update handling of nulls in inspect results

packages/veilid_support/lib/dht_support/src/dht_record/dht_record.dart

@@ -511,7 +511,7 @@ class DHTRecord implements DHTDeleteable<DHTRecord> {
       key,
       subkeys: [ValueSubkeyRange.single(subkey)],
     );
-    return rr.localSeqs.firstOrNull ?? emptySeq;
+    return rr.localSeqs.firstOrNull;
   }
 
   void _addValueChange(
@@ -566,6 +566,4 @@ class DHTRecord implements DHTDeleteable<DHTRecord> {
   int _openCount;
   StreamController<DHTRecordWatchChange>? _watchController;
   _WatchState? _watchState;
-
-  static const int emptySeq = 0xFFFFFFFF;
 }

packages/veilid_support/lib/dht_support/src/dht_record/dht_record_pool.dart

@@ -875,7 +875,7 @@ class DHTRecordPool with TableDBBackedJson<DHTRecordPoolAllocations> {
       if (fsc == null) {
         return null;
       }
-      final newerSubkeys = currentReport.newerSubkeys;
+      final newerSubkeys = currentReport.newerOnlineSubkeys;
 
       final valueData = await dhtctx.getDHTValue(openedRecordKey, fsc.subkey,
           forceRefresh: true);
@@ -887,7 +887,7 @@ class DHTRecordPool with TableDBBackedJson<DHTRecordPoolAllocations> {
         log('inspect returned a newer seq than get: ${valueData.seq} < $fsc');
       }
 
-      if (valueData.seq > fsc.oldSeq && valueData.seq != DHTRecord.emptySeq) {
+      if (fsc.oldSeq == null || valueData.seq > fsc.oldSeq!) {
         processRemoteValueChange(VeilidUpdateValueChange(
             key: openedRecordKey,
             subkeys: newerSubkeys,

packages/veilid_support/lib/dht_support/src/dht_record/extensions.dart

@@ -1,15 +1,14 @@
 import 'package:veilid/veilid.dart';
-import 'dht_record_pool.dart';
 
 class DHTSeqChange {
   const DHTSeqChange(this.subkey, this.oldSeq, this.newSeq);
   final int subkey;
-  final int oldSeq;
+  final int? oldSeq;
   final int newSeq;
 }
 
 extension DHTReportReportExt on DHTRecordReport {
-  List<ValueSubkeyRange> get newerSubkeys {
+  List<ValueSubkeyRange> get newerOnlineSubkeys {
     if (networkSeqs.isEmpty || localSeqs.isEmpty || subkeys.isEmpty) {
       return [];
     }
@@ -19,8 +18,10 @@ extension DHTReportReportExt on DHTRecordReport {
     var i = 0;
     for (final skr in subkeys) {
       for (var sk = skr.low; sk <= skr.high; sk++) {
-        if (networkSeqs[i] > localSeqs[i] &&
-            networkSeqs[i] != DHTRecord.emptySeq) {
+        final nseq = networkSeqs[i];
+        final lseq = localSeqs[i];
+
+        if (nseq != null && (lseq == null || nseq > lseq)) {
           if (currentSubkeys.isNotEmpty &&
               currentSubkeys.last.high == (sk - 1)) {
             currentSubkeys.add(ValueSubkeyRange(
@@ -29,6 +30,7 @@ extension DHTReportReportExt on DHTRecordReport {
             currentSubkeys.add(ValueSubkeyRange.single(sk));
           }
         }
+
         i++;
       }
     }
@@ -44,9 +46,11 @@ extension DHTReportReportExt on DHTRecordReport {
     var i = 0;
     for (final skr in subkeys) {
       for (var sk = skr.low; sk <= skr.high; sk++) {
-        if (networkSeqs[i] > localSeqs[i] &&
-            networkSeqs[i] != DHTRecord.emptySeq) {
-          return DHTSeqChange(sk, localSeqs[i], networkSeqs[i]);
+        final nseq = networkSeqs[i];
+        final lseq = localSeqs[i];
+
+        if (nseq != null && (lseq == null || nseq > lseq)) {
+          return DHTSeqChange(sk, lseq, nseq);
         }
         i++;
       }

packages/veilid_support/lib/dht_support/src/dht_short_array/dht_short_array_head.dart

@@ -5,7 +5,7 @@ class DHTShortArrayHeadLookup {
       {required this.record, required this.recordSubkey, required this.seq});
   final DHTRecord record;
   final int recordSubkey;
-  final int seq;
+  final int? seq;
 }
 
 class _DHTShortArrayHead {
@@ -41,7 +41,7 @@ class _DHTShortArrayHead {
     final head = proto.DHTShortArray();
     head.keys.addAll(_linkedRecords.map((lr) => lr.key.toProto()));
     head.index = List.of(_index);
-    head.seqs.addAll(_seqs);
+    head.seqs.addAll(_seqs.map((x) => x ?? 0xFFFFFFFF));
     // Do not serialize free list, it gets recreated
     // Do not serialize local seqs, they are only locally relevant
     return head;
@@ -70,10 +70,7 @@ class _DHTShortArrayHead {
   Future<bool> delete() => _headMutex.protect(_headRecord.delete);
 
