1/*
2 * Copyright (c) 1996-2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 *
28 *	@(#)BTreeScanner.h
29 */
30
31#ifndef	_BTREESCANNER_H_
32#define _BTREESCANNER_H_
33
34#include <sys/appleapiopts.h>
35
36#ifdef KERNEL
37#ifdef __APPLE_API_PRIVATE
38#include <sys/time.h>
39
40#include "FileMgrInternal.h"
41#include "BTreesPrivate.h"
42
43// amount of time we are allowed to process a catalog search (in � secs)
44// NOTE - code assumes kMaxMicroSecsInKernel is less than 1,000,000
45enum { kMaxMicroSecsInKernel = (1000 * 100) };	// 1 tenth of a second
46
47// btree node scanner buffer size.  at 32K we get 8 nodes.  this is the size used
48// in Mac OS 9
49enum { kCatSearchBufferSize = (32 * 1024) };
50
51
52/*
53 * ============ W A R N I N G ! ============
54 * DO NOT INCREASE THE SIZE OF THIS STRUCT!
55 * It must be less than or equal to the size of
56 * the opaque searchstate struct (in sys/attr.h).
57 */
58/* Private description used in hfs_search */
59struct CatPosition
60{
61  u_int32_t		writeCount;    	/* The BTree's write count (to see if the catalog writeCount */
62                              	/* changed since the last search).  If 0, the rest */
63                             	/* of the record is invalid, start from beginning. */
64  u_int32_t     nextNode;     	/* node number to resume search */
65  u_int32_t   	nextRecord;  	/* record number to resume search */
66  u_int32_t   	recordsFound; 	/* number of leaf records seen so far */
67};
68typedef struct CatPosition              CatPosition;
69
70
71/*
72	BTScanState - This structure is used to keep track of the current state
73	of a BTree scan.  It contains both the dynamic state information (like
74	the current node number and record number) and information that is static
75	for the duration of a scan (such as buffer pointers).
76
77	NOTE: recordNum may equal or exceed the number of records in the node
78	number nodeNum.  If so, then the next attempt to get a record will move
79	to a new node number.
80*/
81struct BTScanState
82{
83	//	The following fields are set up once at initialization time.
84	//	They are not changed during a scan.
85	u_int32_t			bufferSize;
86	struct buf *		bufferPtr;
87	BTreeControlBlock *	btcb;
88
89	//	The following fields are the dynamic state of the current scan.
90	u_int32_t			nodeNum;			// zero is first node
91	u_int32_t			recordNum;			// zero is first record
92	BTNodeDescriptor *	currentNodePtr;		// points to current node within buffer
93	u_int32_t			nodesLeftInBuffer;	// number of valid nodes still in the buffer
94	u_int32_t			recordsFound;		// number of leaf records seen so far
95	struct timeval		startTime;			// time we started catalog search
96};
97typedef struct BTScanState BTScanState;
98
99
100/* *********************** PROTOTYPES *********************** */
101
102int	BTScanInitialize(	const FCB *		btreeFile,
103						u_int32_t		startingNode,
104						u_int32_t		startingRecord,
105						u_int32_t		recordsFound,
106						u_int32_t		bufferSize,
107						BTScanState	*	scanState     );
108
109int BTScanNextRecord(	BTScanState *	scanState,
110						Boolean			avoidIO,
111						void * *		key,
112						void * *		data,
113						u_int32_t *		dataSize  );
114
115int	BTScanTerminate(	BTScanState *	scanState,
116						u_int32_t *		startingNode,
117						u_int32_t *		startingRecord,
118						u_int32_t *		recordsFound	);
119
120#endif /* __APPLE_API_PRIVATE */
121#endif /* KERNEL */
122#endif /* !_BTREESCANNER_H_ */
123