Ejemplo n.º 1
0
 @Override
 protected LocalResult queryWithoutCache(int maxRows, ResultTarget target) {
   if (maxRows != 0) {
     // maxRows is set (maxRows 0 means no limit)
     int l;
     if (limitExpr == null) {
       l = -1;
     } else {
       Value v = limitExpr.getValue(session);
       l = v == ValueNull.INSTANCE ? -1 : v.getInt();
     }
     if (l < 0) {
       // for limitExpr, 0 means no rows, and -1 means no limit
       l = maxRows;
     } else {
       l = Math.min(l, maxRows);
     }
     limitExpr = ValueExpression.get(ValueInt.get(l));
   }
   if (session.getDatabase().getSettings().optimizeInsertFromSelect) {
     if (unionType == UNION_ALL && target != null) {
       if (sort == null && !distinct && maxRows == 0 && offsetExpr == null && limitExpr == null) {
         left.query(0, target);
         right.query(0, target);
         return null;
       }
     }
   }
   int columnCount = left.getColumnCount();
   LocalResult result = new LocalResult(session, expressionArray, columnCount);
   if (sort != null) {
     result.setSortOrder(sort);
   }
   if (distinct) {
     left.setDistinct(true);
     right.setDistinct(true);
     result.setDistinct();
   }
   if (randomAccessResult) {
     result.setRandomAccess();
   }
   switch (unionType) {
     case UNION:
     case EXCEPT:
       left.setDistinct(true);
       right.setDistinct(true);
       result.setDistinct();
       break;
     case UNION_ALL:
       break;
     case INTERSECT:
       left.setDistinct(true);
       right.setDistinct(true);
       break;
     default:
       DbException.throwInternalError("type=" + unionType);
   }
   ResultInterface l = left.query(0);
   ResultInterface r = right.query(0);
   l.reset();
   r.reset();
   switch (unionType) {
     case UNION_ALL:
     case UNION:
       {
         while (l.next()) {
           result.addRow(convert(l.currentRow(), columnCount));
         }
         while (r.next()) {
           result.addRow(convert(r.currentRow(), columnCount));
         }
         break;
       }
     case EXCEPT:
       {
         while (l.next()) {
           result.addRow(convert(l.currentRow(), columnCount));
         }
         while (r.next()) {
           result.removeDistinct(convert(r.currentRow(), columnCount));
         }
         break;
       }
     case INTERSECT:
       {
         LocalResult temp = new LocalResult(session, expressionArray, columnCount);
         temp.setDistinct();
         temp.setRandomAccess();
         while (l.next()) {
           temp.addRow(convert(l.currentRow(), columnCount));
         }
         while (r.next()) {
           Value[] values = convert(r.currentRow(), columnCount);
           if (temp.containsDistinct(values)) {
             result.addRow(values);
           }
         }
         break;
       }
     default:
       DbException.throwInternalError("type=" + unionType);
   }
   if (offsetExpr != null) {
     result.setOffset(offsetExpr.getValue(session).getInt());
   }
   if (limitExpr != null) {
     Value v = limitExpr.getValue(session);
     if (v != ValueNull.INSTANCE) {
       result.setLimit(v.getInt());
     }
   }
   result.done();
   if (target != null) {
     while (result.next()) {
       target.addRow(result.currentRow());
     }
     result.close();
     return null;
   }
   return result;
 }
Ejemplo n.º 2
0
 // 总共18条命令,这里包含16条
 // 下面这两条在run方法中特殊处理
 // SESSION_CANCEL_STATEMENT
 // SESSION_CHECK_KEY
 // 分三种级别,从大到小: SESSION级、COMMAND级、RESULT级
 private void process() throws IOException {
   int operation = transfer.readInt();
   switch (operation) {
     case SessionRemote.SESSION_PREPARE_READ_PARAMS:
     case SessionRemote.SESSION_PREPARE:
       {
         int id = transfer.readInt();
         String sql = transfer.readString();
         int old = session.getModificationId();
         Command command = session.prepareLocal(sql);
         boolean readonly = command.isReadOnly();
         cache.addObject(id, command);
         boolean isQuery = command.isQuery();
         ArrayList<? extends ParameterInterface> params = command.getParameters();
         transfer
             .writeInt(getState(old))
             .writeBoolean(isQuery)
             .writeBoolean(readonly)
             .writeInt(params.size());
         if (operation == SessionRemote.SESSION_PREPARE_READ_PARAMS) {
           for (ParameterInterface p : params) {
             ParameterRemote.writeMetaData(transfer, p);
           }
         }
         transfer.flush();
         break;
       }
     case SessionRemote.SESSION_CLOSE:
       {
         stop = true;
         closeSession();
         transfer.writeInt(SessionRemote.STATUS_OK).flush();
         close();
