/**
* Parse and prepare the given SQL statement. This method also checks if the connection has been
* closed.
*
* @param sql the SQL statement
* @return the prepared statement
*/
public Command prepareLocal(String sql) {
if (closed) {
throw DbException.get(ErrorCode.CONNECTION_BROKEN_1, "session closed");
}
Command command;
if (queryCacheSize > 0) {
if (queryCache == null) {
queryCache = SmallLRUCache.newInstance(queryCacheSize);
modificationMetaID = database.getModificationMetaId();
} else {
long newModificationMetaID = database.getModificationMetaId();
if (newModificationMetaID != modificationMetaID) {
queryCache.clear();
modificationMetaID = newModificationMetaID;
}
command = queryCache.get(sql);
if (command != null && command.canReuse()) {
command.reuse();
return command;
}
}
}
Parser parser = new Parser(this);
command = parser.prepareCommand(sql);
if (queryCache != null) {
if (command.isCacheable()) {
queryCache.put(sql, command);
}
}
return command;
}
/**
* Get or create a trace object for this module.
*
* @param module the module name
* @return the trace object
*/
public synchronized Trace getTrace(String module) {
Trace t = traces.get(module);
if (t == null) {
t = new Trace(writer, module);
traces.put(module, t);
}
return t;
}
public PlanItem getBestPlanItem(Session session, int[] masks) {
PlanItem item = new PlanItem();
item.cost = index.getCost(session, masks);
IntArray masksArray = new IntArray(masks == null ? Utils.EMPTY_INT_ARRAY : masks);
ViewIndex i2 = indexCache.get(masksArray);
if (i2 == null || i2.getSession() != session) {
i2 = new ViewIndex(this, index, session, masks);
indexCache.put(masksArray, i2);
}
item.setIndex(i2);
return item;
}
public double getCost(Session session, int[] masks) {
if (recursive) {
return 1000;
}
IntArray masksArray = new IntArray(masks == null ? Utils.EMPTY_INT_ARRAY : masks);
CostElement cachedCost = costCache.get(masksArray);
if (cachedCost != null) {
long time = System.currentTimeMillis();
if (time < cachedCost.evaluatedAt + Constants.VIEW_COST_CACHE_MAX_AGE) {
return cachedCost.cost;
}
}
Query q = (Query) session.prepare(querySQL, true);
if (masks != null) {
IntArray paramIndex = new IntArray();
for (int i = 0; i < masks.length; i++) {
int mask = masks[i];
if (mask == 0) {
continue;
}
paramIndex.add(i);
}
int len = paramIndex.size();
for (int i = 0; i < len; i++) {
int idx = paramIndex.get(i);
int mask = masks[idx];
int nextParamIndex = q.getParameters().size() + view.getParameterOffset();
if ((mask & IndexCondition.EQUALITY) != 0) {
Parameter param = new Parameter(nextParamIndex);
q.addGlobalCondition(param, idx, Comparison.EQUAL_NULL_SAFE);
} else {
if ((mask & IndexCondition.START) != 0) {
Parameter param = new Parameter(nextParamIndex);
q.addGlobalCondition(param, idx, Comparison.BIGGER_EQUAL);
}
if ((mask & IndexCondition.END) != 0) {
Parameter param = new Parameter(nextParamIndex);
q.addGlobalCondition(param, idx, Comparison.SMALLER_EQUAL);
}
}
}
String sql = q.getPlanSQL();
q = (Query) session.prepare(sql, true);
}
double cost = q.getCost();
cachedCost = new CostElement();
cachedCost.evaluatedAt = System.currentTimeMillis();
cachedCost.cost = cost;
costCache.put(masksArray, cachedCost);
return cost;
}
private void writeValue(Value v) throws IOException {
if (v.getType() == Value.CLOB || v.getType() == Value.BLOB) {
if (v instanceof ValueLobDb) {
ValueLobDb lob = (ValueLobDb) v;
if (lob.isStored()) {
long id = lob.getLobId();
lobs.put(id, new CachedInputStream(null));
}
}
}
transfer.writeValue(v);
}
/**
* Create a new trace system object.
