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h2database
提交 240ec323 authored 作者: Thomas Mueller's avatar Thomas Mueller
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Version 1.3: when re-running the same query so that the previous result was… 

Version 1.3: when re-running the same query so that the previous result was re-used, and if the result set was large so that it was stored externally (in a temp file or in a temp table), then reading rows from both result sets resulted in an exception or wrong behavior.
上级 7beff649
隐藏空白字符变更
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正在显示 包含 249 行增加 和 44 行删除
h2/src/main/org/h2/result/LocalResult.java
浏览文件 @ 240ec323
......@@ -37,7 +37,7 @@ public class LocalResult implements ResultInterface, ResultTarget {
private ValueHashMap<Value[]> distinctRows;
private Value[] currentRow;
private int offset, limit;
private ResultExternal disk;
private ResultExternal external;
private int diskOffset;
private boolean distinct;
private boolean closed;
......@@ -105,9 +105,16 @@ public class LocalResult implements ResultInterface, ResultTarget {
* @return the copy
*/
public LocalResult createShallowCopy(Session targetSession) {
if (disk == null && (rows == null || rows.size() < rowCount)) {
if (external == null && (rows == null || rows.size() < rowCount)) {
return null;
}
ResultExternal e2 = null;
if (external != null) {
e2 = external.createShallowCopy();
if (e2 == null) {
return null;
}
}
LocalResult copy = new LocalResult();
copy.maxMemoryRows = this.maxMemoryRows;
copy.session = targetSession;
......@@ -122,7 +129,7 @@ public class LocalResult implements ResultInterface, ResultTarget {
copy.currentRow = null;
copy.offset = 0;
copy.limit = 0;
copy.disk = this.disk;
copy.external = e2;
copy.diskOffset = this.diskOffset;
return copy;
}
......@@ -158,7 +165,7 @@ public class LocalResult implements ResultInterface, ResultTarget {
distinctRows.remove(array);
rowCount = distinctRows.size();
} else {
rowCount = disk.removeRow(values);
rowCount = external.removeRow(values);
}
}
......@@ -176,16 +183,16 @@ public class LocalResult implements ResultInterface, ResultTarget {
ValueArray array = ValueArray.get(values);
return distinctRows.get(array) != null;
}
return disk.contains(values);
return external.contains(values);
}
public void reset() {
rowId = -1;
if (disk != null) {
disk.reset();
if (external != null) {
external.reset();
if (diskOffset > 0) {
for (int i = 0; i < diskOffset; i++) {
disk.next();
external.next();
}
}
}
......@@ -199,8 +206,8 @@ public class LocalResult implements ResultInterface, ResultTarget {
if (rowId < rowCount) {
rowId++;
if (rowId < rowCount) {
if (disk != null) {
currentRow = disk.next();
if (external != null) {
currentRow = external.next();
} else {
currentRow = rows.get(rowId);
}
......@@ -228,27 +235,27 @@ public class LocalResult implements ResultInterface, ResultTarget {
rowCount = distinctRows.size();
Database db = session.getDatabase();
if (rowCount > db.getSettings().maxMemoryRowsDistinct && db.isPersistent()) {
disk = new ResultTempTable(session, sort);
disk.addRows(distinctRows.values());
external = new ResultTempTable(session, sort);
external.addRows(distinctRows.values());
distinctRows = null;
}
} else {
rowCount = disk.addRow(values);
rowCount = external.addRow(values);
}
return;
}
rows.add(values);
rowCount++;
if (rows.size() > maxMemoryRows && session.getDatabase().isPersistent()) {
if (disk == null) {
disk = new ResultDiskBuffer(session, sort, values.length);
if (external == null) {
external = new ResultDiskBuffer(session, sort, values.length);
}
addRowsToDisk();
}
}
private void addRowsToDisk() {
disk.addRows(rows);
external.addRows(rows);
rows.clear();
}
......@@ -265,10 +272,10 @@ public class LocalResult implements ResultInterface, ResultTarget {
rows = distinctRows.values();
distinctRows = null;
} else {
if (disk != null && sort != null) {
if (external != null && sort != null) {
// external sort
ResultExternal temp = disk;
disk = null;
ResultExternal temp = external;
external = null;
temp.reset();
rows = New.arrayList();
// TODO use offset directly if possible
......@@ -277,12 +284,12 @@ public class LocalResult implements ResultInterface, ResultTarget {
if (list == null) {
break;
}
if (disk == null) {
disk = new ResultDiskBuffer(session, sort, list.length);
if (external == null) {
external = new ResultDiskBuffer(session, sort, list.length);
}
rows.add(list);
if (rows.size() > maxMemoryRows) {
disk.addRows(rows);
external.addRows(rows);
rows.clear();
}
}
......@@ -291,9 +298,9 @@ public class LocalResult implements ResultInterface, ResultTarget {
}
}
}
if (disk != null) {
if (external != null) {
addRowsToDisk();
disk.done();
external.done();
} else {
if (sort != null) {
sort.sort(rows);
......@@ -321,7 +328,7 @@ public class LocalResult implements ResultInterface, ResultTarget {
if (limit <= 0) {
return;
}
if (disk == null) {
if (external == null) {
if (rows.size() > limit) {
rows = New.arrayList(rows.subList(0, limit));
rowCount = limit;
......@@ -334,13 +341,13 @@ public class LocalResult implements ResultInterface, ResultTarget {
}
public boolean needToClose() {
return disk != null;
return external != null;
}
public void close() {
if (disk != null) {
disk.close();
disk = null;
if (external != null) {
external.close();
external = null;
closed = true;
}
}
......@@ -398,7 +405,7 @@ public class LocalResult implements ResultInterface, ResultTarget {
if (offset <= 0) {
return;
}
if (disk == null) {
if (external == null) {
if (offset >= rows.size()) {
rows.clear();
rowCount = 0;
......