         break;
       }
     case SessionRemote.COMMAND_COMMIT:
       {
         // 并不是通过org.h2.jdbc.JdbcConnection.commit()触发,此方法是通过发送COMMIT SQL触发
         // 触发SessionRemote.COMMAND_COMMIT的是在集群环境下,通过org.h2.engine.SessionRemote.autoCommitIfCluster()触发
         if (commit == null) {
           commit = session.prepareLocal("COMMIT");
         }
         int old = session.getModificationId();
         commit.executeUpdate();
         transfer.writeInt(getState(old)).flush();
         break;
       }
     case SessionRemote.COMMAND_GET_META_DATA:
       {
         int id = transfer.readInt();
         int objectId = transfer.readInt();
         Command command = (Command) cache.getObject(id, false);
         ResultInterface result = command.getMetaData();
         cache.addObject(objectId, result);
         int columnCount = result.getVisibleColumnCount();
         transfer.writeInt(SessionRemote.STATUS_OK).writeInt(columnCount).writeInt(0);
         for (int i = 0; i < columnCount; i++) {
           ResultColumn.writeColumn(transfer, result, i);
         }
         transfer.flush();
         break;
       }
     case SessionRemote.COMMAND_EXECUTE_QUERY:
       {
         int id = transfer.readInt();
         int objectId = transfer.readInt();
         int maxRows = transfer.readInt();
         int fetchSize = transfer.readInt();
         Command command = (Command) cache.getObject(id, false);
         setParameters(command);
         int old = session.getModificationId();
         ResultInterface result;
         synchronized (session) {
           result = command.executeQuery(maxRows, false);
         }
         cache.addObject(objectId, result);
         int columnCount = result.getVisibleColumnCount();
         int state = getState(old);
         transfer.writeInt(state).writeInt(columnCount);
         int rowCount = result.getRowCount();
         transfer.writeInt(rowCount);
         for (int i = 0; i < columnCount; i++) {
           ResultColumn.writeColumn(transfer, result, i);
         }
         int fetch = Math.min(rowCount, fetchSize);
         for (int i = 0; i < fetch; i++) {
           sendRow(result);
         }
         transfer.flush();
         break;
       }
     case SessionRemote.COMMAND_EXECUTE_UPDATE:
       {
         int id = transfer.readInt();
         Command command = (Command) cache.getObject(id, false);
         // if(command!=null)throw new Error();
         setParameters(command);
         int old = session.getModificationId();
         int updateCount;
         synchronized (session) {
           updateCount = command.executeUpdate();
         }
         int status;
         if (session.isClosed()) {
           status = SessionRemote.STATUS_CLOSED;
         } else {
           status = getState(old);
         }
         transfer.writeInt(status).writeInt(updateCount).writeBoolean(session.getAutoCommit());
         transfer.flush();
         break;
       }
     case SessionRemote.COMMAND_CLOSE:
       {
         int id = transfer.readInt();
         Command command = (Command) cache.getObject(id, true);
         if (command != null) {
           command.close();
           cache.freeObject(id);
         }
         break;
       }
     case SessionRemote.RESULT_FETCH_ROWS:
       {
         int id = transfer.readInt();
         int count = transfer.readInt();
         ResultInterface result = (ResultInterface) cache.getObject(id, false);
         transfer.writeInt(SessionRemote.STATUS_OK);
         for (int i = 0; i < count; i++) {
           sendRow(result);
         }
         transfer.flush();
         break;
       }
     case SessionRemote.RESULT_RESET:
       {
         int id = transfer.readInt();
         ResultInterface result = (ResultInterface) cache.getObject(id, false);
         result.reset();
         break;
       }
     case SessionRemote.RESULT_CLOSE:
       {
         int id = transfer.readInt();
         ResultInterface result = (ResultInterface) cache.getObject(id, true);
         if (result != null) {
           result.close();
           cache.freeObject(id);
         }
         break;
       }
     case SessionRemote.CHANGE_ID:
       {
         int oldId = transfer.readInt();
         int newId = transfer.readInt();
         Object obj = cache.getObject(oldId, false);
         cache.freeObject(oldId);
         cache.addObject(newId, obj);
         break;
       }
     case SessionRemote.SESSION_SET_ID:
       {
         sessionId = transfer.readString();
         transfer.writeInt(SessionRemote.STATUS_OK).flush();
         break;
       }
     case SessionRemote.SESSION_SET_AUTOCOMMIT:
       {
         boolean autoCommit = transfer.readBoolean();
