com.sleepycat.bdb.bind.tuple
Class TupleOutput

java.lang.Object
  |
  +--java.io.OutputStream
        |
        +--com.sleepycat.bdb.util.FastOutputStream
              |
              +--com.sleepycat.bdb.bind.tuple.TupleOutput

public class TupleOutput

extends FastOutputStream

Used by tuple bindings to write tuple data.

This class has many methods that have the same signatures as methods in the DataOutput interface. The reason this class does not implement DataOutput is because it would break the interface contract for those methods because of data format differences.

Signed numbers are stored in the buffer in MSB (most significant byte first) order with their sign bit (high-order bit) inverted to cause negative numbers to be sorted first when comparing values as unsigned byte arrays, as done in a database. Unsigned numbers, including characters, are stored in MSB order with no change to their sign bit.

Strings and character arrays are stored either as a fixed length array of unicode characters, where the length must be known by the application, or as a null-terminated UTF byte array.

Floats and doubles are stored in standard integer-bit representation and are therefore not ordered by numeric value.

Field Summary

Fields inherited from class com.sleepycat.bdb.util.FastOutputStream

DEFAULT_BUMP_SIZE, DEFAULT_INIT_SIZE

Constructor Summary

TupleOutput()
Creates a tuple output object for writing a byte array of tuple data.

TupleOutput(byte[] buffer)
Creates a tuple output object for writing a byte array of tuple data, using a given buffer.

Method Summary

void	writeBoolean(boolean val) Writes a boolean (one byte) unsigned value to the buffer, writing one if the value is true and zero if it is false.
void	writeByte(int val) Writes an signed byte (one byte) value to the buffer.
void	writeBytes(char[] chars) Writes the specified bytes to the buffer, converting each character to an unsigned byte value.
void	writeBytes(String val) Writes the specified bytes to the buffer, converting each character to an unsigned byte value.
void	writeChar(int val) Writes a char (two byte) unsigned value to the buffer.
void	writeChars(char[] chars) Writes the specified characters to the buffer, converting each character to a two byte unsigned value.
void	writeChars(String val) Writes the specified characters to the buffer, converting each character to a two byte unsigned value.
void	writeDouble(double val) Writes an signed double (eight byte) value to the buffer.
void	writeFloat(float val) Writes an signed float (four byte) value to the buffer.
void	writeInt(int val) Writes an signed int (four byte) value to the buffer.
void	writeLong(long val) Writes an signed long (eight byte) value to the buffer.
void	writeShort(int val) Writes an signed short (two byte) value to the buffer.
void	writeString(char[] chars) Writes the specified characters to the buffer, converting each character to UTF format.
void	writeString(String val) Writes the specified characters to the buffer, converting each character to UTF format, and adding a null terminator byte.
void	writeUnsignedByte(int val) Writes an unsigned byte (one byte) value to the buffer.
void	writeUnsignedInt(long val) Writes an unsigned int (four byte) value to the buffer.
void	writeUnsignedShort(int val) Writes an unsigned short (two byte) value to the buffer.

Methods inherited from class com.sleepycat.bdb.util.FastOutputStream

addSize, getBufferBytes, getBufferLength, getBufferOffset, makeSpace, reset, size, toByteArray, toByteArray, toString, toString, write, write, write, writeTo

Methods inherited from class java.io.OutputStream

close, flush

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

TupleOutput

public TupleOutput()

Creates a tuple output object for writing a byte array of tuple data.

TupleOutput

public TupleOutput(byte[] buffer)

Creates a tuple output object for writing a byte array of tuple data, using a given buffer. A new buffer will be allocated only if the number of bytes needed is greater than the length of this buffer. A reference to the byte array will be kept by this object and therefore the byte array should not be modified while this object is in use.

Parameters:

buffer - is the byte array to use as the buffer.

