package io.undertow.servlet.spec;
import java.io.IOException;
import java.nio.ByteBuffer;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import io.undertow.servlet.UndertowServletMessages;
import io.undertow.servlet.api.ThreadSetupAction;
import io.undertow.servlet.core.CompositeThreadSetupAction;
import org.xnio.Buffers;
import org.xnio.ChannelListener;
import org.xnio.IoUtils;
import org.xnio.Pool;
import org.xnio.Pooled;
import org.xnio.channels.Channels;
import org.xnio.channels.EmptyStreamSourceChannel;
import org.xnio.channels.StreamSourceChannel;
import static org.xnio.Bits.allAreClear;
import static org.xnio.Bits.anyAreClear;
import static org.xnio.Bits.anyAreSet;
/**
* Servlet input stream implementation. This stream is non-buffered, and is used for both
* HTTP requests and for upgraded streams.
*
* @author Stuart Douglas
*/
public class ServletInputStreamImpl extends ServletInputStream {
private final HttpServletRequestImpl request;
private final StreamSourceChannel channel;
private final Pool<ByteBuffer> bufferPool;
private volatile ReadListener listener;
/**
* If this stream is ready for a read
*/
private static final int FLAG_READY = 1;
private static final int FLAG_CLOSED = 1 << 1;
private static final int FLAG_FINISHED = 1 << 2;
private static final int FLAG_ON_DATA_READ_CALLED = 1 << 3;
private int state;
private AsyncContextImpl asyncContext;
private Pooled<ByteBuffer> pooled;
public ServletInputStreamImpl(final HttpServletRequestImpl request) {
this.request = request;
if(request.getExchange().isRequestChannelAvailable()) {
this.channel = request.getExchange().getRequestChannel();
} else {
this.channel = new EmptyStreamSourceChannel(request.getExchange().getIoThread());
}
this.bufferPool = request.getExchange().getConnection().getBufferPool();
}
@Override
public boolean isFinished() {
return anyAreSet(state, FLAG_FINISHED);
}
@Override
public boolean isReady() {
return anyAreSet(state, FLAG_READY) && !isFinished();
}
@Override
public void setReadListener(final ReadListener readListener) {
if (readListener == null) {
throw UndertowServletMessages.MESSAGES.listenerCannotBeNull();
}
if (listener != null) {
throw UndertowServletMessages.MESSAGES.listenerAlreadySet();
}
if (!request.isAsyncStarted()) {
throw UndertowServletMessages.MESSAGES.asyncNotStarted();
}
asyncContext = request.getAsyncContext();
listener = readListener;
channel.getReadSetter().set(new ServletInputStreamChannelListener());
//we resume from an async task, after the request has been dispatched
asyncContext.addAsyncTask(new Runnable() {
@Override
public void run() {
channel.wakeupReads();
}
});
}
@Override
public int read() throws IOException {
byte[] b = new byte[1];
int read = read(b);
if (read == -1) {
return -1;
}
return b[0] & 0xff;
}
@Override
public int read(final byte[] b) throws IOException {
return read(b, 0, b.length);
}
@Override
public int read(final byte[] b, final int off, final int len) throws IOException {
if (anyAreSet(state, FLAG_CLOSED)) {
throw UndertowServletMessages.MESSAGES.streamIsClosed();
}
readIntoBuffer();
if (anyAreSet(state, FLAG_FINISHED)) {
return -1;
}
if (len == 0) {
return 0;
}
ByteBuffer buffer = pooled.getResource();
int copied = Buffers.copy(ByteBuffer.wrap(b, off, len), buffer);
if (!buffer.hasRemaining()) {
pooled.free();
pooled = null;
}
return copied;
}
private void readIntoBuffer() throws IOException {
if (pooled == null && !anyAreSet(state, FLAG_FINISHED)) {
pooled = bufferPool.allocate();
