tests pass

packages/veilid_support/example/integration_test/app_test.dart

@@ -1,10 +1,6 @@
-//@Timeout(Duration(seconds: 240))
-
-//library veilid_support_integration_test;
-
 import 'package:flutter/foundation.dart';
-import 'package:test/test.dart';
 import 'package:integration_test/integration_test.dart';
+import 'package:test/test.dart';
 import 'package:veilid_test/veilid_test.dart';
 
 import 'fixtures/fixtures.dart';
@@ -26,7 +22,7 @@ void main() {
       tickerFixture: tickerFixture,
       updateProcessorFixture: updateProcessorFixture);
 
-  group('Started Tests', () {
+  group(timeout: const Timeout(Duration(seconds: 240)), 'Started Tests', () {
     setUpAll(veilidFixture.setUp);
     tearDownAll(veilidFixture.tearDown);
     tearDownAll(() {
@@ -74,9 +70,11 @@ void main() {
           for (final stride in [256, 16 /*64, 32, 16, 8, 4, 2, 1 */]) {
             test('create log stride=$stride',
                 makeTestDHTLogCreateDelete(stride: stride));
-            test('add/truncate log stride=$stride',
-                makeTestDHTLogAddTruncate(stride: stride),
-                timeout: const Timeout(Duration(seconds: 480)));
+            test(
+              timeout: const Timeout(Duration(seconds: 480)),
+              'add/truncate log stride=$stride',
+              makeTestDHTLogAddTruncate(stride: stride),
+            );
           }
         });
       });

packages/veilid_support/example/integration_test/test_dht_log.dart

@@ -1,6 +1,6 @@
 import 'dart:convert';
 
-import 'package:flutter_test/flutter_test.dart';
+import 'package:test/test.dart';
 import 'package:veilid_support/veilid_support.dart';
 
 Future<void> Function() makeTestDHTLogCreateDelete({required int stride}) =>
@@ -61,7 +61,7 @@ Future<void> Function() makeTestDHTLogAddTruncate({required int stride}) =>
       print('adding\n');
       {
         final res = await dlog.operateAppend((w) async {
-          const chunk = 50;
+          const chunk = 25;
           for (var n = 0; n < dataset.length; n += chunk) {
             print('$n-${n + chunk - 1} ');
             final success =

packages/veilid_support/example/integration_test/test_dht_record_pool.dart

@@ -1,7 +1,7 @@
 import 'dart:convert';
 
 import 'package:flutter/foundation.dart';
-import 'package:flutter_test/flutter_test.dart';
+import 'package:test/test.dart';
 import 'package:veilid_support/veilid_support.dart';
 
 Future<void> testDHTRecordPoolCreate() async {

packages/veilid_support/example/integration_test/test_dht_short_array.dart

@@ -1,6 +1,6 @@
 import 'dart:convert';
 
-import 'package:flutter_test/flutter_test.dart';
+import 'package:test/test.dart';
 import 'package:veilid_support/veilid_support.dart';
 
 Future<void> Function() makeTestDHTShortArrayCreateDelete(
@@ -118,7 +118,10 @@ Future<void> Function() makeTestDHTShortArrayAdd({required int stride}) =>
 
       //print('clear\n');
       {
-        await arr.operateWrite((w) async => w.clear());
+        await arr.operateWriteEventual((w) async {
+          await w.clear();
+          return true;
+        });
       }
 
       //print('get all\n');

packages/veilid_support/example/pubspec.lock

@@ -196,7 +196,7 @@ packages:
     source: sdk
     version: "0.0.0"
   flutter_test:
-    dependency: "direct dev"
+    dependency: transitive
     description: flutter
     source: sdk
     version: "0.0.0"

packages/veilid_support/example/pubspec.yaml

@@ -15,8 +15,6 @@ dependencies:
 
 dev_dependencies:
   async_tools: ^0.1.1
-  flutter_test:
-    sdk: flutter
   integration_test:
     sdk: flutter
   lint_hard: ^4.0.0

