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1
5 package org.h2.index;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.result.Row;
10 import org.h2.result.SearchRow;
11
12
13 public class TreeCursor implements Cursor {
14 private TreeIndex tree;
15 private TreeNode node;
16 private boolean beforeFirst;
17 private SearchRow first, last;
18
19 TreeCursor(TreeIndex tree, TreeNode node, SearchRow first, SearchRow last) {
20 this.tree = tree;
21 this.node = node;
22 this.first = first;
23 this.last = last;
24 beforeFirst = true;
25 }
26
27 public Row get() {
28 return node == null ? null : node.row;
29 }
30
31 public int getPos() {
32 return node == null ? -1 : node.row.getPos();
33 }
34
35 public boolean next() throws SQLException {
36 if(beforeFirst) {
37 beforeFirst = false;
38 if(node == null) {
39 return false;
40 }
41 if (first != null && tree.compareRows(node.row, first) < 0) {
42 node = tree.next(node);
43 }
44 } else {
45 node = tree.next(node);
46 }
47 if(node != null && last != null) {
48 if (tree.compareRows(node.row, last) > 0) {
49 node = null;
50 }
51 }
52 return node != null;
53 }
54
55 }
56 |
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