perf: reduce graph load memory and clone overhead

index.js

@@ -5423,11 +5423,8 @@ function applyShadowSnapshotToRuntime(
 
   let shadowGraph = null;
   try {
-    shadowGraph = cloneGraphForPersistence(
+    shadowGraph = normalizeGraphRuntimeState(
-      normalizeGraphRuntimeState(
+      deserializeGraph(shadowSnapshot.serializedGraph),
-        deserializeGraph(shadowSnapshot.serializedGraph),
-        normalizedChatId,
-      ),
       normalizedChatId,
     );
   } catch (error) {
@@ -5970,6 +5967,12 @@ function isIndexedDbSnapshotMeaningful(snapshot = null) {
 
   if (Array.isArray(snapshot.nodes) && snapshot.nodes.length > 0) return true;
   if (Array.isArray(snapshot.edges) && snapshot.edges.length > 0) return true;
+  if (
+    snapshot.__stBmeTombstonesOmitted === true &&
+    Number(snapshot?.meta?.tombstoneCount || 0) > 0
+  ) {
+    return true;
+  }
   if (Array.isArray(snapshot.tombstones) && snapshot.tombstones.length > 0)
     return true;
 
@@ -6017,6 +6020,7 @@ function isIndexedDbSnapshotMeaningful(snapshot = null) {
 function cacheIndexedDbSnapshot(chatId, snapshot = null) {
   const normalizedChatId = normalizeChatIdCandidate(chatId);
   if (!normalizedChatId || !snapshot || typeof snapshot !== "object") return;
+  if (snapshot.__stBmeTombstonesOmitted === true) return;
   const snapshotStore = resolveSnapshotGraphStorePresentation(snapshot);
   bmeIndexedDbSnapshotCacheByChatId.set(normalizedChatId, {
     chatId: normalizedChatId,
@@ -6311,10 +6315,7 @@ async function readLocalCacheSnapshotForChat(chatId, source = "luker-sidecar-loa
     const manager = ensureBmeChatManager();
     if (!manager) return null;
     const db = await manager.getCurrentDb(normalizedChatId);
-    const snapshot = await db.exportSnapshot();
+    const snapshot = await db.exportSnapshot({ includeTombstones: false });
-    if (snapshot) {
-      cacheIndexedDbSnapshot(normalizedChatId, snapshot);
-    }
     return snapshot;
   } catch (error) {
     console.warn("[ST-BME] 读取 Luker 本地缓存快照失败:", source, error);
@@ -6394,11 +6395,8 @@ function buildSnapshotFromLukerSidecarState(
   let snapshot = null;
   if (sidecar?.checkpoint?.serializedGraph) {
     try {
-      const checkpointGraph = cloneGraphForPersistence(
+      const checkpointGraph = normalizeGraphRuntimeState(
-        normalizeGraphRuntimeState(
+        deserializeGraph(sidecar.checkpoint.serializedGraph),
-          deserializeGraph(sidecar.checkpoint.serializedGraph),
-          normalizedChatId,
-        ),
         normalizedChatId,
       );
       snapshot = buildSnapshotFromGraph(checkpointGraph, {
@@ -6437,8 +6435,8 @@ function buildSnapshotFromLukerSidecarState(
       headRevision: Number(normalizedManifest.headRevision || 0),
     };
   } else {
-    const emptyGraph = cloneGraphForPersistence(
+    const emptyGraph = normalizeGraphRuntimeState(
-      normalizeGraphRuntimeState(createEmptyGraph(), normalizedChatId),
+      createEmptyGraph(),
       normalizedChatId,
     );
     snapshot = buildSnapshotFromGraph(emptyGraph, {
@@ -7659,11 +7657,8 @@ async function loadGraphFromChatState(
 