*
* @param fileName the file name
* @param init if the trace system should be initialized
*/
public TraceSystem(String fileName, boolean init) {
this.fileName = fileName;
updateLevel();
traces = SmallLRUCache.newInstance(100);
dateFormat = new SimpleDateFormat("MM-dd HH:mm:ss ");
if (fileName != null && init) {
try {
openWriter();
} catch (Exception e) {
logWritingError(e);
}
}
}
/** One server thread is opened per client connection. */
public class TcpServerThread implements Runnable {
protected final Transfer transfer;
private final TcpServer server;
private Session session;
private boolean stop;
private Thread thread;
private Command commit;
private final SmallMap cache = new SmallMap(SysProperties.SERVER_CACHED_OBJECTS); // 默认缓存64个对象
private final SmallLRUCache<Long, CachedInputStream> lobs =
SmallLRUCache.newInstance(
Math.max(
SysProperties.SERVER_CACHED_OBJECTS, SysProperties.SERVER_RESULT_SET_FETCH_SIZE * 5));
private final int threadId;
private int clientVersion;
private String sessionId;
TcpServerThread(Socket socket, TcpServer server, int id) {
this.server = server;
this.threadId = id;
transfer = new Transfer(null);
transfer.setSocket(socket);
}
private void trace(String s) {
server.trace(this + " " + s);
}
@Override
public void run() {
try {
transfer.init();
trace("Connect");
// TODO server: should support a list of allowed databases
// and a list of allowed clients
try {
// 如果没有加-tcpAllowOthers参数，那么只接受本地连接
if (!server.allow(transfer.getSocket())) {
throw DbException.get(ErrorCode.REMOTE_CONNECTION_NOT_ALLOWED);
}
int minClientVersion = transfer.readInt();
if (minClientVersion < Constants.TCP_PROTOCOL_VERSION_6) {
throw DbException.get(
ErrorCode.DRIVER_VERSION_ERROR_2,
"" + clientVersion,
"" + Constants.TCP_PROTOCOL_VERSION_6);
} else if (minClientVersion > Constants.TCP_PROTOCOL_VERSION_12) {
throw DbException.get(
ErrorCode.DRIVER_VERSION_ERROR_2,
"" + clientVersion,
"" + Constants.TCP_PROTOCOL_VERSION_12);
}
int maxClientVersion = transfer.readInt();
if (maxClientVersion >= Constants.TCP_PROTOCOL_VERSION_12) {
clientVersion = Constants.TCP_PROTOCOL_VERSION_12;
} else {
clientVersion = minClientVersion;
}
transfer.setVersion(clientVersion);
String db = transfer.readString();
String originalURL = transfer.readString();
if (db == null && originalURL == null) {
String targetSessionId = transfer.readString();
int command = transfer.readInt();
stop = true;
if (command == SessionRemote.SESSION_CANCEL_STATEMENT) {
// cancel a running statement
int statementId = transfer.readInt();
server.cancelStatement(targetSessionId, statementId);
} else if (command == SessionRemote.SESSION_CHECK_KEY) {
// check if this is the correct server
db = server.checkKeyAndGetDatabaseName(targetSessionId);
if (!targetSessionId.equals(db)) {
transfer.writeInt(SessionRemote.STATUS_OK);
} else {
transfer.writeInt(SessionRemote.STATUS_ERROR);
}
}
}
// 启动TcpServer时加"-baseDir"或者像这样System.setProperty("h2.baseDir", "E:\\H2\\baseDir")
String baseDir = server.getBaseDir();
if (baseDir == null) {
baseDir = SysProperties.getBaseDir();
}
// 例如启动TcpServer时，指定了"-key mydb mydatabase"，
// 如果db变量是mydb，那么实际上就是mydatabase，相当于做一次映射
// 如果db变量不是mydb，那么抛错: org.h2.jdbc.JdbcSQLException: Wrong user name or password [28000-170]
db = server.checkKeyAndGetDatabaseName(db);
ConnectionInfo ci = new ConnectionInfo(db);
ci.setOriginalURL(originalURL);
ci.setUserName(transfer.readString());
// password参数的值已经转换成userPasswordHash和filePasswordHash了，
// 不能由userPasswordHash和filePasswordHash得到原始的password
ci.setUserPasswordHash(transfer.readBytes());
ci.setFilePasswordHash(transfer.readBytes()); // 只有指定"CIPHER"参数时filePasswordHash才是非null的
int len = transfer.readInt();
for (int i = 0; i < len; i++) {