   Future<T> operate<T>(Future<T> Function(_DHTShortArrayHead) closure) async =>
-      // ignore: prefer_expression_function_bodies
-      _headMutex.protect(() async {
-        return closure(this);
-      });
+      _headMutex.protect(() async => closure(this));
 
   Future<T> operateWrite<T>(
           Future<T> Function(_DHTShortArrayHead) closure) async =>
@@ -115,7 +112,7 @@ class _DHTShortArrayHead {
       late List<DHTRecord> oldLinkedRecords;
       late List<int> oldIndex;
       late List<int> oldFree;
-      late List<int> oldSeqs;
+      late List<int?> oldSeqs;
 
       late T out;
       try {
@@ -197,7 +194,8 @@ class _DHTShortArrayHead {
     // Get the set of new linked keys and validate it
     final updatedLinkedKeys = head.keys.map((p) => p.toVeilid()).toList();
     final updatedIndex = List.of(head.index);
-    final updatedSeqs = List.of(head.seqs);
+    final updatedSeqs =
+        List.of(head.seqs.map((x) => x == 0xFFFFFFFF ? null : x));
     final updatedFree = _makeFreeList(updatedLinkedKeys, updatedIndex);
 
     // See which records are actually new
@@ -333,7 +331,7 @@ class _DHTShortArrayHead {
   }
 
   Future<DHTShortArrayHeadLookup> lookupIndex(int idx, bool allowCreate) async {
-    final seq = idx < _seqs.length ? _seqs[idx] : DHTRecord.emptySeq;
+    final seq = idx < _seqs.length ? _seqs[idx] : null;
     final recordNumber = idx ~/ _stride;
     final record = await _getOrCreateLinkedRecord(recordNumber, allowCreate);
     final recordSubkey = (idx % _stride) + ((recordNumber == 0) ? 1 : 0);
@@ -445,18 +443,18 @@ class _DHTShortArrayHead {
 
     // If our local sequence number is unknown or hasnt been written yet
     // then a normal DHT operation is going to pull from the network anyway
-    if (_localSeqs.length < idx || _localSeqs[idx] == DHTRecord.emptySeq) {
+    if (_localSeqs.length < idx || _localSeqs[idx] == null) {
       return false;
     }
 
     // If the remote sequence number record is unknown or hasnt been written
     // at this index yet, then we also do not refresh at this time as it
     // is the first time the index is being written to
-    if (_seqs.length < idx || _seqs[idx] == DHTRecord.emptySeq) {
+    if (_seqs.length < idx || _seqs[idx] == null) {
       return false;
     }
 
-    return _localSeqs[idx] < _seqs[idx];
+    return _localSeqs[idx]! < _seqs[idx]!;
   }
 
   /// Update the sequence number for a particular index in
@@ -466,12 +464,12 @@ class _DHTShortArrayHead {
     final idx = _index[pos];
 
     while (_localSeqs.length <= idx) {
-      _localSeqs.add(DHTRecord.emptySeq);
+      _localSeqs.add(null);
     }
     _localSeqs[idx] = newSeq;
     if (write) {
       while (_seqs.length <= idx) {
-        _seqs.add(DHTRecord.emptySeq);
+        _seqs.add(null);
       }
       _seqs[idx] = newSeq;
     }
@@ -555,7 +553,7 @@ class _DHTShortArrayHead {
   // The sequence numbers of each subkey.
   // Index is by subkey number not by element index.
   // (n-1 for head record and then the next n for linked records)
-  List<int> _seqs;
+  List<int?> _seqs;
   // The local sequence numbers for each subkey.
-  List<int> _localSeqs;
+  List<int?> _localSeqs;
 }

packages/veilid_support/lib/dht_support/src/dht_short_array/dht_short_array_write.dart

@@ -129,7 +129,7 @@ class _DHTShortArrayWrite extends _DHTShortArrayRead
 
     final outSeqNum = Output<int>();
 
-    final result = lookup.seq == DHTRecord.emptySeq
+    final result = lookup.seq == null
         ? null
         : await lookup.record.get(subkey: lookup.recordSubkey);
 
@@ -163,7 +163,7 @@ class _DHTShortArrayWrite extends _DHTShortArrayRead
     final lookup = await _head.lookupPosition(pos, true);
 
     final outSeqNumRead = Output<int>();
-    final oldValue = lookup.seq == DHTRecord.emptySeq
+    final oldValue = lookup.seq == null
         ? null
         : await lookup.record
             .get(subkey: lookup.recordSubkey, outSeqNum: outSeqNumRead);