patch-2.4.20 linux-2.4.20/fs/jfs/jfs_btree.h

• Lines: 164
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/fs/jfs/jfs_btree.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/fs/jfs/jfs_btree.h linux-2.4.20/fs/jfs/jfs_btree.h
@@ -0,0 +1,163 @@
+/*
+ *   Copyright (c) International Business Machines Corp., 2000-2001
+ *
+ *   This program is free software;  you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or 
+ *   (at your option) any later version.
+ * 
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program;  if not, write to the Free Software 
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef	_H_JFS_BTREE
+#define _H_JFS_BTREE
+
+/*
+ *	jfs_btree.h: B+-tree
+ *
+ * JFS B+-tree (dtree and xtree) common definitions
+ */
+
+/*
+ *	basic btree page - btpage
+ *
+struct btpage {
+	s64 next;		right sibling bn
+	s64 prev;		left sibling bn
+
+	u8 flag;
+	u8 rsrvd[7];		type specific
+	s64 self;		self address
+
+	u8 entry[4064];
+};						*/
+
+/* btpaget_t flag */
+#define BT_TYPE		0x07	/* B+-tree index */
+#define	BT_ROOT		0x01	/* root page */
+#define	BT_LEAF		0x02	/* leaf page */
+#define	BT_INTERNAL	0x04	/* internal page */
+#define	BT_RIGHTMOST	0x10	/* rightmost page */
+#define	BT_LEFTMOST	0x20	/* leftmost page */
+#define	BT_SWAPPED	0x80	/* used by fsck for endian swapping */
+
+/* btorder (in inode) */
+#define	BT_RANDOM		0x0000
+#define	BT_SEQUENTIAL		0x0001
+#define	BT_LOOKUP		0x0010
+#define	BT_INSERT		0x0020
+#define	BT_DELETE		0x0040
+
+/*
+ *	btree page buffer cache access
+ */
+#define BT_IS_ROOT(MP) (((MP)->xflag & COMMIT_PAGE) == 0)
+
+/* get page from buffer page */
+#define BT_PAGE(IP, MP, TYPE, ROOT)\
+	(BT_IS_ROOT(MP) ? (TYPE *)&JFS_IP(IP)->ROOT : (TYPE *)(MP)->data)
+
+/* get the page buffer and the page for specified block address */
+#define BT_GETPAGE(IP, BN, MP, TYPE, SIZE, P, RC, ROOT)\
+{\
+	if ((BN) == 0)\
+	{\
+		MP = (struct metapage *)&JFS_IP(IP)->bxflag;\
+		P = (TYPE *)&JFS_IP(IP)->ROOT;\
+		RC = 0;\
+		jEVENT(0,("%d BT_GETPAGE returning root\n", __LINE__));\
+	}\
+	else\
+	{\
+		jEVENT(0,("%d BT_GETPAGE reading block %d\n", __LINE__,\
+			 (int)BN));\
+		MP = read_metapage((IP), BN, SIZE, 1);\
+		if (MP) {\
+			RC = 0;\
+			P = (MP)->data;\
+		} else {\
+			P = NULL;\
+			jERROR(1,("bread failed!\n"));\
+			RC = EIO;\
+		}\
+	}\
+}
+
+#define BT_MARK_DIRTY(MP, IP)\
+{\
+	if (BT_IS_ROOT(MP))\
+		mark_inode_dirty(IP);\
+	else\
+		mark_metapage_dirty(MP);\
+}
+
+/* put the page buffer */
+#define BT_PUTPAGE(MP)\
+{\
+	if (! BT_IS_ROOT(MP)) \
+		release_metapage(MP); \
+}
+
+
+/*
+ *	btree traversal stack
+ *
+ * record the path traversed during the search;
+ * top frame record the leaf page/entry selected.
+ */
+#define	MAXTREEHEIGHT		8
+struct btframe {	/* stack frame */
+	s64 bn;			/* 8: */
+	s16 index;		/* 2: */
+	s16 lastindex;		/* 2: */
+	struct metapage *mp;	/* 4: */
+};				/* (16) */
+
+struct btstack {
+	struct btframe *top;
+	int nsplit;
+	struct btframe stack[MAXTREEHEIGHT];
+};
+
+#define BT_CLR(btstack)\
+	(btstack)->top = (btstack)->stack
+
+#define BT_PUSH(BTSTACK, BN, INDEX)\
+{\
+	(BTSTACK)->top->bn = BN;\
+	(BTSTACK)->top->index = INDEX;\
+	++(BTSTACK)->top;\
+	assert((BTSTACK)->top != &((BTSTACK)->stack[MAXTREEHEIGHT]));\
+}
+
+#define BT_POP(btstack)\
+	( (btstack)->top == (btstack)->stack ? NULL : --(btstack)->top )
+
+#define BT_STACK(btstack)\
+	( (btstack)->top == (btstack)->stack ? NULL : (btstack)->top )
+
+/* retrieve search results */
+#define BT_GETSEARCH(IP, LEAF, BN, MP, TYPE, P, INDEX, ROOT)\
+{\
+	BN = (LEAF)->bn;\
+	MP = (LEAF)->mp;\
+	if (BN)\
+		P = (TYPE *)MP->data;\
+	else\
+		P = (TYPE *)&JFS_IP(IP)->ROOT;\
+	INDEX = (LEAF)->index;\
+}
+
+/* put the page buffer of search */
+#define BT_PUTSEARCH(BTSTACK)\
+{\
+	if (! BT_IS_ROOT((BTSTACK)->top->mp))\
+		release_metapage((BTSTACK)->top->mp);\
+}
+#endif				/* _H_JFS_BTREE */