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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) | |
32 | enum { 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 | */ | |
45 | struct 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 | }; | |
60 | typedef struct BTScanState BTScanState; | |
61 | ||
62 | ||
63 | /* *********************** PROTOTYPES *********************** */ | |
64 | ||
65 | int BTScanInitialize( const SFCB * btreeFile, | |
66 | BTScanState * scanState ); | |
67 | ||
68 | int BTScanNextRecord( BTScanState * scanState, | |
69 | void * * key, | |
70 | void * * data, | |
71 | u_int32_t * dataSize ); | |
72 | ||
73 | int BTScanTerminate( BTScanState * scanState ); | |
74 | ||
75 | #endif /* !_BTREESCANNER_H_ */ |