projects / apple / hfs.git / blame
| Commit | Line | Data |
|---|---|---|
| 51e135ce A |
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_ */ |