Method Detail

writeBytes

public final void writeBytes(String val)
                      throws IOException

Writes the specified bytes to the buffer, converting each character to an unsigned byte value. Writes values that can be read using TupleInput.readBytes(int). Only characters with values below 0x100 may be written using this method, since the high-order 8 bits of all characters are discarded.

Parameters:

val - is the string containing the values to be written.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeChars

public final void writeChars(String val)
                      throws IOException

Writes the specified characters to the buffer, converting each character to a two byte unsigned value. Writes values that can be read using TupleInput.readChars(int).

Parameters:

val - is the string containing the characters to be written.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeString

public final void writeString(String val)
                       throws IOException

Writes the specified characters to the buffer, converting each character to UTF format, and adding a null terminator byte. Writes values that can be read using TupleInput.readString().

Parameters:

val - is the string containing the characters to be written.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeChar

public final void writeChar(int val)
                     throws IOException

Writes a char (two byte) unsigned value to the buffer. Writes values that can be read using TupleInput.readChar().

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeBoolean

public final void writeBoolean(boolean val)
                        throws IOException

Writes a boolean (one byte) unsigned value to the buffer, writing one if the value is true and zero if it is false. Writes values that can be read using TupleInput.readBoolean().

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeByte

public final void writeByte(int val)
                     throws IOException

Writes an signed byte (one byte) value to the buffer. Writes values that can be read using TupleInput.readByte().

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeShort

public final void writeShort(int val)
                      throws IOException

Writes an signed short (two byte) value to the buffer. Writes values that can be read using TupleInput.readShort().

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeInt

public final void writeInt(int val)
                    throws IOException

Writes an signed int (four byte) value to the buffer. Writes values that can be read using TupleInput.readInt().

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeLong

public final void writeLong(long val)
                     throws IOException

Writes an signed long (eight byte) value to the buffer. Writes values that can be read using TupleInput.readLong().

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeFloat

public final void writeFloat(float val)
                      throws IOException

Writes an signed float (four byte) value to the buffer. Writes values that can be read using TupleInput.readFloat(). Float.floatToIntBits is used to convert the signed float value.

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeDouble

public final void writeDouble(double val)
                       throws IOException

Writes an signed double (eight byte) value to the buffer. Writes values that can be read using TupleInput.readDouble(). Double.doubleToLongBits is used to convert the signed double value.

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeBytes

public final void writeBytes(char[] chars)
                      throws IOException

Writes the specified bytes to the buffer, converting each character to an unsigned byte value. Writes values that can be read using TupleInput.readBytes(int). Only characters with values below 0x100 may be written using this method, since the high-order 8 bits of all characters are discarded.

Parameters:

chars - is the array of values to be written.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeChars

public final void writeChars(char[] chars)
                      throws IOException

Writes the specified characters to the buffer, converting each character to a two byte unsigned value. Writes values that can be read using TupleInput.readChars(int).

Parameters:

chars - is the array of characters to be written.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeString

public final void writeString(char[] chars)
                       throws IOException

Writes the specified characters to the buffer, converting each character to UTF format. Writes values that can be read using TupleInput.readString(int) or TupleInput.readString(char[]).

Parameters:

chars - is the array of characters to be written.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeUnsignedByte

public final void writeUnsignedByte(int val)
                             throws IOException

Writes an unsigned byte (one byte) value to the buffer. Writes values that can be read using TupleInput.readUnsignedByte().

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeUnsignedShort

public final void writeUnsignedShort(int val)
                              throws IOException

Writes an unsigned short (two byte) value to the buffer. Writes values that can be read using TupleInput.readUnsignedShort().

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.

writeUnsignedInt

public final void writeUnsignedInt(long val)
                            throws IOException

Writes an unsigned int (four byte) value to the buffer. Writes values that can be read using TupleInput.readUnsignedInt().

Parameters:

val - is the value to write to the buffer.

Throws:

IOException - is never thrown but is declared for compatibility with {java.io.OutputStream#write}.