Author: jplevyak
Date: Fri Nov 12 18:41:31 2010
New Revision: 1034505
URL: http://svn.apache.org/viewvc?rev=1034505&view=rev
Log:
Add back in documentation which was under #if 0
Modified:
trafficserver/traffic/trunk/iocore/cache/P_CacheDir.h
Modified: trafficserver/traffic/trunk/iocore/cache/P_CacheDir.h
URL:
http://svn.apache.org/viewvc/trafficserver/traffic/trunk/iocore/cache/P_CacheDir.h?rev=1034505&r1=1034504&r2=1034505&view=diff
==============================================================================
--- trafficserver/traffic/trunk/iocore/cache/P_CacheDir.h (original)
+++ trafficserver/traffic/trunk/iocore/cache/P_CacheDir.h Fri Nov 12 18:41:31
2010
@@ -54,6 +54,7 @@ struct CacheVC;
#define SYNC_MAX_WRITE (2 * 1024 * 1024)
#define SYNC_DELAY HRTIME_MSECONDS(500)
+#define DO_NOT_REMOVE_THIS 0
// Debugging Options
@@ -112,7 +113,6 @@ struct CacheVC;
struct EvacuationBlock;
typedef uint32 DirInfo;
-// Global Data
// Cache Directory
@@ -124,16 +124,43 @@ typedef uint32 DirInfo;
// on the processor.
struct Dir
{
+#if DO_NOT_REMOVE_THIS
+ // THE BIT-FIELD INTERPRETATION OF THIS STRUCT WHICH HAS TO
+ // USE MACROS TO PREVENT UNALIGNED LOADS
+ // bits are numbered from lowest in u16 to highest
+ // always index as u16 to avoid byte order issues
+ unsigned int offset:24; // (0,1:0-7) 16M * 512 = 8GB
+ unsigned int big:2; // (1:8-9) 512 << (3 * big)
+ unsigned int size:6; // (1:10-15) 6**2 = 64, 64*512 = 32768 ..
64*256=16MB
+ unsigned int tag:12; // (2:0-11) 2048 / 8 entries/bucket = .4%
+ unsigned int phase:1; // (2:12)
+ unsigned int head:1; // (2:13) first segment in a document
+ unsigned int pinned:1; // (2:14)
+ unsigned int token:1; // (2:15)
+ unsigned int next:16; // (3)
+ inku16 offset_high; // 8GB * 65k = 0.5PB (4)
+#else
uint16 w[5];
Dir() { dir_clear(this); }
+#endif
};
// INTERNAL: do not access these members directly, use the
// accessors below (e.g. dir_offset, dir_set_offset)
struct FreeDir
{
+#if DO_NOT_REMOVE_THIS
+ // THE BIT-FIELD INTERPRETATION OF THIS STRUCT WHICH HAS TO
+ // USE MACROS TO PREVENT UNALIGNED LOADS
+ unsigned int offset:24; // 0: empty
+ unsigned int reserved:8;
+ unsigned int prev:16; // (2)
+ unsigned int next:16; // (3)
+ inku16 offset_high; // 0: empty
+#else
uint16 w[5];
FreeDir() { dir_clear(this); }
+#endif
};
#define dir_bit(_e, _w, _b) ((uint32)(((_e)->w[_w] >> (_b)) & 1))
