/**
* Remember that the given LOB value must be un-linked (disconnected from the table) at commit.
*
* @param v the value
*/
public void unlinkAtCommit(Value v) {
if (SysProperties.CHECK && !v.isLinked()) {
DbException.throwInternalError();
}
if (unlinkLobMap == null) {
unlinkLobMap = New.hashMap();
}
unlinkLobMap.put(v.toString(), v);
}
/**
* A session represents an embedded database connection. When using the server mode, this object
* resides on the server side and communicates with a SessionRemote object on the client side.
*/
public class Session extends SessionWithState {
/** This special log position means that the log entry has been written. */
public static final int LOG_WRITTEN = -1;
/**
* The prefix of generated identifiers. It may not have letters, because they are case sensitive.
*/
private static final String SYSTEM_IDENTIFIER_PREFIX = "_";
private static int nextSerialId;
private final int serialId = nextSerialId++;
private final Database database;
private final User user;
private final int id;
private final ArrayList<Table> locks = New.arrayList();
private boolean autoCommit = true;
private Random random;
private int lockTimeout;
private Value lastIdentity = ValueLong.get(0);
private Value lastScopeIdentity = ValueLong.get(0);
private int firstUncommittedLog = Session.LOG_WRITTEN;
private int firstUncommittedPos = Session.LOG_WRITTEN;
private HashMap<String, Savepoint> savepoints;
private HashMap<String, Table> localTempTables;
private HashMap<String, Index> localTempTableIndexes;
private HashMap<String, Constraint> localTempTableConstraints;
private int throttle;
private long lastThrottle;
private Command currentCommand;
private boolean allowLiterals;
private String currentSchemaName;
private String[] schemaSearchPath;
private Trace trace;
private HashMap<String, Value> unlinkLobMap;
private int systemIdentifier;
private HashMap<String, Procedure> procedures;
private boolean autoCommitAtTransactionEnd;
private String currentTransactionName;
private volatile long cancelAt;
private boolean closed;
private final long sessionStart = System.currentTimeMillis();
private long transactionStart;
private long currentCommandStart;
private HashMap<String, Value> variables;
private HashSet<LocalResult> temporaryResults;
private int queryTimeout;
private boolean commitOrRollbackDisabled;
private Table waitForLock;
private Thread waitForLockThread;
private int modificationId;
private int objectId;
private final int queryCacheSize;
private SmallLRUCache<String, Command> queryCache;
private ArrayList<Value> temporaryLobs;
private boolean readOnly;
private int transactionIsolation;
private final Map<String, Connection> connectionHolder = New.hashMap();
public Session(Database database, User user, int id) {
this.database = database;
this.queryTimeout = database.getSettings().maxQueryTimeout;
this.queryCacheSize = database.getSettings().queryCacheSize;
this.user = user;
this.id = id;
Setting setting = database.findSetting(SetTypes.getTypeName(SetTypes.DEFAULT_LOCK_TIMEOUT));
this.lockTimeout = setting == null ? Constants.INITIAL_LOCK_TIMEOUT : setting.getIntValue();
this.currentSchemaName = Constants.SCHEMA_MAIN;
}
public boolean setCommitOrRollbackDisabled(boolean x) {
boolean old = commitOrRollbackDisabled;
commitOrRollbackDisabled = x;
return old;
}
private void initVariables() {
if (variables == null) {
variables = database.newStringMap();
}
}
/**
* Set the value of the given variable for this session.
*
* @param name the name of the variable (may not be null)
* @param value the new value (may not be null)
*/
public void setVariable(String name, Value value) {
initVariables();
modificationId++;
Value old;
if (value == ValueNull.INSTANCE) {
old = variables.remove(name);
} else {
old = variables.put(name, value);
}
if (old != null) {
// close the old value (in case it is a lob)
old.close();
}
}
/**
* Get the value of the specified user defined variable. This method always returns a value; it
* returns ValueNull.INSTANCE if the variable doesn't exist.
*
* @param name the variable name
* @return the value, or NULL
*/
public Value getVariable(String name) {
initVariables();
Value v = variables.get(name);
return v == null ? ValueNull.INSTANCE : v;
}
/**
* Get the list of variable names that are set for this session.
*
* @return the list of names
*/
public String[] getVariableNames() {
if (variables == null) {
return new String[0];
}
String[] list = new String[variables.size()];
variables.keySet().toArray(list);
return list;
}
/**
* Get the local temporary table if one exists with that name, or null if not.
*
* @param name the table name
* @return the table, or null
*/
public Table findLocalTempTable(String name) {
if (localTempTables == null) {
return null;
}
return localTempTables.get(name);
}
public ArrayList<Table> getLocalTempTables() {
if (localTempTables == null) {
return New.arrayList();
}
return New.arrayList(localTempTables.values());
}
/**
* Add a local temporary table to this session.
*
* @param table the table to add
* @throws DbException if a table with this name already exists
*/
public void addLocalTempTable(Table table) {
if (localTempTables == null) {
localTempTables = database.newStringMap();
}
if (localTempTables.get(table.getName()) != null) {
throw DbException.get(ErrorCode.TABLE_OR_VIEW_ALREADY_EXISTS_1, table.getSQL());
}
modificationId++;
localTempTables.put(table.getName(), table);
}
/**
* Drop and remove the given local temporary table from this session.
*
* @param table the table
*/
public void removeLocalTempTable(Table table) {
modificationId++;
localTempTables.remove(table.getName());
synchronized (database) {
table.removeChildrenAndResources(this);
}
}
/**
* Get the local temporary index if one exists with that name, or null if not.
