     *   backoffSchedule: [1000, 5000, 10000],
+     * });
      * ```
      */
     enqueue(
       value: unknown,
-      options?: { delay?: number; keysIfUndelivered?: Deno.KvKey[] },
+      options?: {
+        delay?: number;
+        keysIfUndelivered?: Deno.KvKey[];
+        backoffSchedule?: number[];
+      },
     ): Promise<KvCommitResult>;
 
     /**

ext/kv/01_db.ts

@@ -43,6 +43,20 @@ function validateQueueDelay(delay: number) {
   }
 }
 
+const maxQueueBackoffIntervals = 5;
+const maxQueueBackoffInterval = 60 * 60 * 1000;
+
+function validateBackoffSchedule(backoffSchedule: number[]) {
+  if (backoffSchedule.length > maxQueueBackoffIntervals) {
+    throw new TypeError("invalid backoffSchedule");
+  }
+  for (const interval of backoffSchedule) {
+    if (interval < 0 || interval > maxQueueBackoffInterval || isNaN(interval)) {
+      throw new TypeError("invalid backoffSchedule");
+    }
+  }
+}
+
 interface RawKvEntry {
   key: Deno.KvKey;
   value: RawValue;
@@ -224,18 +238,25 @@ class Kv {
 
   async enqueue(
     message: unknown,
-    opts?: { delay?: number; keysIfUndelivered?: Deno.KvKey[] },
+    opts?: {
+      delay?: number;
+      keysIfUndelivered?: Deno.KvKey[];
+      backoffSchedule?: number[];
+    },
   ) {
     if (opts?.delay !== undefined) {
       validateQueueDelay(opts?.delay);
     }
+    if (opts?.backoffSchedule !== undefined) {
+      validateBackoffSchedule(opts?.backoffSchedule);
+    }
 
     const enqueues = [
       [
         core.serialize(message, { forStorage: true }),
         opts?.delay ?? 0,
         opts?.keysIfUndelivered ?? [],
-        null,
+        opts?.backoffSchedule ?? null,
       ],
     ];
 
@@ -468,16 +489,23 @@ class AtomicOperation {
 
   enqueue(
     message: unknown,
-    opts?: { delay?: number; keysIfUndelivered?: Deno.KvKey[] },
+    opts?: {
+      delay?: number;
+      keysIfUndelivered?: Deno.KvKey[];
+      backoffSchedule?: number[];
+    },
   ): this {
     if (opts?.delay !== undefined) {
       validateQueueDelay(opts?.delay);
     }
+    if (opts?.backoffSchedule !== undefined) {
+      validateBackoffSchedule(opts?.backoffSchedule);
+    }
     this.#enqueues.push([
       core.serialize(message, { forStorage: true }),
       opts?.delay ?? 0,
       opts?.keysIfUndelivered ?? [],
-      null,
+      opts?.backoffSchedule ?? null,
     ]);
     return this;
   }

ext/kv/lib.rs

@@ -802,6 +802,9 @@ where
 
   for enqueue in &enqueues {
     total_payload_size += check_enqueue_payload_size(&enqueue.payload)?;
+    if let Some(schedule) = enqueue.backoff_schedule.as_ref() {
+      total_payload_size += 4 * schedule.len();
+    }
   }
 
   if total_payload_size > MAX_TOTAL_MUTATION_SIZE_BYTES {