Package com.clickhouse.client

Class ClickHouseInputStream

java.lang.Object

java.io.InputStream

com.clickhouse.client.ClickHouseInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

ClickHouseLZ4InputStream

public abstract class ClickHouseInputStream
extends InputStream

Extended input stream for read optimization.

Field Summary

Fields

Modifier and Type	Field	Description
static ByteBuffer	EMPTY_BUFFER	Empty and read-only byte buffer.
static byte[]	EMPTY_BYTES	Empty byte array.

Constructor Summary

Constructors

Constructor	Description
ClickHouseInputStream()

Method Summary

Modifier and Type	Method	Description
abstract boolean	isClosed()	Checks if the input stream has been closed or not.
static ClickHouseInputStream	of(InputStream input)	Wraps the given input stream.
static ClickHouseInputStream	of(InputStream input, int bufferSize)	Wraps the given input stream.
static ClickHouseInputStream	of(BlockingQueue<ByteBuffer> queue, int timeout)	Wraps the given blocking queue.
String	readAsciiString()	Reads ascii string from input stream.
String	readAsciiString(int byteLength)	Reads ascii string from input stream.
abstract byte	readByte()	Reads one single byte from the input stream.
byte[]	readBytes(int length)	Reads length bytes from the input stream.
String	readString(int byteLength, Charset charset)	Reads string from the input stream.
String	readString(Charset charset)	Reads string from the input stream.
String	readUnicodeString()	Reads unicode string from input stream.
String	readUnicodeString(int byteLength)	Reads unicode string from input stream.
int	readUnsignedByte()	Reads an unsigned byte from the input stream.
int	readVarInt()	Read varint from input stream.

Methods inherited from class java.io.InputStream

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

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_BYTES

public static final byte[] EMPTY_BYTES

Empty byte array.

EMPTY_BUFFER

public static final ByteBuffer EMPTY_BUFFER

Empty and read-only byte buffer.

Constructor Detail

ClickHouseInputStream

public ClickHouseInputStream()

Method Detail

of

public static ClickHouseInputStream of(BlockingQueue<ByteBuffer> queue,
                                       int timeout)

Wraps the given blocking queue.

Parameters:

queue - non-null blocking queue

timeout - read timeout in milliseconds

Returns:

wrapped input

of

public static ClickHouseInputStream of(InputStream input)

Wraps the given input stream.

Parameters:

input - non-null input stream

Returns:

wrapped input, or the same input if it's instance of ClickHouseInputStream

of

public static ClickHouseInputStream of(InputStream input,
                                       int bufferSize)

Wraps the given input stream.

Parameters:

input - non-null input stream

bufferSize - buffer size which is always greater than zero(usually 4096 or larger)

Returns:

wrapped input, or the same input if it's instance of ClickHouseInputStream

readUnsignedByte

public int readUnsignedByte()
                     throws IOException

Reads an unsigned byte from the input stream. Unlike InputStream.read(), it will throw IOException if the input stream has been closed.

Returns:

unsigned byte

Throws:

IOException - when failed to read value from input stream or reached end of the stream

readByte

public abstract byte readByte()
                       throws IOException

Reads one single byte from the input stream. Unlike InputStream.read(), it will throw IOException if the input stream has been closed. In general, this method should be faster than InputStream.read(), especially when it's an input stream backed by byte[] or ByteBuffer.

Returns:

byte value if present

Throws:

IOException - when failed to read value from input stream or reached end of the stream

readBytes

public byte[] readBytes(int length)
                 throws IOException

Reads length bytes from the input stream. It behaves in the same way as DataInput.readFully(byte[]), and it will throw IOException when the input stream has been closed.

Parameters:

length - number of bytes to read

Returns:

byte array and its length should be length

Throws:

IOException - when failed to read value from input stream, not able to retrieve all bytes, or reached end of the stream

readString

public String readString(Charset charset)
                  throws IOException

Reads string from the input stream. readVarInt() will be called automatically to understand byte length of the string.

Parameters:

charset - charset, null is treated as StandardCharsets.UTF_8

Returns:

non-null string

Throws:

IOException - when failed to read value from input stream, not able to retrieve all bytes, or reached end of the stream

readString

public String readString(int byteLength,
                         Charset charset)
                  throws IOException

Reads string from the input stream. When byteLength is zero or negative number, this method will always return empty string.

Parameters:

byteLength - length in byte

charset - charset, null is treated as StandardCharsets.UTF_8

Returns:

non-null string

Throws:

IOException - when failed to read value from input stream, not able to retrieve all bytes, or reached end of the stream

readAsciiString

public String readAsciiString()
                       throws IOException

Reads ascii string from input stream. readVarInt() will be called automatically to understand byte length of the string.

Returns:

non-null ascii string

Throws:

IOException - when failed to read value from input stream, not able to retrieve all bytes, or reached end of the stream

readAsciiString

public String readAsciiString(int byteLength)
                       throws IOException

Reads ascii string from input stream. Similar as readString(byteLength, StandardCharsets.US_ASCII).

Parameters:

byteLength - length in byte

Returns:

non-null ascii string

Throws:

IOException - when failed to read value from input stream, not able to retrieve all bytes, or reached end of the stream

readUnicodeString

public String readUnicodeString()
                         throws IOException

Reads unicode string from input stream.

Returns:

non-null unicode string

Throws:

IOException - when failed to read value from input stream, not able to retrieve all bytes, or reached end of the stream

readUnicodeString

public String readUnicodeString(int byteLength)
                         throws IOException

Reads unicode string from input stream. Similar as readString(byteLength, null).

Parameters:

byteLength - length in byte

Returns:

non-null unicode string

Throws:

IOException - when failed to read value from input stream, not able to retrieve all bytes, or reached end of the stream

readVarInt

public int readVarInt()
               throws IOException

Read varint from input stream.

Returns:

varint

Throws:

IOException - when failed to read value from input stream or reached end of the stream

isClosed

public abstract boolean isClosed()

Checks if the input stream has been closed or not.

Returns:

true if the input stream has been closed; false otherwise