ci.setProperty(transfer.readString(), transfer.readString());
}
// override client's requested properties with server settings
if (baseDir != null) {
ci.setBaseDir(baseDir);
}
if (server.getIfExists()) {
// 启动TcpServer时加"-ifExists"，限制只有数据库存在时客户端才能连接，也就是不允许在客户端创建数据库
ci.setProperty("IFEXISTS", "TRUE");
}
session = Engine.getInstance().createSession(ci);
transfer.setSession(session);
transfer.writeInt(SessionRemote.STATUS_OK);
transfer.writeInt(clientVersion);
transfer.flush();
// 每建立一个新的Session对象时，把它保存到内存数据库management_db_9092的SESSIONS表
server.addConnection(threadId, originalURL, ci.getUserName());
trace("Connected");
} catch (Throwable e) {
sendError(e);
stop = true;
}
while (!stop) {
try {
process();
} catch (Throwable e) {
sendError(e);
}
}
trace("Disconnect");
} catch (Throwable e) {
server.traceError(e);
} finally {
close();
}
}
private void closeSession() {
if (session != null) {
RuntimeException closeError = null;
try {
Command rollback = session.prepareLocal("ROLLBACK");
rollback.executeUpdate();
} catch (RuntimeException e) {
closeError = e;
server.traceError(e);
} catch (Exception e) {
server.traceError(e);
}
try {
session.close();
server.removeConnection(threadId);
} catch (RuntimeException e) {
if (closeError == null) {
closeError = e;
server.traceError(e);
}
} catch (Exception e) {
server.traceError(e);
} finally {
session = null;
}
if (closeError != null) {
throw closeError;
}
}
}
/** Close a connection. */
void close() {
try {
stop = true;
closeSession();
} catch (Exception e) {
server.traceError(e);
} finally {
transfer.close();
trace("Close");
server.remove(this);
}
}
private void sendError(Throwable t) {
try {
SQLException e = DbException.convert(t).getSQLException();
StringWriter writer = new StringWriter();
e.printStackTrace(new PrintWriter(writer));
String trace = writer.toString();
String message;
String sql;
if (e instanceof JdbcSQLException) {
JdbcSQLException j = (JdbcSQLException) e;
message = j.getOriginalMessage();
sql = j.getSQL();
} else {
message = e.getMessage();
sql = null;
}
transfer
.writeInt(SessionRemote.STATUS_ERROR)
.writeString(e.getSQLState())
.writeString(message)
.writeString(sql)
.writeInt(e.getErrorCode())
.writeString(trace)
.flush();
} catch (Exception e2) {
if (!transfer.isClosed()) {
server.traceError(e2);
}
// if writing the error does not work, close the connection
stop = true;
}
}
private void setParameters(Command command) throws IOException {
int len = transfer.readInt();
ArrayList<? extends ParameterInterface> params = command.getParameters();
for (int i = 0; i < len; i++) {
Parameter p = (Parameter) params.get(i);
p.setValue(transfer.readValue());
}
}
// 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();
}
}
private int getState(int oldModificationId) {
if (session.getModificationId() == oldModificationId) {
return SessionRemote.STATUS_OK;
}
return SessionRemote.STATUS_OK_STATE_CHANGED;
}
private void sendRow(ResultInterface result) throws IOException {
if (result.next()) {
transfer.writeBoolean(true);
Value[] v = result.currentRow();
for (int i = 0; i < result.getVisibleColumnCount(); i++) {
if (clientVersion >= Constants.TCP_PROTOCOL_VERSION_12) {
transfer.writeValue(v[i]);
} else {
writeValue(v[i]);
}
}
} else {
transfer.writeBoolean(false);
}
}
private void writeValue(Value v) throws IOException {
if (v.getType() == Value.CLOB || v.getType() == Value.BLOB) {
if (v instanceof ValueLobDb) {
ValueLobDb lob = (ValueLobDb) v;
if (lob.isStored()) {
long id = lob.getLobId();
lobs.put(id, new CachedInputStream(null));
}
}
}
transfer.writeValue(v);
}
void setThread(Thread thread) {
this.thread = thread;
}
Thread getThread() {
return thread;
}
/**
* Cancel a running statement.
