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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.Database;
11 import org.h2.engine.Session;
12 import org.h2.message.Message;
13 import org.h2.util.BitField;
14 import org.h2.util.IntArray;
15 import org.h2.util.MathUtils;
16
17
27
28 public class Storage {
29
30 public static final int ALLOCATE_POS = -1;
31 private static final int FREE_LIST_SIZE = Math.max(1024, DiskFile.BLOCKS_PER_PAGE * 4);
32 private DiskFile file;
33 private int recordCount;
34 private RecordReader reader;
35 private IntArray freeList = new IntArray();
36 private IntArray pages = new IntArray();
37 private int id;
38 private Database database;
39 private DataPage dummy;
40
41 public Storage(Database database, DiskFile file, RecordReader reader, int id) {
42 this.database = database;
43 this.file = file;
44 this.reader = reader;
45 this.id = id;
46 dummy = DataPage.create(database, 0);
47 }
48
49 public RecordReader getRecordReader() {
50 return reader;
51 }
52
53 void incrementRecordCount() {
54 recordCount++;
55 }
56
57 public Record getRecord(int pos) throws SQLException {
58 return file.getRecord(pos, reader, id);
59 }
60
61 public Record getRecordIfStored(int pos) throws SQLException {
62 return file.getRecordIfStored(pos, reader, id);
63 }
64
65
70 public int getNext(Record record) {
71 int next;
72 int lastCheckedPage;
73 int pageIndex = -1;
74 if (record == null) {
75 if(pages.size() == 0) {
76 return -1;
77 }
78 pageIndex = 0;
79 lastCheckedPage = pages.get(0);
80 next = lastCheckedPage * DiskFile.BLOCKS_PER_PAGE;
81 } else {
82 int blockCount = record.getBlockCount();
83 lastCheckedPage = file.getPage(record.getPos());
84 next = record.getPos() + blockCount;
85 }
86 BitField used = file.getUsed();
87 while (true) {
88 int page = file.getPage(next);
89 if(lastCheckedPage != page) {
90 if(pageIndex < 0) {
91 pageIndex = pages.findNextValueIndex(page);
92 } else {
93 pageIndex++;
94 }
95 if(pageIndex >= pages.size()) {
96 return -1;
97 }
98 lastCheckedPage = pages.get(pageIndex);
99 next = Math.max(next, DiskFile.BLOCKS_PER_PAGE * lastCheckedPage);
100 }
101 if (used.get(next)) {
102 return next;
103 }
104 if(used.getLong(next) == 0) {
105 next = MathUtils.roundUp(next+1, 64);
106 } else {
107 next++;
108 }
109 }
110 }
111
112 public void updateRecord(Session session, Record record) throws SQLException {
113 record.setDeleted(false);
114 file.updateRecord(session, record);
115 }
116
117 public void addRecord(Session session, Record record, int pos) throws SQLException {
118 record.setStorageId(id);
119 int size = file.getRecordOverhead() + record.getByteCount(dummy);
120 size = MathUtils.roundUp(size, DiskFile.BLOCK_SIZE);
121 record.setDeleted(false);
122 int blockCount = size / DiskFile.BLOCK_SIZE;
123 if(pos == ALLOCATE_POS) {
124 pos = allocate(blockCount);
125 } else {
126 file.setUsed(pos, blockCount);
127 }
128 record.setPos(pos);
129 record.setBlockCount(blockCount);
130 record.setChanged(true);
131 recordCount++;
132 file.addRecord(session, record);
133 }
134
135 public void removeRecord(Session session, int pos) throws SQLException {
136 Record record = getRecord(pos);
137 if(Constants.CHECK && record.getDeleted()) {
138 throw Message.getInternalError("duplicate delete " + pos);
139 }
140 record.setDeleted(true);
141 int blockCount = record.getBlockCount();
142 free(pos, blockCount);
143 recordCount--;
144 file.removeRecord(session, pos, record, blockCount);
145 }
146
147 public void removeRecord(Session session, int pos, int blockCount) throws SQLException {
148
149 }
150
151 private boolean isFreeAndMine(int pos, int blocks) {
152 BitField used = file.getUsed();
153 for(int i=blocks + pos -1; i>=pos; i--) {
154 if(file.getPageOwner(file.getPage(i)) != id || used.get(i)) {
155 return false;
156 }
157 }
158 return true;
159 }
160
161 public int allocate(int blockCount) throws SQLException {
162 if (freeList.size() > 0) {
163 synchronized(file) {
164 BitField used = file.getUsed();
165 for (int i = 0; i < freeList.size(); i++) {
166 int px = freeList.get(i);
167 if (used.get(px)) {
168 freeList.remove(i--);
171 } else {
172 if (isFreeAndMine(px, blockCount)) {
173 int pos = px;
174 freeList.remove(i--);
175 file.setUsed(pos, blockCount);
176 return pos;
177 }
178 }
179 }
180 }
181 }
182 int pos = file.allocate(this, blockCount);
183 file.setUsed(pos, blockCount);
184 return pos;
185 }
186
187 void free(int pos, int blockCount) {
188 file.free(pos, blockCount);
189 if (freeList.size() < FREE_LIST_SIZE) {
190 freeList.add(pos);
191 }
192 }
193
194 public void delete(Session session) throws SQLException {
195 truncate(session);
196 database.removeStorage(id, file);
197 }
198
199
212 public int getId() {
213 return id;
214 }
215
216 public int getRecordCount() {
217 return recordCount;
218 }
219
220 public void truncate(Session session) throws SQLException {
221 freeList = new IntArray();
222 recordCount = 0;
223 file.truncateStorage(session, this, pages);
224 }
225
226 public void setReader(RecordReader reader) {
227 this.reader = reader;
228 }
229
230 public void flushRecord(Record rec) throws SQLException {
231 file.writeBack(rec);
232 }
233
234 public void flushFile() throws SQLException {
235 file.flush();
236 }
237
238 public int getRecordOverhead() {
239 return file.getRecordOverhead();
240 }
241
242 public DiskFile getDiskFile() {
243 return file;
244 }
245
246 public void setRecordCount(int recordCount) {
247 this.recordCount = recordCount;
248 }
249
250 public void addPage(int i) {
251 pages.addValueSorted(i);
252 }
253
254 public void removePage(int i) {
255 pages.removeValue(i);
256 }
257
258 }
259 |
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