org.michailov.async.io

Class AsyncTextStreamReader

java.lang.Object

org.michailov.async.AsyncAgent

org.michailov.async.io.AsyncTextStreamReader

public class AsyncTextStreamReader
extends AsyncAgent

Asynchronous text line reader over a plain old InputStream wrapped in an EOFInputStream. The reader doesn't block as long as the stream correctly reports its available bytes.

The reader reads available bytes from the stream if there are any, decodes the chars, splits lines, and places complete lines in a StringRingBuffer that is accessible through getStringRingBuffer().

Use AsyncAgent.applyAsync() or AsyncAgent.startApplyLoopAsync() to read lines through getStringRingBuffer().

This class is a convenience wrapper around the individual elements of the input stack.

Note: The caller is responsible for opening and closing the stream as needed.

See Also:

EOFInputStream, WhenReady, AsyncAgent, ByteRingBuffer, CharRingBuffer, AsyncLineSplitter

Constructor Summary

Constructors

Constructor and Description
AsyncTextStreamReader(EOFInputStream inputStream, ByteRingBuffer byteRingBuffer, CharRingBuffer charRingBuffer, StringRingBuffer stringRingBuffer, java.util.function.Consumer<StringRingBuffer> onAvailableToRead, TextStreamAsyncOptions textStreamAsyncOptions) Constructs a new AsyncTextStreamReader instance to read from the given InputStream.
AsyncTextStreamReader(EOFInputStream inputStream, java.util.function.Consumer<StringRingBuffer> onAvailableToRead, TextStreamAsyncOptions textStreamAsyncOptions) Constructs a new AsyncTextStreamReader instance to read from the given InputStream.
AsyncTextStreamReader(EOFInputStream inputStream, TextStreamAsyncOptions textStreamAsyncOptions) Constructs a new AsyncTextStreamReader instance to read from the given InputStream.

Method Summary

Modifier and Type	Method and Description
protected void	action() "action" function that gets executed as part of the apply loop.
protected boolean	done() "done" predicate that returns true when this async agent wants to quit the current async loop.
AsyncRingBufferWatcher<StringRingBuffer>	getAsyncStringRingBufferWatcher() Returns the underlying AsyncRingBufferWatcher that watches the StringRingBuffer.
StringRingBuffer	getStringRingBuffer() Returns the underlying StringRingBuffer where text lines are placed.
boolean	isEOF() Checks whether this text stream reader has reached EOF.
protected boolean	ready() "ready" predicate that returns true when lines can be read from the string ring buffer.

Methods inherited from class org.michailov.async.AsyncAgent

applyAsync, isIdle, setIdle, setIdleAndThrow, startApplyLoopAsync

Methods inherited from class java.lang.Object

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

Constructor Detail

AsyncTextStreamReader

public AsyncTextStreamReader(EOFInputStream inputStream,
                             TextStreamAsyncOptions textStreamAsyncOptions)

Constructs a new AsyncTextStreamReader instance to read from the given InputStream.

Parameters:

inputStream - An EOFInputStream to read from.

textStreamAsyncOptions - TextStreamAsyncOptions that will control all async operations on this instance.

AsyncTextStreamReader

public AsyncTextStreamReader(EOFInputStream inputStream,
                             java.util.function.Consumer<StringRingBuffer> onAvailableToRead,
                             TextStreamAsyncOptions textStreamAsyncOptions)

Constructs a new AsyncTextStreamReader instance to read from the given InputStream.

Parameters:

inputStream - An EOFInputStream to read from.

onAvailableToRead - A callback to invoke when there are text lines available to read from the string ring buffer.

textStreamAsyncOptions - TextStreamAsyncOptions that will control all async operations on this instance.

AsyncTextStreamReader

public AsyncTextStreamReader(EOFInputStream inputStream,
                             ByteRingBuffer byteRingBuffer,
                             CharRingBuffer charRingBuffer,
                             StringRingBuffer stringRingBuffer,
                             java.util.function.Consumer<StringRingBuffer> onAvailableToRead,
                             TextStreamAsyncOptions textStreamAsyncOptions)

Constructs a new AsyncTextStreamReader instance to read from the given InputStream.

Parameters:

inputStream - An EOFInputStream to read from.

byteRingBuffer - A ByteRingBuffer to write bytes to. May be null. In that case, an implicit ByteRingBuffer is created.

charRingBuffer - A CharRingBuffer to decode chars into. May be null. In that case, an implicit CharRingBuffer is created.

stringRingBuffer - A StringRingBuffer to place lines into. May be null. In that case, an implicit StringRingBuffer is created.

onAvailableToRead - A callback to invoke when there are text lines available to read from the string ring buffer.

textStreamAsyncOptions - TextStreamAsyncOptions that will control all async operations on this instance.

Method Detail

getStringRingBuffer

public StringRingBuffer getStringRingBuffer()

Returns the underlying StringRingBuffer where text lines are placed.

Returns:

The underlying StringRingBuffer.

getAsyncStringRingBufferWatcher

public AsyncRingBufferWatcher<StringRingBuffer> getAsyncStringRingBufferWatcher()

Returns the underlying AsyncRingBufferWatcher that watches the StringRingBuffer.

Returns:

The underlying AsyncRingBufferWatcher, or null if no AsyncRingBufferWatcher was configured.

isEOF

public boolean isEOF()

Checks whether this text stream reader has reached EOF.

Returns:

true iff EOF has been reached or an exception has been encountered.

ready

protected boolean ready()

"ready" predicate that returns true when lines can be read from the string ring buffer.

Overrides:

ready in class AsyncAgent

Returns:

Derived classes should override this method to return true iff it is time to execute AsyncAgent.action().

done

protected boolean done()

"done" predicate that returns true when this async agent wants to quit the current async loop.

Overrides:

done in class AsyncAgent

Returns:

Derived classes should override this method to return true iff it is time for the loop to stop.

action

protected void action()

"action" function that gets executed as part of the apply loop.

Overrides:

action in class AsyncAgent