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提交 9747f5b6 authored 作者: S.Vladykin's avatar S.Vladykin
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Added updateRow method to make code more readable

上级 f48e3cac
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正在显示 包含 37 行增加 和 38 行删除
h2/src/main/org/h2/table/TableFilter.java
浏览文件 @ 9747f5b6
......@@ -1080,7 +1080,7 @@ public class TableFilter implements ColumnResolver {
public Session getSession() {
return session;
}
/**
* A visitor for table filters.
*/
......@@ -1139,7 +1139,7 @@ public class TableFilter implements ColumnResolver {
* @return column value for current row
*/
private Value getValue(JoinFilter filter, Column column) {
Object x = current.row[filter.id];
Object x = current.row(filter.id);
assert x != null;
Row row = current.isRow(filter.id) ? (Row) x : ((Cursor) x).get();
int columnId = column.getColumnId();
......@@ -1156,7 +1156,7 @@ public class TableFilter implements ColumnResolver {
private void start() {
if (filtersCount > 32) {
// This is because we store state in a 64 bit field, 2 bits per joined table.
throw DbException.getUnsupportedException("To many tables in join (at most 32 supported).");
throw DbException.getUnsupportedException("Too many tables in join (at most 32 supported).");
}
// fill filters
......@@ -1168,9 +1168,7 @@ public class TableFilter implements ColumnResolver {
}
// initialize current row
current = new JoinRow(new Object[filtersCount]);
current.row[top.id] = top.filter.cursor;
current.incrementState(top.id, 2);
assert current.isCursor(top.id);
current.updateRow(top.id, top.filter.cursor, JoinRow.S_NULL, JoinRow.S_CURSOR);
// initialize top cursor
top.filter.cursor.find(top.filter.session, top.filter.indexConditions);
......@@ -1180,7 +1178,7 @@ public class TableFilter implements ColumnResolver {
fake.next = current;
current = fake;
}
private boolean next() {
if (!started) {
start();
......@@ -1233,7 +1231,7 @@ public class TableFilter implements ColumnResolver {
final int lastJfId = filtersCount - 1;
int jfId = lastJfId;
while (current.row[jfId] == null) {
while (current.row(jfId) == null) {
// lookup for the first non fetched filter for the current row
jfId--;
}
......@@ -1252,7 +1250,7 @@ public class TableFilter implements ColumnResolver {
// get future cursors for join and go right to fetch them
current = join.find(current);
}
if (current.row[join.id] != null) {
if (current.row(join.id) != null) {
// either find called or outer join with null row
jfId = join.id;
continue;
......@@ -1271,7 +1269,7 @@ public class TableFilter implements ColumnResolver {
assert jfId != lastJfId;
jfId = 0;
while (current.row[jfId] != null) {
while (current.row(jfId) != null) {
jfId++;
}
// force find on half filled batch (there must be either searchRows
......@@ -1281,7 +1279,7 @@ public class TableFilter implements ColumnResolver {
// here we don't care if the current was dropped
current = current.next;
assert !current.isRow(jfId);
while (current.row[jfId] == null) {
while (current.row(jfId) == null) {
assert jfId != top.id;
// need to go left and fetch more search rows
jfId--;
......@@ -1298,7 +1296,7 @@ public class TableFilter implements ColumnResolver {
assert !current.isRow(jfId) : "double fetching";
Object x = current.row[jfId];
Object x = current.row(jfId);
assert x != null : "x null";
final JoinFilter jf = filters[jfId];
......@@ -1307,9 +1305,8 @@ public class TableFilter implements ColumnResolver {
if (!newCursor && current.isFuture(jfId)) {
// get cursor from a future
current.row[jfId] = x = get((Future<Cursor>) x);
current.incrementState(jfId, 1);
assert current.isCursor(jfId);
x = get((Future<Cursor>) x);
current.updateRow(jfId, x, JoinRow.S_FUTURE, JoinRow.S_CURSOR);
newCursor = true;
}
......@@ -1321,9 +1318,7 @@ public class TableFilter implements ColumnResolver {
