com.codename1.io.BufferedInputStream Maven / Gradle / Ivy
/*
* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores
* CA 94065 USA or visit www.oracle.com if you need additional information or
* have any questions.
*/
package com.codename1.io;
import com.codename1.ui.Display;
import java.io.*;
/**
* Based on the buffered input stream from the JDK with some minor tweaks to allow
* external classes to monitor stream status and progress.
*/
public class BufferedInputStream extends InputStream {
private static int streamCount = 0;
private int actualAvailable = defaultBufferSize;
private Object connection;
private InputStream in;
private static int defaultBufferSize = 8192;
private byte[] buf;
private IOProgressListener progressListener;
private boolean disableBuffering;
private boolean closed;
private boolean stopped;
/**
* The index one greater than the index of the last valid byte in
* the buffer.
* This value is always
* in the range 0 through buf.length;
* elements buf[0] through buf[count-1]
* contain buffered input data obtained
* from the underlying input stream.
*/
private int count;
private long lastActivityTime;
private int totalBytesRead;
private boolean printInput;
private String name;
private int yield = -1;
private long elapsedSinceLastYield;
/**
* Indicates the name of the stream for debugging purposes
*
* @return the name of the stream
*/
public String getName() {
return name;
}
/**
* The current position in the buffer. This is the index of the next
* character to be read from the buf array.
*
* This value is always in the range 0
* through count. If it is less
* than count, then buf[pos]
* is the next byte to be supplied as input;
* if it is equal to count, then
* the next read or skip
* operation will require more bytes to be
* read from the contained input stream.
*
* @see java.io.BufferedInputStream#buf
*/
private int pos;
/**
* The value of the pos field at the time the last
* mark method was called.
*
* This value is always
* in the range -1 through pos.
* If there is no marked position in the input
* stream, this field is -1. If
* there is a marked position in the input
* stream, then buf[markpos]
* is the first byte to be supplied as input
* after a reset operation. If
* markpos is not -1,
* then all bytes from positions buf[markpos]
* through buf[pos-1] must remain
* in the buffer array (though they may be
* moved to another place in the buffer array,
* with suitable adjustments to the values
* of count, pos,
* and markpos); they may not
* be discarded unless and until the difference
* between pos and markpos
* exceeds marklimit.
*
* @see java.io.BufferedInputStream#mark(int)
* @see java.io.BufferedInputStream#pos
*/
private int markpos = -1;
/**
* The maximum read ahead allowed after a call to the
* mark method before subsequent calls to the
* reset method fail.
* Whenever the difference between pos
* and markpos exceeds marklimit,
* then the mark may be dropped by setting
* markpos to -1.
*
* @see java.io.BufferedInputStream#mark(int)
* @see java.io.BufferedInputStream#reset()
*/
private int marklimit;
/**
* Check to make sure that underlying input stream has not been
* nulled out due to close; if not return it;
*/
private InputStream getInIfOpen() throws IOException {
InputStream input = in;
if (input == null) {
throw new IOException("Stream closed");
}
return input;
}
/**
* Check to make sure that buffer has not been nulled out due to
* close; if not return it;
*/
private byte[] getBufIfOpen() throws IOException {
byte[] buffer = buf;
if (buffer == null) {
throw new IOException("Stream closed");
}
return buffer;
}
/**
* Creates a BufferedInputStream
* and saves its argument, the input stream
* in, for later use. An internal
* buffer array is created and stored in buf.
*
* @param in the underlying input stream.
*/
public BufferedInputStream(InputStream in) {
this(in, defaultBufferSize);
}
/**
* Creates a BufferedInputStream
* and saves its argument, the input stream
* in, for later use. An internal
* buffer array is created and stored in buf.
*
* @param in the underlying input stream.
* @param name the name of the stream
*/
public BufferedInputStream(InputStream in, String name) {
this(in, defaultBufferSize, name);
}
/**
* Creates a BufferedInputStream
* with the specified buffer size,
* and saves its argument, the input stream
* in, for later use. An internal
* buffer array of length size
* is created and stored in buf.
*
* @param in the underlying input stream.
* @param size the buffer size.
* @exception IllegalArgumentException if size <= 0.
*/
public BufferedInputStream(InputStream in, int size) {
this(in, size, "unnamed");
}
/**
* Creates a BufferedInputStream
* with the specified buffer size,
* and saves its argument, the input stream
* in, for later use. An internal
* buffer array of length size
* is created and stored in buf.
