NCBC-659: Make KetamaKeyMapper and VBucketKeyMapper Dispose HashAlgor…

…ithm after every use

Change-Id: I33ba2b21789713069f06211c1f353698ff4f771a
Reviewed-on: http://review.couchbase.org/41779
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>
Reviewed-by: Brett Lawson <brett19@gmail.com>

Src/Couchbase.Tests/Core/Buckets/MemcachedBucketTests.cs

@@ -18,7 +18,7 @@ public class MemcachedBucketTests
     {
         private ICouchbaseCluster _cluster;
 
-        [TestFixtureSetUp]
+        [SetUp]
         public void SetUp()
         {
             _cluster = new Cluster();
@@ -415,7 +415,7 @@ public void Test_Multi_Upsert()
             }
         }
 
-        [TestFixtureTearDown]
+        [TearDown]
         public void TestFixtureTearDown()
         {
             _cluster.Dispose();

Src/Couchbase.Tests/Core/Buckets/VBucketKeyMapperTests.cs

@@ -42,27 +42,6 @@ public void TestMapKey()
             Assert.IsNotNull(vBucket);
         }
 
-        [Test]
-        public void Test_That_HashAlgorithm_Is_Not_Null()
-        {
-            IKeyMapper mapper = new VBucketKeyMapper(_servers, _vBucketServerMap);
-            Assert.IsNotNull(mapper.HashAlgorithm);
-        }
-
-        [Test]
-        public void Test_That_HashAlgorithm_Default_Type_Is_Crc32()
-        {
-            IKeyMapper mapper = new VBucketKeyMapper(_servers, _vBucketServerMap);
-            Assert.IsInstanceOf<Crc32>(mapper.HashAlgorithm);
-        }
-
-        [Test]
-        public void Test_That_HashAlgorithm_Default_Type_Can_Be_Overridden()
-        {
-            IKeyMapper mapper = new VBucketKeyMapper(new HMACMD5(), _servers, _vBucketServerMap);
-            Assert.IsInstanceOf<HMACMD5>(mapper.HashAlgorithm);
-        }
-
         [Test(Description = "Note, will probably only work on localhost")]
         public void Test_That_Key_XXXXX_Maps_To_VBucket_389()
         {

Src/Couchbase/Core/Buckets/KetamaKeyMapper.cs

@@ -15,19 +15,13 @@ internal class KetamaKeyMapper : IKeyMapper
         private readonly int _totalWeight;
         private readonly SortedDictionary<long, IServer> _buckets = new SortedDictionary<long, IServer>();
 
-        public KetamaKeyMapper(List<IServer> servers) 
-            : this(servers, MD5.Create())
-        {
-        }
-
-        public KetamaKeyMapper(List<IServer> servers, HashAlgorithm algorithm)
+        public KetamaKeyMapper(List<IServer> servers)
         {
             _servers = servers;
             _totalWeight = _servers.Count;
-            HashAlgorithm = algorithm;
             Initialize();
         }
- 
+
         /// <summary>
         /// Maps a Key to a node in the cluster.
         /// </summary>
@@ -77,12 +71,15 @@ public int FindIndex(long key)
         public long GetHash(string key)
         {
             var bytes = Encoding.UTF8.GetBytes(key);
-            var hash = HashAlgorithm.ComputeHash(bytes);
-            var result = ((long) (hash[3] & 0xFF) << 24)
-                | ((long)(hash[2] & 0xFF) << 16)
-                | ((long)(hash[1] & 0xFF) << 8)
-                | (uint)hash[0] & 0xFF;
-            return result;
+            using (var md5 = MD5.Create())
+            {
+                var hash = md5.ComputeHash(bytes);
+                var result = ((long) (hash[3] & 0xFF) << 24)
+                             | ((long) (hash[2] & 0xFF) << 16)
+                             | ((long) (hash[1] & 0xFF) << 8)
+                             | (uint) hash[0] & 0xFF;
+                return result;
+            }
         }
 
