pruneNewest

lib/algorithm.js

@@ -74,7 +74,8 @@ class Algorithm {
    * @returns {Range}
    */
   #wantOldestRange(localHaveRange, remoteHaveRange, count) {
-    // FIXME:
+    // TODO: implement
+    throw new Error('not implemented')
   }
 
   /**
@@ -140,16 +141,39 @@ class Algorithm {
     }
   }
 
-  async commit(newMsgs, rootMsgHash, cb) {
+  async pruneNewest(rootMsgHash, count) {
+    const tangle = this.#peer.db.getTangle(rootMsgHash)
+    const sorted = tangle.topoSort()
+    if (sorted.length <= count) return
+    const msgHash = sorted[sorted.length - count]
+    const { deletables, erasables } = tangle.getDeletablesAndErasables(msgHash)
+    const del = p(this.#peer.db.del)
+    const erase = p(this.#peer.db.erase)
+    for (const msgHash of deletables) {
+      await del(msgHash)
+    }
+    for (const msgHash of erasables) {
+      await erase(msgHash)
+    }
+  }
+
+  async commit(newMsgs, rootMsgHash, goal) {
+    // Add new messages
     newMsgs.sort((a, b) => {
       const aDepth = a.metadata.tangles[rootMsgHash].depth
       const bDepth = b.metadata.tangles[rootMsgHash].depth
       return aDepth - bDepth
     })
+    // FIXME: if invalid (does not reach root), reject
+    // FIXME: if newMsgs are too new, drop my tangle and reset
+    // FIXME: if newMsgs are too old, reject newMsgs
     for (const msg of newMsgs) {
       await p(this.#peer.db.add)(msg, rootMsgHash)
     }
-    cb()
+
+    const { type, count } = parseGoal(goal)
+    if (type === 'newest') return await this.pruneNewest(rootMsgHash, count)
+    if (type === 'oldest') throw new Error('not implemented') // TODO:
   }
 
   getMsgs(msgIds) {

lib/stream.js

@@ -252,6 +252,7 @@ class SyncStream extends Pipeable {
     this.#debug('%s Stream OUT: send %s msgs in %s', this.#myId, msgs.length, id)
     this.sink.write({ id, phase: 10, payload: msgs })
 
+    const goal = this.#goals.get(id)
     this.#requested.delete(id)
     this.#localHave.delete(id)
     this.#localWant.delete(id)
@@ -260,16 +261,14 @@ class SyncStream extends Pipeable {
     this.#receivableMsgs.delete(id)
     this.#sendableMsgs.delete(id)
     if (msgsForMe.length === 0) return
-    this.#algo.commit(msgsForMe, id, (err) => {
-      // prettier-ignore
-      if (err) throw new Error('sendMissingMsgsRes failed because sink failed', {cause: err})
-    })
+    this.#algo.commit(msgsForMe, id, goal)
   }
 
   #consumeMissingMsgs(id, msgsForMe) {
     // prettier-ignore
     this.#debug('%s Stream IN: received %s msgs in %s', this.#myId, msgsForMe.length, id)
 
+    const goal = this.#goals.get(id)
     this.#requested.delete(id)
     this.#localHave.delete(id)
     this.#localWant.delete(id)
@@ -278,10 +277,7 @@ class SyncStream extends Pipeable {
     this.#receivableMsgs.delete(id)
     this.#sendableMsgs.delete(id)
     if (msgsForMe.length === 0) return
-    this.#algo.commit(msgsForMe, id, (err) => {
-      // prettier-ignore
-      if (err) throw new Error('sendMissingMsgsRes failed because sink failed', {cause: err})
-    })
+    this.#algo.commit(msgsForMe, id, goal)
   }
 
   #sendMsgsInRemoteWant(id, remoteWantRange) {

test/feed-sync.test.js

@@ -13,7 +13,7 @@ const createPeer = SecretStack({ appKey: caps.shs })
   .use(require('ssb-box'))
   .use(require('../'))
 
