From af959268b8245bbb46d792dff8a4f399422a9811 Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Tue, 13 Aug 2024 21:47:29 -0700
Subject: [PATCH 01/11] Initial Snapshot code. Injection Parts 1,2,3 with lots
 of debug + a version bump.

---
 package.json                    |   2 +-
 src/adaptors/yjs-ndn-adaptor.ts | 134 +++++++++++++++++++++++++++++++-
 src/sync-agent/namespace.ts     |   5 ++
 src/sync-agent/sync-agent.ts    |  22 ++++++
 4 files changed, 160 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index 14a7bf1..bf55e5f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@ucla-irl/ndnts-aux",
-  "version": "3.0.3",
+  "version": "4.0.0",
   "description": "NDNts Auxiliary Package for Web and Deno",
   "scripts": {
     "test": "deno test --no-check",
diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index bb35d5d..3cbe099 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -3,6 +3,12 @@ import * as Y from 'yjs';
 import { Awareness } from 'y-protocols/awareness.js';
 import { Bundler } from './bundler.ts';
 
+// Adam Chen Additional Imports
+import { Decoder, Encoder } from '@ndn/tlv';
+import { Component, Data, Name} from '@ndn/packet';
+import { Version } from '@ndn/naming-convention2';
+import { StateVector } from '@ndn/svs';
+
 /**
  * NDN SVS Provider for Yjs. Wraps update into `SyncAgent`'s `update` channel.
  *
@@ -33,11 +39,24 @@ export class NdnSvsAdaptor {
     useBundler: boolean = false,
   ) {
     syncAgent.register('update', topic, (content) => this.handleSyncUpdate(content));
+    // Adam Chen callback on receiving a snapshot blob for Injection Point 3
+    syncAgent.register('blob','snapshot',(content) => this.handleSnapshotUpdate(content))
     doc.on('update', this.callback);
     if (useBundler) {
+      // this.#bundler = new Bundler(
+      //   Y.mergeUpdates,
+      //   (content) => this.syncAgent.publishUpdate(this.topic, content),
+      //   {
+      //     thresholdSize: 3000,
+      //     delayMs: 400,
+      //     maxDelayMs: 1600,
+      //   },
+      // );
+
+      // Adam Chen Injection Point 1 override
       this.#bundler = new Bundler(
         Y.mergeUpdates,
-        (content) => this.syncAgent.publishUpdate(this.topic, content),
+        (content) => this.publishUpdate(this.topic, content),
         {
           thresholdSize: 3000,
           delayMs: 400,
@@ -96,10 +115,121 @@ export class NdnSvsAdaptor {
     if (this.#bundler) {
       await this.#bundler.produce(content);
     } else {
-      await this.syncAgent.publishUpdate(this.topic, content);
+      // await this.syncAgent.publishUpdate(this.topic, content);
+
+      // Adam Chen Injection point 1 override 
+      await this.publishUpdate(this.topic,content)
     }
   }
 
+  // Adam Chen Injection point 1
+  async publishUpdate(topic:any,content:any) {
+    await this.syncAgent.publishUpdate(topic, content)
+    // await new Promise(r => setTimeout(r,500));
+    // forced wait so that publishUpdate() is completed before we check SV.
+    console.log('-- Injection point 1: Check StateVector / Create Snapshot --')
+    let stateVector = this.syncAgent.getUpdateSyncSV()
+    console.log('debug: stateVector object: ',stateVector)
+    let count = 0
+    for (const [id,seq] of stateVector){
+        count += seq
+    }
+    console.log('Total count of state vector', count)
+    console.log('The above number should match the state vector in the debug page')
+    if (count % 5 == 0){
+        console.log('It\'s time to make a snapshot!')
+        console.log('debug: group prefix: ', this.syncAgent.appPrefix.toString())
+        let encodedSV = Encoder.encode(stateVector)
+        let snapshotPrefix = this.syncAgent.appPrefix.append("32=snapshot")
+        // New SVS encodings
+        let snapshotName = snapshotPrefix.append(new Component(Version.type, encodedSV))
+        console.log('debug: targeted snapshot Prefix (persistStore key): ', snapshotPrefix.toString())
+        // /groupPrefix/32=snapshot/
+        console.log('debug: targeted snapshot Name: ', snapshotName.toString())
+        // /groupPrefix/32=snapshot/54=<stateVector>
+        let decodedSV = Decoder.decode(snapshotName.at(-1).value, StateVector)
+        console.log('debug: decoding encoded SV from snapshotName: ', decodedSV)
+        let count = 0
+        for (const [id,seq] of decodedSV){
+            count += seq
+        }
+        console.log('debug: decoding encoded SV total packet count: ', count)
+        console.log('This should match the state vector in the debug page and the previous count before encoding')
+
+        let content = Y.encodeStateAsUpdate(this.doc)
+        // its already in UTF8, transporting currently without any additional encoding.
+        console.log('yjs backend data: ',content)
+
+        // use syncAgent's blob and publish mechanism - use a different topic.
+
+        await this.syncAgent.publishBlob('snapshot',content,snapshotName,true)
+
+        //first segmented object is at /50=%00
+        let firstSegmentName = snapshotName.append('50=%00').toString()
+        console.log('debugTargetName: ', firstSegmentName)
+        let firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName)
+        if (firstSegmentPacketEncoded){
+          let firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded,Data)
+          console.log('persistentStore check: ', firstSegmentPacket)
+          console.log('persistentStore check Data Name:', firstSegmentPacket.name.toString())
+          await this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
+        }
+        
+    }
+}
+// End Injection point 1
+
+// -- Adam Chen Injection Point 3: HandleSnapshotUpdate --
+async handleSnapshotUpdate(snapshotName: Uint8Array){
+    // Maybe it's wise to put this under a try() because it might fail due to network issues.
+    let decodedSnapshotName = Decoder.decode(snapshotName, Name)
+    console.log('-- Adam Chen Injection Point 3: Update Latest Snapshot (Received) --')
+    console.log('Handling received snapshot packet with name: ', decodedSnapshotName.toString())
+
+    let snapshotPrefix = this.syncAgent.appPrefix.append("32=snapshot")
+    console.log('snapshot prefix in persistStorage: ', snapshotPrefix.toString())
+    let oldSnapshotFirstSegmentEncoded = await this.syncAgent.persistStorage.get(snapshotPrefix.toString())
+    let oldSVCount = 0
+    if (oldSnapshotFirstSegmentEncoded){
+        let oldSnapshotFirstSegment = Decoder.decode(oldSnapshotFirstSegmentEncoded, Data)
+        let oldSnapshotVector = Decoder.decode(oldSnapshotFirstSegment.name.at(-2).value,StateVector)
+        for (const [id,seq] of oldSnapshotVector){
+            oldSVCount += seq
+        }
+    }
+
+    let snapshotSV = Decoder.decode(decodedSnapshotName.at(-1).value,StateVector)
+    let snapshotSVcount = 0
+    for (const [id,seq] of snapshotSV){
+        snapshotSVcount += seq
+    }
+
+    console.log('current state vector total count: ', oldSVCount)
+    console.log('snapshot state vector total count: ', snapshotSVcount)
+
+    if (snapshotSVcount>oldSVCount){
+        let firstSegmentName = decodedSnapshotName.append('50=%00').toString()
+        console.log('Retrieving the following from persist Storage: ', firstSegmentName)
+        // await this.syncAgent.getBlob(decodedSnapshotName)
+        await new Promise((r) => setTimeout(r, 1000))
+        let firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName)
+        if (firstSegmentPacketEncoded){
+            console.log('Debug: Retrieval results: ', firstSegmentPacketEncoded)
+            let firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded, Data)
+            console.log('Writing this packet: ', firstSegmentPacket.name.toString())
+            console.log('To this location: ', snapshotPrefix.toString())
+            // this is done to update the key of the prefix so program return latest when blind fetching.
+            this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
+            // should set snapshotPrefix to the newest packet.
+        }
+        else {
+            console.log('PersistentStorage doesnt have the snapshot yet. Skipping update.')
+        }
+        
+    }
+}
+// End Injection point 3
+
   public handleSyncUpdate(content: Uint8Array) {
     // Apply patch
     // Remark: `applyUpdate` will trigger a transaction after the update is decoded.
diff --git a/src/sync-agent/namespace.ts b/src/sync-agent/namespace.ts
index e9f70c4..3956e89 100644
--- a/src/sync-agent/namespace.ts
+++ b/src/sync-agent/namespace.ts
@@ -53,6 +53,9 @@ export type SyncAgentNamespace = {
 