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

@@ -42,7 +42,7 @@ class DHTLogUpdate extends Equatable {
 ///  * The head and tail position of the log
 ///    - subkeyIdx = pos / recordsPerSubkey
 ///    - recordIdx = pos % recordsPerSubkey
-class DHTLog implements DHTOpenable<DHTLog> {
+class DHTLog implements DHTDeleteable<DHTLog, DHTLog> {
   ////////////////////////////////////////////////////////////////
   // Constructors
 
@@ -160,12 +160,16 @@ class DHTLog implements DHTOpenable<DHTLog> {
       );
 
   ////////////////////////////////////////////////////////////////////////////
-  // DHTOpenable
+  // DHTCloseable
 
   /// Check if the DHTLog is open
   @override
   bool get isOpen => _openCount > 0;
 
+  /// The type of the openable scope
+  @override
+  FutureOr<DHTLog> scoped() => this;
+
   /// Add a reference to this log
   @override
   Future<DHTLog> ref() async => _mutex.protect(() async {

packages/veilid_support/lib/dht_support/src/dht_log/dht_log_append.dart

@@ -17,7 +17,7 @@ class _DHTLogAppend extends _DHTLogRead implements DHTAppendTruncateRandomRead {
     }
 
     // Write item to the segment
-    return lookup.shortArray.scope((sa) => sa.operateWrite((write) async {
+    return lookup.scope((sa) => sa.operateWrite((write) async {
           // If this a new segment, then clear it in case we have wrapped around
           if (lookup.pos == 0) {
             await write.clear();
@@ -51,18 +51,17 @@ class _DHTLogAppend extends _DHTLogRead implements DHTAppendTruncateRandomRead {
       final sublistValues = values.sublist(valueIdx, valueIdx + sacount);
 
       dws.add(() async {
-        final ok = await lookup.shortArray
-            .scope((sa) => sa.operateWrite((write) async {
-                  // If this a new segment, then clear it in
-                  // case we have wrapped around
-                  if (lookup.pos == 0) {
-                    await write.clear();
-                  } else if (lookup.pos != write.length) {
-                    // We should always be appending at the length
-                    throw StateError('appending should be at the end');
-                  }
-                  return write.tryAddItems(sublistValues);
-                }));
+        final ok = await lookup.scope((sa) => sa.operateWrite((write) async {
+              // If this a new segment, then clear it in
+              // case we have wrapped around
+              if (lookup.pos == 0) {
+                await write.clear();
+              } else if (lookup.pos != write.length) {
+                // We should always be appending at the length
+                throw StateError('appending should be at the end');
+              }
+              return write.tryAddItems(sublistValues);
+            }));
         if (!ok) {
           success = false;
         }
@@ -71,7 +70,7 @@ class _DHTLogAppend extends _DHTLogRead implements DHTAppendTruncateRandomRead {
       valueIdx += sacount;
     }
 
-    await dws(chunkSize: maxDHTConcurrency);
+    await dws();
 
     return success;
   }

packages/veilid_support/lib/dht_support/src/dht_log/dht_log_read.dart

@@ -19,7 +19,7 @@ class _DHTLogRead implements DHTRandomRead {
       return null;
     }
 
-    return lookup.shortArray.scope((sa) => sa.operate(
+    return lookup.scope((sa) => sa.operate(
         (read) => read.getItem(lookup.pos, forceRefresh: forceRefresh)));
   }
 
@@ -71,7 +71,7 @@ class _DHTLogRead implements DHTRandomRead {
 
       // Check each segment for offline positions
       var foundOffline = false;
-      await lookup.shortArray.scope((sa) => sa.operate((read) async {
+      await lookup.scope((sa) => sa.operate((read) async {
             final segmentOffline = await read.getOfflinePositions();
 
             // For each shortarray segment go through their segment positions

packages/veilid_support/lib/dht_support/src/dht_log/dht_log_spine.dart

@@ -1,9 +1,58 @@
 part of 'dht_log.dart';
 
