Package org.jline.utils

Class NonBlockingInputStreamImpl

java.lang.Object

java.io.InputStream

org.jline.utils.NonBlockingInputStream

org.jline.utils.NonBlockingInputStreamImpl

All Implemented Interfaces:

Closeable, AutoCloseable

public class NonBlockingInputStreamImpl
extends NonBlockingInputStream

This class wraps a regular input stream and allows it to appear as if it is non-blocking; that is, reads can be performed against it that timeout if no data is seen for a period of time. This effect is achieved by having a separate thread perform all non-blocking read requests and then waiting on the thread to complete.

VERY IMPORTANT NOTES

• This class is not thread safe. It expects at most one reader.
• The shutdown() method must be called in order to shut down the thread that handles blocking I/O.

Field Summary

Fields inherited from class org.jline.utils.NonBlockingInputStream

closed, EOF, READ_EXPIRED

Constructor Summary

Constructors

Constructor	Description
NonBlockingInputStreamImpl(String name, InputStream in)	Creates a NonBlockingInputStream out of a normal blocking stream.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this input stream and marks it as closed.
int	read(long timeout, boolean isPeek)	Attempts to read a byte from the input stream for a specific period of time.
void	setPollFunction(IntUnaryOperator pollFn)	Sets a poll function that checks the underlying file descriptor for input readiness using an OS-level mechanism such as poll(2).
void	shutdown()	Shuts down the thread that is handling blocking I/O if any.

Methods inherited from class org.jline.utils.NonBlockingInputStream

checkClosed, peek, read, read, read, readBuffered, readBuffered, readBuffered

Methods inherited from class java.io.InputStream

available, mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

NonBlockingInputStreamImpl

public NonBlockingInputStreamImpl(String name,
 InputStream in)

Creates a NonBlockingInputStream out of a normal blocking stream. Note that this call also spawns a separate thread to perform the blocking I/O on behalf of the thread that is using this class. The shutdown() method must be called in order to shut this thread down.

Parameters:

name - The stream name

in - The stream to wrap

Method Details

setPollFunction

public void setPollFunction(IntUnaryOperator pollFn)

Description copied from class: NonBlockingInputStream

Sets a poll function that checks the underlying file descriptor for input readiness using an OS-level mechanism such as poll(2).

When set, the pump thread uses short-timeout polls instead of an indefinite blocking read, allowing it to be cancelled promptly when a consumer's timed read expires. This prevents the pump from stealing keystrokes from subprocesses that share the same tty fd (see #2219).

Must be called before the first read. The default implementation is a no-op; subclasses that support poll-based reads should override.

Overrides:

setPollFunction in class NonBlockingInputStream

Parameters:

pollFn - (timeoutMs) → poll result: positive if data is ready, 0 on timeout, negative on error. The fd must be captured by the caller. Pass null to disable.

shutdown

public void shutdown()

Description copied from class: NonBlockingInputStream

Shuts down the thread that is handling blocking I/O if any. Note that if the thread is currently blocked waiting for I/O it may not actually shut down until the I/O is received.

Overrides:

shutdown in class NonBlockingInputStream

close

public void close()
           throws IOException

Description copied from class: NonBlockingInputStream

Closes this input stream and marks it as closed.

Subsequent read operations behavior depends on the PROP_CLOSE_MODE setting:

• "strict" - Throw ClosedException (default in JLine 4.x)
• "warn" - Log a warning but continue (default in JLine 3.x)
• "lenient" - Silently allow access

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class NonBlockingInputStream

Throws:

IOException - if an I/O error occurs

read

public int read(long timeout,
 boolean isPeek)
         throws IOException

Attempts to read a byte from the input stream for a specific period of time.

Specified by:

read in class NonBlockingInputStream

Parameters:

timeout - The amount of time to wait for the character

isPeek - trueif the byte read must not be consumed

Returns:

The byte read, -1 if EOF is reached, or -2 if the read timed out.

Throws:

IOException - if anything wrong happens