   /** Keyword component for latest only delivery. Default is `32=late` */
   readonly latestOnlyKeyword: Component;
+
+  /** Adam Chen: Keyword component for snapshots. Default is `32=snapshot` */
+  readonly snapshotKeyword: Component;
 };
 
 export function getNamespace(): SyncAgentNamespace {
@@ -103,6 +106,8 @@ function createDefaultNamespace(): SyncAgentNamespace {
     syncKeyword: KeywordComponent.create('sync'),
     atLeastOnceKeyword: KeywordComponent.create('alo'),
     latestOnlyKeyword: KeywordComponent.create('late'),
+    // Adam Chen Add snapshotKeyword
+    snapshotKeyword: KeywordComponent.create('snapshot'),
   };
   return ret;
 }
diff --git a/src/sync-agent/sync-agent.ts b/src/sync-agent/sync-agent.ts
index f265d7b..b8ed134 100644
--- a/src/sync-agent/sync-agent.ts
+++ b/src/sync-agent/sync-agent.ts
@@ -260,6 +260,8 @@ export class SyncAgent implements AsyncDisposable {
     }
 
     const buffers: Uint8Array[] = [];
+    //Adam Chen Debug
+    console.log('SyncAgent fetchBlob fetching: ', blobName.toString())
     try {
       const result = fetch(blobName, {
         verifier: this.verifier,
@@ -282,6 +284,8 @@ export class SyncAgent implements AsyncDisposable {
 
     // Save blob (SA getBlob())
     await this.persistStorage.set(blobName.toString(), blob);
+    //Adam Chen Debug
+    console.log('SyncAgent fetchBlob complete.')
   }
 
   public register(channel: ChannelType, topic: string, handler: (content: Uint8Array, id: Name) => void) {
@@ -354,6 +358,24 @@ export class SyncAgent implements AsyncDisposable {
 
   async serve(interest: Interest) {
     const intName = interest.name;
+
+    // -- Adam Chen Injection point 2 --
+
+    if (intName.get(this.appPrefix.length)?.equals(getNamespace().snapshotKeyword)) {
+      // console.log('snapshot interest detected, custom routine activated')
+      let wire = await this.persistStorage.get(intName.toString())
+      if (wire === undefined || wire.length === 0) {
+          // console.warn(`A remote peer is fetching a non-existing object: ${intName.toString()}`);
+          console.log('MISS: SnapshotInterest: ', intName.toString())
+          return undefined;
+      }
+      let data = Decoder.decode(wire, Data)
+      console.log('HIT: SnapshotInterest and Returned Data: ',intName.toString(),data.name.toString())
+      return data
+      }
+
+      // -- End Injection point 2 --
+
     if (intName.length <= this.appPrefix.length + 1) {
       // The name should be at least two components plus app prefix
       return undefined;

From 8102741dd6370a1268a7213c855eb4aa15d26c2f Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Tue, 13 Aug 2024 23:08:22 -0700
Subject: [PATCH 02/11] Lint fixes 1

---
 src/adaptors/yjs-ndn-adaptor.ts | 46 ++++++++++++++++-----------------
 src/sync-agent/sync-agent.ts    |  4 +--
 2 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index 3cbe099..ddfa7eb 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -123,15 +123,15 @@ export class NdnSvsAdaptor {
   }
 
   // Adam Chen Injection point 1
-  async publishUpdate(topic:any,content:any) {
+  private async publishUpdate(topic:string,content:Uint8Array) {
     await this.syncAgent.publishUpdate(topic, content)
     // await new Promise(r => setTimeout(r,500));
     // forced wait so that publishUpdate() is completed before we check SV.
     console.log('-- Injection point 1: Check StateVector / Create Snapshot --')
-    let stateVector = this.syncAgent.getUpdateSyncSV()
+    const stateVector = this.syncAgent.getUpdateSyncSV()
     console.log('debug: stateVector object: ',stateVector)
     let count = 0
-    for (const [id,seq] of stateVector){
+    for (const [_id,seq] of stateVector){
         count += seq
     }
     console.log('Total count of state vector', count)
@@ -139,24 +139,24 @@ export class NdnSvsAdaptor {
     if (count % 5 == 0){
         console.log('It\'s time to make a snapshot!')
         console.log('debug: group prefix: ', this.syncAgent.appPrefix.toString())
-        let encodedSV = Encoder.encode(stateVector)
-        let snapshotPrefix = this.syncAgent.appPrefix.append("32=snapshot")
+        const encodedSV = Encoder.encode(stateVector)
+        const snapshotPrefix = this.syncAgent.appPrefix.append("32=snapshot")
         // New SVS encodings
-        let snapshotName = snapshotPrefix.append(new Component(Version.type, encodedSV))
+        const snapshotName = snapshotPrefix.append(new Component(Version.type, encodedSV))
         console.log('debug: targeted snapshot Prefix (persistStore key): ', snapshotPrefix.toString())
         // /groupPrefix/32=snapshot/
         console.log('debug: targeted snapshot Name: ', snapshotName.toString())
         // /groupPrefix/32=snapshot/54=<stateVector>
-        let decodedSV = Decoder.decode(snapshotName.at(-1).value, StateVector)
+        const decodedSV = Decoder.decode(snapshotName.at(-1).value, StateVector)
         console.log('debug: decoding encoded SV from snapshotName: ', decodedSV)
         let count = 0
-        for (const [id,seq] of decodedSV){
+        for (const [_id,seq] of decodedSV){
             count += seq
         }
         console.log('debug: decoding encoded SV total packet count: ', count)
         console.log('This should match the state vector in the debug page and the previous count before encoding')
 
-        let content = Y.encodeStateAsUpdate(this.doc)
+        const content = Y.encodeStateAsUpdate(this.doc)
         // its already in UTF8, transporting currently without any additional encoding.
         console.log('yjs backend data: ',content)
 
@@ -165,11 +165,11 @@ export class NdnSvsAdaptor {
         await this.syncAgent.publishBlob('snapshot',content,snapshotName,true)
 
         //first segmented object is at /50=%00
-        let firstSegmentName = snapshotName.append('50=%00').toString()
+        const firstSegmentName = snapshotName.append('50=%00').toString()
         console.log('debugTargetName: ', firstSegmentName)
-        let firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName)
+        const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName)
         if (firstSegmentPacketEncoded){
-          let firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded,Data)
+          const firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded,Data)
           console.log('persistentStore check: ', firstSegmentPacket)
           console.log('persistentStore check Data Name:', firstSegmentPacket.name.toString())
           await this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
@@ -182,25 +182,25 @@ export class NdnSvsAdaptor {
 // -- Adam Chen Injection Point 3: HandleSnapshotUpdate --
 async handleSnapshotUpdate(snapshotName: Uint8Array){
     // Maybe it's wise to put this under a try() because it might fail due to network issues.
-    let decodedSnapshotName = Decoder.decode(snapshotName, Name)
+    const decodedSnapshotName = Decoder.decode(snapshotName, Name)
     console.log('-- Adam Chen Injection Point 3: Update Latest Snapshot (Received) --')
     console.log('Handling received snapshot packet with name: ', decodedSnapshotName.toString())
 