-class DHTLogPositionLookup {
-  const DHTLogPositionLookup({required this.shortArray, required this.pos});
-  final DHTShortArray shortArray;
+class _DHTLogPosition extends DHTCloseable<_DHTLogPosition, DHTShortArray> {
+  _DHTLogPosition._({
+    required _DHTLogSpine dhtLogSpine,
+    required DHTShortArray shortArray,
+    required this.pos,
+    required int segmentNumber,
+  })  : _segmentShortArray = shortArray,
+        _dhtLogSpine = dhtLogSpine,
+        _segmentNumber = segmentNumber;
   final int pos;
+
+  final _DHTLogSpine _dhtLogSpine;
+  final DHTShortArray _segmentShortArray;
+  var _openCount = 1;
+  final int _segmentNumber;
+  final Mutex _mutex = Mutex();
+
+  /// Check if the DHTLogPosition is open
+  @override
+  bool get isOpen => _openCount > 0;
+
+  /// The type of the openable scope
+  @override
+  FutureOr<DHTShortArray> scoped() => _segmentShortArray;
+
+  /// Add a reference to this log
+  @override
+  Future<_DHTLogPosition> ref() async => _mutex.protect(() async {
+        _openCount++;
+        return this;
+      });
+
+  /// Free all resources for the DHTLogPosition
+  @override
+  Future<void> close() async => _mutex.protect(() async {
+        if (_openCount == 0) {
+          throw StateError('already closed');
+        }
+        _openCount--;
+        if (_openCount != 0) {
+          return;
+        }
+        await _dhtLogSpine._segmentClosed(_segmentNumber);
+      });
+}
+
+class _OpenedSegment {
+  _OpenedSegment._({
+    required this.shortArray,
+  });
+
+  final DHTShortArray shortArray;
+  int openCount = 1;
 }
 
 class _DHTLogSegmentLookup extends Equatable {
@@ -32,6 +81,7 @@ class _DHTLogSpine {
         _head = head,
         _tail = tail,
         _segmentStride = stride,
+        _openedSegments = {},
         _spineCache = [];
 
   // Create a new spine record and push it to the network
@@ -85,6 +135,8 @@ class _DHTLogSpine {
         futures.add(sc.close());
       }
       await Future.wait(futures);
+
+      assert(_openedSegments.isEmpty, 'should have closed all segments by now');
     });
   }
 
@@ -247,7 +299,7 @@ class _DHTLogSpine {
 
     // Lookup what subkey and segment subrange has this position's segment
     // shortarray
-    final l = lookupSegment(segmentNumber);
+    final l = _lookupSegment(segmentNumber);
     final subkey = l.subkey;
     final segment = l.segment;
 
@@ -304,7 +356,7 @@ class _DHTLogSpine {
 
     // Lookup what subkey and segment subrange has this position's segment
     // shortarray
-    final l = lookupSegment(segmentNumber);
+    final l = _lookupSegment(segmentNumber);
     final subkey = l.subkey;
     final segment = l.segment;
 
@@ -381,7 +433,7 @@ class _DHTLogSpine {
     return segment;
   }
 
-  _DHTLogSegmentLookup lookupSegment(int segmentNumber) {
+  _DHTLogSegmentLookup _lookupSegment(int segmentNumber) {
     assert(_spineMutex.isLocked, 'should be in mutex here');
 
     if (segmentNumber < 0) {
@@ -400,30 +452,60 @@ class _DHTLogSpine {
   ///////////////////////////////////////////
   // API for public interfaces
 
-  Future<DHTLogPositionLookup?> lookupPosition(int pos) async {
+  Future<_DHTLogPosition?> lookupPosition(int pos) async {
     assert(_spineMutex.isLocked, 'should be locked');
+    return _spineCacheMutex.protect(() async {
+      // Check if our position is in bounds
+      final endPos = length;
+      if (pos < 0 || pos >= endPos) {
+        throw IndexError.withLength(pos, endPos);
+      }
 
