--- /dev/null
+/*
+ * Jexer - Java Text User Interface
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (C) 2017 Kevin Lamonte
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * @author Kevin Lamonte [kevin.lamonte@gmail.com]
+ * @version 1
+ */
+package jexer.io;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * This class provides an optional millisecond timeout on its read()
+ * operations. This permits callers to bail out rather than block.
+ */
+public class TimeoutInputStream extends InputStream {
+
+ /**
+ * The wrapped stream.
+ */
+ private InputStream stream;
+
+ /**
+ * The timeout value in millis. If it takes longer than this for bytes
+ * to be available for read then a ReadTimeoutException is thrown. A
+ * value of 0 means to block as a normal InputStream would.
+ */
+ private int timeoutMillis;
+
+ /**
+ * If true, the current read() will timeout soon.
+ */
+ private volatile boolean cancel = false;
+
+ /**
+ * Request that the current read() operation timeout immediately.
+ */
+ public synchronized void cancelRead() {
+ cancel = true;
+ }
+
+ /**
+ * Public constructor, at the default timeout of 10000 millis (10
+ * seconds).
+ *
+ * @param stream the wrapped InputStream
+ */
+ public TimeoutInputStream(final InputStream stream) {
+ this.stream = stream;
+ this.timeoutMillis = 10000;
+ }
+
+ /**
+ * Public constructor, using the default 10 bits per byte.
+ *
+ * @param stream the wrapped InputStream
+ * @param timeoutMillis the timeout value in millis. If it takes longer
+ * than this for bytes to be available for read then a
+ * ReadTimeoutException is thrown. A value of 0 means to block as a
+ * normal InputStream would.
+ */
+ public TimeoutInputStream(final InputStream stream,
+ final int timeoutMillis) {
+
+ if (timeoutMillis < 0) {
+ throw new IllegalArgumentException("Invalid timeoutMillis value, " +
+ "must be >= 0");
+ }
+
+ this.stream = stream;
+ this.timeoutMillis = timeoutMillis;
+ }
+
+ /**
+ * Reads the next byte of data from the input stream.
+ *
+ * @return the next byte of data, or -1 if there is no more data because
+ * the end of the stream has been reached.
+ * @throws IOException if an I/O error occurs
+ */
+ @Override
+ public int read() throws IOException {
+
+ if (timeoutMillis == 0) {
+ // Block on the read().
+ return stream.read();
+ }
+
+ if (stream.available() > 0) {
+ // A byte is available now, return it.
+ return stream.read();
+ }
+
+ // We will wait up to timeoutMillis to see if a byte is available.
+ // If not, we throw ReadTimeoutException.
+ long checkTime = System.currentTimeMillis();
+ while (stream.available() == 0) {
+ long now = System.currentTimeMillis();
+ synchronized (this) {
+ if ((now - checkTime > timeoutMillis) || (cancel == true)) {
+ if (cancel == true) {
+ cancel = false;
+ }
+ throw new ReadTimeoutException("Timeout on read(): " +
+ (int) (now - checkTime) + " millis and still no data");
+ }
+ }
+ try {
+ // How long do we sleep for, eh? For now we will go with 2
+ // millis.
+ Thread.currentThread().sleep(2);
+ } catch (InterruptedException e) {
+ // SQUASH
+ }
+ }
+
+ if (stream.available() > 0) {
+ // A byte is available now, return it.
+ return stream.read();
+ }
+
+ throw new IOException("InputStream claimed a byte was available, but " +
+ "now it is not. What is going on?");
+ }
+
+ /**
+ * Reads some number of bytes from the input stream and stores them into
+ * the buffer array b.
+ *
+ * @param b the buffer into which the data is read.
+ * @return the total number of bytes read into the buffer, or -1 if there
+ * is no more data because the end of the stream has been reached.
+ * @throws IOException if an I/O error occurs
+ */
+ @Override
+ public int read(final byte[] b) throws IOException {
+ if (timeoutMillis == 0) {
+ // Block on the read().
+ return stream.read(b);
+ }
+
+ int remaining = b.length;
+
+ if (stream.available() >= remaining) {
+ // Enough bytes are available now, return them.
+ return stream.read(b);
+ }
+
+ while (remaining > 0) {
+
+ // We will wait up to timeoutMillis to see if a byte is
+ // available. If not, we throw ReadTimeoutException.
+ long checkTime = System.currentTimeMillis();
+ while (stream.available() == 0) {
+ long now = System.currentTimeMillis();
+
+ synchronized (this) {
+ if ((now - checkTime > timeoutMillis) || (cancel == true)) {
+ if (cancel == true) {
+ cancel = false;
+ }
+ throw new ReadTimeoutException("Timeout on read(): " +
+ (int) (now - checkTime) + " millis and still no " +
+ "data");
+ }
+ }
+ try {
+ // How long do we sleep for, eh? For now we will go with
+ // 2 millis.