-    let snapshotPrefix = this.syncAgent.appPrefix.append("32=snapshot")
+    const snapshotPrefix = this.syncAgent.appPrefix.append("32=snapshot")
     console.log('snapshot prefix in persistStorage: ', snapshotPrefix.toString())
-    let oldSnapshotFirstSegmentEncoded = await this.syncAgent.persistStorage.get(snapshotPrefix.toString())
+    const oldSnapshotFirstSegmentEncoded = await this.syncAgent.persistStorage.get(snapshotPrefix.toString())
     let oldSVCount = 0
     if (oldSnapshotFirstSegmentEncoded){
-        let oldSnapshotFirstSegment = Decoder.decode(oldSnapshotFirstSegmentEncoded, Data)
-        let oldSnapshotVector = Decoder.decode(oldSnapshotFirstSegment.name.at(-2).value,StateVector)
-        for (const [id,seq] of oldSnapshotVector){
+        const oldSnapshotFirstSegment = Decoder.decode(oldSnapshotFirstSegmentEncoded, Data)
+        const oldSnapshotVector = Decoder.decode(oldSnapshotFirstSegment.name.at(-2).value,StateVector)
+        for (const [_id,seq] of oldSnapshotVector){
             oldSVCount += seq
         }
     }
 
-    let snapshotSV = Decoder.decode(decodedSnapshotName.at(-1).value,StateVector)
+    const snapshotSV = Decoder.decode(decodedSnapshotName.at(-1).value,StateVector)
     let snapshotSVcount = 0
-    for (const [id,seq] of snapshotSV){
+    for (const [_id,seq] of snapshotSV){
         snapshotSVcount += seq
     }
 
@@ -208,14 +208,14 @@ async handleSnapshotUpdate(snapshotName: Uint8Array){
     console.log('snapshot state vector total count: ', snapshotSVcount)
 
     if (snapshotSVcount>oldSVCount){
-        let firstSegmentName = decodedSnapshotName.append('50=%00').toString()
+        const firstSegmentName = decodedSnapshotName.append('50=%00').toString()
         console.log('Retrieving the following from persist Storage: ', firstSegmentName)
         // await this.syncAgent.getBlob(decodedSnapshotName)
         await new Promise((r) => setTimeout(r, 1000))
-        let firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName)
+        const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName)
         if (firstSegmentPacketEncoded){
             console.log('Debug: Retrieval results: ', firstSegmentPacketEncoded)
-            let firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded, Data)
+            const firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded, Data)
             console.log('Writing this packet: ', firstSegmentPacket.name.toString())
             console.log('To this location: ', snapshotPrefix.toString())
             // this is done to update the key of the prefix so program return latest when blind fetching.
diff --git a/src/sync-agent/sync-agent.ts b/src/sync-agent/sync-agent.ts
index b8ed134..aa57d9a 100644
--- a/src/sync-agent/sync-agent.ts
+++ b/src/sync-agent/sync-agent.ts
@@ -363,13 +363,13 @@ export class SyncAgent implements AsyncDisposable {
 
     if (intName.get(this.appPrefix.length)?.equals(getNamespace().snapshotKeyword)) {
       // console.log('snapshot interest detected, custom routine activated')
-      let wire = await this.persistStorage.get(intName.toString())
+      const wire = await this.persistStorage.get(intName.toString())
       if (wire === undefined || wire.length === 0) {
           // console.warn(`A remote peer is fetching a non-existing object: ${intName.toString()}`);
           console.log('MISS: SnapshotInterest: ', intName.toString())
           return undefined;
       }
-      let data = Decoder.decode(wire, Data)
+      const data = Decoder.decode(wire, Data)
       console.log('HIT: SnapshotInterest and Returned Data: ',intName.toString(),data.name.toString())
       return data
       }

From 2f1e98fcbbcd66c06a13af2491df4e8654a2bbbf Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Tue, 13 Aug 2024 23:41:32 -0700
Subject: [PATCH 03/11] lint fixes 2

---
 src/adaptors/yjs-ndn-adaptor.ts | 183 ++++++++++++++++----------------
 src/sync-agent/sync-agent.ts    |  24 ++---
 2 files changed, 101 insertions(+), 106 deletions(-)

diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index ddfa7eb..e0316ea 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -5,7 +5,7 @@ import { Bundler } from './bundler.ts';
 
 // Adam Chen Additional Imports
 import { Decoder, Encoder } from '@ndn/tlv';
-import { Component, Data, Name} from '@ndn/packet';
+import { Component, Data, Name } from '@ndn/packet';
 import { Version } from '@ndn/naming-convention2';
 import { StateVector } from '@ndn/svs';
 
@@ -40,7 +40,7 @@ export class NdnSvsAdaptor {
   ) {
     syncAgent.register('update', topic, (content) => this.handleSyncUpdate(content));
     // Adam Chen callback on receiving a snapshot blob for Injection Point 3
-    syncAgent.register('blob','snapshot',(content) => this.handleSnapshotUpdate(content))
+    syncAgent.register('blob', 'snapshot', (content) => this.handleSnapshotUpdate(content));
     doc.on('update', this.callback);
     if (useBundler) {
       // this.#bundler = new Bundler(
@@ -117,118 +117,115 @@ export class NdnSvsAdaptor {
     } else {
       // await this.syncAgent.publishUpdate(this.topic, content);
 
-      // Adam Chen Injection point 1 override 
-      await this.publishUpdate(this.topic,content)
+      // Adam Chen Injection point 1 override
+      await this.publishUpdate(this.topic, content);
     }
   }
 