   let chatStateGraph = null;
   try {
-    chatStateGraph = cloneGraphForPersistence(
+    chatStateGraph = normalizeGraphRuntimeState(
-      normalizeGraphRuntimeState(
+      deserializeGraph(payload.serializedGraph),
-        deserializeGraph(payload.serializedGraph),
-        normalizedChatId,
-      ),
       normalizedChatId,
     );
   } catch (error) {
@@ -7953,13 +7948,9 @@ async function readPersistedGraphForChatStateTarget(
   });
   if (sidecarResult?.ok && sidecarResult?.snapshot) {
     try {
-      return cloneGraphForPersistence(
+      return buildGraphFromSnapshot(sidecarResult.snapshot, {
-        normalizeGraphRuntimeState(
+        chatId: targetChatId,
-          buildGraphFromSnapshot(sidecarResult.snapshot),
+      });
-          targetChatId,
-        ),
-        targetChatId,
-      );
     } catch (error) {
       console.warn("[ST-BME] 读取 Luker branch source snapshot 失败:", error);
     }
@@ -7971,11 +7962,8 @@ async function readPersistedGraphForChatStateTarget(
   });
   if (legacySnapshot?.serializedGraph) {
     try {
-      return cloneGraphForPersistence(
+      return normalizeGraphRuntimeState(
-        normalizeGraphRuntimeState(
+        deserializeGraph(legacySnapshot.serializedGraph),
-          deserializeGraph(legacySnapshot.serializedGraph),
-          targetChatId,
-        ),
         targetChatId,
       );
     } catch (error) {
@@ -8175,10 +8163,13 @@ function readLegacyGraphFromChatMetadata(chatId, context = getContext()) {
       typeof legacyGraph === "string"
         ? deserializeGraph(legacyGraph)
         : legacyGraph;
-    return cloneGraphForPersistence(
+    const normalizedLegacyGraph = normalizeGraphRuntimeState(
-      normalizeGraphRuntimeState(hydratedLegacyGraph, normalizedChatId),
+      hydratedLegacyGraph,
       normalizedChatId,
     );
+    return typeof legacyGraph === "string"
+      ? normalizedLegacyGraph
+      : cloneGraphForPersistence(normalizedLegacyGraph, normalizedChatId);
   } catch (error) {
     console.warn("[ST-BME] 读取 legacy chat_metadata 图谱失败:", error);
     return null;
@@ -9218,10 +9209,7 @@ function applyIndexedDbSnapshotToRuntime(
       attemptIndex,
     };
   }
-  currentGraph = cloneGraphForPersistence(
+  currentGraph = graphFromSnapshot;
-    normalizeGraphRuntimeState(graphFromSnapshot, normalizedChatId),
-    normalizedChatId,
-  );
   stampGraphPersistenceMeta(currentGraph, {
     revision,
     reason: `${reasonPrefix}:${String(source || reasonPrefix)}`,
@@ -9485,7 +9473,7 @@ async function loadGraphFromIndexedDb(
       identityRecoveryResult?.snapshot ||
       localStoreMigrationResult?.snapshot ||
       migrationResult?.snapshot ||
-      (await db.exportSnapshot());
+      (await db.exportSnapshot({ includeTombstones: false }));
     const shadowSnapshot = resolveCompatibleGraphShadowSnapshot(
       resolveCurrentChatIdentity(getContext()),
     );
@@ -10802,11 +10790,8 @@ function resolvePendingPersistGraphSource(chatId = "") {
     shadowSnapshot.serializedGraph
   ) {
     try {
-      const shadowGraph = cloneGraphForPersistence(
+      const shadowGraph = normalizeGraphRuntimeState(
-        normalizeGraphRuntimeState(
+        deserializeGraph(shadowSnapshot.serializedGraph),
-          deserializeGraph(shadowSnapshot.serializedGraph),
-          normalizedChatId,
-        ),
         normalizedChatId,
       );
       return {
@@ -11376,7 +11361,9 @@ async function persistExtractionBatchResult({
   const context = getContext();
   const persistGraph =
     graphSnapshot && typeof graphSnapshot === "object"
-      ? cloneGraphSnapshot(graphSnapshot)
+      ? graphSnapshot === currentGraph
+        ? cloneGraphSnapshot(graphSnapshot)
+        : graphSnapshot
       : currentGraph;
   if (!context || !persistGraph) {
     return buildGraphPersistResult({
@@ -12847,10 +12834,14 @@ function loadGraphFromChat(options = {}) {
     : undefined;
   if (savedData != null && savedData !== "") {
     try {
-      const officialGraph = cloneGraphForPersistence(
+      const hydratedOfficialGraph = normalizeGraphRuntimeState(
-        normalizeGraphRuntimeState(deserializeGraph(savedData), chatId),
+        deserializeGraph(savedData),
         chatId,
       );
+      const officialGraph =
+        typeof savedData === "string"
+          ? hydratedOfficialGraph
+          : cloneGraphForPersistence(hydratedOfficialGraph, chatId);
       const shadowDecision = shouldPreferShadowSnapshotOverOfficial(
         officialGraph,
         shadowSnapshot,

