From 5742164567b507dd5433ebaf55949c8aa7f73d71 Mon Sep 17 00:00:00 2001
From: Chris Anderson <jchris@gmail.com>
Date: Thu, 19 Sep 2024 16:34:57 -0700
Subject: [PATCH 1/3] subscribe test

---
 tests/fireproof/all-gateway.test.ts | 48 +++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/tests/fireproof/all-gateway.test.ts b/tests/fireproof/all-gateway.test.ts
index e33fdb61..24d16a73 100644
--- a/tests/fireproof/all-gateway.test.ts
+++ b/tests/fireproof/all-gateway.test.ts
@@ -297,6 +297,54 @@ describe("noop Gateway", function () {
   });
 });
 
+describe("noop Gateway subscribe", function () {
+  let db: Database;
+
+  let metaStore: ExtendedStore;
+
+  let metaGateway: ExtendedGateway;
+
+  afterEach(async function () {
+    await db.close();
+    await db.destroy();
+  });
+  beforeEach(async function () {
+    db = new Database("test-gateway-" + Math.random().toString(36).substring(7));
+
+    // Extract stores from the loader
+    metaStore = (await db.blockstore.loader?.metaStore()) as unknown as ExtendedStore;
+
+    metaGateway = metaStore?.gateway;
+  });
+  it("should subscribe to meta Gateway", async function () {
+    const metaUrl = await metaGateway?.buildUrl(metaStore?._url, "main");
+    await metaGateway?.start(metaStore?._url);
+
+    if (metaGateway.subscribe) {
+      let resolve: () => void;
+      let didCall = false;
+      const p = new Promise<void>((r) => {
+        resolve = r;
+      });
+
+      const metaSubscribeResult = await metaGateway?.subscribe?.(metaUrl?.Ok(), async (data: Uint8Array) => {
+        const decodedData = new TextDecoder().decode(data);
+        expect(decodedData).toContain("parents");
+        didCall = true
+        resolve();
+      });
+      expect(metaSubscribeResult?.Ok()).toBeTruthy();
+      const ok = await db.put({ _id: "key1", hello: "world1" });
+      expect(ok).toBeTruthy();
+      expect(ok.id).toBe("key1");
+      await p
+      expect(didCall).toBeTruthy();
+    }
+  });
+    
+  });
+});
+
 describe("Gateway", function () {
   let db: Database;
   // let carStore: ExtendedStore;

From fa8b28f9c896783a36d5466f84caa165cbcf2720 Mon Sep 17 00:00:00 2001
From: Chris Anderson <jchris@gmail.com>
Date: Thu, 19 Sep 2024 17:03:48 -0700
Subject: [PATCH 2/3] susbcribe tests pass on local gateways

---
 src/blockstore/fragment-gateway.ts  | 22 +++++++++++++++++++++-
 tests/fireproof/all-gateway.test.ts |  6 ++----
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/blockstore/fragment-gateway.ts b/src/blockstore/fragment-gateway.ts
index ed0fe6f0..75753cd2 100644
--- a/src/blockstore/fragment-gateway.ts
+++ b/src/blockstore/fragment-gateway.ts
@@ -171,7 +171,27 @@ export class FragmentGateway implements bs.Gateway {
     if (this.innerGW.subscribe) {
       return this.innerGW.subscribe(url, callback);
     } else {
-      return Result.Err(this.logger.Error().Msg("Subscribe not supported").AsError());
+      let lastData: Uint8Array | undefined = undefined;
+      let interval = 100;
+      const fetchData = async () => {
+        const result = await this.innerGW.get(url);
+        if (result.isOk()) {
+          const data = result.Ok();
+          if (!lastData || !data.every((value, index) => lastData && value === lastData[index])) {
+            lastData = data;
+            callback(data);
+            interval = 100; // Reset interval when data changes
+          } else {
+            interval *= 2; // Double the interval when data is unchanged
+          }
+        }
+        timeoutId = setTimeout(fetchData, interval);
+      };
+      let timeoutId = setTimeout(fetchData, interval);
+
+      return Result.Ok(() => {
+        clearTimeout(timeoutId);
+      });
     }
   }
 
diff --git a/tests/fireproof/all-gateway.test.ts b/tests/fireproof/all-gateway.test.ts
index 24d16a73..36f4d7ba 100644
--- a/tests/fireproof/all-gateway.test.ts
+++ b/tests/fireproof/all-gateway.test.ts
@@ -330,19 +330,17 @@ describe("noop Gateway subscribe", function () {
       const metaSubscribeResult = await metaGateway?.subscribe?.(metaUrl?.Ok(), async (data: Uint8Array) => {
         const decodedData = new TextDecoder().decode(data);
         expect(decodedData).toContain("parents");
-        didCall = true
+        didCall = true;
         resolve();
       });
       expect(metaSubscribeResult?.Ok()).toBeTruthy();
       const ok = await db.put({ _id: "key1", hello: "world1" });
       expect(ok).toBeTruthy();
       expect(ok.id).toBe("key1");
-      await p
+      await p;
       expect(didCall).toBeTruthy();
     }
   });
-    
-  });
 });
 
 describe("Gateway", function () {

From cb011496ac5336bac082a26bf1232e17355f69bb Mon Sep 17 00:00:00 2001
From: Chris Anderson <jchris@gmail.com>
Date: Thu, 19 Sep 2024 17:24:52 -0700
Subject: [PATCH 3/3] test is better

---
 tests/fireproof/all-gateway.test.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tests/fireproof/all-gateway.test.ts b/tests/fireproof/all-gateway.test.ts
index 36f4d7ba..b00e04f6 100644
--- a/tests/fireproof/all-gateway.test.ts
+++ b/tests/fireproof/all-gateway.test.ts
@@ -326,10 +326,9 @@ describe("noop Gateway subscribe", function () {
       const p = new Promise<void>((r) => {
         resolve = r;
       });
-
       const metaSubscribeResult = await metaGateway?.subscribe?.(metaUrl?.Ok(), async (data: Uint8Array) => {
         const decodedData = new TextDecoder().decode(data);
-        expect(decodedData).toContain("parents");
+        expect(decodedData).toContain("[]");
         didCall = true;
         resolve();
       });