   // Adam Chen Injection point 1
-  private async publishUpdate(topic:string,content:Uint8Array) {
-    await this.syncAgent.publishUpdate(topic, content)
+  private async publishUpdate(topic: string, content: Uint8Array) {
+    await this.syncAgent.publishUpdate(topic, content);
     // await new Promise(r => setTimeout(r,500));
     // forced wait so that publishUpdate() is completed before we check SV.
-    console.log('-- Injection point 1: Check StateVector / Create Snapshot --')
-    const stateVector = this.syncAgent.getUpdateSyncSV()
-    console.log('debug: stateVector object: ',stateVector)
-    let count = 0
-    for (const [_id,seq] of stateVector){
-        count += seq
+    console.log('-- Injection point 1: Check StateVector / Create Snapshot --');
+    const stateVector = this.syncAgent.getUpdateSyncSV();
+    console.log('debug: stateVector object: ', stateVector);
+    let count = 0;
+    for (const [_id, seq] of stateVector) {
+      count += seq;
     }
-    console.log('Total count of state vector', count)
-    console.log('The above number should match the state vector in the debug page')
-    if (count % 5 == 0){
-        console.log('It\'s time to make a snapshot!')
-        console.log('debug: group prefix: ', this.syncAgent.appPrefix.toString())
-        const encodedSV = Encoder.encode(stateVector)
-        const snapshotPrefix = this.syncAgent.appPrefix.append("32=snapshot")
-        // New SVS encodings
-        const snapshotName = snapshotPrefix.append(new Component(Version.type, encodedSV))
-        console.log('debug: targeted snapshot Prefix (persistStore key): ', snapshotPrefix.toString())
-        // /groupPrefix/32=snapshot/
-        console.log('debug: targeted snapshot Name: ', snapshotName.toString())
-        // /groupPrefix/32=snapshot/54=<stateVector>
-        const decodedSV = Decoder.decode(snapshotName.at(-1).value, StateVector)
-        console.log('debug: decoding encoded SV from snapshotName: ', decodedSV)
-        let count = 0
-        for (const [_id,seq] of decodedSV){
-            count += seq
-        }
-        console.log('debug: decoding encoded SV total packet count: ', count)
-        console.log('This should match the state vector in the debug page and the previous count before encoding')
+    console.log('Total count of state vector', count);
+    console.log('The above number should match the state vector in the debug page');
+    if (count % 5 == 0) {
+      console.log("It's time to make a snapshot!");
+      console.log('debug: group prefix: ', this.syncAgent.appPrefix.toString());
+      const encodedSV = Encoder.encode(stateVector);
+      const snapshotPrefix = this.syncAgent.appPrefix.append('32=snapshot');
+      // New SVS encodings
+      const snapshotName = snapshotPrefix.append(new Component(Version.type, encodedSV));
+      console.log('debug: targeted snapshot Prefix (persistStore key): ', snapshotPrefix.toString());
+      // /groupPrefix/32=snapshot/
+      console.log('debug: targeted snapshot Name: ', snapshotName.toString());
+      // /groupPrefix/32=snapshot/54=<stateVector>
+      const decodedSV = Decoder.decode(snapshotName.at(-1).value, StateVector);
+      console.log('debug: decoding encoded SV from snapshotName: ', decodedSV);
+      let count = 0;
+      for (const [_id, seq] of decodedSV) {
+        count += seq;
+      }
+      console.log('debug: decoding encoded SV total packet count: ', count);
+      console.log('This should match the state vector in the debug page and the previous count before encoding');
 
-        const content = Y.encodeStateAsUpdate(this.doc)
-        // its already in UTF8, transporting currently without any additional encoding.
-        console.log('yjs backend data: ',content)
+      const content = Y.encodeStateAsUpdate(this.doc);
+      // its already in UTF8, transporting currently without any additional encoding.
+      console.log('yjs backend data: ', content);
 
-        // use syncAgent's blob and publish mechanism - use a different topic.
+      // use syncAgent's blob and publish mechanism - use a different topic.
 
-        await this.syncAgent.publishBlob('snapshot',content,snapshotName,true)
+      await this.syncAgent.publishBlob('snapshot', content, snapshotName, true);
 
-        //first segmented object is at /50=%00
-        const firstSegmentName = snapshotName.append('50=%00').toString()
-        console.log('debugTargetName: ', firstSegmentName)
-        const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName)
-        if (firstSegmentPacketEncoded){
-          const firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded,Data)
-          console.log('persistentStore check: ', firstSegmentPacket)
-          console.log('persistentStore check Data Name:', firstSegmentPacket.name.toString())
-          await this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
-        }
-        
+      //first segmented object is at /50=%00
+      const firstSegmentName = snapshotName.append('50=%00').toString();
+      console.log('debugTargetName: ', firstSegmentName);
+      const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName);
+      if (firstSegmentPacketEncoded) {
+        const firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded, Data);
+        console.log('persistentStore check: ', firstSegmentPacket);
+        console.log('persistentStore check Data Name:', firstSegmentPacket.name.toString());
+        await this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
+      }
     }
-}
-// End Injection point 1
+  }
+  // End Injection point 1
 
-// -- Adam Chen Injection Point 3: HandleSnapshotUpdate --
-async handleSnapshotUpdate(snapshotName: Uint8Array){
+  // -- Adam Chen Injection Point 3: HandleSnapshotUpdate --
+  async handleSnapshotUpdate(snapshotName: Uint8Array) {
     // Maybe it's wise to put this under a try() because it might fail due to network issues.
-    const decodedSnapshotName = Decoder.decode(snapshotName, Name)
-    console.log('-- Adam Chen Injection Point 3: Update Latest Snapshot (Received) --')
-    console.log('Handling received snapshot packet with name: ', decodedSnapshotName.toString())
+    const decodedSnapshotName = Decoder.decode(snapshotName, Name);
+    console.log('-- Adam Chen Injection Point 3: Update Latest Snapshot (Received) --');
+    console.log('Handling received snapshot packet with name: ', decodedSnapshotName.toString());
 
-    const snapshotPrefix = this.syncAgent.appPrefix.append("32=snapshot")
-    console.log('snapshot prefix in persistStorage: ', snapshotPrefix.toString())
-    const oldSnapshotFirstSegmentEncoded = await this.syncAgent.persistStorage.get(snapshotPrefix.toString())
-    let oldSVCount = 0
-    if (oldSnapshotFirstSegmentEncoded){
-        const oldSnapshotFirstSegment = Decoder.decode(oldSnapshotFirstSegmentEncoded, Data)
-        const oldSnapshotVector = Decoder.decode(oldSnapshotFirstSegment.name.at(-2).value,StateVector)
-        for (const [_id,seq] of oldSnapshotVector){
-            oldSVCount += seq
-        }
+    const snapshotPrefix = this.syncAgent.appPrefix.append('32=snapshot');
+    console.log('snapshot prefix in persistStorage: ', snapshotPrefix.toString());
+    const oldSnapshotFirstSegmentEncoded = await this.syncAgent.persistStorage.get(snapshotPrefix.toString());
+    let oldSVCount = 0;
+    if (oldSnapshotFirstSegmentEncoded) {
+      const oldSnapshotFirstSegment = Decoder.decode(oldSnapshotFirstSegmentEncoded, Data);
+      const oldSnapshotVector = Decoder.decode(oldSnapshotFirstSegment.name.at(-2).value, StateVector);
+      for (const [_id, seq] of oldSnapshotVector) {
+        oldSVCount += seq;
+      }
     }
 
-    const snapshotSV = Decoder.decode(decodedSnapshotName.at(-1).value,StateVector)
-    let snapshotSVcount = 0
-    for (const [_id,seq] of snapshotSV){
-        snapshotSVcount += seq
+    const snapshotSV = Decoder.decode(decodedSnapshotName.at(-1).value, StateVector);
+    let snapshotSVcount = 0;
+    for (const [_id, seq] of snapshotSV) {
+      snapshotSVcount += seq;
     }
 
-    console.log('current state vector total count: ', oldSVCount)
-    console.log('snapshot state vector total count: ', snapshotSVcount)
+    console.log('current state vector total count: ', oldSVCount);
+    console.log('snapshot state vector total count: ', snapshotSVcount);
 