maintenance/extraction-controller.js

@@ -297,7 +297,7 @@ function buildCommittedBatchPersistSnapshot(
       : null,
     rangeEnd,
   ];
-  const afterSnapshot = runtime.cloneGraphSnapshot(graph);
+  const afterSnapshot = graph;
   const effectiveArtifacts = Array.isArray(postProcessArtifacts)
     ? [...postProcessArtifacts]
     : [];
@@ -357,17 +357,12 @@ function buildCommittedBatchPersistSnapshot(
     persistGraphSnapshot: committedGraphSnapshot,
     committedBatchJournalEntry,
     afterSnapshot,
-    committedAfterSnapshot: runtime.cloneGraphSnapshot(committedGraphSnapshot),
+    committedAfterSnapshot: committedGraphSnapshot,
     postProcessArtifacts: effectiveArtifacts,
   };
 }
 
 function isPersistenceRevisionAccepted(runtime, persistence = null) {
-  if (!persistence || persistence.accepted === true) return true;
-  const graphPersistenceState = runtime?.getGraphPersistenceState?.() || {};
-  if (graphPersistenceState.pendingPersist === true) {
-    return false;
-  }
   const persistenceRevision = Number(persistence?.revision || 0);
   if (!Number.isFinite(persistenceRevision) || persistenceRevision <= 0) {
     return false;
@@ -645,7 +640,7 @@ export async function executeExtractionBatchController(
     processedRange: [startIdx, endIdx],
     postProcessArtifacts: runtime.computePostProcessArtifacts(
       beforeSnapshot,
-      runtime.cloneGraphSnapshot(runtime.getCurrentGraph()),
+      runtime.getCurrentGraph(),
       effects?.postProcessArtifacts || [],
     ),
     vectorHashesInserted: effects?.vectorHashesInserted || [],

sync/bme-db.js

@@ -2013,6 +2013,14 @@ export function buildGraphFromSnapshot(snapshot, options = {}) {
     normalizeChatId(options.chatId) ||
     normalizeChatId(snapshotMeta?.chatId) ||
     normalizeChatId(snapshotState?.chatId);
+  const snapshotHistoryState = toPlainData(
+    snapshotMeta?.[BME_RUNTIME_HISTORY_META_KEY],
+    {},
+  );
+  const snapshotVectorState = toPlainData(
+    snapshotMeta?.[BME_RUNTIME_VECTOR_META_KEY],
+    {},
+  );
 
   const runtimeGraph = createEmptyGraph();
   runtimeGraph.version = Number.isFinite(
@@ -2020,21 +2028,17 @@ export function buildGraphFromSnapshot(snapshot, options = {}) {
   )
     ? Number(snapshotMeta[BME_RUNTIME_GRAPH_VERSION_META_KEY])
     : runtimeGraph.version;
-  runtimeGraph.nodes = toArray(snapshotView.nodes).map((node) => ({
+  runtimeGraph.nodes = toArray(toPlainData(snapshotView.nodes, []));
-    ...(node || {}),
+  runtimeGraph.edges = toArray(toPlainData(snapshotView.edges, []));
-  }));
-  runtimeGraph.edges = toArray(snapshotView.edges).map((edge) => ({
-    ...(edge || {}),
-  }));
   runtimeGraph.batchJournal = toArray(
-    snapshotMeta?.[BME_RUNTIME_BATCH_JOURNAL_META_KEY],
+    toPlainData(snapshotMeta?.[BME_RUNTIME_BATCH_JOURNAL_META_KEY], []),
   );
   runtimeGraph.lastRecallResult = toPlainData(
     snapshotMeta?.[BME_RUNTIME_LAST_RECALL_META_KEY],
     null,
   );
   runtimeGraph.maintenanceJournal = toArray(
-    snapshotMeta?.[BME_RUNTIME_MAINTENANCE_JOURNAL_META_KEY],
+    toPlainData(snapshotMeta?.[BME_RUNTIME_MAINTENANCE_JOURNAL_META_KEY], []),
   );
   runtimeGraph.knowledgeState = toPlainData(
     snapshotMeta?.[BME_RUNTIME_KNOWLEDGE_STATE_META_KEY],
@@ -2073,22 +2077,21 @@ export function buildGraphFromSnapshot(snapshot, options = {}) {
 