h2/src/main/org/h2/result/ResultDiskBuffer.java
浏览文件 @ 240ec323
......@@ -25,14 +25,19 @@ class ResultDiskBuffer implements ResultExternal {
private static final int READ_AHEAD = 128;
private Data rowBuff;
private FileStore file;
private ArrayList<ResultDiskTape> tapes;
private ResultDiskTape mainTape;
private SortOrder sort;
private int columnCount;
private final Data rowBuff;
private final ArrayList<ResultDiskTape> tapes;
private final ResultDiskTape mainTape;
private final SortOrder sort;
private final int columnCount;
private final int maxBufferSize;
private FileStore file;
private final ResultDiskBuffer parent;
private boolean closed;
private int childCount;
/**
* Represents a virtual disk tape for the merge sort algorithm.
* Each virtual disk tape is a region of the temp file.
......@@ -61,23 +66,62 @@ class ResultDiskBuffer implements ResultExternal {
}
ResultDiskBuffer(Session session, SortOrder sort, int columnCount) {
this.parent = null;
this.sort = sort;
this.columnCount = columnCount;
Database db = session.getDatabase();
rowBuff = Data.create(db, Constants.DEFAULT_PAGE_SIZE);
rowBuff = Data.create(null, Constants.DEFAULT_PAGE_SIZE);
String fileName = session.getDatabase().createTempFile();
file = session.getDatabase().openFile(fileName, "rw", false);
file.setCheckedWriting(false);
file.seek(FileStore.HEADER_LENGTH);
if (sort != null) {
tapes = New.arrayList();
mainTape = null;
} else {
tapes = null;
mainTape = new ResultDiskTape();
mainTape.pos = FileStore.HEADER_LENGTH;
}
this.maxBufferSize = db.getSettings().largeResultBufferSize;
}
private ResultDiskBuffer(ResultDiskBuffer parent) {
this.parent = parent;
rowBuff = Data.create(null, Constants.DEFAULT_PAGE_SIZE);
file = parent.file;
if (parent.tapes != null) {
tapes = New.arrayList();
for (ResultDiskTape t : parent.tapes) {
ResultDiskTape t2 = new ResultDiskTape();
t2.pos = t2.start = t.start;
t2.end = t.end;
tapes.add(t2);
}
} else {
tapes = null;
}
if (parent.mainTape != null) {
mainTape = new ResultDiskTape();
mainTape.pos = FileStore.HEADER_LENGTH;
mainTape.start = parent.mainTape.start;
mainTape.end = parent.mainTape.end;
} else {
mainTape = null;
}
sort = parent.sort;
columnCount = parent.columnCount;
maxBufferSize = parent.maxBufferSize;
}
public synchronized ResultDiskBuffer createShallowCopy() {
if (closed || parent != null) {
return null;
}
childCount++;
return new ResultDiskBuffer(this);
}
public void addRows(ArrayList<Value[]> rows) {
if (sort != null) {
sort.sort(rows);
......@@ -212,13 +256,28 @@ class ResultDiskBuffer implements ResultExternal {
close();
}
public void close() {
if (file != null) {
private synchronized void closeChild() {
if (--childCount == 0 && closed) {
file.closeAndDeleteSilently();
file = null;
}
}
public synchronized void close() {
if (closed) {
return;
}
closed = true;
if (parent != null) {
parent.closeChild();
} else if (file != null) {
if (childCount == 0) {
file.closeAndDeleteSilently();
file = null;
}
}
}
public int removeRow(Value[] values) {
throw DbException.throwInternalError();
}
......
h2/src/main/org/h2/result/ResultExternal.java
浏览文件 @ 240ec323
......@@ -69,4 +69,11 @@ public interface ResultExternal {
*/
int addRow(Value[] values);
/**
* Create a shallow copy of this object if possible.