-    if (snapshotSVcount>oldSVCount){
-        const firstSegmentName = decodedSnapshotName.append('50=%00').toString()
-        console.log('Retrieving the following from persist Storage: ', firstSegmentName)
-        // await this.syncAgent.getBlob(decodedSnapshotName)
-        await new Promise((r) => setTimeout(r, 1000))
-        const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName)
-        if (firstSegmentPacketEncoded){
-            console.log('Debug: Retrieval results: ', firstSegmentPacketEncoded)
-            const firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded, Data)
-            console.log('Writing this packet: ', firstSegmentPacket.name.toString())
-            console.log('To this location: ', snapshotPrefix.toString())
-            // this is done to update the key of the prefix so program return latest when blind fetching.
-            this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
-            // should set snapshotPrefix to the newest packet.
-        }
-        else {
-            console.log('PersistentStorage doesnt have the snapshot yet. Skipping update.')
-        }
-        
+    if (snapshotSVcount > oldSVCount) {
+      const firstSegmentName = decodedSnapshotName.append('50=%00').toString();
+      console.log('Retrieving the following from persist Storage: ', firstSegmentName);
+      // await this.syncAgent.getBlob(decodedSnapshotName)
+      await new Promise((r) => setTimeout(r, 1000));
+      const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName);
+      if (firstSegmentPacketEncoded) {
+        console.log('Debug: Retrieval results: ', firstSegmentPacketEncoded);
+        const firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded, Data);
+        console.log('Writing this packet: ', firstSegmentPacket.name.toString());
+        console.log('To this location: ', snapshotPrefix.toString());
+        // this is done to update the key of the prefix so program return latest when blind fetching.
+        this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
+        // should set snapshotPrefix to the newest packet.
+      } else {
+        console.log('PersistentStorage doesnt have the snapshot yet. Skipping update.');
+      }
     }
-}
-// End Injection point 3
+  }
+  // End Injection point 3
 
   public handleSyncUpdate(content: Uint8Array) {
     // Apply patch
diff --git a/src/sync-agent/sync-agent.ts b/src/sync-agent/sync-agent.ts
index aa57d9a..d1e3fa3 100644
--- a/src/sync-agent/sync-agent.ts
+++ b/src/sync-agent/sync-agent.ts
@@ -261,7 +261,7 @@ export class SyncAgent implements AsyncDisposable {
 
     const buffers: Uint8Array[] = [];
     //Adam Chen Debug
-    console.log('SyncAgent fetchBlob fetching: ', blobName.toString())
+    console.log('SyncAgent fetchBlob fetching: ', blobName.toString());
     try {
       const result = fetch(blobName, {
         verifier: this.verifier,
@@ -285,7 +285,7 @@ export class SyncAgent implements AsyncDisposable {
     // Save blob (SA getBlob())
     await this.persistStorage.set(blobName.toString(), blob);
     //Adam Chen Debug
-    console.log('SyncAgent fetchBlob complete.')
+    console.log('SyncAgent fetchBlob complete.');
   }
 
   public register(channel: ChannelType, topic: string, handler: (content: Uint8Array, id: Name) => void) {
@@ -360,21 +360,19 @@ export class SyncAgent implements AsyncDisposable {
     const intName = interest.name;
 
     // -- Adam Chen Injection point 2 --
-
     if (intName.get(this.appPrefix.length)?.equals(getNamespace().snapshotKeyword)) {
       // console.log('snapshot interest detected, custom routine activated')
-      const wire = await this.persistStorage.get(intName.toString())
+      const wire = await this.persistStorage.get(intName.toString());
       if (wire === undefined || wire.length === 0) {
-          // console.warn(`A remote peer is fetching a non-existing object: ${intName.toString()}`);
-          console.log('MISS: SnapshotInterest: ', intName.toString())
-          return undefined;
-      }
-      const data = Decoder.decode(wire, Data)
-      console.log('HIT: SnapshotInterest and Returned Data: ',intName.toString(),data.name.toString())
-      return data
+        // console.warn(`A remote peer is fetching a non-existing object: ${intName.toString()}`);
+        console.log('MISS: SnapshotInterest: ', intName.toString());
+        return undefined;
       }
-
-      // -- End Injection point 2 --
+      const data = Decoder.decode(wire, Data);
+      console.log('HIT: SnapshotInterest and Returned Data: ', intName.toString(), data.name.toString());
+      return data;
+    }
+    // -- End Injection point 2 --
 
     if (intName.length <= this.appPrefix.length + 1) {
       // The name should be at least two components plus app prefix

From bf95bab1542e804fb3b43b9cccbeb33695c136f6 Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Wed, 14 Aug 2024 12:04:48 -0700
Subject: [PATCH 04/11] Annotations 1

---
 src/adaptors/yjs-ndn-adaptor.ts | 39 +++++++++++++++++++++++++++++----
 src/sync-agent/sync-agent.ts    |  2 ++
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index e0316ea..0298ffe 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -136,10 +136,16 @@ export class NdnSvsAdaptor {
     }
     console.log('Total count of state vector', count);
     console.log('The above number should match the state vector in the debug page');
+    // Snapshot Interval configuration: Currently hard-coded
+    // TODO: make the interval configurable
     if (count % 5 == 0) {
       console.log("It's time to make a snapshot!");
       console.log('debug: group prefix: ', this.syncAgent.appPrefix.toString());
       const encodedSV = Encoder.encode(stateVector);
+
+      // NOTE: The following code depend on snapshot naming convention to work.
+      // Verify this part if there's a change in naming convention.
+      // TODO: Currently naming convention is hard-coded. May need organizing.
       const snapshotPrefix = this.syncAgent.appPrefix.append('32=snapshot');
       // New SVS encodings
       const snapshotName = snapshotPrefix.append(new Component(Version.type, encodedSV));
@@ -156,15 +162,20 @@ export class NdnSvsAdaptor {
       console.log('debug: decoding encoded SV total packet count: ', count);
       console.log('This should match the state vector in the debug page and the previous count before encoding');
 
+      // Snapshot content generation
       const content = Y.encodeStateAsUpdate(this.doc);
-      // its already in UTF8, transporting currently without any additional encoding.
+      // its already in UInt8Array (binary), transporting currently without any additional encoding.
       console.log('yjs backend data: ', content);
 
-      // use syncAgent's blob and publish mechanism - use a different topic.
-
+      // use syncAgent's blob and publish mechanism
       await this.syncAgent.publishBlob('snapshot', content, snapshotName, true);
 
-      //first segmented object is at /50=%00
+      // NOTE: The following code depend on snapshot naming convention to work.
+      // Verify this part if there's a change in naming convention.
+      // Race Condition note: Testing suggests that the write above with publishBlob()
+      //                      is near certainly done before the read happens below.
+      //                      Hence no delay is added.
+      // first segmented object is at /50=%00
       const firstSegmentName = snapshotName.append('50=%00').toString();
       console.log('debugTargetName: ', firstSegmentName);
       const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName);
@@ -185,8 +196,14 @@ export class NdnSvsAdaptor {
     console.log('-- Adam Chen Injection Point 3: Update Latest Snapshot (Received) --');
     console.log('Handling received snapshot packet with name: ', decodedSnapshotName.toString());
 
+    // NOTE: The following code depend on snapshot naming convention to work.
+    // Verify this part if there's a change in naming convention.
     const snapshotPrefix = this.syncAgent.appPrefix.append('32=snapshot');
+    // /groupPrefix/32=snapshot/
     console.log('snapshot prefix in persistStorage: ', snapshotPrefix.toString());
+
+    // NOTE: The following code depend on snapshot naming convention to work.
+    // Verify this part if there's a change in naming convention.
     const oldSnapshotFirstSegmentEncoded = await this.syncAgent.persistStorage.get(snapshotPrefix.toString());
     let oldSVCount = 0;
     if (oldSnapshotFirstSegmentEncoded) {
@@ -197,18 +214,29 @@ export class NdnSvsAdaptor {
       }
     }
 
+    // NOTE: The following code depend on snapshot naming convention to work.
+    // Verify this part if there's a change in naming convention.
     const snapshotSV = Decoder.decode(decodedSnapshotName.at(-1).value, StateVector);
     let snapshotSVcount = 0;
     for (const [_id, seq] of snapshotSV) {
       snapshotSVcount += seq;
     }
 
+    // debug
     console.log('current state vector total count: ', oldSVCount);
     console.log('snapshot state vector total count: ', snapshotSVcount);
 