         session.setAutoCommit(autoCommit);
         transfer.writeInt(SessionRemote.STATUS_OK).flush();
         break;
       }
     case SessionRemote.SESSION_HAS_PENDING_TRANSACTION:
       {
         transfer
             .writeInt(SessionRemote.STATUS_OK)
             .writeInt(session.hasPendingTransaction() ? 1 : 0)
             .flush();
         break;
       }
     case SessionRemote.LOB_READ:
       {
         long lobId = transfer.readLong();
         byte[] hmac;
         CachedInputStream in;
         boolean verifyMac;
         if (clientVersion >= Constants.TCP_PROTOCOL_VERSION_11) {
           if (clientVersion >= Constants.TCP_PROTOCOL_VERSION_12) {
             hmac = transfer.readBytes();
             verifyMac = true;
           } else {
             hmac = null;
             verifyMac = false;
           }
           in = lobs.get(lobId);
           if (in == null && verifyMac) {
             in = new CachedInputStream(null);
             lobs.put(lobId, in);
           }
         } else {
           verifyMac = false;
           hmac = null;
           in = lobs.get(lobId);
         }
         long offset = transfer.readLong();
         int length = transfer.readInt();
         if (verifyMac) {
           transfer.verifyLobMac(hmac, lobId);
         }
         if (in == null) {
           throw DbException.get(ErrorCode.OBJECT_CLOSED);
         }
         if (in.getPos() != offset) {
           LobStorageInterface lobStorage = session.getDataHandler().getLobStorage();
           InputStream lobIn = lobStorage.getInputStream(lobId, hmac, -1);
           in = new CachedInputStream(lobIn);
           lobs.put(lobId, in);
           lobIn.skip(offset);
         }
         // limit the buffer size
         length = Math.min(16 * Constants.IO_BUFFER_SIZE, length);
         byte[] buff = new byte[length];
         length = IOUtils.readFully(in, buff, 0, length);
         transfer.writeInt(SessionRemote.STATUS_OK);
         transfer.writeInt(length);
         transfer.writeBytes(buff, 0, length);
         transfer.flush();
         break;
       }
     default:
       trace("Unknown operation: " + operation);
       closeSession();
       close();
   }
 }
Ejemplo n.º 3
0
 public Cursor find(Session session, SearchRow first, SearchRow last) {
   if (recursive) {
     if (view.getRecursiveResult() != null) {
       ResultInterface r = view.getRecursiveResult();
       r.reset();
       return new ViewCursor(table, r);
     }
     if (query == null) {
       query = (Query) createSession.prepare(querySQL, true);
       planSQL = query.getPlanSQL();
     }
     if (!(query instanceof SelectUnion)) {
       throw DbException.get(ErrorCode.SYNTAX_ERROR_2, "recursive queries without UNION ALL");
     }
     SelectUnion union = (SelectUnion) query;
     if (union.getUnionType() != SelectUnion.UNION_ALL) {
       throw DbException.get(ErrorCode.SYNTAX_ERROR_2, "recursive queries without UNION ALL");
     }
     Query left = union.getLeft();
     ResultInterface r = left.query(0);
     LocalResult result = union.getEmptyResult();
     while (r.next()) {
       result.addRow(r.currentRow());
     }
     Query right = union.getRight();
     r.reset();
     view.setRecursiveResult(r);
     while (true) {
       r = right.query(0);
       if (r.getRowCount() == 0) {
         break;
       }
       while (r.next()) {
         result.addRow(r.currentRow());
       }
       r.reset();
       view.setRecursiveResult(r);
     }
     return new ViewCursor(table, result);
   }
   ArrayList<Parameter> paramList = query.getParameters();
   for (int i = 0; originalParameters != null && i < originalParameters.size(); i++) {
     Parameter orig = originalParameters.get(i);
     int idx = orig.getIndex();
     Value value = orig.getValue(session);
     setParameter(paramList, idx, value);
   }
   int len;
   if (first != null) {
     len = first.getColumnCount();
   } else if (last != null) {
     len = last.getColumnCount();
   } else {
     len = 0;
   }
   int idx = originalParameters == null ? 0 : originalParameters.size();
   idx += view.getParameterOffset();
   for (int i = 0; i < len; i++) {
     if (first != null) {
       Value v = first.getValue(i);
       if (v != null) {
         int x = idx++;
         setParameter(paramList, x, v);
       }
     }
     // for equality, only one parameter is used (first == last)
     if (last != null && indexMasks[i] != IndexCondition.EQUALITY) {
       Value v = last.getValue(i);
       if (v != null) {
         int x = idx++;
         setParameter(paramList, x, v);
       }
     }
   }
   ResultInterface result = query.query(0);
   return new ViewCursor(table, result);
 }