+ Thread.currentThread().sleep(2);
+ } catch (InterruptedException e) {
+ // SQUASH
+ }
+ }
+
+ if (stream.available() > 0) {
+ // At least one byte is available now, read it.
+ int n = stream.available();
+ if (remaining < n) {
+ n = remaining;
+ }
+ int rc = stream.read(b, b.length - remaining, n);
+ if (rc == -1) {
+ // This shouldn't happen.
+ throw new IOException("InputStream claimed bytes were " +
+ "available, but read() returned -1. What is going " +
+ "on?");
+ }
+ remaining -= rc;
+ return rc;
+ }
+ }
+
+ throw new IOException("InputStream claimed all bytes were available, " +
+ "but now it is not. What is going on?");
+ }
+
+ /**
+ * Reads up to len bytes of data from the input stream into an array of
+ * bytes.
+ *
+ * @param b the buffer into which the data is read.
+ * @param off the start offset in array b at which the data is written.
+ * @param len the maximum number of bytes to read.
+ * @return the total number of bytes read into the buffer, or -1 if there
+ * is no more data because the end of the stream has been reached.
+ * @throws IOException if an I/O error occurs
+ */
+ @Override
+ public int read(final byte[] b, final int off,
+ final int len) throws IOException {
+
+ if (timeoutMillis == 0) {
+ // Block on the read().
+ return stream.read(b);
+ }
+
+ int remaining = len;
+
+ if (stream.available() >= remaining) {
+ // Enough bytes are available now, return them.
+ return stream.read(b, off, remaining);
+ }
+
+ while (remaining > 0) {
+
+ // We will wait up to timeoutMillis to see if a byte is
+ // available. If not, we throw ReadTimeoutException.
+ long checkTime = System.currentTimeMillis();
+ while (stream.available() == 0) {
+ long now = System.currentTimeMillis();
+ synchronized (this) {
+ if ((now - checkTime > timeoutMillis) || (cancel == true)) {
+ if (cancel == true) {
+ cancel = false;
+ }
+ throw new ReadTimeoutException("Timeout on read(): " +
+ (int) (now - checkTime) + " millis and still no " +
+ "data");
+ }
+ }
+ try {
+ // How long do we sleep for, eh? For now we will go with
+ // 2 millis.
+ Thread.currentThread().sleep(2);
+ } catch (InterruptedException e) {
+ // SQUASH
+ }
+ }
+
+ if (stream.available() > 0) {
+ // At least one byte is available now, read it.
+ int n = stream.available();
+ if (remaining < n) {
+ n = remaining;
+ }
+ int rc = stream.read(b, off + len - remaining, n);
+ if (rc == -1) {
+ // This shouldn't happen.
+ throw new IOException("InputStream claimed bytes were " +
+ "available, but read() returned -1. What is going " +
+ "on?");
+ }
+ return rc;
+ }
+ }
+
+ throw new IOException("InputStream claimed all bytes were available, " +
+ "but now it is not. What is going on?");
+ }
+
+ /**
+ * Returns an estimate of the number of bytes that can be read (or
+ * skipped over) from this input stream without blocking by the next
+ * invocation of a method for this input stream.
+ *
+ * @return an estimate of the number of bytes that can be read (or
+ * skipped over) from this input stream without blocking or 0 when it
+ * reaches the end of the input stream.
+ * @throws IOException if an I/O error occurs
+ */
+ @Override
+ public int available() throws IOException {
+ return stream.available();
+ }
+
+ /**
+ * Closes this input stream and releases any system resources associated
+ * with the stream.
+ *
+ * @throws IOException if an I/O error occurs
+ */
+ @Override
+ public void close() throws IOException {
+ stream.close();
+ }
+
+ /**
+ * Marks the current position in this input stream.
+ *
+ * @param readLimit the maximum limit of bytes that can be read before
+ * the mark position becomes invalid
+ */
+ @Override
+ public void mark(final int readLimit) {
+ stream.mark(readLimit);
+ }
+
+ /**
+ * Tests if this input stream supports the mark and reset methods.
+ *
+ * @return true if this stream instance supports the mark and reset
+ * methods; false otherwise
+ */
+ @Override
+ public boolean markSupported() {
+ return stream.markSupported();
+ }
+
+ /**
+ * Repositions this stream to the position at the time the mark method
+ * was last called on this input stream.
+ *
+ * @throws IOException if an I/O error occurs
+ */
+ @Override
+ public void reset() throws IOException {
+ stream.reset();
+ }
+
+ /**
+ * Skips over and discards n bytes of data from this input stream.
+ *
+ * @param n the number of bytes to be skipped
+ * @return the actual number of bytes skipped
+ * @throws IOException if an I/O error occurs
+ */
+ @Override
+ public long skip(final long n) throws IOException {
+ return stream.skip(n);
+ }
+
+}
git://git.nikiroo.be / fanfix.git / blobdiff