+    // NOTE: The following code depend on snapshot naming convention to work.
+    // Verify this part if there's a change in naming convention.
     if (snapshotSVcount > oldSVCount) {
       const firstSegmentName = decodedSnapshotName.append('50=%00').toString();
       console.log('Retrieving the following from persist Storage: ', firstSegmentName);
+      // Race Condition Note: The callback to here is faster than
+      //                      fetchBlob() finish writing to persistStore.
+      //                      (in syncAgent before listener callback to here)
+      //                      Tested getBlob() to guarantee item arrival
+      //                      But ends up having multiple active sessions of fetchBlob(). bad.
+      //                      Hence a delay of 1 second.
       // await this.syncAgent.getBlob(decodedSnapshotName)
       await new Promise((r) => setTimeout(r, 1000));
       const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName);
@@ -217,11 +245,14 @@ export class NdnSvsAdaptor {
         const firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded, Data);
         console.log('Writing this packet: ', firstSegmentPacket.name.toString());
         console.log('To this location: ', snapshotPrefix.toString());
+        // utilize snapshotPrefix above, with the same namingConvention warning.
         // this is done to update the key of the prefix so program return latest when blind fetching.
         this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
         // should set snapshotPrefix to the newest packet.
       } else {
         console.log('PersistentStorage doesnt have the snapshot yet. Skipping update.');
+        // If the above race condition fails (reads before data arrives),
+        // 'endpoint's blind fetch mechanism' is not updated to latest, should be fine.
       }
     }
   }
diff --git a/src/sync-agent/sync-agent.ts b/src/sync-agent/sync-agent.ts
index d1e3fa3..1822787 100644
--- a/src/sync-agent/sync-agent.ts
+++ b/src/sync-agent/sync-agent.ts
@@ -360,6 +360,8 @@ export class SyncAgent implements AsyncDisposable {
     const intName = interest.name;
 
     // -- Adam Chen Injection point 2 --
+    // NOTE: The following code depend on snapshot naming convention to work.
+    // Verify this part if there's a change in naming convention.
     if (intName.get(this.appPrefix.length)?.equals(getNamespace().snapshotKeyword)) {
       // console.log('snapshot interest detected, custom routine activated')
       const wire = await this.persistStorage.get(intName.toString());

From 9d48e9696dc27d926a90a6b9dcb59ba28604ad95 Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Wed, 14 Aug 2024 12:24:47 -0700
Subject: [PATCH 05/11] Move snapshot keyword out of namespace.ts

---
 src/sync-agent/namespace.ts  | 5 -----
 src/sync-agent/sync-agent.ts | 4 ++--
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/sync-agent/namespace.ts b/src/sync-agent/namespace.ts
index 3956e89..e9f70c4 100644
--- a/src/sync-agent/namespace.ts
+++ b/src/sync-agent/namespace.ts
@@ -53,9 +53,6 @@ export type SyncAgentNamespace = {
 
   /** Keyword component for latest only delivery. Default is `32=late` */
   readonly latestOnlyKeyword: Component;
-
-  /** Adam Chen: Keyword component for snapshots. Default is `32=snapshot` */
-  readonly snapshotKeyword: Component;
 };
 
 export function getNamespace(): SyncAgentNamespace {
@@ -106,8 +103,6 @@ function createDefaultNamespace(): SyncAgentNamespace {
     syncKeyword: KeywordComponent.create('sync'),
     atLeastOnceKeyword: KeywordComponent.create('alo'),
     latestOnlyKeyword: KeywordComponent.create('late'),
-    // Adam Chen Add snapshotKeyword
-    snapshotKeyword: KeywordComponent.create('snapshot'),
   };
   return ret;
 }
diff --git a/src/sync-agent/sync-agent.ts b/src/sync-agent/sync-agent.ts
index 1822787..362b7a1 100644
--- a/src/sync-agent/sync-agent.ts
+++ b/src/sync-agent/sync-agent.ts
@@ -1,6 +1,6 @@
 import * as endpoint from '@ndn/endpoint';
 import type { Forwarder } from '@ndn/fw';
-import { Data, type Interest, Name, Signer, type Verifier } from '@ndn/packet';
+import { Component, Data, type Interest, Name, Signer, type Verifier } from '@ndn/packet';
 import { Decoder, Encoder } from '@ndn/tlv';
 import { BufferChunkSource, DataProducer, fetch } from '@ndn/segmented-object';
 import { concatBuffers, fromHex } from '@ndn/util';
@@ -362,7 +362,7 @@ export class SyncAgent implements AsyncDisposable {
     // -- Adam Chen Injection point 2 --
     // NOTE: The following code depend on snapshot naming convention to work.
     // Verify this part if there's a change in naming convention.
-    if (intName.get(this.appPrefix.length)?.equals(getNamespace().snapshotKeyword)) {
+    if (intName.get(this.appPrefix.length)?.equals(Component.from('32=snapshot'))) {
       // console.log('snapshot interest detected, custom routine activated')
       const wire = await this.persistStorage.get(intName.toString());
       if (wire === undefined || wire.length === 0) {

From 05a716e82fa39fb81c1f247999569468fe743cd7 Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Sat, 28 Sep 2024 15:40:53 -0700
Subject: [PATCH 06/11] cleanup

---
 src/adaptors/yjs-ndn-adaptor.ts | 53 ++-------------------------------
 src/sync-agent/sync-agent.ts    |  7 -----
 2 files changed, 2 insertions(+), 58 deletions(-)

diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index 0298ffe..3848d67 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -43,16 +43,6 @@ export class NdnSvsAdaptor {
     syncAgent.register('blob', 'snapshot', (content) => this.handleSnapshotUpdate(content));
     doc.on('update', this.callback);
     if (useBundler) {
-      // this.#bundler = new Bundler(
-      //   Y.mergeUpdates,
-      //   (content) => this.syncAgent.publishUpdate(this.topic, content),
-      //   {
-      //     thresholdSize: 3000,
-      //     delayMs: 400,
-      //     maxDelayMs: 1600,
-      //   },
-      // );
-
       // Adam Chen Injection Point 1 override
       this.#bundler = new Bundler(
         Y.mergeUpdates,
@@ -115,8 +105,6 @@ export class NdnSvsAdaptor {
     if (this.#bundler) {
       await this.#bundler.produce(content);
     } else {
-      // await this.syncAgent.publishUpdate(this.topic, content);
-
       // Adam Chen Injection point 1 override
       await this.publishUpdate(this.topic, content);
     }
@@ -125,22 +113,15 @@ export class NdnSvsAdaptor {
   // Adam Chen Injection point 1
   private async publishUpdate(topic: string, content: Uint8Array) {
     await this.syncAgent.publishUpdate(topic, content);
-    // await new Promise(r => setTimeout(r,500));
-    // forced wait so that publishUpdate() is completed before we check SV.
-    console.log('-- Injection point 1: Check StateVector / Create Snapshot --');
+
     const stateVector = this.syncAgent.getUpdateSyncSV();
-    console.log('debug: stateVector object: ', stateVector);
     let count = 0;
     for (const [_id, seq] of stateVector) {
       count += seq;
     }
-    console.log('Total count of state vector', count);
-    console.log('The above number should match the state vector in the debug page');
     // Snapshot Interval configuration: Currently hard-coded
     // TODO: make the interval configurable
     if (count % 5 == 0) {
-      console.log("It's time to make a snapshot!");
-      console.log('debug: group prefix: ', this.syncAgent.appPrefix.toString());
       const encodedSV = Encoder.encode(stateVector);
 