if (c == null || !c.next()) {
if (newCursor && jf.isOuterJoin()) {
// replace cursor with null-row
current.row[jfId] = jf.getNullRow();
current.incrementState(jfId, 1);
assert current.isRow(jfId);
current.updateRow(jfId, jf.getNullRow(), JoinRow.S_CURSOR, JoinRow.S_ROW);
c = null;
newCursor = false;
} else {
......@@ -1348,15 +1343,10 @@ public class TableFilter implements ColumnResolver {
if (c != null) {
current = current.copyBehind(jf.id);
// get current row from cursor
current.row[jfId] = c.get();
current.incrementState(jfId, 1);
assert current.isRow(jfId);
current.updateRow(jfId, c.get(), JoinRow.S_CURSOR, JoinRow.S_ROW);
}
if (joinEmpty) {
assert current.row[join.id] == null;
current.row[join.id] = EMPTY_CURSOR;
current.incrementState(join.id, 2);
assert current.isCursor(join.id);
current.updateRow(join.id, EMPTY_CURSOR, JoinRow.S_NULL, JoinRow.S_CURSOR);
}
return;
}
......@@ -1457,21 +1447,17 @@ public class TableFilter implements ColumnResolver {
ListIterator<Future<Cursor>> iter = result.listIterator(result.size());
for (;;) {
assert current.isRow(id - 1);
if (current.row[id] == EMPTY_CURSOR) {
if (current.row(id) == EMPTY_CURSOR) {
// outer join support - skip row with existing empty cursor
current = current.prev;
continue;
}
assert current.row[id] == null;
assert current.row(id) == null;
Future<Cursor> future = iter.previous();
if (future == null) {
current.row[id] = EMPTY_CURSOR;
current.incrementState(id, 2);
assert current.isCursor(id);
current.updateRow(id, EMPTY_CURSOR, JoinRow.S_NULL, JoinRow.S_CURSOR);
} else {
current.row[id] = future;
current.incrementState(id, 1);
assert current.isFuture(id);
current.updateRow(id, future, JoinRow.S_NULL, JoinRow.S_FUTURE);
}
if (current.prev == null || !iter.hasPrevious()) {
break;
......@@ -1479,15 +1465,15 @@ public class TableFilter implements ColumnResolver {
current = current.prev;
}
}
// handle empty cursors (because of outer joins) at the beginning
while (current.prev != null && current.prev.row[id] == EMPTY_CURSOR) {
while (current.prev != null && current.prev.row(id) == EMPTY_CURSOR) {
current = current.prev;
}
assert current.prev == null || current.prev.isRow(id);
assert current.row[id] != null;
assert current.row(id) != null;
assert !current.isRow(id);
// the last updated row
return current;
}
......@@ -1502,6 +1488,7 @@ public class TableFilter implements ColumnResolver {
* Linked row in batched join.
*/
private static final class JoinRow {
private static final long S_NULL = 0;
private static final long S_FUTURE = 1;
private static final long S_CURSOR = 2;
private static final long S_ROW = 3;
......@@ -1538,7 +1525,7 @@ public class TableFilter implements ColumnResolver {
/**
* Allows to do a state transition in the following order:
* 0. Slot contains {@code null} (no constant because simple null check is sufficient).
* 0. Slot contains {@code null} ({@link #S_NULL}).
* 1. Slot contains {@link Future} ({@link #S_FUTURE}).
* 2. Slot contains {@link Cursor} ({@link #S_CURSOR}).
* 3. Slot contains {@link Row} ({@link #S_ROW}).
......@@ -1547,9 +1534,21 @@ public class TableFilter implements ColumnResolver {
* @param i Increment by this number of moves.
*/
private void incrementState(int joinFilterId, long i) {
assert i > 0 : i;
state += i << (joinFilterId << 1);
}
private void updateRow(int joinFilterId, Object x, long oldState, long newState) {
assert getState(joinFilterId) == oldState : "old state: " + getState(joinFilterId);
row[joinFilterId] = x;
incrementState(joinFilterId, newState - oldState);
assert getState(joinFilterId) == newState : "new state: " + getState(joinFilterId);
}
private Object row(int joinFilterId) {
return row[joinFilterId];
}
private boolean isRow(int joinFilterId) {
return getState(joinFilterId) == S_ROW;
}
......
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