*
* @param name the table name
* @return the table, or null
*/
public Index findLocalTempTableIndex(String name) {
if (localTempTableIndexes == null) {
return null;
}
return localTempTableIndexes.get(name);
}
public HashMap<String, Index> getLocalTempTableIndexes() {
if (localTempTableIndexes == null) {
return New.hashMap();
}
return localTempTableIndexes;
}
/**
* Add a local temporary index to this session.
*
* @param index the index to add
* @throws DbException if a index with this name already exists
*/
public void addLocalTempTableIndex(Index index) {
if (localTempTableIndexes == null) {
localTempTableIndexes = database.newStringMap();
}
if (localTempTableIndexes.get(index.getName()) != null) {
throw DbException.get(ErrorCode.INDEX_ALREADY_EXISTS_1, index.getSQL());
}
localTempTableIndexes.put(index.getName(), index);
}
/**
* Drop and remove the given local temporary index from this session.
*
* @param index the index
*/
public void removeLocalTempTableIndex(Index index) {
if (localTempTableIndexes != null) {
localTempTableIndexes.remove(index.getName());
synchronized (database) {
index.removeChildrenAndResources(this);
}
}
}
/**
* Get the local temporary constraint if one exists with that name, or null if not.
*
* @param name the constraint name
* @return the constraint, or null
*/
public Constraint findLocalTempTableConstraint(String name) {
if (localTempTableConstraints == null) {
return null;
}
return localTempTableConstraints.get(name);
}
/**
* Get the map of constraints for all constraints on local, temporary tables, if any. The map's
* keys are the constraints' names.
*
* @return the map of constraints, or null
*/
public HashMap<String, Constraint> getLocalTempTableConstraints() {
if (localTempTableConstraints == null) {
return New.hashMap();
}
return localTempTableConstraints;
}
/**
* Add a local temporary constraint to this session.
*
* @param constraint the constraint to add
* @throws DbException if a constraint with the same name already exists
*/
public void addLocalTempTableConstraint(Constraint constraint) {
if (localTempTableConstraints == null) {
localTempTableConstraints = database.newStringMap();
}
String name = constraint.getName();
if (localTempTableConstraints.get(name) != null) {
throw DbException.get(ErrorCode.CONSTRAINT_ALREADY_EXISTS_1, constraint.getSQL());
}
localTempTableConstraints.put(name, constraint);
}
/**
* Drop and remove the given local temporary constraint from this session.
*
* @param constraint the constraint
*/
void removeLocalTempTableConstraint(Constraint constraint) {
if (localTempTableConstraints != null) {
localTempTableConstraints.remove(constraint.getName());
synchronized (database) {
constraint.removeChildrenAndResources(this);
}
}
}
@Override
public boolean getAutoCommit() {
return autoCommit;
}
public User getUser() {
return user;
}
@Override
public void setAutoCommit(boolean b) {
autoCommit = b;
}
public int getLockTimeout() {
return lockTimeout;
}
public void setLockTimeout(int lockTimeout) {
this.lockTimeout = lockTimeout;
}
@Override
public synchronized CommandInterface prepareCommand(String sql, int fetchSize) {
return prepareLocal(sql);
}
/**
* Parse and prepare the given SQL statement. This method also checks the rights.
*
* @param sql the SQL statement
* @return the prepared statement
*/
public Prepared prepare(String sql) {
return prepare(sql, false);
}
/**
* Parse and prepare the given SQL statement.
*
* @param sql the SQL statement
* @param rightsChecked true if the rights have already been checked
* @return the prepared statement
*/
public Prepared prepare(String sql, boolean rightsChecked) {
Parser parser = new Parser(this);
parser.setRightsChecked(rightsChecked);
return parser.prepare(sql);
}
/**
* 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 {
// ignore table structure modification
/*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;
}
public Database getDatabase() {
return database;
}
/**
* Commit the current transaction. If the statement was not a data definition statement, and if
* there are temporary tables that should be dropped or truncated at commit, this is done as well.