       // NOTE: The following code depend on snapshot naming convention to work.
@@ -149,24 +130,10 @@ export class NdnSvsAdaptor {
       const snapshotPrefix = this.syncAgent.appPrefix.append('32=snapshot');
       // New SVS encodings
       const snapshotName = snapshotPrefix.append(new Component(Version.type, encodedSV));
-      console.log('debug: targeted snapshot Prefix (persistStore key): ', snapshotPrefix.toString());
-      // /groupPrefix/32=snapshot/
-      console.log('debug: targeted snapshot Name: ', snapshotName.toString());
-      // /groupPrefix/32=snapshot/54=<stateVector>
-      const decodedSV = Decoder.decode(snapshotName.at(-1).value, StateVector);
-      console.log('debug: decoding encoded SV from snapshotName: ', decodedSV);
-      let count = 0;
-      for (const [_id, seq] of decodedSV) {
-        count += seq;
-      }
-      console.log('debug: decoding encoded SV total packet count: ', count);
-      console.log('This should match the state vector in the debug page and the previous count before encoding');
 
       // Snapshot content generation
       const content = Y.encodeStateAsUpdate(this.doc);
       // its already in UInt8Array (binary), transporting currently without any additional encoding.
-      console.log('yjs backend data: ', content);
-
       // use syncAgent's blob and publish mechanism
       await this.syncAgent.publishBlob('snapshot', content, snapshotName, true);
 
@@ -177,12 +144,9 @@ export class NdnSvsAdaptor {
       //                      Hence no delay is added.
       // first segmented object is at /50=%00
       const firstSegmentName = snapshotName.append('50=%00').toString();
-      console.log('debugTargetName: ', firstSegmentName);
       const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName);
       if (firstSegmentPacketEncoded) {
         const firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded, Data);
-        console.log('persistentStore check: ', firstSegmentPacket);
-        console.log('persistentStore check Data Name:', firstSegmentPacket.name.toString());
         await this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
       }
     }
@@ -193,14 +157,10 @@ export class NdnSvsAdaptor {
   async handleSnapshotUpdate(snapshotName: Uint8Array) {
     // Maybe it's wise to put this under a try() because it might fail due to network issues.
     const decodedSnapshotName = Decoder.decode(snapshotName, Name);
-    console.log('-- Adam Chen Injection Point 3: Update Latest Snapshot (Received) --');
-    console.log('Handling received snapshot packet with name: ', decodedSnapshotName.toString());
 
     // NOTE: The following code depend on snapshot naming convention to work.
     // Verify this part if there's a change in naming convention.
     const snapshotPrefix = this.syncAgent.appPrefix.append('32=snapshot');
-    // /groupPrefix/32=snapshot/
-    console.log('snapshot prefix in persistStorage: ', snapshotPrefix.toString());
 
     // NOTE: The following code depend on snapshot naming convention to work.
     // Verify this part if there's a change in naming convention.
@@ -222,35 +182,26 @@ export class NdnSvsAdaptor {
       snapshotSVcount += seq;
     }
 
-    // debug
-    console.log('current state vector total count: ', oldSVCount);
-    console.log('snapshot state vector total count: ', snapshotSVcount);
-
     // NOTE: The following code depend on snapshot naming convention to work.
     // Verify this part if there's a change in naming convention.
     if (snapshotSVcount > oldSVCount) {
       const firstSegmentName = decodedSnapshotName.append('50=%00').toString();
-      console.log('Retrieving the following from persist Storage: ', firstSegmentName);
       // Race Condition Note: The callback to here is faster than
       //                      fetchBlob() finish writing to persistStore.
       //                      (in syncAgent before listener callback to here)
       //                      Tested getBlob() to guarantee item arrival
       //                      But ends up having multiple active sessions of fetchBlob(). bad.
       //                      Hence a delay of 1 second.
-      // await this.syncAgent.getBlob(decodedSnapshotName)
       await new Promise((r) => setTimeout(r, 1000));
       const firstSegmentPacketEncoded = await this.syncAgent.persistStorage.get(firstSegmentName);
       if (firstSegmentPacketEncoded) {
-        console.log('Debug: Retrieval results: ', firstSegmentPacketEncoded);
         const firstSegmentPacket = Decoder.decode(firstSegmentPacketEncoded, Data);
-        console.log('Writing this packet: ', firstSegmentPacket.name.toString());
-        console.log('To this location: ', snapshotPrefix.toString());
         // utilize snapshotPrefix above, with the same namingConvention warning.
         // this is done to update the key of the prefix so program return latest when blind fetching.
         this.syncAgent.persistStorage.set(snapshotPrefix.toString(), Encoder.encode(firstSegmentPacket));
         // should set snapshotPrefix to the newest packet.
       } else {
-        console.log('PersistentStorage doesnt have the snapshot yet. Skipping update.');
+        console.debug('PersistentStorage doesnt have the snapshot yet. Skipping update.');
         // If the above race condition fails (reads before data arrives),
         // 'endpoint's blind fetch mechanism' is not updated to latest, should be fine.
       }
diff --git a/src/sync-agent/sync-agent.ts b/src/sync-agent/sync-agent.ts
index e2b550a..f0e953a 100644
--- a/src/sync-agent/sync-agent.ts
+++ b/src/sync-agent/sync-agent.ts
@@ -260,8 +260,6 @@ export class SyncAgent implements AsyncDisposable {
     }
 
     const buffers: Uint8Array[] = [];
-    //Adam Chen Debug
-    console.log('SyncAgent fetchBlob fetching: ', blobName.toString());
     try {
       const result = fetch(blobName, {
         verifier: this.verifier,
@@ -283,8 +281,6 @@ export class SyncAgent implements AsyncDisposable {
 
     // Save blob (SA getBlob())
     await this.persistStorage.set(blobName.toString(), blob);
-    //Adam Chen Debug
-    console.log('SyncAgent fetchBlob complete.');
   }
 
   public register(channel: ChannelType, topic: string, handler: (content: Uint8Array, id: Name) => void) {
@@ -362,15 +358,12 @@ export class SyncAgent implements AsyncDisposable {
     // NOTE: The following code depend on snapshot naming convention to work.
     // Verify this part if there's a change in naming convention.
     if (intName.get(this.appPrefix.length)?.equals(Component.from('32=snapshot'))) {
-      // console.log('snapshot interest detected, custom routine activated')
       const wire = await this.persistStorage.get(intName.toString());
       if (wire === undefined || wire.length === 0) {
         // console.warn(`A remote peer is fetching a non-existing object: ${intName.toString()}`);
-        console.log('MISS: SnapshotInterest: ', intName.toString());
         return undefined;
       }
       const data = Decoder.decode(wire, Data);
-      console.log('HIT: SnapshotInterest and Returned Data: ', intName.toString(), data.name.toString());
       return data;
     }
     // -- End Injection point 2 --

From 715aa878ff3d0fa1fe0100f377d84190a64a174d Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Mon, 30 Sep 2024 14:28:00 -0700
Subject: [PATCH 07/11] comment fix

---
 src/adaptors/yjs-ndn-adaptor.ts | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index 3848d67..27c77d2 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -2,8 +2,6 @@ import { SyncAgent } from '../sync-agent/mod.ts';
 import * as Y from 'yjs';
 import { Awareness } from 'y-protocols/awareness.js';
 import { Bundler } from './bundler.ts';
-
-// Adam Chen Additional Imports
 import { Decoder, Encoder } from '@ndn/tlv';
 import { Component, Data, Name } from '@ndn/packet';
 import { Version } from '@ndn/naming-convention2';
@@ -43,7 +41,6 @@ export class NdnSvsAdaptor {
     syncAgent.register('blob', 'snapshot', (content) => this.handleSnapshotUpdate(content));
     doc.on('update', this.callback);
     if (useBundler) {
-      // Adam Chen Injection Point 1 override
       this.#bundler = new Bundler(
         Y.mergeUpdates,
         (content) => this.publishUpdate(this.topic, content),

