1/*
2 * Copyright (c) 1996-2002 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_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. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 *
23 *	@(#)BTreeScanner.h
24 */
25
26#ifndef	_BTREESCANNER_H_
27#define _BTREESCANNER_H_
28
29#include "BTreePrivate.h"
30
31// btree node scanner buffer size.  Joe Sokol suggests 128K as a max (2002 WWDC)
32enum { kCatScanBufferSize = (128 * 1024) };
33
34
35/*
36	BTScanState - This structure is used to keep track of the current state
37	of a BTree scan.  It contains both the dynamic state information (like
38	the current node number and record number) and information that is static
39	for the duration of a scan (such as buffer pointers).
40
41	NOTE: recordNum may equal or exceed the number of records in the node
42	number nodeNum.  If so, then the next attempt to get a record will move
43	to a new node number.
44*/
45struct BTScanState
46{
47	//	The following fields are set up once at initialization time.
48	//	They are not changed during a scan.
49	u_int32_t			bufferSize;
50	void *				bufferPtr;
51	BTreeControlBlock *	btcb;
52
53	//	The following fields are the dynamic state of the current scan.
54	u_int32_t			nodeNum;			// zero is first node
55	u_int32_t			recordNum;			// zero is first record
56	BTNodeDescriptor *	currentNodePtr;		// points to current node within buffer
57	int32_t				nodesLeftInBuffer;	// number of valid nodes still in the buffer
58	int64_t				recordsFound;		// number of leaf records seen so far
59};
60typedef struct BTScanState BTScanState;
61
62
63/* *********************** PROTOTYPES *********************** */
64
65int	BTScanInitialize(	const SFCB *	btreeFile,
66							BTScanState	*	scanState     );
67
68int BTScanNextRecord(	BTScanState *	scanState,
69						void * *		key,
70						void * *		data,
71						u_int32_t *		dataSize  );
72
73int	BTScanTerminate(	BTScanState *	scanState	);
74
75#endif /* !_BTREESCANNER_H_ */
76