*
* @param ddl if the statement was a data definition statement
*/
public void commit(boolean ddl) {
checkCommitRollback();
currentTransactionName = null;
transactionStart = 0;
if (containsUncommitted()) {
// need to commit even if rollback is not possible
// (create/drop table and so on)
database.commit(this);
}
if (temporaryLobs != null) {
for (Value v : temporaryLobs) {
if (!v.isLinked()) {
v.close();
}
}
temporaryLobs.clear();
}
if (!ddl) {
// do not clean the temp tables if the last command was a
// create/drop
cleanTempTables(false);
if (autoCommitAtTransactionEnd) {
autoCommit = true;
autoCommitAtTransactionEnd = false;
}
}
endTransaction();
boolean commit = true;
List<SQLException> commitExceptions = New.arrayList();
StringBuilder buf = new StringBuilder();
for (Map.Entry<String, Connection> entry : connectionHolder.entrySet()) {
if (commit) {
try {
entry.getValue().commit();
buf.append("\ncommit shard " + entry.getKey() + " transaction succeed.");
} catch (SQLException ex) {
commit = false;
commitExceptions.add(ex);
buf.append("\ncommit shard " + entry.getKey() + " transaction failure.");
}
} else {
// after unsucessfull commit we must try to rollback
// remaining connections
try {
entry.getValue().rollback();
buf.append("\nrollback shard " + entry.getKey() + " transaction succeed.");
} catch (SQLException ex) {
buf.append("\nrollback shard " + entry.getKey() + " transaction failure.");
}
}
}
if (commitExceptions.isEmpty()) {
trace.debug("commit multiple group transaction succeed. commit track list:{0}", buf);
} else {
trace.error(
commitExceptions.get(0),
"fail to commit multiple group transaction. commit track list:{0}",
buf);
DbException.convert(commitExceptions.get(0));
}
}
private void checkCommitRollback() {
if (commitOrRollbackDisabled && locks.size() > 0) {
throw DbException.get(ErrorCode.COMMIT_ROLLBACK_NOT_ALLOWED);
}
}
private void endTransaction() {
if (unlinkLobMap != null && unlinkLobMap.size() > 0) {
// need to flush the transaction log, because we can't unlink lobs
// if the commit record is not written
unlinkLobMap = null;
}
unlockAll();
}
/** Fully roll back the current transaction. */
public void rollback() {
checkCommitRollback();
currentTransactionName = null;
boolean needCommit = false;
if (locks.size() > 0 || needCommit) {
database.commit(this);
}
cleanTempTables(false);
if (autoCommitAtTransactionEnd) {
autoCommit = true;
autoCommitAtTransactionEnd = false;
}
endTransaction();
List<SQLException> rollbackExceptions = New.arrayList();
for (Map.Entry<String, Connection> entry : connectionHolder.entrySet()) {
try {
entry.getValue().rollback();
} catch (SQLException ex) {
rollbackExceptions.add(ex);
}
}
if (!rollbackExceptions.isEmpty()) {
throw DbException.convert(rollbackExceptions.get(0));
}
}
/**
* Partially roll back the current transaction.
*
* @param savepoint the savepoint to which should be rolled back
* @param trimToSize if the list should be trimmed
*/
public void rollbackTo(Savepoint savepoint, boolean trimToSize) {
int index = savepoint == null ? 0 : savepoint.logIndex;
if (savepoints != null) {
String[] names = new String[savepoints.size()];
savepoints.keySet().toArray(names);
for (String name : names) {
Savepoint sp = savepoints.get(name);
int savepointIndex = sp.logIndex;
if (savepointIndex > index) {
savepoints.remove(name);
}
}
}
}
@Override
public boolean hasPendingTransaction() {
return false;
}
/**
* Create a savepoint to allow rolling back to this state.
*
* @return the savepoint
*/
public Savepoint setSavepoint() {
Savepoint sp = new Savepoint();
return sp;
}
public int getId() {
return id;
}
@Override
public void cancel() {
cancelAt = System.currentTimeMillis();
}
@Override
public void close() {
if (!closed) {
try {
for (Connection conn : connectionHolder.values()) {
JdbcUtils.closeSilently(conn);
}
connectionHolder.clear();
cleanTempTables(true);
database.removeSession(this);
} finally {
closed = true;
}
}
}
/**
* Add a lock for the given table. The object is unlocked on commit or rollback.
*
* @param table the table that is locked
*/
public void addLock(Table table) {
if (SysProperties.CHECK) {
if (locks.contains(table)) {
DbException.throwInternalError();
}
}
locks.add(table);
}
/**
* Unlock just this table.
*
* @param t the table to unlock
*/
void unlock(Table t) {
locks.remove(t);
}
private void unlockAll() {
if (locks.size() > 0) {
// don't use the enhanced for loop to save memory
for (int i = 0, size = locks.size(); i < size; i++) {
Table t = locks.get(i);
t.unlock(this);
}
locks.clear();
}
savepoints = null;
sessionStateChanged = true;
}
private void cleanTempTables(boolean closeSession) {
if (localTempTables != null && localTempTables.size() > 0) {
synchronized (database) {
for (Table table : New.arrayList(localTempTables.values())) {
if (closeSession || table.getOnCommitDrop()) {
modificationId++;
localTempTables.remove(table.getName());
table.removeChildrenAndResources(this);
if (closeSession) {
// need to commit, otherwise recovery might
// ignore the table removal
database.commit(this);
}
} else if (table.getOnCommitTruncate()) {
table.truncate(this);
}
}
}
}
}
public Random getRandom() {
if (random == null) {
random = new Random();
}
return random;
}
@Override
public Trace getTrace() {
if (trace != null && !closed) {
return trace;
}
String traceModuleName = Trace.JDBC + "[" + id + "]";
if (closed) {
return new TraceSystem(null).getTrace(traceModuleName);
}
trace = database.getTrace(traceModuleName);
return trace;
}
public void setLastIdentity(Value last) {
this.lastIdentity = last;
this.lastScopeIdentity = last;
}
public Value getLastIdentity() {
return lastIdentity;
}
public void setLastScopeIdentity(Value last) {
this.lastScopeIdentity = last;
}
public Value getLastScopeIdentity() {
return lastScopeIdentity;
}
/**
* Called when a log entry for this session is added. The session keeps track of the first entry
* in the transaction log that is not yet committed.
*
* @param logId the transaction log id
* @param pos the position of the log entry in the transaction log
*/
public void addLogPos(int logId, int pos) {
if (firstUncommittedLog == Session.LOG_WRITTEN) {
firstUncommittedLog = logId;
firstUncommittedPos = pos;
}
}
public int getFirstUncommittedLog() {
return firstUncommittedLog;
}
/**
* This method is called after the transaction log has written the commit entry for this session.