*
* @param targetSessionId the session id
* @param statementId the statement to cancel
*/
void cancelStatement(String targetSessionId, int statementId) {
if (StringUtils.equals(targetSessionId, this.sessionId)) {
Command cmd = (Command) cache.getObject(statementId, false);
cmd.cancel();
}
}
/** An input stream with a position. */
static class CachedInputStream extends FilterInputStream {
private static final ByteArrayInputStream DUMMY = new ByteArrayInputStream(new byte[0]);
private long pos;
CachedInputStream(InputStream in) {
super(in == null ? DUMMY : in);
if (in == null) {
pos = -1;
}
}
@Override
public int read(byte[] buff, int off, int len) throws IOException {
len = super.read(buff, off, len);
if (len > 0) {
pos += len;
}
return len;
}
@Override
public int read() throws IOException {
int x = in.read();
if (x >= 0) {
pos++;
}
return x;
}
@Override
public long skip(long n) throws IOException {
n = super.skip(n);
if (n > 0) {
pos += n;
}
return n;
}
public long getPos() {
return pos;
}
}
}
// 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();
}
}
/** A view is a virtual table that is defined by a query. */
public class TableView extends Table {
private static final long ROW_COUNT_APPROXIMATION = 100;
private String querySQL;
private ArrayList<Table> tables;
private final String[] columnNames;
private Query viewQuery;
private ViewIndex index;
private boolean recursive;
private DbException createException;
private SmallLRUCache<IntArray, ViewIndex> indexCache =
SmallLRUCache.newInstance(Constants.VIEW_INDEX_CACHE_SIZE);
private long lastModificationCheck;
private long maxDataModificationId;
private User owner;
private Query topQuery;
private ResultInterface recursiveResult;
private boolean tableExpression;
public TableView(
Schema schema,
int id,
String name,
String querySQL,
ArrayList<Parameter> params,
String[] columnNames,
Session session,
boolean recursive) {
super(schema, id, name, false, true);
this.querySQL = querySQL;
this.columnNames = columnNames;
this.recursive = recursive;
index = new ViewIndex(this, querySQL, params, recursive);
initColumnsAndTables(session);
}
/**
* Re-compile the query, updating the SQL statement.
*
* @param session the session
* @return the query
*/
public Query recompileQuery(Session session) {
Prepared p = session.prepare(querySQL);
if (!(p instanceof Query)) {
throw DbException.getSyntaxError(querySQL, 0);
}
Query query = (Query) p;
querySQL = query.getPlanSQL();
return query;
}
private void initColumnsAndTables(Session session) {
Column[] cols;
removeViewFromTables();
try {
Query query = recompileQuery(session);
tables = New.arrayList(query.getTables());
ArrayList<Expression> expressions = query.getExpressions();
ArrayList<Column> list = New.arrayList();
for (int i = 0; i < query.getColumnCount(); i++) {
Expression expr = expressions.get(i);
String name = null;
if (columnNames != null && columnNames.length > i) {
name = columnNames[i];
}
if (name == null) {
name = expr.getAlias();
}
int type = expr.getType();
long precision = expr.getPrecision();
int scale = expr.getScale();
int displaySize = expr.getDisplaySize();
Column col = new Column(name, type, precision, scale, displaySize);
col.setTable(this, i);
list.add(col);
}
cols = new Column[list.size()];
list.toArray(cols);
createException = null;
viewQuery = query;
} catch (DbException e) {
createException = e;
// if it can't be compiled, then it's a 'zero column table'
// this avoids problems when creating the view when opening the
// database
tables = New.arrayList();
cols = new Column[0];
if (recursive && columnNames != null) {
cols = new Column[columnNames.length];
for (int i = 0; i < columnNames.length; i++) {
cols[i] = new Column(columnNames[i], Value.STRING);
}
index.setRecursive(true);
createException = null;
}
}
setColumns(cols);
if (getId() != 0) {
addViewToTables();
}
}
/**
* Check if this view is currently invalid.
