Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.IdentityModel/System/IdentityModel/SignatureResourcePool.cs

@@ -0,0 +1,127 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace System.IdentityModel
+{
+    using System.IO;
+    using System.Security.Cryptography;
+    using System.IdentityModel.Tokens;
+    using System.Xml;
+    using System.Text;
+
+    // for sequential use by one thread
+    sealed class SignatureResourcePool
+    {
+        const int BufferSize = 64;
+        CanonicalizationDriver canonicalizationDriver;
+        HashStream hashStream;
+        HashAlgorithm hashAlgorithm;
+#if NO
+        XmlC14NWriter integratedWriter;
+#endif
+        XmlDictionaryWriter utf8Writer;
+        byte[] encodingBuffer;
+        char[] base64Buffer;
+
+        public char[] TakeBase64Buffer()
+        {
+            if (this.base64Buffer == null)
+            {
+                this.base64Buffer = new char[BufferSize];
+            }
+            return this.base64Buffer;
+        }
+
+        public CanonicalizationDriver TakeCanonicalizationDriver()
+        {
+            if (this.canonicalizationDriver == null)
+            {
+                this.canonicalizationDriver = new CanonicalizationDriver();
+            }
+            else
+            {
+                this.canonicalizationDriver.Reset();
+            }
+            return this.canonicalizationDriver;
+        }
+
+        public byte[] TakeEncodingBuffer()
+        {
+            if (this.encodingBuffer == null)
+            {
+                this.encodingBuffer = new byte[BufferSize];
+            }
+            return this.encodingBuffer;
+        }
+
+        public HashAlgorithm TakeHashAlgorithm(string algorithm)
+        {
+            if ( this.hashAlgorithm == null )
+            {
+                if ( string.IsNullOrEmpty( algorithm ) )
+                {
+                    throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgument( algorithm, SR.GetString( SR.EmptyOrNullArgumentString, "algorithm" ) );
+                }
+
+                this.hashAlgorithm = CryptoHelper.CreateHashAlgorithm( algorithm );
+            }
+            else
+            {
+                this.hashAlgorithm.Initialize();
+            }
+           
+            return this.hashAlgorithm;
+        }
+
+        public HashStream TakeHashStream(HashAlgorithm hash)
+        {
+            if (this.hashStream == null)
+            {
+                this.hashStream = new HashStream(hash);
+            }
+            else
+            {
+                this.hashStream.Reset(hash);
+            }
+            return this.hashStream;
+        }
+
+        public HashStream TakeHashStream(string algorithm)
+        {
+            return TakeHashStream(TakeHashAlgorithm(algorithm));
+        }
+#if NO
+        public XmlC14NWriter TakeIntegratedWriter(Stream stream)
+        {
+            return TakeIntegratedWriter(stream, false, null);
+        }
+
+        public XmlC14NWriter TakeIntegratedWriter(Stream stream, bool includeComments, string[] inclusivePrefixes)
+        {
+            if (this.integratedWriter == null)
+            {
+                this.integratedWriter = new XmlC14NWriter(stream, includeComments, inclusivePrefixes);
+            }
+            else
+            {
+                this.integratedWriter.SetOutput(stream, includeComments, inclusivePrefixes);
+            }
+            return this.integratedWriter;
+        }
+#endif
+
+        public XmlDictionaryWriter TakeUtf8Writer()
+        {
+            if (this.utf8Writer == null)
+            {
+                this.utf8Writer = XmlDictionaryWriter.CreateTextWriter(Stream.Null, Encoding.UTF8, false);
+            }
+            else
+            {
+                ((IXmlTextWriterInitializer) this.utf8Writer).SetOutput(Stream.Null, Encoding.UTF8, false);
+            }
+            return this.utf8Writer;
+        }
+    }
+}