*/
void setAllCommitted() {
firstUncommittedLog = Session.LOG_WRITTEN;
firstUncommittedPos = Session.LOG_WRITTEN;
}
/**
* Whether the session contains any uncommitted changes.
*
* @return true if yes
*/
public boolean containsUncommitted() {
return firstUncommittedLog != Session.LOG_WRITTEN;
}
/**
* Create a savepoint that is linked to the current log position.
*
* @param name the savepoint name
*/
public void addSavepoint(String name) {
if (savepoints == null) {
savepoints = database.newStringMap();
}
Savepoint sp = new Savepoint();
savepoints.put(name, sp);
}
/**
* Undo all operations back to the log position of the given savepoint.
*
* @param name the savepoint name
*/
public void rollbackToSavepoint(String name) {
checkCommitRollback();
if (savepoints == null) {
throw DbException.get(ErrorCode.SAVEPOINT_IS_INVALID_1, name);
}
Savepoint savepoint = savepoints.get(name);
if (savepoint == null) {
throw DbException.get(ErrorCode.SAVEPOINT_IS_INVALID_1, name);
}
rollbackTo(savepoint, false);
}
/**
* Prepare the given transaction.
*
* @param transactionName the name of the transaction
*/
public void prepareCommit(String transactionName) {
throw DbException.getUnsupportedException("Does not support two-phase commit.");
}
/**
* Commit or roll back the given transaction.
*
* @param transactionName the name of the transaction
* @param commit true for commit, false for rollback
*/
public void setPreparedTransaction(String transactionName, boolean commit) {
if (currentTransactionName != null && currentTransactionName.equals(transactionName)) {
if (commit) {
commit(false);
} else {
rollback();
}
}
}
@Override
public boolean isClosed() {
return closed;
}
public void setThrottle(int throttle) {
this.throttle = throttle;
}
/** Wait for some time if this session is throttled (slowed down). */
public void throttle() {
if (currentCommandStart == 0) {
currentCommandStart = System.currentTimeMillis();
}
if (throttle == 0) {
return;
}
long time = System.currentTimeMillis();
if (lastThrottle + Constants.THROTTLE_DELAY > time) {
return;
}
lastThrottle = time + throttle;
try {
Thread.sleep(throttle);
} catch (Exception e) {
// ignore InterruptedException
}
}
/**
* Set the current command of this session. This is done just before executing the statement.
*
* @param command the command
*/
public void setCurrentCommand(Command command) {
this.currentCommand = command;
if (queryTimeout > 0 && command != null) {
long now = System.currentTimeMillis();
currentCommandStart = now;
cancelAt = now + queryTimeout;
}
}
/**
* Check if the current transaction is canceled by calling Statement.cancel() or because a session
* timeout was set and expired.
*
* @throws DbException if the transaction is canceled
*/
public void checkCanceled() {
throttle();
if (cancelAt == 0) {
return;
}
long time = System.currentTimeMillis();
if (time >= cancelAt) {
cancelAt = 0;
throw DbException.get(ErrorCode.STATEMENT_WAS_CANCELED);
}
}
/**
* Get the cancel time.
*
* @return the time or 0 if not set
*/
public long getCancel() {
return cancelAt;
}
public Command getCurrentCommand() {
return currentCommand;
}
public long getCurrentCommandStart() {
return currentCommandStart;
}
public boolean getAllowLiterals() {
return allowLiterals;
}
public void setAllowLiterals(boolean b) {
this.allowLiterals = b;
}
public void setCurrentSchema(Schema schema) {
modificationId++;
this.currentSchemaName = schema.getName();
}
public String getCurrentSchemaName() {
return currentSchemaName;
}
/**
* Create an internal connection. This connection is used when initializing triggers, and when
* calling user defined functions.
*
* @param columnList if the url should be 'jdbc:columnlist:connection'
* @return the internal connection
*/
public JdbcConnection createConnection(boolean columnList) {
throw DbException.getUnsupportedException("TODO");
}
/**
* Remember that the given LOB value must be un-linked (disconnected from the table) at commit.
*
* @param v the value
*/
public void unlinkAtCommit(Value v) {
if (SysProperties.CHECK && !v.isLinked()) {
DbException.throwInternalError();
}
if (unlinkLobMap == null) {
unlinkLobMap = New.hashMap();
}
unlinkLobMap.put(v.toString(), v);
}
/**
* Do not unlink this LOB value at commit any longer.
*
* @param v the value
*/
public void unlinkAtCommitStop(Value v) {
if (unlinkLobMap != null) {
unlinkLobMap.remove(v.toString());
}
}
/**
* Get the next system generated identifiers. The identifier returned does not occur within the
* given SQL statement.
*
* @param sql the SQL statement
* @return the new identifier
*/
public String getNextSystemIdentifier(String sql) {
String identifier;
do {
identifier = SYSTEM_IDENTIFIER_PREFIX + systemIdentifier++;
} while (sql.contains(identifier));
return identifier;
}
/**
* Add a procedure to this session.
*
* @param procedure the procedure to add
*/
public void addProcedure(Procedure procedure) {
if (procedures == null) {
procedures = database.newStringMap();
}
procedures.put(procedure.getName(), procedure);
}
/**
* Remove a procedure from this session.
*
* @param name the name of the procedure to remove
*/
public void removeProcedure(String name) {
if (procedures != null) {
procedures.remove(name);
}
}
/**
* Get the procedure with the given name, or null if none exists.