-    // Check if our position is in bounds
-    final endPos = length;
-    if (pos < 0 || pos >= endPos) {
-      throw IndexError.withLength(pos, endPos);
-    }
+      // Calculate absolute position, ring-buffer style
+      final absolutePosition = (_head + pos) % _positionLimit;
 
-    // Calculate absolute position, ring-buffer style
-    final absolutePosition = (_head + pos) % _positionLimit;
+      // Determine the segment number and position within the segment
+      final segmentNumber = absolutePosition ~/ DHTShortArray.maxElements;
+      final segmentPos = absolutePosition % DHTShortArray.maxElements;
 
-    // Determine the segment number and position within the segment
-    final segmentNumber = absolutePosition ~/ DHTShortArray.maxElements;
-    final segmentPos = absolutePosition % DHTShortArray.maxElements;
+      // Get the segment shortArray
+      final openedSegment = _openedSegments[segmentNumber];
+      late final DHTShortArray shortArray;
+      if (openedSegment != null) {
+        openedSegment.openCount++;
+        shortArray = openedSegment.shortArray;
+      } else {
+        final newShortArray = (_spineRecord.writer == null)
+            ? await _openSegment(segmentNumber)
+            : await _openOrCreateSegment(segmentNumber);
+        if (newShortArray == null) {
+          return null;
+        }
 
-    // Get the segment shortArray
-    final shortArray = (_spineRecord.writer == null)
-        ? await _openSegment(segmentNumber)
-        : await _openOrCreateSegment(segmentNumber);
-    if (shortArray == null) {
-      return null;
-    }
-    return DHTLogPositionLookup(shortArray: shortArray, pos: segmentPos);
+        _openedSegments[segmentNumber] =
+            _OpenedSegment._(shortArray: newShortArray);
+
+        shortArray = newShortArray;
+      }
+
+      return _DHTLogPosition._(
+          dhtLogSpine: this,
+          shortArray: shortArray,
+          pos: segmentPos,
+          segmentNumber: segmentNumber);
+    });
+  }
+
+  Future<void> _segmentClosed(int segmentNumber) async {
+    assert(_spineMutex.isLocked, 'should be locked');
+    await _spineCacheMutex.protect(() async {
+      final os = _openedSegments[segmentNumber]!;
+      os.openCount--;
+      if (os.openCount == 0) {
+        _openedSegments.remove(segmentNumber);
+        await os.shortArray.close();
+      }
+    });
   }
 
   void allocateTail(int count) {
@@ -479,7 +561,7 @@ class _DHTLogSpine {
         segmentNumber++) {
       // Lookup what subkey and segment subrange has this position's segment
       // shortarray
-      final l = lookupSegment(segmentNumber);
+      final l = _lookupSegment(segmentNumber);
       final subkey = l.subkey;
       final segment = l.segment;
 
@@ -608,6 +690,8 @@ class _DHTLogSpine {
 
   // Spine DHT record
   final DHTRecord _spineRecord;
+  // Segment stride to use for spine elements
+  final int _segmentStride;
 
   // Position of the start of the log (oldest items)
   int _head;
@@ -616,8 +700,8 @@ class _DHTLogSpine {
 
   // LRU cache of DHT spine elements accessed recently
   // Pair of position and associated shortarray segment
+  final Mutex _spineCacheMutex = Mutex();
   final List<(int, DHTShortArray)> _spineCache;
+  final Map<int, _OpenedSegment> _openedSegments;
   static const int _spineCacheLength = 3;
-  // Segment stride to use for spine elements
-  final int _segmentStride;
 }

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

@@ -36,7 +36,7 @@ enum DHTRecordRefreshMode {
 
 /////////////////////////////////////////////////
 
-class DHTRecord implements DHTOpenable<DHTRecord> {
+class DHTRecord implements DHTDeleteable<DHTRecord, DHTRecord> {
   DHTRecord._(
       {required VeilidRoutingContext routingContext,
       required SharedDHTRecordData sharedDHTRecordData,
@@ -52,12 +52,16 @@ class DHTRecord implements DHTOpenable<DHTRecord> {
         _sharedDHTRecordData = sharedDHTRecordData;
 
