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1
5 package org.h2.store;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.engine.Constants;
10 import org.h2.engine.Session;
11 import org.h2.index.Cursor;
12 import org.h2.index.Index;
13 import org.h2.message.Message;
14 import org.h2.result.Row;
15 import org.h2.table.Table;
16 import org.h2.value.Value;
17
18
21 public class UndoLogRecord {
22 public static final short INSERT = 0, DELETE = 1;
23 private static final int IN_MEMORY = 0, STORED = 1, IN_MEMORY_READ_POS = 2;
24 private Table table;
25 private Row row;
26 private short operation;
27 private short state;
28 private int filePos;
29
30 public boolean isStored() {
31 return state == STORED;
32 }
33
34 public boolean canStore() {
35 return table.getUniqueIndex() != null;
36 }
37
38 public UndoLogRecord(Table table, short op, Row row) {
39 this.table = table;
40 this.row = row;
41 this.operation = op;
42 this.state = IN_MEMORY;
43 }
44
45 public void undo(Session session) throws SQLException {
46 switch (operation) {
47 case INSERT:
48 if(state == IN_MEMORY_READ_POS) {
49 Index index = table.getUniqueIndex();
50 Cursor cursor = index.find(session, row, row);
51 cursor.next();
52 int pos = cursor.getPos();
53 row.setPos(pos);
54 state = IN_MEMORY;
55 }
56 if(session.getDatabase().getLockMode()==Constants.LOCK_MODE_OFF) {
57 if(row.getDeleted()) {
58 return;
60 }
61 }
62 try {
63 table.removeRow(session, row);
64 } catch(SQLException e) {
65 if(session.getDatabase().getLockMode()==Constants.LOCK_MODE_OFF && e.getErrorCode() == Message.ROW_NOT_FOUND_WHEN_DELETING_1) {
66 } else {
69 throw e;
70 }
71 }
72 break;
73 case DELETE:
74 try {
75 row.setPos(0);
76 table.addRow(session, row);
77 } catch(SQLException e) {
78 if(session.getDatabase().getLockMode()==Constants.LOCK_MODE_OFF && e.getErrorCode() == Message.DUPLICATE_KEY_1) {
79 } else {
82 throw e;
83 }
84 }
85 break;
86 default:
87 throw Message.getInternalError("op=" + operation);
88 }
89 }
90
91 public void save(DataPage buff, FileStore file) throws SQLException {
92 buff.reset();
93 buff.writeInt(0);
94 buff.writeInt(operation);
95 buff.writeInt(row.getColumnCount());
96 for (int i = 0; i < row.getColumnCount(); i++) {
97 buff.writeValue(row.getValue(i));
98 }
99 buff.fillAligned();
100 buff.setInt(0, buff.length() / Constants.FILE_BLOCK_SIZE);
101 buff.updateChecksum();
102 filePos = (int) (file.getFilePointer() / Constants.FILE_BLOCK_SIZE);
103 file.write(buff.getBytes(), 0, buff.length());
104 row = null;
105 state = STORED;
106 }
107
108 public void seek(FileStore file) throws SQLException {
109 file.seek(filePos * Constants.FILE_BLOCK_SIZE);
110 }
111
112 public void load(DataPage buff, FileStore file, Session session) throws SQLException {
113 int min = Constants.FILE_BLOCK_SIZE;
114 seek(file);
115 buff.reset();
116 file.readFully(buff.getBytes(), 0, min);
117 int len = buff.readInt() * Constants.FILE_BLOCK_SIZE;
118 buff.checkCapacity(len);
119 if (len - min > 0) {
120 file.readFully(buff.getBytes(), min, len - min);
121 }
122 buff.check(len);
123 int op = buff.readInt();
124 if (Constants.CHECK) {
125 if (operation != op) {
126 throw Message.getInternalError("operation=" + operation + " op=" + op);
127 }
128 }
129 int columnCount = buff.readInt();
130 Value[] values = new Value[columnCount];
131 for (int i = 0; i < columnCount; i++) {
132 values[i] = buff.readValue();
133 }
134 row = new Row(values);
135 state = IN_MEMORY_READ_POS;
136 }
137
138 public Table getTable() {
139 return table;
140 }
141 }
142 |
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