*
* @param name the procedure name
* @return the procedure or null
*/
public Procedure getProcedure(String name) {
if (procedures == null) {
return null;
}
return procedures.get(name);
}
public void setSchemaSearchPath(String[] schemas) {
modificationId++;
this.schemaSearchPath = schemas;
}
public String[] getSchemaSearchPath() {
return schemaSearchPath;
}
@Override
public int hashCode() {
return serialId;
}
@Override
public String toString() {
return "#" + serialId + " (user: "******")";
}
/** Begin a transaction. */
public void begin() {
autoCommitAtTransactionEnd = true;
autoCommit = false;
}
public long getSessionStart() {
return sessionStart;
}
public long getTransactionStart() {
if (transactionStart == 0) {
transactionStart = System.currentTimeMillis();
}
return transactionStart;
}
public Table[] getLocks() {
// copy the data without synchronizing
ArrayList<Table> copy = New.arrayList();
for (int i = 0; i < locks.size(); i++) {
try {
copy.add(locks.get(i));
} catch (Exception e) {
// ignore
break;
}
}
Table[] list = new Table[copy.size()];
copy.toArray(list);
return list;
}
/**
* Remember the result set and close it as soon as the transaction is committed (if it needs to be
* closed). This is done to delete temporary files as soon as possible, and free object ids of
* temporary tables.
*
* @param result the temporary result set
*/
public void addTemporaryResult(LocalResult result) {
if (!result.needToClose()) {
return;
}
if (temporaryResults == null) {
temporaryResults = New.hashSet();
}
if (temporaryResults.size() < 100) {
// reference at most 100 result sets to avoid memory problems
temporaryResults.add(result);
}
}
private void closeTemporaryResults() {
if (temporaryResults != null) {
for (LocalResult result : temporaryResults) {
result.close();
}
temporaryResults = null;
}
}
public void setQueryTimeout(int queryTimeout) {
int max = database.getSettings().maxQueryTimeout;
if (max != 0 && (max < queryTimeout || queryTimeout == 0)) {
// the value must be at most max
queryTimeout = max;
}
this.queryTimeout = queryTimeout;
// must reset the cancel at here,
// otherwise it is still used
this.cancelAt = 0;
}
public int getQueryTimeout() {
return queryTimeout;
}
/**
* Set the table this session is waiting for, and the thread that is waiting.
*
* @param waitForLock the table
* @param waitForLockThread the current thread (the one that is waiting)
*/
public void setWaitForLock(Table waitForLock, Thread waitForLockThread) {
this.waitForLock = waitForLock;
this.waitForLockThread = waitForLockThread;
}
public Table getWaitForLock() {
return waitForLock;
}
public Thread getWaitForLockThread() {
return waitForLockThread;
}
public int getModificationId() {
return modificationId;
}
@Override
public boolean isReconnectNeeded(boolean write) {
return false;
}
@Override
public SessionInterface reconnect(boolean write) {
readSessionState();
close();
Session newSession = database.createSession(this.user);
newSession.sessionState = sessionState;
newSession.recreateSessionState();
return newSession;
}
public Value getTransactionId() {
return ValueString.get(firstUncommittedLog + "-" + firstUncommittedPos + "-" + id);
}
/**
* Get the next object id.
*
* @return the next object id
*/
public int nextObjectId() {
return objectId++;
}
/** Start a new statement within a transaction. */
public void startStatementWithinTransaction() {}
/**
* Mark the statement as completed. This also close all temporary result set, and deletes all
* temporary files held by the result sets.
*/
public void endStatement() {
closeTemporaryResults();
}
@Override
public void addTemporaryLob(Value v) {
if (temporaryLobs == null) {
temporaryLobs = new ArrayList<Value>();
}
temporaryLobs.add(v);
}
@Override
public void setTransactionIsolation(int level) {
switch (level) {
case Connection.TRANSACTION_NONE:
case Connection.TRANSACTION_READ_UNCOMMITTED:
case Connection.TRANSACTION_READ_COMMITTED:
case Connection.TRANSACTION_REPEATABLE_READ:
case Connection.TRANSACTION_SERIALIZABLE:
break;
default:
throw DbException.getInvalidValueException("transaction isolation", level);
}
transactionIsolation = level;
}
@Override
public int getTransactionIsolation() {
return transactionIsolation;
}
@Override
public boolean isReadOnly() {
return readOnly;
}
@Override
public void setReadOnly(boolean readOnly) {
this.readOnly = readOnly;
}
public Connection getDataNodeConnection(String dataNode) throws SQLException {
Connection result = connectionHolder.get(dataNode);
if (result == null) {
DataSource ds = database.getDataNode(dataNode);
result = ds.getConnection();
if (result.getAutoCommit() != getAutoCommit()) {
result.setAutoCommit(getAutoCommit());
}
connectionHolder.put(dataNode, result);
}
return result;
}
/** Represents a savepoint (a position in a transaction to where one can roll back to). */
public static class Savepoint {
/** The undo log index. */
int logIndex;
/** The transaction savepoint id. */
long transactionSavepoint;
}
}
public HashMap<String, Index> getLocalTempTableIndexes() {
if (localTempTableIndexes == null) {
return New.hashMap();
}
return localTempTableIndexes;
}
/**
* Get the map of constraints for all constraints on local, temporary tables, if any. The map's
* keys are the constraints' names.
