io.vertx.ext.jdbc.impl.actions.JDBCSQLRowStream Maven / Gradle / Ivy
/*
* Copyright (c) 2011-2014 The original author or authors
* ------------------------------------------------------
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Apache License v2.0 which accompanies this distribution.
*
* The Eclipse Public License is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* The Apache License v2.0 is available at
* http://www.opensource.org/licenses/apache2.0.php
*
* You may elect to redistribute this code under either of these licenses.
*/
package io.vertx.ext.jdbc.impl.actions;
import io.vertx.core.AsyncResult;
import io.vertx.core.Future;
import io.vertx.core.Handler;
import io.vertx.core.Promise;
import io.vertx.core.impl.ContextInternal;
import io.vertx.core.impl.TaskQueue;
import io.vertx.core.impl.logging.Logger;
import io.vertx.core.impl.logging.LoggerFactory;
import io.vertx.core.json.JsonArray;
import io.vertx.core.streams.ReadStream;
import io.vertx.core.streams.impl.InboundBuffer;
import io.vertx.ext.jdbc.spi.JDBCDecoder;
import io.vertx.ext.sql.SQLRowStream;
import io.vertx.ext.jdbc.spi.JDBCColumnDescriptorProvider;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* @author Paulo Lopes
*/
class JDBCSQLRowStream implements SQLRowStream {
private static final Logger log = LoggerFactory.getLogger(JDBCSQLRowStream.class);
private final ContextInternal ctx;
private final TaskQueue statementsQueue;
private final Statement st;
private final int fetchSize;
private final InboundBuffer pending;
private final AtomicBoolean ended = new AtomicBoolean(false);
private final AtomicBoolean stClosed = new AtomicBoolean(false);
private final AtomicBoolean rsClosed = new AtomicBoolean(false);
private final AtomicBoolean more = new AtomicBoolean(false);
private ResultSet rs;
private ResultSetMetaData metaData;
private JDBCDecoder decoder;
private List columns;
private int cols;
private Handler exceptionHandler;
private Handler endHandler;
private Handler rsClosedHandler;
JDBCSQLRowStream(ContextInternal ctx, TaskQueue statementsQueue, Statement st, ResultSet rs, JDBCDecoder decoder, int fetchSize) throws SQLException {
this.ctx = ctx;
this.statementsQueue = statementsQueue;
this.st = st;
this.fetchSize = fetchSize;
this.rs = rs;
this.decoder = decoder;
this.pending = new InboundBuffer(ctx, fetchSize)
.drainHandler(v -> readBatch())
.emptyHandler(v -> checkEndHandler());
metaData = rs.getMetaData();
cols = metaData.getColumnCount();
stClosed.set(false);
rsClosed.set(false);
// the first rs is populated in the constructor
more.set(true);
}
private void checkEndHandler() {
if (ended.get() && pending.isEmpty()) {
if (endHandler != null) {
endHandler.handle(null);
}
}
}
@Override
public int column(String name) {
try {
return rs.findColumn(name) - 1;
} catch (SQLException e) {
return -1;
}
}
@Override
public List columns() {
if (columns == null) {
try {
if (cols > 0) {
final List columns = new ArrayList<>(cols);
for (int i = 0; i < cols; i++) {
columns.add(i, metaData.getColumnLabel(i + 1));
}
this.columns = Collections.unmodifiableList(columns);
} else {
this.columns = Collections.emptyList();
}
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
return columns;
}
@Override
public SQLRowStream exceptionHandler(Handler handler) {
this.exceptionHandler = handler;
return this;
}
@Override
public SQLRowStream handler(Handler handler) {
pending.handler(handler);
if (handler != null && pending.isWritable()) {
readBatch();
}
return this;
}
@Override
public SQLRowStream pause() {
pending.pause();
return this;
}
@Override
public ReadStream fetch(long amount) {
pending.fetch(amount);
return this;
}
@Override
public SQLRowStream resume() {
pending.resume();
return this;
}
private void readBatch() {
if (!rsClosed.get()) {
ctx.>executeBlocking(fut -> {
try {
JDBCColumnDescriptorProvider provider = JDBCColumnDescriptorProvider.fromResultMetaData(metaData);
List rows = new ArrayList<>(fetchSize);
for (int i = 0; i < fetchSize && rs.next(); i++) {
JsonArray result = new JsonArray();
for (int j = 1; j <= cols; j++) {
Object res = decoder.parse(rs, j, provider);
if (res != null) {
result.add(res);
} else {
result.addNull();
}
}
rows.add(result);
}
fut.complete(rows);
} catch (SQLException e) {
fut.fail(e);
}
}, statementsQueue, ar -> {
if (ar.succeeded()) {
List rows = ar.result();
if (rows.isEmpty()) {
empty(null);
} else if (pending.write(rows)) {
readBatch();
}
} else {
empty(ar.cause());
}
});
}
}
private void empty(Throwable err) {
// mark as ended if the handler was registered too late
ended.set(true);
// automatically close resources
if (rsClosedHandler != null) {
// only close the result set and notify
closeRS(pending.isEmpty(), c -> {
if (err != null) {
if (exceptionHandler != null) {
exceptionHandler.handle(err);
} else {
log.debug(err);
}
} else {
rsClosedHandler.handle(null);
}
});
} else {
// default behavior close result set + statement
closeAll(pending.isEmpty(), c -> {
if (err != null) {
if (exceptionHandler != null) {
exceptionHandler.handle(err);
} else {
log.debug(err);
}
} else {
checkEndHandler();
}
});
}
}
@Override
public SQLRowStream endHandler(Handler handler) {
this.endHandler = handler;
checkEndHandler();
return this;
}
private void closeRS(boolean pause, Handler> handler) {
// stop pumping data if needed
if (pause) {
pause();
}
// close the cursor
close(rs, rsClosed, handler);
}
@Override
public void close() {
close(null);
}
@Override
public void close(Handler> handler) {
closeAll(true, handler);
}
private void closeAll(boolean pauseBuffer, Handler> handler) {
closeRS(pauseBuffer, res -> {
// close the statement
close(st, stClosed, handler);
});
}
@Override
public SQLRowStream resultSetClosedHandler(Handler handler) {
this.rsClosedHandler = handler;
return this;
}
@Override
public void moreResults() {
if (more.compareAndSet(true, false)) {
// pause streaming if rs is not complete
pause();
ctx.executeBlocking(this::getNextResultSet, statementsQueue, res -> {
if (res.failed()) {
if (exceptionHandler != null) {
exceptionHandler.handle(res.cause());
} else {
log.debug(res.cause());
}
} else {
if (more.get()) {
resume();
} else {
if (endHandler != null) {
endHandler.handle(null);
}
}
}
});
}
}
private void getNextResultSet(Promise f) {
try {
// close if not already closed
if (rsClosed.compareAndSet(false, true)) {
rs.close();
}
// is there more rs data?
if (st.getMoreResults()) {
rs = st.getResultSet();
metaData = rs.getMetaData();
cols = metaData.getColumnCount();
columns = null;
// reset
// paused.set(true);
stClosed.set(false);
rsClosed.set(false);
more.set(true);
}
f.complete();
} catch (SQLException e) {
f.fail(e);
}
}
private void close(AutoCloseable closeable, AtomicBoolean lock, Handler> handler) {
if (lock.compareAndSet(false, true)) {
ctx.executeBlocking(f -> {
try {
closeable.close();
f.complete();
} catch (Exception e) {
f.fail(e);
}
}, statementsQueue, handler);
} else {
if (handler != null) {
handler.handle(Future.succeededFuture());
}
}
}
}
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