*
* @param in the underlying input stream.
* @param size the buffer size.
* @param name the name of the stream
* @exception IllegalArgumentException if size <= 0.
*/
public BufferedInputStream(InputStream in, int size, String name) {
this.in = in;
if (size <= 0) {
throw new IllegalArgumentException("Buffer size <= 0");
}
buf = new byte[size];
streamCount++;
this.name = name;
Util.getImplementation().logStreamCreate(name, true, streamCount);
}
/**
* Fills the buffer with more data, taking into account
* shuffling and other tricks for dealing with marks.
* Assumes that it is being called by a synchronized method.
* This method also assumes that all data has already been read in,
* hence pos > count.
*/
private void fill() throws IOException {
byte[] buffer = getBufIfOpen();
if (markpos < 0) {
pos = 0; /* no mark: throw away the buffer */
} else if (pos >= buffer.length) /* no room left in buffer */ {
if (markpos > 0) { /* can throw away early part of the buffer */
int sz = pos - markpos;
System.arraycopy(buffer, markpos, buffer, 0, sz);
pos = sz;
markpos = 0;
} else if (buffer.length >= marklimit) {
markpos = -1; /* buffer got too big, invalidate mark */
pos = 0; /* drop buffer contents */
} else { /* grow buffer */
int nsz = pos * 2;
if (nsz > marklimit) {
nsz = marklimit;
}
byte nbuf[] = new byte[nsz];
System.arraycopy(buffer, 0, nbuf, 0, pos);
if (buffer != buf) {
throw new IOException("Stream closed");
}
buf = nbuf;
buffer = nbuf;
}
}
count = pos;
if(actualAvailable < 0) {
return;
}
int sizeOfBuffer = (buffer.length - pos);
int n = getInIfOpen().read(buffer, pos, sizeOfBuffer);
if (n > 0) {
count = n + pos;
} else {
if(n < 0) {
actualAvailable = -1;
}
}
}
/**
* Allows access to the underlying input stream if desired
* @return the internal input stream
*/
public InputStream getInternal() {
return in;
}
/**
* See
* the general contract of the read
* method of InputStream.
*
* @return the next byte of data, or -1 if the end of the
* stream is reached.
* @exception IOException if this input stream has been closed by
* invoking its {@link #close()} method,
* or an I/O error occurs.
*/
public synchronized int read() throws IOException {
if(stopped){
return -1;
}
lastActivityTime = System.currentTimeMillis();
if(disableBuffering) {
int v = getInIfOpen().read();
if(printInput && v > -1) {
System.out.print((char)v);
}
totalBytesRead++;
fireProgress();
return v;
}
if (pos >= count) {
fill();
if (pos >= count) {
return -1;
}
}
totalBytesRead++;
fireProgress();
int v = getBufIfOpen()[pos++] & 0xff;
if(printInput) {
System.out.print((char)v);
}
return v;
}
private void fireProgress() {
if (progressListener != null) {
progressListener.ioStreamUpdate(this, totalBytesRead);
}
}
/**
* Read characters into a portion of an array, reading from the underlying
* stream at most once if necessary.
*/
private int read1(byte[] b, int off, int len) throws IOException {
int avail = count - pos;
if (avail <= 0) {
/* If the requested length is at least as large as the buffer, and
if there is no mark/reset activity, do not bother to copy the
bytes into the local buffer. In this way buffered streams will
cascade harmlessly. */
if (len >= getBufIfOpen().length && markpos < 0) {
int val = getInIfOpen().read(b, off, len);
if(val < 0) {
actualAvailable = -1;
} else {
if(printInput) {
System.out.print(new String(b, off, val));
}
}
return val;
}
fill();
avail = count - pos;
if (avail <= 0) {
return -1;
}
}
int cnt = (avail < len) ? avail : len;
System.arraycopy(getBufIfOpen(), pos, b, off, cnt);
if(printInput) {
System.out.print(new String(b, off, cnt));
}
pos += cnt;
return cnt;
}
private void yieldTime() {
long time = System.currentTimeMillis();
if(time - elapsedSinceLastYield > 300) {
try {
Thread.sleep(yield);
} catch (InterruptedException ex) {
}
elapsedSinceLastYield = time;
}
}
/**
* Reads bytes from this byte-input stream into the specified byte array,
* starting at the given offset.