*
* @return the map of constraints, or null
*/
public HashMap<String, Constraint> getLocalTempTableConstraints() {
if (localTempTableConstraints == null) {
return New.hashMap();
}
return localTempTableConstraints;
}
/** Implements the integrated aggregate functions, such as COUNT, MAX, SUM. */
public class Aggregate extends Expression {
/** The aggregate type for COUNT(*). */
public static final int COUNT_ALL = 0;
/** The aggregate type for COUNT(expression). */
public static final int COUNT = 1;
/** The aggregate type for GROUP_CONCAT(...). */
public static final int GROUP_CONCAT = 2;
/** The aggregate type for SUM(expression). */
static final int SUM = 3;
/** The aggregate type for MIN(expression). */
static final int MIN = 4;
/** The aggregate type for MAX(expression). */
static final int MAX = 5;
/** The aggregate type for AVG(expression). */
static final int AVG = 6;
/** The aggregate type for STDDEV_POP(expression). */
static final int STDDEV_POP = 7;
/** The aggregate type for STDDEV_SAMP(expression). */
static final int STDDEV_SAMP = 8;
/** The aggregate type for VAR_POP(expression). */
static final int VAR_POP = 9;
/** The aggregate type for VAR_SAMP(expression). */
static final int VAR_SAMP = 10;
/** The aggregate type for BOOL_OR(expression). */
static final int BOOL_OR = 11;
/** The aggregate type for BOOL_AND(expression). */
static final int BOOL_AND = 12;
/** The aggregate type for SELECTIVITY(expression). */
static final int SELECTIVITY = 13;
/** The aggregate type for HISTOGRAM(expression). */
static final int HISTOGRAM = 14;
private static final HashMap<String, Integer> AGGREGATES = New.hashMap();
private final int type;
private final Select select;
private final boolean distinct;
private Expression on;
private Expression groupConcatSeparator;
private ArrayList<SelectOrderBy> groupConcatOrderList;
private SortOrder groupConcatSort;
private int dataType, scale;
private long precision;
private int displaySize;
private int lastGroupRowId;
/**
* Create a new aggregate object.
*
* @param type the aggregate type
* @param on the aggregated expression
* @param select the select statement
* @param distinct if distinct is used
*/
public Aggregate(int type, Expression on, Select select, boolean distinct) {
this.type = type;
this.on = on;
this.select = select;
this.distinct = distinct;
}
static {
addAggregate("COUNT", COUNT);
addAggregate("SUM", SUM);
addAggregate("MIN", MIN);
addAggregate("MAX", MAX);
addAggregate("AVG", AVG);
addAggregate("GROUP_CONCAT", GROUP_CONCAT);
addAggregate("STDDEV_SAMP", STDDEV_SAMP);
addAggregate("STDDEV", STDDEV_SAMP);
addAggregate("STDDEV_POP", STDDEV_POP);
addAggregate("STDDEVP", STDDEV_POP);
addAggregate("VAR_POP", VAR_POP);
addAggregate("VARP", VAR_POP);
addAggregate("VAR_SAMP", VAR_SAMP);
addAggregate("VAR", VAR_SAMP);
addAggregate("VARIANCE", VAR_SAMP);
addAggregate("BOOL_OR", BOOL_OR);
// HSQLDB compatibility, but conflicts with x > EVERY(...)
addAggregate("SOME", BOOL_OR);
addAggregate("BOOL_AND", BOOL_AND);
// HSQLDB compatibility, but conflicts with x > SOME(...)
addAggregate("EVERY", BOOL_AND);
addAggregate("SELECTIVITY", SELECTIVITY);
addAggregate("HISTOGRAM", HISTOGRAM);
}
private static void addAggregate(String name, int type) {
AGGREGATES.put(name, type);
}
/**
* Get the aggregate type for this name, or -1 if no aggregate has been found.
*
* @param name the aggregate function name
* @return -1 if no aggregate function has been found, or the aggregate type
*/
public static int getAggregateType(String name) {
Integer type = AGGREGATES.get(name);
return type == null ? -1 : type.intValue();
}
/**
* Set the order for GROUP_CONCAT() aggregate.
*
* @param orderBy the order by list
*/
public void setGroupConcatOrder(ArrayList<SelectOrderBy> orderBy) {
this.groupConcatOrderList = orderBy;
}
/**
* Set the separator for the GROUP_CONCAT() aggregate.
