1 files changed, 67 insertions, 0 deletions
diff --git a/src/vm/classhash.inl b/src/vm/classhash.inl
new file mode 100644
index 0000000000..5158e876aa
--- /dev/null
+++ b/src/vm/classhash.inl
@@ -0,0 +1,67 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+// 
+// Hash table associated with each module that records for all types defined in that module the mapping
+// between type name and token (or TypeHandle).
+//
+
+
+#ifndef CLASSHASH_INL
+#define CLASSHASH_INL
+
+//  Low bit is discriminator between unresolved and resolved.
+//     Low bit == 0:  Resolved:   data == TypeHandle
+//     Low bit == 1:  Unresolved: data encodes either a typeDef or exportTypeDef. Use bit 31 as discriminator.
+//
+//  If not resolved, bit 31 (64-bit: yes, it's bit31, not the high bit!) is discriminator between regular typeDef and exportedType
+//
+//     Bit31   == 0:  mdTypeDef:      000t tttt tttt tttt tttt tttt tttt ttt1
+//     Bit31   == 1:  mdExportedType: 100e eeee eeee eeee eeee eeee eeee eee1
+//
+//
+
+/* static */
+inline PTR_VOID EEClassHashTable::CompressClassDef(mdToken cl)
+{
+    LIMITED_METHOD_CONTRACT;
+
+    _ASSERTE(TypeFromToken(cl) == mdtTypeDef || TypeFromToken(cl) == mdtExportedType);
+
+    switch (TypeFromToken(cl))
+    {
+        case mdtTypeDef:      return (PTR_VOID)(                         0 | (((ULONG_PTR)cl & 0x00ffffff) << 1) | EECLASSHASH_TYPEHANDLE_DISCR);
+        case mdtExportedType: return (PTR_VOID)(EECLASSHASH_MDEXPORT_DISCR | (((ULONG_PTR)cl & 0x00ffffff) << 1) | EECLASSHASH_TYPEHANDLE_DISCR);
+        default:
+            _ASSERTE(!"Can't get here.");
+            return 0;
+    }
+}
+
+inline DWORD EEClassHashTable::Hash(LPCUTF8 pszNamespace, LPCUTF8 pszClassName)
+{
+    CONTRACTL
+    {
+        NOTHROW;
+        GC_NOTRIGGER;
+        MODE_ANY;
+        FORBID_FAULT;
+        SUPPORTS_DAC;
+    }
+    CONTRACTL_END;
+
+
+    DWORD dwHash = 5381;
+    DWORD dwChar;
+
+    while ((dwChar = *pszNamespace++) != 0)
+        dwHash = ((dwHash << 5) + dwHash) ^ dwChar;
+
+    while ((dwChar = *pszClassName++) != 0)
+        dwHash = ((dwHash << 5) + dwHash) ^ dwChar;
+
+    return  dwHash;
+}
+
+#endif // CLASSHASH_INL