/*
* Copyright 2004-2023 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.jdbc;
import java.io.IOException;
import java.io.InputStream;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.io.Reader;
import java.io.Writer;
import java.sql.SQLException;
import org.h2.api.ErrorCode;
import org.h2.message.DbException;
import org.h2.message.TraceObject;
import org.h2.mvstore.DataUtils;
import org.h2.util.IOUtils;
import org.h2.util.Task;
import org.h2.value.Value;
/**
* Represents a large object value.
*/
public abstract class JdbcLob extends TraceObject {
static final class LobPipedOutputStream extends PipedOutputStream {
private final Task task;
LobPipedOutputStream(PipedInputStream snk, Task task) throws IOException {
super(snk);
this.task = task;
}
@Override
public void close() throws IOException {
super.close();
try {
task.get();
} catch (Exception e) {
throw DataUtils.convertToIOException(e);
}
}
}
/**
* State of the object.
*/
public enum State {
/**
* New object without a value.
*/
NEW,
/**
* One of setter methods is invoked, but stream is not closed yet.
*/
SET_CALLED,
/**
* A value is set.
*/
WITH_VALUE,
/**
* Object is closed.
*/
CLOSED;
}
/**
* JDBC connection.
*/
final JdbcConnection conn;
/**
* Value.
*/
Value value;
/**
* State.
*/
State state;
JdbcLob(JdbcConnection conn, Value value, State state, int type, int id) {
setTrace(conn.getSession().getTrace(), type, id);
this.conn = conn;
this.value = value;
this.state = state;
}
/**
* Check that connection and LOB is not closed, otherwise throws exception with
* error code {@link org.h2.api.ErrorCode#OBJECT_CLOSED}.
*/
void checkClosed() {
conn.checkClosed();
if (state == State.CLOSED) {
throw DbException.get(ErrorCode.OBJECT_CLOSED);
}
}
/**
* Check the state of the LOB and throws the exception when check failed
* (set is supported only for a new LOB).
*/
void checkEditable() {
checkClosed();
if (state != State.NEW) {
throw DbException.getUnsupportedException("Allocate a new object to set its value.");
}
}
/**
* Check the state of the LOB and throws the exception when check failed
* (the LOB must be set completely before read).
*
* @throws SQLException on SQL exception
* @throws IOException on I/O exception
*/
void checkReadable() throws SQLException, IOException {
checkClosed();
if (state == State.SET_CALLED) {
throw DbException.getUnsupportedException("Stream setter is not yet closed.");
}
}
/**
* Change the state LOB state (LOB value is set completely and available to read).
* @param blob LOB value.
*/
void completeWrite(Value blob) {
checkClosed();
state = State.WITH_VALUE;
value = blob;
}
/**
* Release all resources of this object.
*/
public void free() {
debugCodeCall("free");
state = State.CLOSED;
value = null;
}
/**
* Returns the input stream.
*
* @return the input stream
* @throws SQLException on failure
*/
InputStream getBinaryStream() throws SQLException {
try {
debugCodeCall("getBinaryStream");
checkReadable();
return value.getInputStream();
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Returns the reader.
*
* @return the reader
* @throws SQLException on failure
*/
Reader getCharacterStream() throws SQLException {
try {
debugCodeCall("getCharacterStream");
checkReadable();
return value.getReader();
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Returns the writer.
*
* @return Writer.
* @throws IOException If an I/O error occurs.
*/
Writer setCharacterStreamImpl() throws IOException {
return IOUtils.getBufferedWriter(setClobOutputStreamImpl());
}
/**
* Returns the writer stream.
*
* @return Output stream..
* @throws IOException If an I/O error occurs.
*/
LobPipedOutputStream setClobOutputStreamImpl() throws IOException {
// PipedReader / PipedWriter are a lot slower
// than PipedInputStream / PipedOutputStream
// (Sun/Oracle Java 1.6.0_20)
final PipedInputStream in = new PipedInputStream();
final Task task = new Task() {
@Override
public void call() {
completeWrite(conn.createClob(IOUtils.getReader(in), -1));
}
};
LobPipedOutputStream out = new LobPipedOutputStream(in, task);
task.execute();
return out;
}
/**
* INTERNAL
*/
@Override
public String toString() {
StringBuilder builder = new StringBuilder().append(getTraceObjectName()).append(": ");
if (state == State.SET_CALLED) {
builder.append("<setter_in_progress>");
} else if (state == State.CLOSED) {
builder.append("<closed>");
} else {
builder.append(value.getTraceSQL());
}
return builder.toString();
}
}