[Core Plugin] adopt more change from pr 3414

src/Plugins/LevelDBStore/IO/Data/LevelDB/DB.cs

@@ -9,10 +9,13 @@
 // Redistribution and use in source and binary forms with or without
 // modifications are permitted.
 
+#nullable enable
+
 using System;
+using System.Collections.Generic;
 using System.IO;
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     /// <summary>
     /// A DB is a persistent ordered map from keys to values.
@@ -90,9 +93,9 @@ public static DB Open(string name)
 
         public static DB Open(string name, Options options)
         {
-            var Handle = Native.leveldb_open(options.Handle, Path.GetFullPath(name), out var error);
+            var handle = Native.leveldb_open(options.Handle, Path.GetFullPath(name), out var error);
             NativeHelper.CheckError(error);
-            return new DB(Handle);
+            return new DB(handle);
         }
 
         /// <summary>
@@ -122,5 +125,19 @@ public void Write(WriteOptions options, WriteBatch write_batch)
             Native.leveldb_write(Handle, options.Handle, write_batch.Handle, out var error);
             NativeHelper.CheckError(error);
         }
+
+        public IEnumerable<KeyValuePair<byte[], byte[]>> GetAll(Snapshot? snapshot = null)
+        {
+            using var options = new ReadOptions();
+            if (snapshot != null) options.Snapshot = snapshot;
+
+            using var iterator = NewIterator(options);
+            iterator.SeekToFirst();
+            while (iterator.Valid())
+            {
+                yield return new KeyValuePair<byte[], byte[]>(iterator.Key(), iterator.Value());
+                iterator.Next();
+            }
+        }
     }
 }

src/Plugins/LevelDBStore/IO/Data/LevelDB/Helper.cs

@@ -14,17 +14,17 @@
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     public static class Helper
     {
-        public static IEnumerable<T> Seek<T>(this DB db, ReadOptions options, byte[] prefix, SeekDirection direction, Func<byte[], byte[], T> resultSelector)
+        public static IEnumerable<(byte[], byte[])> Seek(this DB db, ReadOptions options, byte[] prefix, SeekDirection direction)
         {
             using Iterator it = db.NewIterator(options);
             if (direction == SeekDirection.Forward)
             {
                 for (it.Seek(prefix); it.Valid(); it.Next())
-                    yield return resultSelector(it.Key(), it.Value());
+                    yield return new(it.Key(), it.Value());
             }
             else
             {
@@ -37,18 +37,7 @@ public static IEnumerable<T> Seek<T>(this DB db, ReadOptions options, byte[] pre
                     it.Prev();
 
                 for (; it.Valid(); it.Prev())
-                    yield return resultSelector(it.Key(), it.Value());
-            }
-        }
-
-        public static IEnumerable<T> FindRange<T>(this DB db, ReadOptions options, byte[] startKey, byte[] endKey, Func<byte[], byte[], T> resultSelector)
-        {
-            using Iterator it = db.NewIterator(options);
-            for (it.Seek(startKey); it.Valid(); it.Next())
-            {
-                byte[] key = it.Key();
-                if (key.AsSpan().SequenceCompareTo(endKey) > 0) break;
-                yield return resultSelector(key, it.Value());
+                    yield return new(it.Key(), it.Value());
             }
         }
 

src/Plugins/LevelDBStore/IO/Data/LevelDB/Iterator.cs

@@ -11,7 +11,7 @@
 
 using System;
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     /// <summary>
     /// An iterator yields a sequence of key/value pairs from a database.

src/Plugins/LevelDBStore/IO/Data/LevelDB/LevelDBException.cs

@@ -11,7 +11,7 @@
 
 using System.Data.Common;
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     public class LevelDBException : DbException
     {

src/Plugins/LevelDBStore/IO/Data/LevelDB/LevelDBHandle.cs

@@ -11,7 +11,7 @@
 
 using System;
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     /// <summary>
     /// Base class for all LevelDB objects

src/Plugins/LevelDBStore/IO/Data/LevelDB/Options.cs

@@ -11,7 +11,7 @@
 
 using System;
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     /// <summary>
     /// Options to control the behavior of a database (passed to Open)

src/Plugins/LevelDBStore/IO/Data/LevelDB/ReadOptions.cs

@@ -9,7 +9,7 @@
 // Redistribution and use in source and binary forms with or without
 // modifications are permitted.
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     /// <summary>
     /// Options that control read operations.

src/Plugins/LevelDBStore/IO/Data/LevelDB/Snapshot.cs

@@ -11,7 +11,7 @@
 
 using System;
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     /// <summary>
     /// A Snapshot is an immutable object and can therefore be safely

src/Plugins/LevelDBStore/IO/Data/LevelDB/WriteBatch.cs

@@ -11,7 +11,7 @@
 
 using System;
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     /// <summary>
     /// WriteBatch holds a collection of updates to apply atomically to a DB.

src/Plugins/LevelDBStore/IO/Data/LevelDB/WriteOptions.cs

@@ -9,7 +9,7 @@
 // Redistribution and use in source and binary forms with or without
 // modifications are permitted.
 
-namespace Neo.IO.Data.LevelDB
+namespace Neo.IO.Storage.LevelDB
 {
     /// <summary>
     /// Options that control write operations.

src/Plugins/LevelDBStore/Plugins/Storage/LevelDBStore.cs

@@ -9,7 +9,7 @@
 // Redistribution and use in source and binary forms with or without
 // modifications are permitted.
 
-using Neo.IO.Data.LevelDB;
+using Neo.IO.Storage.LevelDB;
 using Neo.Persistence;
 using System;
 using System.Linq;

src/Plugins/LevelDBStore/Plugins/Storage/Snapshot.cs

@@ -9,10 +9,10 @@
 // Redistribution and use in source and binary forms with or without
 // modifications are permitted.
 
-using Neo.IO.Data.LevelDB;
+using Neo.IO.Storage.LevelDB;
 using Neo.Persistence;
 using System.Collections.Generic;
-using LSnapshot = Neo.IO.Data.LevelDB.Snapshot;
+using LSnapshot = Neo.IO.Storage.LevelDB.Snapshot;
 
 namespace Neo.Plugins.Storage
 {
@@ -44,11 +44,12 @@ public void Delete(byte[] key)
         public void Dispose()
         {
             _snapshot.Dispose();
+            _options.Dispose();
         }
 
         public IEnumerable<(byte[] Key, byte[] Value)> Seek(byte[] prefix, SeekDirection direction = SeekDirection.Forward)
         {
-            return _db.Seek(_options, prefix, direction, (k, v) => (k, v));
+            return _db.Seek(_options, prefix, direction);
         }
 
         public void Put(byte[] key, byte[] value)

src/Plugins/LevelDBStore/Plugins/Storage/Store.cs

@@ -9,7 +9,7 @@
 // Redistribution and use in source and binary forms with or without
 // modifications are permitted.
 
-using Neo.IO.Data.LevelDB;
+using Neo.IO.Storage.LevelDB;
 using Neo.Persistence;
 using System.Collections.Generic;
 
@@ -18,18 +18,24 @@ namespace Neo.Plugins.Storage
     internal class Store : IStore
     {
         private readonly DB _db;
+        private readonly Options _options;
 
         public Store(string path)
         {
-            _db = DB.Open(path, new Options { CreateIfMissing = true, FilterPolicy = Native.leveldb_filterpolicy_create_bloom(15) });
+            _options = new Options { CreateIfMissing = true, FilterPolicy = Native.leveldb_filterpolicy_create_bloom(15) };
+            _db = DB.Open(path, _options);
         }
 
         public void Delete(byte[] key)
         {
             _db.Delete(WriteOptions.Default, key);
         }
 
-        public void Dispose() => _db.Dispose();
+        public void Dispose()
+        {
+            _db.Dispose();
+            _options.Dispose();
+        }
 
         public ISnapshot GetSnapshot() =>
             new Snapshot(_db);
@@ -53,6 +59,6 @@ public bool TryGet(byte[] key, out byte[] value)
         }
 
         public IEnumerable<(byte[], byte[])> Seek(byte[] prefix, SeekDirection direction = SeekDirection.Forward) =>
-            _db.Seek(ReadOptions.Default, prefix, direction, (k, v) => (k, v));
+            _db.Seek(ReadOptions.Default, prefix, direction);
     }
 }