diff --git a/mozilla/netwerk/cache/src/nsDiskCacheMap.cpp b/mozilla/netwerk/cache/src/nsDiskCacheMap.cpp
new file mode 100644
index 00000000000..7b4c4eaea2b
--- /dev/null
+++ b/mozilla/netwerk/cache/src/nsDiskCacheMap.cpp
@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ * 
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ * 
+ * The Original Code is nsDiskCacheMap.cpp, released March 23, 2001.
+ * 
+ * The Initial Developer of the Original Code is Netscape Communications
+ * Corporation.  Portions created by Netscape are
+ * Copyright (C) 2001 Netscape Communications Corporation.  All
+ * Rights Reserved.
+ * 
+ * Contributor(s): 
+ *    Patrick C. Beard <beard@netscape.com>
+ */
+
+#include "nsDiskCacheMap.h"
+#include "nsIInputStream.h"
+#include "nsIOutputStream.h"
+
+nsDiskCacheMap::nsDiskCacheMap()
+{
+}
+
+nsDiskCacheMap::~nsDiskCacheMap()
+{
+}
+
+nsDiskCacheRecord* nsDiskCacheMap::GetRecord(PRUint32 hashNumber)
+{
+    PRUint32 index = (hashNumber & (kBucketsPerTable - 1));
+    nsDiskCacheBucket& bucket = mBuckets[index];
+    nsDiskCacheRecord* oldestRecord = &bucket.mRecords[0];
+
+    for (int i = 0; i < kRecordsPerBucket; ++i) {
+        nsDiskCacheRecord* record = &bucket.mRecords[i];
+        if (record->HashNumber() == 0 || record->HashNumber() == hashNumber)
+            return record;
+        if (record->EvictionRank() > oldestRecord->EvictionRank())
+            oldestRecord = record;
+    }
+
+    // record not found, so must evict a record.
+    oldestRecord->SetHashNumber(0);
+    oldestRecord->SetEvictionRank(0);
+    return oldestRecord;
+}
+
+nsresult nsDiskCacheMap::Read(nsIInputStream* input)
+{
+    // XXX need a header, etc.
+    PRUint32 count;
+    nsresult rv = input->Read((char*)&mBuckets, sizeof(mBuckets), &count);
+    if (NS_FAILED(rv)) return rv;
+    
+    // unswap all of the active records.
+    for (int b = 0; b < kBucketsPerTable; ++b) {
+        nsDiskCacheBucket& bucket = mBuckets[b];
+        for (int r = 0; r < kRecordsPerBucket; ++r) {
+            nsDiskCacheRecord* record = &bucket.mRecords[r];
+            if (record->HashNumber() == 0)
+                break;
+            record->Unswap();
+        }
+    }
+    
+    return NS_OK;
+}
+
+nsresult nsDiskCacheMap::Write(nsIOutputStream* output)
+{
+    // swap all of the active records.
+    for (int b = 0; b < kBucketsPerTable; ++b) {
+        nsDiskCacheBucket& bucket = mBuckets[b];
+        for (int r = 0; r < kRecordsPerBucket; ++r) {
+            nsDiskCacheRecord* record = &bucket.mRecords[r];
+            if (record->HashNumber() == 0)
+                break;
+            record->Swap();
+        }
+    }
+    
+    // XXX need a header, etc.
+    PRUint32 count;
+    nsresult rv = output->Write((char*)&mBuckets, sizeof(mBuckets), &count);
+
+    // unswap all of the active records.
+    for (int b = 0; b < kBucketsPerTable; ++b) {
+        nsDiskCacheBucket& bucket = mBuckets[b];
+        for (int r = 0; r < kRecordsPerBucket; ++r) {
+            nsDiskCacheRecord* record = &bucket.mRecords[r];
+            if (record->HashNumber() == 0)
+                break;
+            record->Unswap();
+        }
+    }
+    
+    return rv;
+}
diff --git a/mozilla/netwerk/cache/src/nsDiskCacheMap.h b/mozilla/netwerk/cache/src/nsDiskCacheMap.h
new file mode 100644
index 00000000000..74e36d336b9
--- /dev/null
+++ b/mozilla/netwerk/cache/src/nsDiskCacheMap.h
@@ -0,0 +1,54 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ * 
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ * 
+ * The Original Code is nsDiskCacheMap.h, released March 23, 2001.
+ * 
+ * The Initial Developer of the Original Code is Netscape Communications
+ * Corporation.  Portions created by Netscape are
+ * Copyright (C) 2001 Netscape Communications Corporation.  All
+ * Rights Reserved.
+ * 
+ * Contributor(s): 
+ *    Patrick C. Beard <beard@netscape.com>
+ */
+
+#ifndef _nsDiskCacheMap_h_
+
+#include "nsDiskCache.h"
+#include "nsError.h"
+
+class nsIInputStream;
+class nsIOutputStream;
+
+// XXX initial capacity, enough for 8192 distint entries.
+const PRUint32 kRecordsPerBucket = 256;
+const PRUint32 kBucketsPerTable = (1 << 4);       // must be a power of 2!
+ 
+class nsDiskCacheMap {
+public:
+    nsDiskCacheMap();
+    ~nsDiskCacheMap();
+
+    nsDiskCacheRecord* GetRecord(PRUint32 hashNumber);
+    
+    nsresult Read(nsIInputStream* input);
+    nsresult Write(nsIOutputStream* output);
+    
+private:
+    // XXX need a bitmap?
+    struct nsDiskCacheBucket {
+        nsDiskCacheRecord mRecords[kRecordsPerBucket];
+    };
+    nsDiskCacheBucket mBuckets[kBucketsPerTable];
+};
+
+#endif // _nsDiskCacheMap_h_