   runtimeGraph.historyState = {
     ...(runtimeGraph.historyState || {}),
-    ...(snapshotMeta?.[BME_RUNTIME_HISTORY_META_KEY] || {}),
+    ...snapshotHistoryState,
     lastProcessedAssistantFloor: Number.isFinite(
       Number(snapshotState?.lastProcessedFloor),
     )
       ? Number(snapshotState.lastProcessedFloor)
       : Number(
-          snapshotMeta?.[BME_RUNTIME_HISTORY_META_KEY]
+          snapshotHistoryState?.lastProcessedAssistantFloor ??
-            ?.lastProcessedAssistantFloor ?? META_DEFAULT_LAST_PROCESSED_FLOOR,
+            META_DEFAULT_LAST_PROCESSED_FLOOR,
         ),
     extractionCount: Number.isFinite(
       Number(snapshotState?.extractionCount),
     )
       ? Number(snapshotState.extractionCount)
       : Number(
-          snapshotMeta?.[BME_RUNTIME_HISTORY_META_KEY]
+          snapshotHistoryState?.extractionCount ?? META_DEFAULT_EXTRACTION_COUNT,
-            ?.extractionCount ?? META_DEFAULT_EXTRACTION_COUNT,
         ),
   };
   if (
@@ -2146,10 +2149,10 @@ export function buildGraphFromSnapshot(snapshot, options = {}) {
   }
   runtimeGraph.vectorIndexState = {
     ...(runtimeGraph.vectorIndexState || {}),
-    ...(snapshotMeta?.[BME_RUNTIME_VECTOR_META_KEY] || {}),
+    ...snapshotVectorState,
     collectionId: buildVectorCollectionId(
       chatId ||
-        snapshotMeta?.[BME_RUNTIME_HISTORY_META_KEY]?.chatId ||
+        snapshotHistoryState?.chatId ||
         runtimeGraph.historyState?.chatId ||
         "",
     ),
@@ -3032,23 +3035,47 @@ export class BmeDatabase {
     };
   }
 
-  async exportSnapshot() {
+  async exportSnapshot(options = {}) {
     const db = await this.open();
 
-    const [nodes, edges, tombstones, metaRows] = await db.transaction(
+    const includeTombstones =
-      "r",
+      options && typeof options === "object"
-      db.table("nodes"),
+        ? options.includeTombstones !== false
-      db.table("edges"),
+        : options !== false;
-      db.table("tombstones"),
+    let nodes = [];
-      db.table("meta"),
+    let edges = [];
-      async () =>
+    let tombstones = [];
-        await Promise.all([
+    let metaRows = [];
-          db.table("nodes").toArray(),
+
-          db.table("edges").toArray(),
+    if (includeTombstones) {
-          db.table("tombstones").toArray(),
+      [nodes, edges, tombstones, metaRows] = await db.transaction(
-          db.table("meta").toArray(),
+        "r",
-        ]),
+        db.table("nodes"),
-    );
+        db.table("edges"),
+        db.table("tombstones"),
+        db.table("meta"),
+        async () =>
+          await Promise.all([
+            db.table("nodes").toArray(),
+            db.table("edges").toArray(),
+            db.table("tombstones").toArray(),
+            db.table("meta").toArray(),
+          ]),
+      );
+    } else {
+      [nodes, edges, metaRows] = await db.transaction(
+        "r",
+        db.table("nodes"),
+        db.table("edges"),
+        db.table("meta"),
+        async () =>
+          await Promise.all([
+            db.table("nodes").toArray(),
+            db.table("edges").toArray(),
+            db.table("meta").toArray(),
+          ]),
+      );
+    }
 
