From afa182609ab881ed5dfab291b15e70f2fa661005 Mon Sep 17 00:00:00 2001
From: Christophe Diederichs <chm-diederichs@protonmail.com>
Date: Wed, 2 Oct 2024 17:25:57 +0100
Subject: [PATCH 1/2] commit acquires lock directly

---
 lib/core.js | 73 +++++++++++++++++++++++++----------------------------
 1 file changed, 35 insertions(+), 38 deletions(-)

diff --git a/lib/core.js b/lib/core.js
index 4790f3cd..f8639958 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -389,32 +389,6 @@ class SessionState {
       this.mutex.unlock()
     }
   }
-
-  async upgrade (start, end, batch, values, keyPair) {
-    await this.mutex.lock()
-
-    const update = this.createUpdate()
-
-    try {
-      // upsert compat manifest
-      if (this.core.verifier === null && keyPair) this.core._setManifest(update, null, keyPair)
-
-      this.blocks.putBatch(update.batch, start, values)
-
-      update.bitfield.setRange(start, end, true)
-      update.flushTreeBatch(batch)
-
-      const bitfield = { start, length: end - start, drop: false }
-      const status = batch.upgraded ? 0b0001 : 0
-
-      update.coreUpdate({ status, bitfield, value: null, from: null })
-
-      await this.flushUpdate(update)
-    } finally {
-      this._clearActiveBatch()
-      this.mutex.unlock()
-    }
-  }
 }
 
 module.exports = class Core {
@@ -863,24 +837,47 @@ module.exports = class Core {
       }
     }
 
-    const promises = []
+    await this.state.mutex.lock()
 
-    const reader = state.storage.createReadBatch()
-    for (let i = treeLength; i < length; i++) promises.push(reader.getBlock(i))
-    reader.tryFlush()
+    const update = this.state.createUpdate()
 
-    const values = await Promise.all(promises)
+    try {
+      const promises = []
 
-    const batch = await this.tree.reconcile(state.tree, length, treeLength)
-    if (batch.upgraded) batch.signature = signature || this.verifier.sign(batch, keyPair)
+      const reader = state.storage.createReadBatch()
+      for (let i = treeLength; i < length; i++) promises.push(reader.getBlock(i))
+      reader.tryFlush()
 
-    await this.state.upgrade(treeLength, length, batch, values, keyPair)
+      const values = await Promise.all(promises)
 
-    state.treeLength = batch.length
+      const batch = await this.tree.reconcile(state.tree, length, treeLength)
+      if (batch.upgraded) batch.signature = signature || this.verifier.sign(batch, keyPair)
 
-    return {
-      length: batch.length,
-      byteLength: batch.byteLength
+      // upsert compat manifest
+      if (this.verifier === null && keyPair) this._setManifest(update, null, keyPair)
+
+      this.state.blocks.putBatch(update.batch, treeLength, values)
+
+      update.bitfield.setRange(treeLength, length, true)
+      update.flushTreeBatch(batch)
+
+      const bitfield = { start: treeLength, length: length - treeLength, drop: false }
+      const status = batch.upgraded ? 0b0001 : 0
+
+      update.coreUpdate({ status, bitfield, value: null, from: null })
+
+      await this.state.flushUpdate(update)
+
+      state.treeLength = batch.length
+
+      return {
+        length: batch.length,
+        byteLength: batch.byteLength
+      }
+    } finally {
+      this.state._clearActiveBatch()
+      this.updating = false
+      this.state.mutex.unlock()
     }
   }
 

From 2f590a9c791e7887dcddadeec81348e8b969e1fb Mon Sep 17 00:00:00 2001
From: Christophe Diederichs <chm-diederichs@protonmail.com>
Date: Mon, 7 Oct 2024 16:44:00 +0100
Subject: [PATCH 2/2] check conditions after acquiring lock

---
 lib/core.js | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/lib/core.js b/lib/core.js
index f8639958..e2634e63 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -824,24 +824,24 @@ module.exports = class Core {
   }
 
   async commit (state, { signature, keyPair = this.header.keyPair, length = state.tree.length, treeLength = state.treeLength } = {}) {
-    if (this.tree.fork !== state.tree.fork) return null
-
-    if (this.tree.length > state.tree.length) return null // TODO: partial commit in the future if possible
-
-    if (this.tree.length > treeLength) {
-      for (const root of this.tree.roots) {
-        const batchRoot = await state.tree.get(root.index)
-        if (batchRoot.size !== root.size || !b4a.equals(batchRoot.hash, root.hash)) {
-          return null
-        }
-      }
-    }
-
     await this.state.mutex.lock()
 
     const update = this.state.createUpdate()
 
     try {
+      if (this.tree.fork !== state.tree.fork) return null
+
+      if (this.tree.length > state.tree.length) return null // TODO: partial commit in the future if possible
+
+      if (this.tree.length > treeLength) {
+        for (const root of this.tree.roots) {
+          const batchRoot = await state.tree.get(root.index)
+          if (batchRoot.size !== root.size || !b4a.equals(batchRoot.hash, root.hash)) {
+            return null
+          }
+        }
+      }
+
       const promises = []
 
       const reader = state.storage.createReadBatch()