*
* @return true if it is
*/
public boolean isInvalid() {
return createException != null;
}
public PlanItem getBestPlanItem(Session session, int[] masks) {
PlanItem item = new PlanItem();
item.cost = index.getCost(session, masks);
IntArray masksArray = new IntArray(masks == null ? Utils.EMPTY_INT_ARRAY : masks);
ViewIndex i2 = indexCache.get(masksArray);
if (i2 == null || i2.getSession() != session) {
i2 = new ViewIndex(this, index, session, masks);
indexCache.put(masksArray, i2);
}
item.setIndex(i2);
return item;
}
public String getDropSQL() {
StatementBuilder buff = new StatementBuilder("DROP VIEW IF EXISTS ");
buff.append(getSQL());
return buff.toString();
}
public String getCreateSQL() {
return getCreateSQL(false, true);
}
/**
* Generate "CREATE" SQL statement for the view.
*
* @param orReplace if true, then include the OR REPLACE clause
* @param force if true, then include the FORCE clause
* @return the SQL statement
*/
public String getCreateSQL(boolean orReplace, boolean force) {
StatementBuilder buff = new StatementBuilder("CREATE ");
if (orReplace) {
buff.append("OR REPLACE ");
}
if (force) {
buff.append("FORCE ");
}
buff.append("VIEW ");
buff.append(getSQL());
if (comment != null) {
buff.append(" COMMENT ").append(StringUtils.quoteStringSQL(comment));
}
if (columns.length > 0) {
buff.append('(');
for (Column c : columns) {
buff.appendExceptFirst(", ");
buff.append(c.getSQL());
}
buff.append(')');
} else if (columnNames != null) {
buff.append('(');
for (String n : columnNames) {
buff.appendExceptFirst(", ");
buff.append(n);
}
buff.append(')');
}
return buff.append(" AS\n").append(querySQL).toString();
}
public void checkRename() {
// ok
}
public void lock(Session session, boolean exclusive, boolean force) {
// exclusive lock means: the view will be dropped
}
public void close(Session session) {
// nothing to do
}
public void unlock(Session s) {
// nothing to do
}
public boolean isLockedExclusively() {
return false;
}
public Index addIndex(
Session session,
String indexName,
int indexId,
IndexColumn[] cols,
IndexType indexType,
boolean create,
String indexComment) {
throw DbException.getUnsupportedException("VIEW");
}
public void removeRow(Session session, Row row) {
throw DbException.getUnsupportedException("VIEW");
}
public void addRow(Session session, Row row) {
throw DbException.getUnsupportedException("VIEW");
}
public void checkSupportAlter() {
throw DbException.getUnsupportedException("VIEW");
}
public void truncate(Session session) {
throw DbException.getUnsupportedException("VIEW");
}
public long getRowCount(Session session) {
throw DbException.throwInternalError();
}
public boolean canGetRowCount() {
// TODO view: could get the row count, but not that easy
return false;
}
public boolean canDrop() {
return true;
}
public String getTableType() {
return Table.VIEW;
}
public void removeChildrenAndResources(Session session) {
removeViewFromTables();
super.removeChildrenAndResources(session);
database.removeMeta(session, getId());
querySQL = null;
index = null;
invalidate();
}
public String getSQL() {
if (isTemporary()) {
return "(" + querySQL + ")";
}
return super.getSQL();
}
public String getQuery() {
return querySQL;
}
public Index getScanIndex(Session session) {
if (createException != null) {
String msg = createException.getMessage();
throw DbException.get(ErrorCode.VIEW_IS_INVALID_2, createException, getSQL(), msg);
}
PlanItem item = getBestPlanItem(session, null);
return item.getIndex();
}
public ArrayList<Index> getIndexes() {
return null;
}
/**
* Re-compile the view query.