*
* @param separator the separator expression
*/
public void setGroupConcatSeparator(Expression separator) {
this.groupConcatSeparator = separator;
}
private SortOrder initOrder(Session session) {
int size = groupConcatOrderList.size();
int[] index = new int[size];
int[] sortType = new int[size];
for (int i = 0; i < size; i++) {
SelectOrderBy o = groupConcatOrderList.get(i);
index[i] = i + 1;
int order = o.descending ? SortOrder.DESCENDING : SortOrder.ASCENDING;
sortType[i] = order;
}
return new SortOrder(session.getDatabase(), index, sortType, null);
}
@Override
public void updateAggregate(Session session) {
// TODO aggregates: check nested MIN(MAX(ID)) and so on
// if (on != null) {
// on.updateAggregate();
// }
HashMap<Expression, Object> group = select.getCurrentGroup();
if (group == null) {
// this is a different level (the enclosing query)
return;
}
int groupRowId = select.getCurrentGroupRowId();
if (lastGroupRowId == groupRowId) {
// already visited
return;
}
lastGroupRowId = groupRowId;
AggregateData data = (AggregateData) group.get(this);
if (data == null) {
data = AggregateData.create(type);
group.put(this, data);
}
Value v = on == null ? null : on.getValue(session);
if (type == GROUP_CONCAT) {
if (v != ValueNull.INSTANCE) {
v = v.convertTo(Value.STRING);
if (groupConcatOrderList != null) {
int size = groupConcatOrderList.size();
Value[] array = new Value[1 + size];
array[0] = v;
for (int i = 0; i < size; i++) {
SelectOrderBy o = groupConcatOrderList.get(i);
array[i + 1] = o.expression.getValue(session);
}
v = ValueArray.get(array);
}
}
}
data.add(session.getDatabase(), dataType, distinct, v);
}
@Override
public Value getValue(Session session) {
if (select.isQuickAggregateQuery()) {
switch (type) {
case COUNT:
case COUNT_ALL:
Table table = select.getTopTableFilter().getTable();
return ValueLong.get(table.getRowCount(session));
case MIN:
case MAX:
boolean first = type == MIN;
Index index = getColumnIndex();
int sortType = index.getIndexColumns()[0].sortType;
if ((sortType & SortOrder.DESCENDING) != 0) {
first = !first;
}
Cursor cursor = index.findFirstOrLast(session, first);
SearchRow row = cursor.getSearchRow();
Value v;
if (row == null) {
v = ValueNull.INSTANCE;
} else {
v = row.getValue(index.getColumns()[0].getColumnId());
}
return v;
default:
DbException.throwInternalError("type=" + type);
}
}
HashMap<Expression, Object> group = select.getCurrentGroup();
if (group == null) {
throw DbException.get(ErrorCode.INVALID_USE_OF_AGGREGATE_FUNCTION_1, getSQL());
}
AggregateData data = (AggregateData) group.get(this);
if (data == null) {
data = AggregateData.create(type);
}
Value v = data.getValue(session.getDatabase(), dataType, distinct);
if (type == GROUP_CONCAT) {
ArrayList<Value> list = ((AggregateDataGroupConcat) data).getList();
if (list == null || list.size() == 0) {
return ValueNull.INSTANCE;
}
if (groupConcatOrderList != null) {
final SortOrder sortOrder = groupConcatSort;
Collections.sort(
list,
new Comparator<Value>() {
@Override
public int compare(Value v1, Value v2) {
Value[] a1 = ((ValueArray) v1).getList();
Value[] a2 = ((ValueArray) v2).getList();
return sortOrder.compare(a1, a2);
}
});
}
StatementBuilder buff = new StatementBuilder();
String sep =
groupConcatSeparator == null ? "," : groupConcatSeparator.getValue(session).getString();
for (Value val : list) {
String s;
if (val.getType() == Value.ARRAY) {
s = ((ValueArray) val).getList()[0].getString();
} else {
s = val.getString();
}
if (s == null) {
continue;
}
if (sep != null) {
buff.appendExceptFirst(sep);
}
buff.append(s);
}
v = ValueString.get(buff.toString());
}
return v;
}
@Override
public int getType() {
return dataType;
}
@Override
public void mapColumns(ColumnResolver resolver, int level) {
if (on != null) {
on.mapColumns(resolver, level);
}
if (groupConcatOrderList != null) {
for (SelectOrderBy o : groupConcatOrderList) {
o.expression.mapColumns(resolver, level);
}
}
if (groupConcatSeparator != null) {
groupConcatSeparator.mapColumns(resolver, level);
}
}
@Override
public Expression optimize(Session session) {
if (on != null) {
on = on.optimize(session);
dataType = on.getType();
scale = on.getScale();
precision = on.getPrecision();
displaySize = on.getDisplaySize();
}
if (groupConcatOrderList != null) {
for (SelectOrderBy o : groupConcatOrderList) {
o.expression = o.expression.optimize(session);
}
groupConcatSort = initOrder(session);
}
if (groupConcatSeparator != null) {
groupConcatSeparator = groupConcatSeparator.optimize(session);
}
switch (type) {
case GROUP_CONCAT:
dataType = Value.STRING;
scale = 0;
precision = displaySize = Integer.MAX_VALUE;
break;
case COUNT_ALL:
case COUNT:
dataType = Value.LONG;
scale = 0;
precision = ValueLong.PRECISION;
displaySize = ValueLong.DISPLAY_SIZE;
break;
case SELECTIVITY:
dataType = Value.INT;
scale = 0;
precision = ValueInt.PRECISION;
displaySize = ValueInt.DISPLAY_SIZE;
break;
case HISTOGRAM:
dataType = Value.ARRAY;
scale = 0;
precision = displaySize = Integer.MAX_VALUE;
break;
case SUM:
