Fix for ArrayPool allocating buffers larger than requested

Author: bennydiamond

Maploader/World/SubChunkData.cs

@@ -7,6 +7,7 @@ public class SubChunkData
     {
         public byte[] Key { get; set; }
         public byte[] Data { get; set; }
+        public int DataLength { get; set; }
         public UInt32 Crc32 { get; set; }
         public byte Index { get; set; }
         public bool FoundInDb { get; set; }

Maploader/World/World.cs

@@ -47,16 +47,17 @@ public ChunkData GetOverworldChunkData(int x, int z)
             for (byte subChunkIdx = 0; subChunkIdx < 15; subChunkIdx++)
             {
                 key[9] = subChunkIdx;
-
-                var data = db.Get(key);
+                UIntPtr length;     
+                var data = db.Get(key, out length);
                 if (data != null)
                 {
                     var subChunkData = new SubChunkData()
                     {
                         Index = subChunkIdx,
                         Data = data,
+                        DataLength = (int)length,
                         Key = key,
-                        Crc32 = Force.Crc32.Crc32CAlgorithm.Compute(data)
+                        Crc32 = Force.Crc32.Crc32CAlgorithm.Compute(data, 0, (int)length)
                     };
                     ret.SubChunks.Add(subChunkData);
                 }
@@ -100,8 +101,8 @@ public Chunk GetChunk(int x, int z)
             for (byte subChunkIdx = 0; subChunkIdx < 15; subChunkIdx++)
             {
                 key[9] = subChunkIdx;
-
-                var data = db.Get(key);
+                UIntPtr length;
+                var data = db.Get(key, out length);
                 if (data != null)
                 {
                     subChunks[subChunkIdx] = data;
@@ -461,16 +462,17 @@ public ChunkData GetChunkData(GroupedChunkSubKeys groupedChunkSubKeys)
             foreach (var kvp in groupedChunkSubKeys.Subchunks)
             {
                 var key = kvp.Value;
-
-                var data = db.Get(key.Key);
+                UIntPtr length;
+                var data = db.Get(key.Key, out length);
                 if (data != null)
                 {
                     var subChunkData = new SubChunkData()
                     {
                         Index = kvp.Key,
                         Data = data,
+                        DataLength = (int)length,
                         Key = kvp.Value.Key,
-                        Crc32 = Force.Crc32.Crc32CAlgorithm.Compute(data),
+                        Crc32 = Force.Crc32.Crc32CAlgorithm.Compute(data, 0, (int)length),
                     };
                     ret.SubChunks.Add(subChunkData);
                 }
@@ -499,16 +501,17 @@ public ChunkData GetChunkData(IGrouping<ulong, LevelDbWorldKey2> groupedChunkSub
             foreach (var kvp in groupedChunkSubKeys)
             {
                 var key = kvp;
-
-                var data = db.Get(key.Key);
+                UIntPtr length;
+                var data = db.Get(key.Key, out length);
                 if (data != null)
                 {
                     var subChunkData = new SubChunkData()
                     {
                         Index = key.SubChunkId,
                         Data = data,
+                        DataLength = (int)length,
                         Key = key.Key,
-                       // Crc32 = Force.Crc32.Crc32CAlgorithm.Compute(data),
+                       // Crc32 = Force.Crc32.Crc32CAlgorithm.Compute(data, 0, (int)length),
                     };
                     ret.SubChunks.Add(subChunkData);
                 }
@@ -534,15 +537,17 @@ public ChunkData GetChunkData(int x, int z)
                 var key = CreateKey(x, z);
                 key[9] = (byte)kvp;
 
-                var data = db.Get(key);
+                UIntPtr length;
+                var data = db.Get(key, out length);
                 if (data != null)
                 {
                     var subChunkData = new SubChunkData()
                     {
                         Index = (byte)kvp,
                         Data = data,
+                        DataLength = (int)length,
                         Key = key,
-                        Crc32 = Force.Crc32.Crc32CAlgorithm.Compute(data),
+                        Crc32 = Force.Crc32.Crc32CAlgorithm.Compute(data, 0, (int)length),
                     };
                     ret.SubChunks.Add(subChunkData);
                 }

leveldb-sharp-std/DB.cs

@@ -62,7 +62,8 @@ public class DB : IDisposable, IEnumerable<KeyValuePair<byte[], byte[]>>
 
         public byte[] this[byte[] key] {
             get {
-                return Get(null, key);
+                UIntPtr unusedLength;
+                return Get(null, key, out unusedLength);
             }
             set {
                 Put(null, key, value);
@@ -183,18 +184,18 @@ public void Write(WriteBatch writeBatch)
             Write(null, writeBatch);
         }
 
-        public byte[] Get(ReadOptions options, byte[] key)
+        public byte[] Get(ReadOptions options, byte[] key, out UIntPtr length)
         {
             CheckDisposed();
             if (options == null) {
                 options = new ReadOptions();
             }
-            return Native.leveldb_get(Handle, options.Handle, key);
+            return Native.leveldb_get(Handle, options.Handle, key, out length);
         }
 
-        public byte[] Get(byte[] key)
+        public byte[] Get(byte[] key, out UIntPtr length)
         {
-            return Get(null, key);
+            return Get(null, key, out length);
         }
 
         IEnumerator IEnumerable.GetEnumerator()

leveldb-sharp-std/Native.cs

@@ -196,15 +196,15 @@ public static extern IntPtr leveldb_get(IntPtr db,
 
         public static byte[] leveldb_get(IntPtr db,
                                          IntPtr readOptions,
-                                         byte[] key)
+                                         byte[] key,
+                                         out UIntPtr valueLength)
         {
 
 
             unsafe
             {
                 fixed (byte* p = key)
                 {
-                    UIntPtr valueLength;
                     string error;
                     var keyLength = (UIntPtr) key.Length;
                     IntPtr keyPtr = (IntPtr)p;