From 0041767bdd0306676852ed5a422715ffc6edf797 Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Mon, 30 Sep 2024 15:32:32 -0700
Subject: [PATCH 08/11] untested: constructor arguments

---
 src/adaptors/yjs-ndn-adaptor.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index 27c77d2..6937ede 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -34,11 +34,13 @@ export class NdnSvsAdaptor {
     public syncAgent: SyncAgent,
     public readonly doc: Y.Doc,
     public readonly topic: string,
+    public readonly snapshotTopic: string = 'snapshot',
+    public readonly snapshotFrequency: number = 10,
     useBundler: boolean = false,
   ) {
     syncAgent.register('update', topic, (content) => this.handleSyncUpdate(content));
     // Adam Chen callback on receiving a snapshot blob for Injection Point 3
-    syncAgent.register('blob', 'snapshot', (content) => this.handleSnapshotUpdate(content));
+    syncAgent.register('blob', snapshotTopic, (content) => this.handleSnapshotUpdate(content));
     doc.on('update', this.callback);
     if (useBundler) {
       this.#bundler = new Bundler(
@@ -118,7 +120,7 @@ export class NdnSvsAdaptor {
     }
     // Snapshot Interval configuration: Currently hard-coded
     // TODO: make the interval configurable
-    if (count % 5 == 0) {
+    if (count % this.snapshotFrequency == 0) {
       const encodedSV = Encoder.encode(stateVector);
 
       // NOTE: The following code depend on snapshot naming convention to work.

From f7904889365f390b53323ad5bcf7c22a77f131f7 Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Wed, 2 Oct 2024 13:26:02 -0700
Subject: [PATCH 09/11] clean up part 2

---
 src/adaptors/yjs-ndn-adaptor.ts | 11 ++---------
 src/sync-agent/sync-agent.ts    |  2 --
 2 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index 6937ede..fdbe1ef 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -39,7 +39,6 @@ export class NdnSvsAdaptor {
     useBundler: boolean = false,
   ) {
     syncAgent.register('update', topic, (content) => this.handleSyncUpdate(content));
-    // Adam Chen callback on receiving a snapshot blob for Injection Point 3
     syncAgent.register('blob', snapshotTopic, (content) => this.handleSnapshotUpdate(content));
     doc.on('update', this.callback);
     if (useBundler) {
@@ -104,12 +103,10 @@ export class NdnSvsAdaptor {
     if (this.#bundler) {
       await this.#bundler.produce(content);
     } else {
-      // Adam Chen Injection point 1 override
       await this.publishUpdate(this.topic, content);
     }
   }
 
-  // Adam Chen Injection point 1
   private async publishUpdate(topic: string, content: Uint8Array) {
     await this.syncAgent.publishUpdate(topic, content);
 
@@ -118,14 +115,13 @@ export class NdnSvsAdaptor {
     for (const [_id, seq] of stateVector) {
       count += seq;
     }
-    // Snapshot Interval configuration: Currently hard-coded
-    // TODO: make the interval configurable
+
     if (count % this.snapshotFrequency == 0) {
       const encodedSV = Encoder.encode(stateVector);
 
       // NOTE: The following code depend on snapshot naming convention to work.
       // Verify this part if there's a change in naming convention.
-      // TODO: Currently naming convention is hard-coded. May need organizing.
+      // NOTE: Currently naming convention is hard-coded. May need organizing.
       const snapshotPrefix = this.syncAgent.appPrefix.append('32=snapshot');
       // New SVS encodings
       const snapshotName = snapshotPrefix.append(new Component(Version.type, encodedSV));
@@ -150,9 +146,7 @@ export class NdnSvsAdaptor {
       }
     }
   }
-  // End Injection point 1
 
-  // -- Adam Chen Injection Point 3: HandleSnapshotUpdate --
   async handleSnapshotUpdate(snapshotName: Uint8Array) {
     // Maybe it's wise to put this under a try() because it might fail due to network issues.
     const decodedSnapshotName = Decoder.decode(snapshotName, Name);
@@ -206,7 +200,6 @@ export class NdnSvsAdaptor {
       }
     }
   }
-  // End Injection point 3
 
   public handleSyncUpdate(content: Uint8Array) {
     // Apply patch
diff --git a/src/sync-agent/sync-agent.ts b/src/sync-agent/sync-agent.ts
index f0e953a..e94f446 100644
--- a/src/sync-agent/sync-agent.ts
+++ b/src/sync-agent/sync-agent.ts
@@ -354,7 +354,6 @@ export class SyncAgent implements AsyncDisposable {
   async serve(interest: Interest) {
     const intName = interest.name;
 
-    // -- Adam Chen Injection point 2 --
     // NOTE: The following code depend on snapshot naming convention to work.
     // Verify this part if there's a change in naming convention.
     if (intName.get(this.appPrefix.length)?.equals(Component.from('32=snapshot'))) {
@@ -366,7 +365,6 @@ export class SyncAgent implements AsyncDisposable {
       const data = Decoder.decode(wire, Data);
       return data;
     }
-    // -- End Injection point 2 --
 
     if (intName.length <= this.appPrefix.length + 1) {
       // The name should be at least two components plus app prefix

From c24e5eb31c17dfac261fcb7192083f5056d6957c Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Wed, 2 Oct 2024 13:37:06 -0700
Subject: [PATCH 10/11] add comment

---
 src/adaptors/yjs-ndn-adaptor.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index fdbe1ef..2d4989b 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -177,6 +177,11 @@ export class NdnSvsAdaptor {
 
     // NOTE: The following code depend on snapshot naming convention to work.
     // Verify this part if there's a change in naming convention.
+    // NOTE: From Github Discussion:
+    // Though, this "update the snapshot response strategy on receiving new snapshot from SVS" logic is somewhat optional in nature. 
+    // It is ran, such that if a blind fetch request reaches an endpoint, endpoint returns a good response. 
+    // Just like snapshot responses, we don't have to guarantee absolute latest when it is about blind fetching.
+    // hence we can just use a rough "total count" for determining if it needs an update.
     if (snapshotSVcount > oldSVCount) {
       const firstSegmentName = decodedSnapshotName.append('50=%00').toString();
       // Race Condition Note: The callback to here is faster than

From 2427535a584f14e2b775208ef31bee163bfe0b55 Mon Sep 17 00:00:00 2001
From: Adam Chen <mr.adam@foxmail.com>
Date: Wed, 2 Oct 2024 21:29:37 -0700
Subject: [PATCH 11/11] hotfix lint

---
 src/adaptors/yjs-ndn-adaptor.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/adaptors/yjs-ndn-adaptor.ts b/src/adaptors/yjs-ndn-adaptor.ts
index 2d4989b..813529c 100644
--- a/src/adaptors/yjs-ndn-adaptor.ts
+++ b/src/adaptors/yjs-ndn-adaptor.ts
@@ -178,8 +178,8 @@ export class NdnSvsAdaptor {
     // NOTE: The following code depend on snapshot naming convention to work.
     // Verify this part if there's a change in naming convention.
     // NOTE: From Github Discussion:
-    // Though, this "update the snapshot response strategy on receiving new snapshot from SVS" logic is somewhat optional in nature. 
-    // It is ran, such that if a blind fetch request reaches an endpoint, endpoint returns a good response. 
+    // Though, this "update the snapshot response strategy on receiving new snapshot from SVS" logic is somewhat optional in nature.
+    // It is ran, such that if a blind fetch request reaches an endpoint, endpoint returns a good response.
     // Just like snapshot responses, we don't have to guarantee absolute latest when it is about blind fetching.
     // hence we can just use a rough "total count" for determining if it needs an update.
     if (snapshotSVcount > oldSVCount) {