if (listener == null) {
int res = Channels.readBlocking(channel, pooled.getResource());
pooled.getResource().flip();
if (res == -1) {
state |= FLAG_FINISHED;
pooled.free();
pooled = null;
}
} else {
if (anyAreClear(state, FLAG_READY)) {
throw UndertowServletMessages.MESSAGES.streamNotReady();
}
int res = channel.read(pooled.getResource());
pooled.getResource().flip();
if (res == -1) {
state |= FLAG_FINISHED;
pooled.free();
pooled = null;
} else if (res == 0) {
state &= ~FLAG_READY;
//we don't free the buffer, that will be done on next read
}
}
}
}
private void readIntoBufferNonBlocking() throws IOException {
if (pooled == null && !anyAreSet(state, FLAG_FINISHED)) {
pooled = bufferPool.allocate();
if (listener == null) {
int res = channel.read(pooled.getResource());
if(res == 0) {
pooled.free();
pooled = null;
return;
}
pooled.getResource().flip();
if (res == -1) {
state |= FLAG_FINISHED;
pooled.free();
pooled = null;
}
} else {
if (anyAreClear(state, FLAG_READY)) {
throw UndertowServletMessages.MESSAGES.streamNotReady();
}
int res = channel.read(pooled.getResource());
pooled.getResource().flip();
if (res == -1) {
state |= FLAG_FINISHED;
pooled.free();
pooled = null;
} else if (res == 0) {
state &= ~FLAG_READY;
//we don't free the buffer, that will be done on next read
}
}
}
}
@Override
public int available() throws IOException {
if (anyAreSet(state, FLAG_CLOSED)) {
throw UndertowServletMessages.MESSAGES.streamIsClosed();
}
readIntoBufferNonBlocking();
if (anyAreSet(state, FLAG_FINISHED)) {
return 0;
}
if(pooled == null) {
return 0;
}
return pooled.getResource().remaining();
}
@Override
public void close() throws IOException {
if (anyAreSet(state, FLAG_CLOSED)) {
return;
}
while (allAreClear(state, FLAG_FINISHED)) {
readIntoBuffer();
if(pooled != null) {
pooled.free();
pooled = null;
}
}
if(pooled != null) {
pooled.free();
pooled = null;
}
channel.shutdownReads();
state |= FLAG_FINISHED | FLAG_CLOSED;
}
private class ServletInputStreamChannelListener implements ChannelListener<StreamSourceChannel> {
@Override
public void handleEvent(final StreamSourceChannel channel) {
channel.suspendReads();
asyncContext.addAsyncTask(new Runnable() {
@Override
public void run() {
if (asyncContext.isDispatched()) {
//this is no longer an async request
//we just return
//TODO: what do we do here? Revert back to blocking mode?
return;
}
if (anyAreSet(state, FLAG_FINISHED)) {
return;
}
state |= FLAG_READY;
try {
CompositeThreadSetupAction action = request.getServletContext().getDeployment().getThreadSetupAction();
ThreadSetupAction.Handle handle = action.setup(request.getExchange());
try {
listener.onDataAvailable();
} finally {
handle.tearDown();
}
} catch (Exception e) {
CompositeThreadSetupAction action = request.getServletContext().getDeployment().getThreadSetupAction();
ThreadSetupAction.Handle handle = action.setup(request.getExchange());
try {
listener.onError(e);
} finally {
handle.tearDown();
}
IoUtils.safeClose(channel);
}
if (anyAreSet(state, FLAG_FINISHED)) {
if (anyAreClear(state, FLAG_ON_DATA_READ_CALLED)) {
try {
state |= FLAG_ON_DATA_READ_CALLED;
channel.shutdownReads();
CompositeThreadSetupAction action = request.getServletContext().getDeployment().getThreadSetupAction();
ThreadSetupAction.Handle handle = action.setup(request.getExchange());
try {
listener.onAllDataRead();
} finally {
handle.tearDown();
}
} catch (IOException e) {
listener.onError(e);
IoUtils.safeClose(channel);
}
}
} else if (!isReady()) {
channel.resumeReads();
}
}
});
}
}
}