*
*
This method implements the general contract of the corresponding
* {@link InputStream#read(byte[], int, int) read} method of
* the {@link InputStream} class. As an additional
* convenience, it attempts to read as many bytes as possible by repeatedly
* invoking the read method of the underlying stream. This
* iterated read continues until one of the following
* conditions becomes true:
*
* - The specified number of bytes have been read,
*
*
- The
read method of the underlying stream returns
* -1, indicating end-of-file, or
*
* - The
available method of the underlying stream
* returns zero, indicating that further input requests would block.
*
*
If the first read on the underlying stream returns
* -1 to indicate end-of-file then this method returns
* -1. Otherwise this method returns the number of bytes
* actually read.
*
* Subclasses of this class are encouraged, but not required, to
* attempt to read as many bytes as possible in the same fashion.
*
* @param b destination buffer.
* @param off offset at which to start storing bytes.
* @param len maximum number of bytes to read.
* @return the number of bytes read, or -1 if the end of
* the stream has been reached.
* @exception IOException if this input stream has been closed by
* invoking its {@link #close()} method,
* or an I/O error occurs.
*/
public synchronized int read(byte b[], int off, int len)
throws IOException {
if(stopped){
return -1;
}
if(yield > -1 && !Display.getInstance().isEdt()) {
yieldTime();
}
lastActivityTime = System.currentTimeMillis();
if(disableBuffering) {
int v = getInIfOpen().read(b, off, len);
if (v > -1) {
if(printInput) {
System.out.print(new String(b, off, v));
}
totalBytesRead += v;
fireProgress();
}
return v;
}
getBufIfOpen(); // Check for closed stream
if ((off | len | (off + len) | (b.length - (off + len))) < 0) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return 0;
}
int n = 0;
for (;;) {
if(stopped){
return -1;
}
lastActivityTime = System.currentTimeMillis();
int nread = read1(b, off + n, len - n);
if (nread <= 0) {
n = (n == 0) ? nread : n;
break;
}
n += nread;
if (n >= len) {
break;
}
// if not closed but no bytes available, return
InputStream input = in;
if (input != null && superAvailable() <= 0) {
break;
}
if(yield > -1 && !Display.getInstance().isEdt()) {
yieldTime();
}
}
if (n > 0) {
totalBytesRead += n;
fireProgress();
}
lastActivityTime = System.currentTimeMillis();
return n;
}
/**
* See the general contract of the skip
* method of InputStream.
*
* @exception IOException if the stream does not support seek,
* or if this input stream has been closed by
* invoking its {@link #close()} method, or an
* I/O error occurs.
*/
public synchronized long skip(long n) throws IOException {
if(disableBuffering) {
long v = getInIfOpen().skip(n);
totalBytesRead += v;
fireProgress();
return v;
}
getBufIfOpen(); // Check for closed stream
if (n <= 0) {
return 0;
}
long avail = count - pos;
if (avail <= 0) {
// If no mark position set then don't keep in buffer
if (markpos < 0) {
return getInIfOpen().skip(n);
}
// Fill in buffer to save bytes for reset
fill();
avail = count - pos;
if (avail <= 0) {
return 0;
}
}
long skipped = (avail < n) ? avail : n;
pos += skipped;
totalBytesRead += (int) skipped;
fireProgress();
lastActivityTime = System.currentTimeMillis();
return skipped;
}
/**
* 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. The next invocation might be
* the same thread or another thread. A single read or skip of this
* many bytes will not block, but may read or skip fewer bytes.
*
* This method returns the sum of the number of bytes remaining to be read in
* the buffer (count - pos) and the result of calling the
* {@link java.io.FilterInputStream#in in}.available().
*
* @return an estimate of the number of bytes that can be read (or skipped
* over) from this input stream without blocking.
* @exception IOException if this input stream has been closed by
* invoking its close() method,
* or an I/O error occurs.
*/
public synchronized int available() throws IOException {
if(disableBuffering) {
return available();
}
return superAvailable() + (count - pos);
}
/**
* See the general contract of the mark
* method of InputStream.
*
* @param readlimit the maximum limit of bytes that can be read before
* the mark position becomes invalid.
*/
public synchronized void mark(int readlimit) {
marklimit = readlimit;
markpos = pos;
}
/**
* See the general contract of the reset
* method of InputStream.
*
* If markpos is -1
* (no mark has been set or the mark has been
* invalidated), an IOException
* is thrown. Otherwise, pos is
* set equal to markpos.
