net.snowflake.client.jdbc

Class FileBackedOutputStream

java.lang.Object

java.io.OutputStream

net.snowflake.client.jdbc.FileBackedOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

@Beta
public final class FileBackedOutputStream
extends OutputStream

An OutputStream that starts buffering to a byte array, but switches to file buffering once the data reaches a configurable size.

This class is thread-safe.

Adapted by Snowflake to return File object when file is spilled to disk.

Since:

1.0

Author:

Chris Nokleberg

Constructor Summary

Constructors

Constructor and Description
FileBackedOutputStream(int fileThreshold) Creates a new instance that uses the given file threshold, and does not reset the data when the ByteSource returned by asByteSource() is finalized.
FileBackedOutputStream(int fileThreshold, boolean resetOnFinalize) Creates a new instance that uses the given file threshold, and optionally resets the data when the ByteSource returned by asByteSource() is finalized.

Method Summary

Modifier and Type	Method and Description
com.google.common.io.ByteSource	asByteSource()
void	close()
void	flush()
File	getFile()
void	reset() Calls close() if not already closed, and then resets this object back to its initial state, for reuse.
void	write(byte[] b)
void	write(byte[] b, int off, int len)
void	write(int b)

Methods inherited from class java.lang.Object

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

Constructor Detail

FileBackedOutputStream

public FileBackedOutputStream(int fileThreshold)

Creates a new instance that uses the given file threshold, and does not reset the data when the ByteSource returned by asByteSource() is finalized.

Parameters:

fileThreshold - the number of bytes before the stream should switch to buffering to a file

FileBackedOutputStream

public FileBackedOutputStream(int fileThreshold,
                              boolean resetOnFinalize)

Creates a new instance that uses the given file threshold, and optionally resets the data when the ByteSource returned by asByteSource() is finalized.

Parameters:

fileThreshold - the number of bytes before the stream should switch to buffering to a file

resetOnFinalize - if true, the reset() method will be called when the ByteSource returned by asByteSource() is finalized

Method Detail

getFile

public File getFile()

Returns:

the file holding the data (possibly null).

asByteSource

public com.google.common.io.ByteSource asByteSource()

Returns:

a readable ByteSource view of the data that has been written to this stream.

Since:

15.0

reset

public void reset()
           throws IOException

Calls close() if not already closed, and then resets this object back to its initial state, for reuse. If data was buffered to a file, it will be deleted.

Throws:

IOException - if an I/O error occurred while deleting the file buffer

write

public void write(int b)
           throws IOException

Specified by:

write in class OutputStream

Throws:

IOException

write

public void write(byte[] b)
           throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class OutputStream

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException