Fixes #946

neo.UnitTests/UT_DataCache.cs

@@ -0,0 +1,126 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Neo.IO.Caching;
+using Neo.Ledger;
+using System.Linq;
+
+namespace Neo.UnitTests
+{
+ [TestClass]
+ public class UT_DataCache
+ {
+ [TestInitialize]
+ public void TestSetup()
+ {
+ TestBlockchain.InitializeMockNeoSystem();
+ }
+
+ [TestMethod]
+ public void TestCachedFind_Between()
+ {
+ var snapshot = TestBlockchain.GetStore().GetSnapshot();
+ var storages = snapshot.Storages;
+ var cache = new CloneCache<StorageKey, StorageItem>(storages);
+
+ storages.DeleteWhere((k, v) => k.ScriptHash == UInt160.Zero);
+
+ storages.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x01, 0x01 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+ storages.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x00, 0x01 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+ storages.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x00, 0x03 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+ cache.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x01, 0x02 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+ cache.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x00, 0x02 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+
+ CollectionAssert.AreEqual(
+ cache.Find(new byte[] { 0x00 }).Select(u => u.Key.Key[1]).ToArray(),
+ new byte[] { 0x01, 0x02, 0x03 }
+ );
+
+ storages.DeleteWhere((k, v) => k.ScriptHash == UInt160.Zero);
+ }
+
+ [TestMethod]
+ public void TestCachedFind_Last()
+ {
+ var snapshot = TestBlockchain.GetStore().GetSnapshot();
+ var storages = snapshot.Storages;
+ var cache = new CloneCache<StorageKey, StorageItem>(storages);
+
+ storages.DeleteWhere((k, v) => k.ScriptHash == UInt160.Zero);
+
+ storages.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x00, 0x01 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+ storages.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x01, 0x01 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+ cache.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x00, 0x02 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+ cache.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x01, 0x02 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+
+ CollectionAssert.AreEqual(
+ cache.Find(new byte[] { 0x00 }).Select(u => u.Key.Key[1]).ToArray(),
+ new byte[] { 0x01, 0x02 }
+ );
+
+ storages.DeleteWhere((k, v) => k.ScriptHash == UInt160.Zero);
+ }
+
+ [TestMethod]
+ public void TestCachedFind_Empty()
+ {
+ var snapshot = TestBlockchain.GetStore().GetSnapshot();
+ var storages = snapshot.Storages;
+ var cache = new CloneCache<StorageKey, StorageItem>(storages);
+
+ storages.DeleteWhere((k, v) => k.ScriptHash == UInt160.Zero);
+
+ cache.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x00, 0x02 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+ cache.Add
+ (
+ new StorageKey() { Key = new byte[] { 0x01, 0x02 }, ScriptHash = UInt160.Zero },
+ new StorageItem() { IsConstant = false, Value = new byte[] { } }
+ );
+
+ CollectionAssert.AreEqual(
+ cache.Find(new byte[] { 0x00 }).Select(u => u.Key.Key[1]).ToArray(),
+ new byte[] { 0x02 }
+ );
+
+ storages.DeleteWhere((k, v) => k.ScriptHash == UInt160.Zero);
+ }
+ }
+}

neo/IO/ByteArrayComparer.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+
+namespace Neo.IO
+{
+ internal class ByteArrayComparer : IComparer<byte[]>
+ {
+ public static readonly ByteArrayComparer Default = new ByteArrayComparer();
+
+ public int Compare(byte[] x, byte[] y)
+ {
+ int length = Math.Min(x.Length, y.Length);
+ for (int i = 0; i < length; i++)
+ {
+ int r = x[i].CompareTo(y[i]);
+ if (r != 0) return r;
+ }
+ return x.Length.CompareTo(y.Length);
+ }
+ }
+}

neo/IO/Caching/DataCache.cs

@@ -118,16 +118,65 @@ public void DeleteWhere(Func<TKey, TValue, bool> predicate)
  }
  }
 
+ public byte[] ToByteArray(TKey x)
+ {
+ if (x is StorageKey xx)
+ {
+ return xx.Key;
+ }
+ else
+ {
+ return x.ToArray();
+ }
+ }
+
  public IEnumerable<KeyValuePair<TKey, TValue>> Find(byte[] key_prefix = null)
  {
+ IEnumerable<(byte[], TKey, TValue)> cached;
  lock (dictionary)
  {
- foreach (var pair in FindInternal(key_prefix ?? new byte[0]))
- if (!dictionary.ContainsKey(pair.Key))
- yield return pair;
- foreach (var pair in dictionary)
- if (pair.Value.State != TrackState.Deleted && (key_prefix == null || pair.Key.ToArray().Take(key_prefix.Length).SequenceEqual(key_prefix)))
- yield return new KeyValuePair<TKey, TValue>(pair.Key, pair.Value.Item);
+ cached = dictionary
+ .Where(p => p.Value.State != TrackState.Deleted && (key_prefix == null || ToByteArray(p.Key).Take(key_prefix.Length).SequenceEqual(key_prefix)))
+ .Select(p =>
+ (
+ KeyBytes: p.Key.ToArray(),
+ p.Key,
+ p.Value.Item
+ ))
+ .OrderBy(p => p.KeyBytes, ByteArrayComparer.Default)
+ .ToArray();
+ }
+ var uncached = FindInternal(key_prefix ?? new byte[0])
+ .Where(p => !dictionary.ContainsKey(p.Key))
+ .Select(p =>
+ (
+ KeyBytes: ToByteArray(p.Key),
+ p.Key,
+ p.Value
+ ));
+ using (var e1 = cached.GetEnumerator())
+ using (var e2 = uncached.GetEnumerator())
+ {
+ (byte[] KeyBytes, TKey Key, TValue Item) i1, i2;
+ bool c1 = e1.MoveNext();
+ bool c2 = e2.MoveNext();
+ i1 = c1 ? e1.Current : default;
+ i2 = c2 ? e2.Current : default;
+ while (c1 || c2)
+ {
+ if (!c2 || (c1 && ByteArrayComparer.Default.Compare(i1.KeyBytes, i2.KeyBytes) < 0))
+ {
+ yield return new KeyValuePair<TKey, TValue>(i1.Key, i1.Item);
+ c1 = e1.MoveNext();
+ i1 = c1 ? e1.Current : default;
+ }
+ else
+ {
+ yield return new KeyValuePair<TKey, TValue>(i2.Key, i2.Item);
+ c2 = e2.MoveNext();
+ i2 = c2 ? e2.Current : default;
+ }
+ }
  }
  }