-test('sync a normal feed', async (t) => {
+test('sync a feed with goal=all', async (t) => {
   const ALICE_DIR = path.join(os.tmpdir(), 'dagsync-alice')
   const BOB_DIR = path.join(os.tmpdir(), 'dagsync-bob')
 
@@ -92,11 +92,7 @@ test('sync a normal feed', async (t) => {
   await p(bob.close)(true)
 })
 
-// FIXME:
-test.skip('sync a sliced feed', async (t) => {})
-
-// FIXME:
-test.skip('delete old msgs and sync latest msgs', async (t) => {
+test('sync a feed with goal=newest', async (t) => {
   const ALICE_DIR = path.join(os.tmpdir(), 'dagsync-alice')
   const BOB_DIR = path.join(os.tmpdir(), 'dagsync-bob')
 
@@ -111,9 +107,6 @@ test.skip('delete old msgs and sync latest msgs', async (t) => {
   const bob = createPeer({
     keys: generateKeypair('bob'),
     path: BOB_DIR,
-    feedSync: {
-      limit: 3,
-    },
   })
 
   await alice.db.loaded()
@@ -122,39 +115,55 @@ test.skip('delete old msgs and sync latest msgs', async (t) => {
   const carolKeys = generateKeypair('carol')
   const carolMsgs = []
   const carolID = carolKeys.id
+  const carolID_b58 = FeedV1.stripAuthor(carolID)
   for (let i = 1; i <= 10; i++) {
-    const msg = await p(alice.db.create)({
-      feedFormat: 'classic',
-      content: { type: 'post', text: 'm' + i },
+    const rec = await p(alice.db.create)({
+      type: 'post',
+      content: { text: 'm' + i },
       keys: carolKeys,
     })
-    carolMsgs.push(msg)
+    carolMsgs.push(rec.msg)
   }
   t.pass('alice has msgs 1..10 from carol')
 
-  await p(bob.db.add)(carolMsgs[5].value)
-  await p(bob.db.add)(carolMsgs[6].value)
-  await p(bob.db.add)(carolMsgs[7].value)
+  const carolRootHash = alice.db.getFeedRoot(carolID, 'post')
+  const carolRootMsg = alice.db.get(carolRootHash)
+
+  await p(bob.db.add)(carolRootMsg, carolRootHash)
+  for (let i = 0; i < 7; i++) {
+    await p(bob.db.add)(carolMsgs[i], carolRootHash)
+  }
 
   {
-    const arr = bob.db
-      .filterAsArray((msg) => msg?.value.author === carolID)
-      .map((msg) => msg.value.content.text)
-    t.deepEquals(arr, ['m6', 'm7', 'm8'], 'bob has msgs 6..8 from carol')
+    const arr = [...bob.db.msgs()]
+      .filter((msg) => msg.metadata.who === carolID_b58 && msg.content)
+      .map((msg) => msg.content.text)
+    t.deepEquals(
+      arr,
+      ['m1', 'm2', 'm3', 'm4', 'm5', 'm6', 'm7'],
+      'bob has msgs 1..7 from carol'
+    )
   }
 
+  bob.tangleSync.setGoal(carolRootHash, 'newest-5')
+  alice.tangleSync.setGoal(carolRootHash, 'all')
+
   const remoteAlice = await p(bob.connect)(alice.getAddress())
   t.pass('bob connected to alice')
 
-  bob.feedSync.request(carolID)
+  bob.tangleSync.initiate()
   await p(setTimeout)(1000)
-  t.pass('feedSync!')
+  t.pass('tangleSync!')
 
   {
-    const arr = bob.db
-      .filterAsArray((msg) => msg?.value.author === carolID)
-      .map((msg) => msg.value.content.text)
-    t.deepEquals(arr, ['m8', 'm9', 'm10'], 'bob has msgs 8..10 from carol')
+    const arr = [...bob.db.msgs()]
+      .filter((msg) => msg.metadata.who === carolID_b58 && msg.content)
+      .map((msg) => msg.content.text)
+    t.deepEquals(
+      arr,
+      ['m6', 'm7', 'm8', 'm9', 'm10'],
+      'bob has msgs 6..10 from carol'
+    )
   }
 
   await p(remoteAlice.close)(true)