[not part of build] Header file for disk cache record structures.

netwerk/cache/src/nsDiskCache.h

@@ -0,0 +1,167 @@
+/* -*- 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 nsCacheDevice.h, released March 9, 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 Beard   <beard@netscape.com>
+ *    Gordon Sheridan <gordon@netscape.com>
+ */
+
+
+#ifndef _nsDiskCache_h_
+#define _nsDiskCache_h_
+
+enum {
+    eEvictionRankMask       = 0xFF000000;
+    eLocationSelectorMask   = 0x00C00000;
+
+    eExtraBlocksMask        = 0x00300000;
+    eBlockNumberMask        = 0x000FFFFF;
+
+    eFileReservedMask       = 0x003F0000;
+    eFileGenerationMask     = 0x0000FFFF;
+};
+
+class DiskCacheRecord {
+public:
+    PRUint32   HashNumber(void)       { return mHashNumber; }
+    void       SetHashNumber(PRUint32 hashNumber) { mHashNumber = hashNumber; }
+
+    PRUint8    EvictionRank(void)
+    {
+        return (PRUint8)(mInfo & eEvictionRankMask) >> 24;
+    }
+
+    void       SetEvictionRank(PRUint8 rank)
+    {
+        mInfo &= ~eEvictionRankMask; // clear eviction rank bits
+        mInfo |=  rank << 24;
+    }
+
+    PRUint32   LocationSelector(void)
+    {
+        return (PRUint32)(mInfo & eLocationSelectorMask) >> 22;
+    }
+
+    void       SetLocationSelector(PRUint32  selector)
+    {
+        mInfo &= ~eLocationSelectorMask; // clear location selector bits
+        mInfo |= (selector & eLocationSelectorMask) << 22;
+    }
+
+    PRUint32   BlockCount(void)
+    {
+        return (PRUint32)((mInfo & eExtraBlocksMask) >> 20) + 1;
+    }
+
+    void       SetBlockCount(PRUint32  count)
+    {
+        NS_ASSERTION( (count>=1) && (count<=4),"invalid block count");
+        count = --count;
+        mInfo &= ~eExtraBlocksMask; // clear extra blocks bits
+        mInfo |= (count & eExtraBlocksMask) << 20;
+    }
+
+    PRUint32   BlockNumber(void)
+    {
+        return mInfo & eBlockNumberMask;
+    }
+
+    void       SetBlockNumber(PRUint32  blockNumber)
+    {
+        mInfo &= ~eBlockNumberMask;  // clear block number bits
+        mInfo |= blockNumber & eBlockNumberMask;
+    }
+
+    PRUint16   FileGeneration(void)
+    {
+        return mInfo & eFileGenerationMask;
+    }
+
+    void       SetFileGeneration(PRUint16 generation)
+    {
+        mInfo &= ~eFileGenerationMask;  // clear file generation bits
+        mInfo |= generation & eFileGenerationMask;
+    }
+
+
+private:
+    PRUint32   mHashNumber;
+    PRUint32   mInfo;
+};
+
+
+/*
+
+Cache Extent Table
+
+
+1111 1111 0000 0000 0000 0000 0000 0000 : eEvictionRankMask
+0000 0000 1100 0000 0000 0000 0000 0000 : eLocationSelectorMask   (0-3)
+0000 0000 0011 0000 0000 0000 0000 0000 : number of extra contiguous blocks 1-4
+0000 0000 0000 1111 1111 1111 1111 1111 : block#  0-1,048,575
+
+0000 0000 0011 1111 0000 0000 0000 0000 : eFileReservedMask
+0000 0000 0000 0000 1111 1111 1111 1111 : eFileGenerationMask
+
+0  file
+1   256 bytes
+2  1024
+3  4096
+
+
+	log2 of seconds = 5 bits
+
+log2	minutes	hours	days   years
+00000	   1
+00001	   2
+00010	   4
+00011	   8
+00100	  16
+00101	  32
+00110	  64	  1
+00111	 128	  2
+01000	 256	  4
+01001	 512	  8.5
+01010	1024	 17
+01011	2048	 34
+01100		 68
+01101		136
+01110		273	 11
+01111			 22
+10000			 45.5
+10001			 91
+10010			182
+10011			364	1
+10100				2
+10101				3
+10110				4
+10111
+11000
+11001
+11010
+11011
+11100
+11101
+11110
+11111
+
+*/
+
+
+#endif // _nsDiskCache_h_