*
* @exception IOException if this stream has not been marked or,
* if the mark has been invalidated, or the stream
* has been closed by invoking its {@link #close()}
* method, or an I/O error occurs.
*/
public synchronized void reset() throws IOException {
getBufIfOpen(); // Cause exception if closed
if (markpos < 0) {
throw new IOException("Resetting to invalid mark");
}
pos = markpos;
}
/**
* Tests if this input stream supports the mark
* and reset methods. The markSupported
* method of BufferedInputStream returns
* true.
*
* @return a boolean indicating if this stream type supports
* the mark and reset methods.
* @see java.io.InputStream#mark(int)
* @see java.io.InputStream#reset()
*/
public boolean markSupported() {
return in.markSupported();
}
private int superAvailable() {
try {
if(actualAvailable < 0) {
return -1;
}
return in.available();
} catch(IOException err) {
// Available sometimes fails on MIDP devices and shouldn't be used
return actualAvailable;
}
}
/**
* Closes this input stream and releases any system resources
* associated with the stream.
* Once the stream has been closed, further read(), available(), reset(),
* or skip() invocations will throw an IOException.
* Closing a previously closed stream has no effect.
*
* @exception IOException if an I/O error occurs.
*/
public void close() throws IOException {
if(closed) {
Util.getImplementation().logStreamDoubleClose(name, true);
return;
}
closed = true;
streamCount--;
Util.getImplementation().logStreamClose(name, true, streamCount);
if(connection != null) {
Util.getImplementation().cleanup(connection);
}
byte[] buffer;
while ((buffer = buf) != null) {
if (buf == buffer) { //bufUpdater.compareAndSet(this, buffer, null)) {
buf = null;
InputStream input = in;
in = null;
if (input != null) {
input.close();
}
return;
}
// Else retry in case a new buf was CASed in fill()
}
}
/**
* Returns the time of the last activity
*
* @return time of the last activity on this stream
*/
public long getLastActivityTime() {
return lastActivityTime;
}
/**
* Returns the total amount of bytes read from this stream so far
*
* @return the total amount of bytes read from this stream so far
*/
public int getTotalBytesRead() {
return totalBytesRead;
}
/**
* Sets the callback for IO updates from a buffered stream
*
* @param progressListener the progressListener to set
*/
public void setProgressListener(IOProgressListener progressListener) {
this.progressListener = progressListener;
}
/**
* {@inheritDoc}
*/
public int read(byte b[]) throws IOException {
return read(b, 0, b.length);
}
/**
* The default size for a stream buffer
*
* @return the defaultBufferSize
*/
public static int getDefaultBufferSize() {
return defaultBufferSize;
}
/**
* The default size for a stream buffer
*
* @param aDefaultBufferSize the defaultBufferSize to set
*/
public static void setDefaultBufferSize(int aDefaultBufferSize) {
defaultBufferSize = aDefaultBufferSize;
}
/**
* If applicable this member represents the connection object for the stream
*
* @return the connection
*/
public Object getConnection() {
return connection;
}
/**
* If applicable this member represents the connection object for the stream
*
* @param connection the connection to set
*/
public void setConnection(Object connection) {
this.connection = connection;
}
/**
* @return the disableBuffering
*/
public boolean isDisableBuffering() {
return disableBuffering;
}
/**
* @param disableBuffering the disableBuffering to set
*/
public void setDisableBuffering(boolean disableBuffering) {
this.disableBuffering = disableBuffering;
}
/**
* Prints out all the data that passes through this stream to the console.
* This is a very useful debugging tool.
*
* @return the printInput
*/
public boolean isPrintInput() {
return printInput;
}
/**
* Prints out all the data that passes through this stream to the console.
* This is a very useful debugging tool.
*
* @param printInput the printInput to set
*/
public void setPrintInput(boolean printInput) {
this.printInput = printInput;
}
/**
* Allows setting a yield duration for this stream which is useful for background
* operations to release CPU
*
* @return the yield
*/
public int getYield() {
return yield;
}
/**
* Allows setting a yield duration for this stream which is useful for background
* operations to release CPU
* @param yield the yield to set
*/
public void setYield(int yield) {
this.yield = yield;
}
/**
* Stop reading from the stream, invoking this will cause the read() to
* return -1
*/
public void stop(){
stopped = true;
}
}