*
* @param session the session
*/
public void recompile(Session session) {
for (Table t : tables) {
t.removeView(this);
}
tables.clear();
initColumnsAndTables(session);
}
public long getMaxDataModificationId() {
if (createException != null) {
return Long.MAX_VALUE;
}
if (viewQuery == null) {
return Long.MAX_VALUE;
}
// if nothing was modified in the database since the last check, and the
// last is known, then we don't need to check again
// this speeds up nested views
long dbMod = database.getModificationDataId();
if (dbMod > lastModificationCheck && maxDataModificationId <= dbMod) {
maxDataModificationId = viewQuery.getMaxDataModificationId();
lastModificationCheck = dbMod;
}
return maxDataModificationId;
}
public Index getUniqueIndex() {
return null;
}
private void removeViewFromTables() {
if (tables != null) {
for (Table t : tables) {
t.removeView(this);
}
tables.clear();
}
}
private void addViewToTables() {
for (Table t : tables) {
t.addView(this);
}
}
private void setOwner(User owner) {
this.owner = owner;
}
public User getOwner() {
return owner;
}
/**
* Create a temporary view out of the given query.
*
* @param session the session
* @param owner the owner of the query
* @param name the view name
* @param query the query
* @param topQuery the top level query
* @return the view table
*/
public static TableView createTempView(
Session session, User owner, String name, Query query, Query topQuery) {
Schema mainSchema = session.getDatabase().getSchema(Constants.SCHEMA_MAIN);
String querySQL = query.getPlanSQL();
TableView v =
new TableView(mainSchema, 0, name, querySQL, query.getParameters(), null, session, false);
v.setTopQuery(topQuery);
if (v.createException != null) {
throw v.createException;
}
v.setOwner(owner);
v.setTemporary(true);
return v;
}
private void setTopQuery(Query topQuery) {
this.topQuery = topQuery;
}
public long getRowCountApproximation() {
return ROW_COUNT_APPROXIMATION;
}
public int getParameterOffset() {
return topQuery == null ? 0 : topQuery.getParameters().size();
}
public boolean isDeterministic() {
if (recursive) {
return false;
}
return viewQuery.isEverything(ExpressionVisitor.DETERMINISTIC);
}
public void setRecursiveResult(ResultInterface recursiveResult) {
this.recursiveResult = recursiveResult;
}
public ResultInterface getRecursiveResult() {
return recursiveResult;
}
public void setTableExpression(boolean tableExpression) {
this.tableExpression = tableExpression;
}
public boolean isTableExpression() {
return tableExpression;
}
}
/**
* This object represents a virtual index for a query. Actually it only represents a prepared SELECT
* statement.
*/
public class ViewIndex extends BaseIndex {
private final TableView view;
private final String querySQL;
private final ArrayList<Parameter> originalParameters;
private final SmallLRUCache<IntArray, CostElement> costCache =
SmallLRUCache.newInstance(Constants.VIEW_INDEX_CACHE_SIZE);
private boolean recursive;
private int[] indexMasks;
private String planSQL;
private Query query;
private Session createSession;
public ViewIndex(
TableView view, String querySQL, ArrayList<Parameter> originalParameters, boolean recursive) {
initBaseIndex(view, 0, null, null, IndexType.createNonUnique(false));
this.view = view;
this.querySQL = querySQL;
this.originalParameters = originalParameters;
this.recursive = recursive;
columns = new Column[0];
}
public ViewIndex(TableView view, ViewIndex index, Session session, int[] masks) {
initBaseIndex(view, 0, null, null, IndexType.createNonUnique(false));
this.view = view;
this.querySQL = index.querySQL;
this.originalParameters = index.originalParameters;
this.recursive = index.recursive;
this.indexMasks = masks;
this.createSession = session;
columns = new Column[0];
if (!recursive) {
query = getQuery(session, masks);
planSQL = query.getPlanSQL();
}
}
public Session getSession() {
return createSession;
}
public String getPlanSQL() {
return planSQL;
}
public void close(Session session) {
// nothing to do
}
public void add(Session session, Row row) {
throw DbException.getUnsupportedException("VIEW");
}
public void remove(Session session, Row row) {