     const metaMap = toMetaMap(metaRows);
     const meta = {
@@ -3058,7 +3085,10 @@ export class BmeDatabase {
       revision: normalizeRevision(metaMap?.revision),
       nodeCount: nodes.length,
       edgeCount: edges.length,
-      tombstoneCount: tombstones.length,
+      tombstoneCount: normalizeNonNegativeInteger(
+        metaMap?.tombstoneCount,
+        tombstones.length,
+      ),
     };
 
     const state = {
@@ -3070,13 +3100,19 @@ export class BmeDatabase {
         : META_DEFAULT_EXTRACTION_COUNT,
     };
 
-    return {
+    const snapshot = {
       meta,
       nodes,
       edges,
-      tombstones,
+      tombstones: includeTombstones ? tombstones : [],
       state,
     };
+
+    if (!includeTombstones) {
+      snapshot.__stBmeTombstonesOmitted = true;
+    }
+
+    return snapshot;
   }
 
   async importSnapshot(snapshot, options = {}) {

sync/bme-opfs-store.js

@@ -1345,15 +1345,23 @@ class LegacyOpfsGraphStore {
     };
   }
 
-  async exportSnapshot() {
+  async exportSnapshot(options = {}) {
-    const snapshot = await this._loadSnapshot();
+    const includeTombstones =
-    return {
+      options && typeof options === "object"
+        ? options.includeTombstones !== false
+        : options !== false;
+    const snapshot = await this._loadSnapshot({ includeTombstones });
+    const exported = {
       meta: toPlainData(snapshot.meta, {}),
       nodes: toPlainData(snapshot.nodes, []),
       edges: toPlainData(snapshot.edges, []),
-      tombstones: toPlainData(snapshot.tombstones, []),
+      tombstones: includeTombstones ? toPlainData(snapshot.tombstones, []) : [],
       state: toPlainData(snapshot.state, {}),
     };
+    if (!includeTombstones) {
+      exported.__stBmeTombstonesOmitted = true;
+    }
+    return exported;
   }
 
   async importSnapshot(snapshot, options = {}) {
@@ -2643,15 +2651,23 @@ export class OpfsGraphStore {
     };
   }
 
-  async exportSnapshot() {
+  async exportSnapshot(options = {}) {
-    const snapshot = await this._loadSnapshot();
+    const includeTombstones =
-    return {
+      options && typeof options === "object"
+        ? options.includeTombstones !== false
+        : options !== false;
+    const snapshot = await this._loadSnapshot({ includeTombstones });
+    const exported = {
       meta: toPlainData(snapshot.meta, {}),
       nodes: toPlainData(snapshot.nodes, []),
       edges: toPlainData(snapshot.edges, []),
-      tombstones: toPlainData(snapshot.tombstones, []),
+      tombstones: includeTombstones ? toPlainData(snapshot.tombstones, []) : [],
       state: toPlainData(snapshot.state, {}),
     };
+    if (!includeTombstones) {
+      exported.__stBmeTombstonesOmitted = true;
+    }
+    return exported;
   }
 
   async importSnapshot(snapshot, options = {}) {
@@ -3263,7 +3279,7 @@ export class OpfsGraphStore {
     return records;
   }
 