   ////////////////////////////////////////////////////////////////////////////
-  // DHTOpenable
+  // DHTCloseable
 
   /// Check if the DHTRecord is open
   @override
   bool get isOpen => _openCount > 0;
 
+  /// The type of the openable scope
+  @override
+  FutureOr<DHTRecord> scoped() => this;
+
   /// Add a reference to this DHTRecord
   @override
   Future<DHTRecord> ref() async => _mutex.protect(() async {

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

@@ -13,7 +13,7 @@ part 'dht_short_array_write.dart';
 
 ///////////////////////////////////////////////////////////////////////
 
-class DHTShortArray implements DHTOpenable<DHTShortArray> {
+class DHTShortArray implements DHTDeleteable<DHTShortArray, DHTShortArray> {
   ////////////////////////////////////////////////////////////////
   // Constructors
 
@@ -136,12 +136,16 @@ class DHTShortArray implements DHTOpenable<DHTShortArray> {
       );
 
   ////////////////////////////////////////////////////////////////////////////
-  // DHTOpenable
+  // DHTCloseable
 
   /// Check if the shortarray is open
   @override
   bool get isOpen => _openCount > 0;
 
+  /// The type of the openable scope
+  @override
+  FutureOr<DHTShortArray> scoped() => this;
+
   /// Add a reference to this shortarray
   @override
   Future<DHTShortArray> ref() async => _mutex.protect(() async {

packages/veilid_support/lib/dht_support/src/interfaces/dht_closeable.dart

@@ -1,27 +1,36 @@
 import 'dart:async';
 
-abstract class DHTOpenable<C> {
+import 'package:meta/meta.dart';
+
+abstract class DHTCloseable<C, D> {
   bool get isOpen;
+  @protected
+  FutureOr<D> scoped();
   Future<C> ref();
   Future<void> close();
+}
+
+abstract class DHTDeleteable<C, D> extends DHTCloseable<C, D> {
   Future<void> delete();
 }
 
-extension DHTOpenableExt<D extends DHTOpenable<D>> on D {
-  /// Runs a closure that guarantees the DHTOpenable
+extension DHTCloseableExt<C, D> on DHTCloseable<C, D> {
+  /// Runs a closure that guarantees the DHTCloseable
   /// will be closed upon exit, even if an uncaught exception is thrown
   Future<T> scope<T>(Future<T> Function(D) scopeFunction) async {
     if (!isOpen) {
       throw StateError('not open in scope');
     }
     try {
-      return await scopeFunction(this);
+      return await scopeFunction(await scoped());
     } finally {
       await close();
     }
   }
+}
 
-  /// Runs a closure that guarantees the DHTOpenable
+extension DHTDeletableExt<C, D> on DHTDeleteable<C, D> {
+  /// Runs a closure that guarantees the DHTCloseable
   /// will be closed upon exit, and deleted if an an
   /// uncaught exception is thrown
   Future<T> deleteScope<T>(Future<T> Function(D) scopeFunction) async {
@@ -30,7 +39,7 @@ extension DHTOpenableExt<D extends DHTOpenable<D>> on D {
     }
 
     try {
-      return await scopeFunction(this);
+      return await scopeFunction(await scoped());
     } on Exception {
       await delete();
       rethrow;
@@ -39,7 +48,7 @@ extension DHTOpenableExt<D extends DHTOpenable<D>> on D {
     }
   }
 
-  /// Scopes a closure that conditionally deletes the DHTOpenable on exit
+  /// Scopes a closure that conditionally deletes the DHTCloseable on exit
   Future<T> maybeDeleteScope<T>(
       bool delete, Future<T> Function(D) scopeFunction) async {
     if (delete) {

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

@@ -1,4 +1,4 @@
-export 'dht_openable.dart';
+export 'dht_closeable.dart';
 export 'dht_random_read.dart';
 export 'dht_random_write.dart';
 export 'exceptions.dart';