Fix build breakage occuring when INVARIANTS not defined and introduced
[dragonfly.git] / sys / vfs / hammer / hammer_cursor.h
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1/*
2 * Copyright (c) 2007 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
eaeff70d 34 * $DragonFly: src/sys/vfs/hammer/hammer_cursor.h,v 1.9 2008/01/21 00:00:19 dillon Exp $
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35 */
36
37/*
38 * The hammer_cursor structure is the primary in-memory management structure
39 * for B-Tree operations.
40 *
41 * The most important issue to make note of is that a hammer_cursor is a
42 * tracking structure. Any active hammer_cursor structure will be linked into
43 * hammer_node based lists and B-Tree operations executed by unrelated
44 * treads MAY MODIFY YOUR CURSOR when you are not holding an exclusive
45 * lock on the cursor's nodes.
46 *
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47 * The cursor module maintains a shared lock on cursor->node and
48 * cursor->parent.
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49 */
50struct hammer_cursor {
51 /*
52 * Parent B-Tree node, current B-Tree node, and related element
53 * indices.
54 */
55 hammer_node_t parent;
56 int parent_index;
6a37e7e4 57
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58 hammer_node_t node;
59 int index;
60
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61 /*
62 * Set of a deadlock occurs. hammer_done_cursor() will block on
63 * this after releasing parent and node, before returning.
64 */
65 hammer_node_t deadlk_node;
66
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67 /*
68 * Pointer to the current node's bounds. Typically points to the
69 * appropriate boundary elements in the parent or points to bounds
70 * stored in the cluster. The right-boundary is range-exclusive.
71 */
72 hammer_base_elm_t left_bound;
73 hammer_base_elm_t right_bound;
74
75 /*
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76 * Key or key range governing search. The cursor code may adjust
77 * key_beg/key_end if asof is non-zero.
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78 */
79 struct hammer_base_elm key_beg;
80 struct hammer_base_elm key_end;
d5530d22 81 hammer_tid_t asof;
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82
83 /*
84 * Related data and record references. Note that the related buffers
85 * can be NULL when data and/or record is not, typically indicating
86 * information referenced via an in-memory record.
87 */
88 struct hammer_buffer *data_buffer; /* extracted data & record */
89 union hammer_data_ondisk *data;
90 struct hammer_buffer *record_buffer;
91 union hammer_record_ondisk *record;
92
93 /*
94 * Iteration and extraction control variables
95 */
96 int flags;
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97
98 /*
99 * Merged in-memory/on-disk iterations also use these fields.
100 */
101 struct hammer_inode *ip;
102 struct hammer_record *iprec;
6b4f890b 103 struct hammer_rec_rb_tree_scan_info scan;
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104};
105
106typedef struct hammer_cursor *hammer_cursor_t;
107
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108#define HAMMER_CURSOR_GET_RECORD 0x0001
109#define HAMMER_CURSOR_GET_DATA 0x0002
d26d0ae9 110#define HAMMER_CURSOR_INCLUSTER 0x0004 /* stay in the cluster */
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111#define HAMMER_CURSOR_INSERT 0x0008 /* adjust for insert */
112#define HAMMER_CURSOR_DELETE 0x0010 /* adjust for delete */
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113#define HAMMER_CURSOR_END_INCLUSIVE 0x0020 /* key_end is inclusive */
114#define HAMMER_CURSOR_END_EXCLUSIVE 0x0040 /* key_end is exclusive (def) */
eaeff70d 115#define HAMMER_CURSOR_RECOVER 0x0080 /* recovery insertion case */
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116
117#define HAMMER_CURSOR_ATEDISK 0x0100
118#define HAMMER_CURSOR_ATEMEM 0x0200
119#define HAMMER_CURSOR_DISKEOF 0x0400
120#define HAMMER_CURSOR_MEMEOF 0x0800
195c19a1 121#define HAMMER_CURSOR_DELBTREE 0x1000 /* ip_delete from b-tree */
d26d0ae9 122#define HAMMER_CURSOR_DATA_EMBEDDED 0x2000 /* embedded flag on extract */
d5530d22 123#define HAMMER_CURSOR_ASOF 0x4000 /* as-of lookup */
8cd0a023 124