-  async _loadBaseSnapshotFromV2(manifest = null) {
+  async _loadBaseSnapshotFromV2(manifest = null, { includeTombstones = true } = {}) {
     const normalizedManifest = manifest || (await this._ensureV2Ready());
     const runtimeMeta = await this._readRuntimeMetaEntries();
     const nodes = [];
@@ -3275,8 +3291,10 @@ export class OpfsGraphStore {
     for (let index = 0; index < OPFS_V2_EDGE_BUCKET_COUNT; index += 1) {
       edges.push(...(await this._readShardRecords("edges", index)));
     }
-    for (let index = 0; index < OPFS_V2_TOMBSTONE_BUCKET_COUNT; index += 1) {
+    if (includeTombstones) {
-      tombstones.push(...(await this._readShardRecords("tombstones", index)));
+      for (let index = 0; index < OPFS_V2_TOMBSTONE_BUCKET_COUNT; index += 1) {
+        tombstones.push(...(await this._readShardRecords("tombstones", index)));
+      }
     }
     const meta = {
       ...createDefaultMetaValues(this.chatId),
@@ -3311,7 +3329,7 @@ export class OpfsGraphStore {
     return snapshot;
   }
 
-  async _loadSnapshot({ awaitWrites = true } = {}) {
+  async _loadSnapshot({ awaitWrites = true, includeTombstones = true } = {}) {
     if (awaitWrites) {
       await this._awaitPendingWrites();
     }
@@ -3319,10 +3337,24 @@ export class OpfsGraphStore {
     const headRevision = normalizeRevision(
       manifest?.headRevision || manifest?.meta?.revision,
     );
-    if (this._snapshotCache && normalizeRevision(this._snapshotCache.meta?.revision) === headRevision) {
+    if (
-      return this._snapshotCache;
+      this._snapshotCache &&
+      normalizeRevision(this._snapshotCache.meta?.revision) === headRevision
+    ) {
+      if (includeTombstones) {
+        return this._snapshotCache;
+      }
+      return {
+        meta: this._snapshotCache.meta,
+        state: this._snapshotCache.state,
+        nodes: this._snapshotCache.nodes,
+        edges: this._snapshotCache.edges,
+        tombstones: [],
+      };
     }
-    const snapshot = await this._loadBaseSnapshotFromV2(manifest);
+    const snapshot = await this._loadBaseSnapshotFromV2(manifest, {
+      includeTombstones,
+    });
     const walRecords = await this._readWalRecords(manifest);
     for (const walRecord of walRecords) {
       const nextSnapshot = applyOpfsV2DeltaToSnapshot(snapshot, walRecord.delta, walRecord.committedAt);
@@ -3355,7 +3387,11 @@ export class OpfsGraphStore {
     snapshot.state = normalizeSnapshotState(snapshot);
     snapshot.meta.lastProcessedFloor = snapshot.state.lastProcessedFloor;
     snapshot.meta.extractionCount = snapshot.state.extractionCount;
-    this._snapshotCache = snapshot;
+    if (includeTombstones) {
+      this._snapshotCache = snapshot;
+      return snapshot;
+    }
+    snapshot.tombstones = [];
     return snapshot;
   }
 

tests/indexeddb-persistence.mjs

@@ -2,6 +2,9 @@ import assert from "node:assert/strict";
 
 import {
   BME_DB_SCHEMA_VERSION,
+  BME_RUNTIME_BATCH_JOURNAL_META_KEY,
+  BME_RUNTIME_HISTORY_META_KEY,
+  BME_RUNTIME_VECTOR_META_KEY,
   BME_TOMBSTONE_RETENTION_MS,
   BmeDatabase,
   buildBmeDbName,
@@ -20,6 +23,7 @@ const chatIdsForCleanup = new Set([
   "chat-manager-a",
   "chat-manager-b",
   "chat-manager-selector",
+  "chat-export-without-tombstones",
   "chat-replace-reset",
 ]);
 
@@ -196,6 +200,41 @@ async function testSnapshotExportImport() {
   await db.close();
 }
 