throw DbException.getUnsupportedException("VIEW");
}
/** A calculated cost value. */
static class CostElement {
/** The time in milliseconds when this cost was calculated. */
long evaluatedAt;
/** The cost. */
double cost;
}
public double getCost(Session session, int[] masks) {
if (recursive) {
return 1000;
}
IntArray masksArray = new IntArray(masks == null ? Utils.EMPTY_INT_ARRAY : masks);
CostElement cachedCost = costCache.get(masksArray);
if (cachedCost != null) {
long time = System.currentTimeMillis();
if (time < cachedCost.evaluatedAt + Constants.VIEW_COST_CACHE_MAX_AGE) {
return cachedCost.cost;
}
}
Query q = (Query) session.prepare(querySQL, true);
if (masks != null) {
IntArray paramIndex = new IntArray();
for (int i = 0; i < masks.length; i++) {
int mask = masks[i];
if (mask == 0) {
continue;
}
paramIndex.add(i);
}
int len = paramIndex.size();
for (int i = 0; i < len; i++) {
int idx = paramIndex.get(i);
int mask = masks[idx];
int nextParamIndex = q.getParameters().size() + view.getParameterOffset();
if ((mask & IndexCondition.EQUALITY) != 0) {
Parameter param = new Parameter(nextParamIndex);
q.addGlobalCondition(param, idx, Comparison.EQUAL_NULL_SAFE);
} else {
if ((mask & IndexCondition.START) != 0) {
Parameter param = new Parameter(nextParamIndex);
q.addGlobalCondition(param, idx, Comparison.BIGGER_EQUAL);
}
if ((mask & IndexCondition.END) != 0) {
Parameter param = new Parameter(nextParamIndex);
q.addGlobalCondition(param, idx, Comparison.SMALLER_EQUAL);
}
}
}
String sql = q.getPlanSQL();
q = (Query) session.prepare(sql, true);
}
double cost = q.getCost();
cachedCost = new CostElement();
cachedCost.evaluatedAt = System.currentTimeMillis();
cachedCost.cost = cost;
costCache.put(masksArray, cachedCost);
return cost;
}
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);
}
private void setParameter(ArrayList<Parameter> paramList, int x, Value v) {
if (x >= paramList.size()) {
// the parameter may be optimized away as in
// select * from (select null as x) where x=1;
return;
}
Parameter param = paramList.get(x);
param.setValue(v);
}
private Query getQuery(Session session, int[] masks) {
Query q = (Query) session.prepare(querySQL, true);
if (masks == null) {
return q;
}
int firstIndexParam = originalParameters == null ? 0 : originalParameters.size();
firstIndexParam += view.getParameterOffset();
IntArray paramIndex = new IntArray();
for (int i = 0; i < masks.length; i++) {
int mask = masks[i];
if (mask == 0) {
continue;
}
paramIndex.add(i);
if ((mask & IndexCondition.RANGE) == IndexCondition.RANGE) {
// two parameters for range queries: >= x AND <= y
paramIndex.add(i);
}
}
int len = paramIndex.size();
columns = new Column[len];
for (int i = 0; i < len; ) {
int idx = paramIndex.get(i);
Column col = table.getColumn(idx);
columns[i] = col;
int mask = masks[idx];
if ((mask & IndexCondition.EQUALITY) == IndexCondition.EQUALITY) {
Parameter param = new Parameter(firstIndexParam + i);
q.addGlobalCondition(param, idx, Comparison.EQUAL_NULL_SAFE);
i++;
} else {
if ((mask & IndexCondition.START) == IndexCondition.START) {
Parameter param = new Parameter(firstIndexParam + i);
q.addGlobalCondition(param, idx, Comparison.BIGGER_EQUAL);
i++;
}
if ((mask & IndexCondition.END) == IndexCondition.END) {
Parameter param = new Parameter(firstIndexParam + i);
q.addGlobalCondition(param, idx, Comparison.SMALLER_EQUAL);
i++;
}
}
}
String sql = q.getPlanSQL();
q = (Query) session.prepare(sql, true);
return q;
}
public void remove(Session session) {
throw DbException.getUnsupportedException("VIEW");
}
public void truncate(Session session) {
throw DbException.getUnsupportedException("VIEW");
}
public void checkRename() {
throw DbException.getUnsupportedException("VIEW");
}
public boolean needRebuild() {
return false;
}
public boolean canGetFirstOrLast() {
return false;
}
public Cursor findFirstOrLast(Session session, boolean first) {
throw DbException.getUnsupportedException("VIEW");
}
public void setRecursive(boolean value) {
this.recursive = value;
}
public long getRowCount(Session session) {
return 0;
}
public long getRowCountApproximation() {
return 0;
}
public boolean isRecursive() {
return recursive;
}
}