         /// <summary>
@@ -98,25 +95,23 @@ public void Initialize()
                 for (long n = 0; n < factor; n++)
                 {
                     var bytes = Encoding.UTF8.GetBytes(server.EndPoint + "-" + n);
-                    var hash = HashAlgorithm.ComputeHash(bytes);
-                    for (var j = 0; j < 4; j++)
+                    using (var md5 = MD5.Create())
                     {
-                        var key = ((long) (hash[3 + j*4] & 0xFF) << 24)
-                                  | ((long) (hash[2 + j*4] & 0xFF) << 16)
-                                  | ((long) (hash[1 + j*4] & 0xFF) << 8)
-                                  | (uint) (hash[0 + j*4] & 0xFF);
+                        var hash = md5.ComputeHash(bytes);
+                        for (var j = 0; j < 4; j++)
+                        {
+                            var key = ((long) (hash[3 + j*4] & 0xFF) << 24)
+                                      | ((long) (hash[2 + j*4] & 0xFF) << 16)
+                                      | ((long) (hash[1 + j*4] & 0xFF) << 8)
+                                      | (uint) (hash[0 + j*4] & 0xFF);
 
-                        _buckets[key] = server;
+                            _buckets[key] = server;
+                        }
                     }
                 }
             }
         }
 
-        /// <summary>
-        /// The alogrithm for hashing the keys.
-        /// </summary>
-        public HashAlgorithm HashAlgorithm { get; set; }
-
         public int Rev { get; set; }
     }
 }

Src/Couchbase/Core/Buckets/VBucketKeyMapper.cs

@@ -20,30 +20,13 @@ internal class VBucketKeyMapper : IKeyMapper
         private readonly VBucketServerMap _vBucketServerMap;
         private readonly List<IServer> _servers;
 
-        public VBucketKeyMapper(List<IServer> servers, VBucketServerMap vBucketServerMap) 
-            : this(new Crc32(), servers, vBucketServerMap)
+        public VBucketKeyMapper(List<IServer> servers, VBucketServerMap vBucketServerMap)
         {
-        }
-
-        public VBucketKeyMapper(HashAlgorithm algorithm, List<IServer> servers, VBucketServerMap vBucketServerMap)
-        {
-            HashAlgorithm = algorithm;
             _servers = servers;
             _vBucketServerMap = vBucketServerMap;
             _vBuckets = CreateVBucketMap();
             _vForwardBuckets = CreateVBucketMapForwards();
         }
-
-        public VBucketKeyMapper(HashAlgorithm algorithm, Dictionary<int, IVBucket> vBuckets)
-        {
-            HashAlgorithm = algorithm;
-            _vBuckets = vBuckets;
-        }
-
-        public VBucketKeyMapper(Dictionary<int, IVBucket> vBuckets) 
-            : this(new Crc32(), vBuckets)
-        {
-        }
 
         /// <summary>
         /// Maps a given Key to it's node in a Couchbase Cluster.
@@ -57,17 +40,15 @@ public IMappedNode MapKey(string key)
             return _vBuckets[index];
         }
 
-        /// <summary>
-        /// The alogrithm for hashing the keys. Couchbase Buckets use CRC32.
-        /// </summary>
-        public HashAlgorithm HashAlgorithm { get; set; }
-
         public int GetIndex(string key)
         {
-            var keyBytes = Encoding.UTF8.GetBytes(key);
-            var hashedKeyBytes = HashAlgorithm.ComputeHash(keyBytes);
-            var hash = BitConverter.ToUInt32(hashedKeyBytes, 0);
-            return (int)hash & Mask;
+            using (var crc32 = new Crc32())
+            {
+                var keyBytes = Encoding.UTF8.GetBytes(key);
+                var hashedKeyBytes = crc32.ComputeHash(keyBytes);
+                var hash = BitConverter.ToUInt32(hashedKeyBytes, 0);
+                return (int)hash & Mask;
+            }
         }
 
         /// <summary>
@@ -79,7 +60,7 @@ public int GetIndex(string key)
             var vBuckets = new Dictionary<int, IVBucket>();
             var vBucketForwardMap = _vBucketServerMap.VBucketMapForward;
             var vBucketMap = _vBucketServerMap.VBucketMap;
-            
+
             Log.Info(m => m("Creating VBuckets {0} and FMaps {1} for Rev#{2}", vBucketMap.Length,
                 vBucketForwardMap == null ? 0: vBucketForwardMap.Length, Rev));
 

Src/Couchbase/Core/IKeyMapper.cs

@@ -1,13 +1,9 @@
-using System.Security.Cryptography;
-
-namespace Couchbase.Core
+namespace Couchbase.Core
 {
     internal interface IKeyMapper
     {
         IMappedNode MapKey(string key);
 
-        HashAlgorithm HashAlgorithm { get; set; }
-
         int Rev { get; set; }
     }
 }