*
* @return the shallow copy, or null
*/
ResultExternal createShallowCopy();
}
h2/src/main/org/h2/result/ResultTempTable.java
浏览文件 @ 240ec323
......@@ -28,13 +28,17 @@ import org.h2.value.ValueArray;
public class ResultTempTable implements ResultExternal {
private static final String COLUMN_NAME = "DATA";
private Session session;
private final SortOrder sort;
private final Session session;
private final Index index;
private RegularTable table;
private SortOrder sort;
private Index index;
private Cursor resultCursor;
public ResultTempTable(Session session, SortOrder sort) {
private final ResultTempTable parent;
private boolean closed;
private int childCount;
ResultTempTable(Session session, SortOrder sort) {
this.session = session;
this.sort = sort;
Schema schema = session.getDatabase().getSchema(Constants.SCHEMA_MAIN);
......@@ -60,6 +64,25 @@ public class ResultTempTable implements ResultExternal {
index = new PageBtreeIndex(table, indexId, data.tableName, indexCols, indexType, true, session);
index.setTemporary(true);
table.getIndexes().add(index);
parent = null;
}
private ResultTempTable(ResultTempTable parent) {
this.parent = parent;
this.session = parent.session;
this.table = parent.table;
this.index = parent.index;
// sort is only used when adding rows
this.sort = null;
reset();
}
public synchronized ResultExternal createShallowCopy() {
if (closed || parent != null) {
return null;
}
childCount++;
return new ResultTempTable(this);
}
public int removeRow(Value[] values) {
......@@ -94,7 +117,27 @@ public class ResultTempTable implements ResultExternal {
}
}
public void close() {
private synchronized void closeChild() {
if (--childCount == 0 && closed) {
dropTable();
}
}
public synchronized void close() {
if (closed) {
return;
}
closed = true;
if (parent != null) {
parent.closeChild();
} else {
if (childCount == 0) {
dropTable();
}
}
}
private void dropTable() {
if (table == null) {
return;
}
......
h2/src/test/org/h2/test/db/TestTempTables.java
浏览文件 @ 240ec323
......@@ -30,6 +30,8 @@ public class TestTempTables extends TestBase {
public void test() throws SQLException {
deleteDb("tempTables");
testTempFileResultSet();
testTempTableResultSet();
testTransactionalTemp();
testDeleteGlobalTempTableWhenClosing();
Connection c1 = getConnection("tempTables");
......@@ -43,6 +45,93 @@ public class TestTempTables extends TestBase {
deleteDb("tempTables");
}
private void testTempFileResultSet() throws SQLException {
deleteDb("tempTables");
Connection conn = getConnection("tempTables;MAX_MEMORY_ROWS=10");
ResultSet rs1, rs2;
Statement stat1 = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
Statement stat2 = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
rs1 = stat1.executeQuery("select * from system_range(1, 20)");
rs2 = stat2.executeQuery("select * from system_range(1, 20)");
for (int i = 0; i < 20; i++) {
rs1.next();
rs2.next();
rs1.getInt(1);
rs2.getInt(1);
}
rs2.close();
// verify the temp table is not deleted yet
rs1.beforeFirst();
for (int i = 0; i < 20; i++) {
rs1.next();
rs1.getInt(1);
}
rs1.close();
rs1 = stat1.executeQuery("select * from system_range(1, 20) order by x desc");
rs2 = stat2.executeQuery("select * from system_range(1, 20) order by x desc");
for (int i = 0; i < 20; i++) {
rs1.next();
rs2.next();
rs1.getInt(1);
rs2.getInt(1);
}
rs1.close();
// verify the temp table is not deleted yet
rs2.beforeFirst();
for (int i = 0; i < 20; i++) {
rs2.next();
rs2.getInt(1);
}
rs2.close();
conn.close();
}
private void testTempTableResultSet() throws SQLException {
deleteDb("tempTables");
Connection conn = getConnection("tempTables;MAX_MEMORY_ROWS_DISTINCT=10");
Statement stat1 = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
Statement stat2 = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
ResultSet rs1, rs2;
rs1 = stat1.executeQuery("select distinct * from system_range(1, 20)");
// this will re-use the same temp table
rs2 = stat2.executeQuery("select distinct * from system_range(1, 20)");
for (int i = 0; i < 20; i++) {
rs1.next();
rs2.next();
rs1.getInt(1);
rs2.getInt(1);
}
rs2.close();
// verify the temp table is not deleted yet
rs1.beforeFirst();
for (int i = 0; i < 20; i++) {
rs1.next();
rs1.getInt(1);
}
rs1.close();
rs1 = stat1.executeQuery("select distinct * from system_range(1, 20)");
rs2 = stat2.executeQuery("select distinct * from system_range(1, 20)");
for (int i = 0; i < 20; i++) {
rs1.next();
rs2.next();
rs1.getInt(1);
rs2.getInt(1);
}
rs1.close();
// verify the temp table is not deleted yet
rs2.beforeFirst();
for (int i = 0; i < 20; i++) {
rs2.next();
rs2.getInt(1);
}
rs2.close();
conn.close();
}
private void testTransactionalTemp() throws SQLException {
deleteDb("tempTables");
Connection conn = getConnection("tempTables");
......
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