if (dataType == Value.BOOLEAN) {
// example: sum(id > 3) (count the rows)
dataType = Value.LONG;
} else if (!DataType.supportsAdd(dataType)) {
throw DbException.get(ErrorCode.SUM_OR_AVG_ON_WRONG_DATATYPE_1, getSQL());
} else {
dataType = DataType.getAddProofType(dataType);
}
break;
case AVG:
if (!DataType.supportsAdd(dataType)) {
throw DbException.get(ErrorCode.SUM_OR_AVG_ON_WRONG_DATATYPE_1, getSQL());
}
break;
case MIN:
case MAX:
break;
case STDDEV_POP:
case STDDEV_SAMP:
case VAR_POP:
case VAR_SAMP:
dataType = Value.DOUBLE;
precision = ValueDouble.PRECISION;
displaySize = ValueDouble.DISPLAY_SIZE;
scale = 0;
break;
case BOOL_AND:
case BOOL_OR:
dataType = Value.BOOLEAN;
precision = ValueBoolean.PRECISION;
displaySize = ValueBoolean.DISPLAY_SIZE;
scale = 0;
break;
default:
DbException.throwInternalError("type=" + type);
}
return this;
}
@Override
public void setEvaluatable(TableFilter tableFilter, boolean b) {
if (on != null) {
on.setEvaluatable(tableFilter, b);
}
if (groupConcatOrderList != null) {
for (SelectOrderBy o : groupConcatOrderList) {
o.expression.setEvaluatable(tableFilter, b);
}
}
if (groupConcatSeparator != null) {
groupConcatSeparator.setEvaluatable(tableFilter, b);
}
}
@Override
public int getScale() {
return scale;
}
@Override
public long getPrecision() {
return precision;
}
@Override
public int getDisplaySize() {
return displaySize;
}
private String getSQLGroupConcat() {
StatementBuilder buff = new StatementBuilder("GROUP_CONCAT(");
if (distinct) {
buff.append("DISTINCT ");
}
buff.append(on.getSQL());
if (groupConcatOrderList != null) {
buff.append(" ORDER BY ");
for (SelectOrderBy o : groupConcatOrderList) {
buff.appendExceptFirst(", ");
buff.append(o.expression.getSQL());
if (o.descending) {
buff.append(" DESC");
}
}
}
if (groupConcatSeparator != null) {
buff.append(" SEPARATOR ").append(groupConcatSeparator.getSQL());
}
return buff.append(')').toString();
}
@Override
public String getSQL() {
String text;
switch (type) {
case GROUP_CONCAT:
return getSQLGroupConcat();
case COUNT_ALL:
return "COUNT(*)";
case COUNT:
text = "COUNT";
break;
case SELECTIVITY:
text = "SELECTIVITY";
break;
case HISTOGRAM:
text = "HISTOGRAM";
break;
case SUM:
text = "SUM";
break;
case MIN:
text = "MIN";
break;
case MAX:
text = "MAX";
break;
case AVG:
text = "AVG";
break;
case STDDEV_POP:
text = "STDDEV_POP";
break;
case STDDEV_SAMP:
text = "STDDEV_SAMP";
break;
case VAR_POP:
text = "VAR_POP";
break;
case VAR_SAMP:
text = "VAR_SAMP";
break;
case BOOL_AND:
text = "BOOL_AND";
break;
case BOOL_OR:
text = "BOOL_OR";
break;
default:
throw DbException.throwInternalError("type=" + type);
}
if (distinct) {
return text + "(DISTINCT " + on.getSQL() + ")";
}
return text + StringUtils.enclose(on.getSQL());
}
private Index getColumnIndex() {
if (on instanceof ExpressionColumn) {
ExpressionColumn col = (ExpressionColumn) on;
Column column = col.getColumn();
TableFilter filter = col.getTableFilter();
if (filter != null) {
Table table = filter.getTable();
Index index = table.getIndexForColumn(column);
return index;
}
}
return null;
}
@Override
public boolean isEverything(ExpressionVisitor visitor) {
if (visitor.getType() == ExpressionVisitor.OPTIMIZABLE_MIN_MAX_COUNT_ALL) {
switch (type) {
case COUNT:
if (!distinct && on.getNullable() == Column.NOT_NULLABLE) {
return visitor.getTable().canGetRowCount();
}
return false;
case COUNT_ALL:
return visitor.getTable().canGetRowCount();
case MIN:
case MAX:
Index index = getColumnIndex();
return index != null;
default:
return false;
}
}
if (on != null && !on.isEverything(visitor)) {
return false;
}
if (groupConcatSeparator != null && !groupConcatSeparator.isEverything(visitor)) {
return false;
}
if (groupConcatOrderList != null) {
for (int i = 0, size = groupConcatOrderList.size(); i < size; i++) {
SelectOrderBy o = groupConcatOrderList.get(i);
if (!o.expression.isEverything(visitor)) {
return false;
}
}
}
return true;
}
@Override
public int getCost() {
return (on == null) ? 1 : on.getCost() + 1;
}
/* (non-Javadoc)
* @see com.suning.snfddal.command.expression.Expression#exportParameters(java.util.List)
*/
@Override
public String exportParameters(TableFilter filter, List<Value> container) {
String text;
switch (type) {
case GROUP_CONCAT:
return getSQLGroupConcat();
case COUNT_ALL:
return "COUNT(*)";
case COUNT:
text = "COUNT";
break;
case SELECTIVITY:
text = "SELECTIVITY";
break;
case HISTOGRAM:
text = "HISTOGRAM";
break;
case SUM:
text = "SUM";
break;
case MIN:
text = "MIN";
break;
case MAX:
text = "MAX";
break;
case AVG:
text = "AVG";
break;
case STDDEV_POP:
text = "STDDEV_POP";
break;
case STDDEV_SAMP:
text = "STDDEV_SAMP";
break;
case VAR_POP:
text = "VAR_POP";
break;
case VAR_SAMP:
text = "VAR_SAMP";
break;
case BOOL_AND:
text = "BOOL_AND";
break;
case BOOL_OR:
text = "BOOL_OR";
break;
default:
throw DbException.throwInternalError("type=" + type);
}
if (distinct) {
return text + "(DISTINCT " + on.exportParameters(filter, container) + ")";
}
return text + StringUtils.enclose(on.exportParameters(filter, container));
}
}