+async function testSnapshotExportWithoutTombstones() {
+  const db = new BmeDatabase("chat-export-without-tombstones", {
+    dexieClass: globalThis.Dexie,
+  });
+  await db.open();
+
+  await db.bulkUpsertNodes([
+    {
+      id: "node-light-snapshot",
+      type: "event",
+      sourceFloor: 3,
+      archived: false,
+      updatedAt: Date.now(),
+    },
+  ]);
+  await db.bulkUpsertTombstones([
+    {
+      id: "tomb-light-snapshot",
+      kind: "node",
+      targetId: "node-deleted-light-snapshot",
+      deletedAt: Date.now(),
+      sourceDeviceId: "device-light-snapshot",
+    },
+  ]);
+
+  const exported = await db.exportSnapshot({ includeTombstones: false });
+  assert.equal(exported.__stBmeTombstonesOmitted, true);
+  assert.ok(Array.isArray(exported.nodes));
+  assert.ok(Array.isArray(exported.edges));
+  assert.deepEqual(exported.tombstones, []);
+  assert.equal(exported.meta.tombstoneCount, 1);
+
+  await db.close();
+}
+
 async function testReplaceImportResetsStaleMeta() {
   const chatId = "chat-replace-reset";
   const db = new BmeDatabase(chatId, { dexieClass: globalThis.Dexie });
@@ -532,6 +571,9 @@ async function testGraphSnapshotConverters() {
     id: "node-converter",
     type: "event",
     sourceFloor: 9,
+    fields: {
+      title: "Converter Node",
+    },
     updatedAt: Date.now(),
   });
 
@@ -583,6 +625,32 @@ async function testGraphSnapshotConverters() {
   assert.equal(rebuilt.regionState.activeRegion, "camp");
   assert.equal(rebuilt.timelineState.activeSegmentId, "segment-1");
   assert.equal(rebuilt.summaryState.entries[0].id, "summary-1");
+
+  rebuilt.nodes[0].fields.title = "Mutated Converter Node";
+  rebuilt.historyState.processedMessageHashes[1] = "mutated-hash";
+  rebuilt.vectorIndexState.hashToNodeId["vec-hash"] = "node-mutated";
+  rebuilt.batchJournal[0].processedRange[0] = 99;
+
+  assert.equal(
+    snapshot.nodes[0].fields.title,
+    "Converter Node",
+    "buildGraphFromSnapshot 不应复用 snapshot 节点的嵌套字段引用",
+  );
+  assert.equal(
+    snapshot.meta[BME_RUNTIME_HISTORY_META_KEY].processedMessageHashes[1],
+    "hash-1",
+    "buildGraphFromSnapshot 不应复用 snapshot historyState 的嵌套对象引用",
+  );
+  assert.equal(
+    snapshot.meta[BME_RUNTIME_VECTOR_META_KEY].hashToNodeId["vec-hash"],
+    "node-converter",
+    "buildGraphFromSnapshot 不应复用 snapshot vectorState 的嵌套对象引用",
+  );
+  assert.equal(
+    snapshot.meta[BME_RUNTIME_BATCH_JOURNAL_META_KEY][0].processedRange[0],
+    8,
+    "buildGraphFromSnapshot 不应复用 snapshot batchJournal 的嵌套数组引用",
+  );
 }
 
 async function main() {
@@ -593,6 +661,7 @@ async function main() {
   await testCrudAndMeta();
   await testTransactionRollback();
   await testSnapshotExportImport();
+  await testSnapshotExportWithoutTombstones();
   await testReplaceImportResetsStaleMeta();
   await testRevisionMonotonicity();
   await testTombstonePrune();

tests/opfs-persistence.mjs

@@ -311,6 +311,12 @@ async function testImportExportPersistenceAndFileRotation() {
   assert.equal(firstExportedSnapshot.state.extractionCount, 2);
   assert.equal(firstExportedSnapshot.meta.storagePrimary, "opfs");
   assert.equal(firstExportedSnapshot.meta.storageMode, "opfs-primary");
+  const lightweightSnapshot = await store.exportSnapshot({
+    includeTombstones: false,
+  });
+  assert.equal(lightweightSnapshot.__stBmeTombstonesOmitted, true);
+  assert.deepEqual(lightweightSnapshot.tombstones, []);
+  assert.equal(lightweightSnapshot.meta.tombstoneCount, 1);
   assert.deepEqual(firstExportedSnapshot.meta[BME_RUNTIME_BATCH_JOURNAL_META_KEY], {
     pending: ["job-1"],
   });