Package io.deephaven.util.channel

Class CachedChannelProvider

java.lang.Object

io.deephaven.util.channel.CachedChannelProvider

All Implemented Interfaces:

SeekableChannelsProvider, SafeCloseable, AutoCloseable

public class CachedChannelProvider
extends Object
implements SeekableChannelsProvider

Channel provider that will cache a bounded number of unused channels.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	CachedChannelProvider.ContextHolder

Nested classes/interfaces inherited from interface io.deephaven.util.channel.SeekableChannelsProvider

SeekableChannelsProvider.WriteContext

Method Summary

Modifier and Type	Method	Description
void	close()
static CachedChannelProvider	create(@NotNull SeekableChannelsProvider wrappedProvider, int maximumPooledCount)
boolean	exists(@NotNull URI uri)	Returns true if the given URI exists in the underlying storage.
InputStream	getInputStream(SeekableByteChannel channel, int sizeHint)	Creates an InputStream from the current position of channel from which the caller expects to read sizeHint number of bytes.
final CompletableOutputStream	getOutputStream(@NotNull SeekableChannelsProvider.WriteContext channelContext, @NotNull URI uri, int bufferSizeHint)	Creates a CompletableOutputStream to write to the given URI.
SeekableByteChannel	getReadChannel(@NotNull SeekableChannelContext channelContext, @NotNull URI uri)
boolean	isCompatibleWith(@NotNull SeekableChannelContext channelContext)	Check if the given context is compatible with this provider for reading.
Stream<URI>	list(@NotNull URI directory)	Returns a stream of URIs, the elements of which are the entries in the directory.
SeekableChannelContext	makeReadContext()	Create a new SeekableChannelContext object for creating read channels via this provider.
SeekableChannelContext	makeSingleUseReadContext()	Create a new "single-use" SeekableChannelContext object for creating read channels via this provider.
SeekableChannelsProvider.WriteContext	makeWriteContext()	Create a new context object for creating output streams via this provider.
Stream<URI>	walk(@NotNull URI directory)	Returns a stream of URIs, the elements of which are all the files in the file tree rooted at the given starting directory.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.deephaven.util.channel.SeekableChannelsProvider

getReadChannel

Method Details

create

public static CachedChannelProvider create(@NotNull
 @NotNull SeekableChannelsProvider wrappedProvider,
 int maximumPooledCount)

makeReadContext

public SeekableChannelContext makeReadContext()

Description copied from interface: SeekableChannelsProvider

Create a new SeekableChannelContext object for creating read channels via this provider.

Specified by:

makeReadContext in interface SeekableChannelsProvider

makeSingleUseReadContext

public SeekableChannelContext makeSingleUseReadContext()

Description copied from interface: SeekableChannelsProvider

Create a new "single-use" SeekableChannelContext object for creating read channels via this provider. This is meant for contexts that have a short lifecycle and expect to read a small amount from a read channel.

Specified by:

makeSingleUseReadContext in interface SeekableChannelsProvider

makeWriteContext

public SeekableChannelsProvider.WriteContext makeWriteContext()

Description copied from interface: SeekableChannelsProvider

Create a new context object for creating output streams via this provider.

Specified by:

makeWriteContext in interface SeekableChannelsProvider

isCompatibleWith

public boolean isCompatibleWith(@NotNull
 @NotNull SeekableChannelContext channelContext)

Description copied from interface: SeekableChannelsProvider

Check if the given context is compatible with this provider for reading. Useful to test if we can use provided channelContext object for creating read channels with this provider.

Specified by:

isCompatibleWith in interface SeekableChannelsProvider

exists

public boolean exists(@NotNull
 @NotNull URI uri)

Description copied from interface: SeekableChannelsProvider

Returns true if the given URI exists in the underlying storage.

Specified by:

exists in interface SeekableChannelsProvider

Parameters:

uri - the URI to check

Returns:

true if the URI exists

getReadChannel

public SeekableByteChannel getReadChannel(@NotNull
 @NotNull SeekableChannelContext channelContext,
 @NotNull
 @NotNull URI uri)
                                   throws IOException

Specified by:

getReadChannel in interface SeekableChannelsProvider

Throws:

IOException

getInputStream

public InputStream getInputStream(SeekableByteChannel channel,
 int sizeHint)
                           throws IOException

Description copied from interface: SeekableChannelsProvider

Creates an InputStream from the current position of channel from which the caller expects to read sizeHint number of bytes. Closing the resulting input stream does not close the channel. The InputStream will be buffered; either explicitly in the case where the implementation uses an unbuffered SeekableChannelsProvider.getReadChannel(SeekableChannelContext, URI), or implicitly when the implementation uses a buffered SeekableChannelsProvider.getReadChannel(SeekableChannelContext, URI). channel must have been created by this provider. The caller can't assume the position of channel after consuming the InputStream. For use-cases that require the channel's position to be incremented the exact amount the InputStream has been consumed, use SeekableChannelsProvider.channelPositionInputStream(SeekableChannelsProvider, SeekableByteChannel, int).

Specified by:

getInputStream in interface SeekableChannelsProvider

Parameters:

channel - the channel

sizeHint - the number of bytes the caller expects to read from the input stream

Returns:

the input stream

Throws:

IOException - if an IO exception occurs

getOutputStream

public final CompletableOutputStream getOutputStream(@NotNull
 @NotNull SeekableChannelsProvider.WriteContext channelContext,
 @NotNull
 @NotNull URI uri,
 int bufferSizeHint)
                                              throws IOException

Description copied from interface: SeekableChannelsProvider

Creates a CompletableOutputStream to write to the given URI.

Specified by:

getOutputStream in interface SeekableChannelsProvider

Parameters:

channelContext - the channel context to use for creating the output stream

uri - the URI to write to

bufferSizeHint - the number of bytes the caller expects to buffer before flushing

Returns:

the output stream

Throws:

IOException - if an IO exception occurs

See Also:

• CompletableOutputStream

list

public Stream<URI> list(@NotNull
 @NotNull URI directory)
                 throws IOException

Description copied from interface: SeekableChannelsProvider

Returns a stream of URIs, the elements of which are the entries in the directory. The listing is non-recursive. The URIs supplied by the stream will not have any unnecessary slashes or path separators. Also, the URIs will be file URIs (not ending with "/") irrespective of whether the URI corresponds to a file or a directory. The caller should manage file vs. directory handling in the processor. The caller is also responsible for closing the stream, preferably using a try-with-resources block.

Specified by:

list in interface SeekableChannelsProvider

Parameters:

directory - the URI of the directory to list

Returns:

The Stream of URIs

Throws:

IOException

walk

public Stream<URI> walk(@NotNull
 @NotNull URI directory)
                 throws IOException

Description copied from interface: SeekableChannelsProvider

Returns a stream of URIs, the elements of which are all the files in the file tree rooted at the given starting directory. The URIs supplied by the stream will not have any unnecessary slashes or path separators. Also, the URIs will be file URIs (not ending with "/") irrespective of whether the URI corresponds to a file or a directory. The caller should manage file vs. directory handling in the processor. The caller is also responsible for closing the stream, preferably using a try-with-resources block.

Specified by:

walk in interface SeekableChannelsProvider

Parameters:

directory - the URI of the directory to walk

Returns:

The Stream of URIs

Throws:

IOException

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface SafeCloseable