com.oracle.graal.compiler.common.util

Class UnsafeArrayTypeWriter

java.lang.Object

com.oracle.graal.compiler.common.util.UnsafeArrayTypeWriter

All Implemented Interfaces:

TypeWriter

Direct Known Subclasses:

AlignedUnsafeArrayTypeWriter, UnalignedUnsafeArrayTypeWriter

public abstract class UnsafeArrayTypeWriter
extends Object
implements TypeWriter

Provides low-level sequential write access to a byte[] array for signed and unsigned values of size 1, 2, 4, and 8 bytes. To avoid copying an array when the buffer size is no longer sufficient, the buffer is split into chunks of a fixed size. The flag supportsUnalignedMemoryAccess must be set according to the capabilities of the hardware architecture: the value true allows more efficient memory access on architectures that support unaligned memory accesses; the value false is the safe fallback that works on every hardware.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	UnsafeArrayTypeWriter.Chunk

Field Summary

Fields

Modifier and Type	Field and Description
protected UnsafeArrayTypeWriter.Chunk	firstChunk
private static int	MAX_CHUNK_LENGTH
private static int	MIN_CHUNK_LENGTH
protected int	totalSize
protected UnsafeArrayTypeWriter.Chunk	writeChunk

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	UnsafeArrayTypeWriter()

Method Summary

Modifier and Type	Method and Description
static UnsafeArrayTypeWriter	create(boolean supportsUnalignedMemoryAccess)
long	getBytesWritten() Returns the number of bytes that have been written, i.e., the byte index of the next byte to be written.
void	putS1(long value) Writes a signed 1 byte value.
void	putU1(long value) Writes an unsigned 1 byte value.
void	putU2(long value) Writes an unsigned 2 byte value.
void	putU4(long value) Writes an unsigned 4 byte value.
byte[]	toArray(byte[] result) Copies the buffer into the provided byte[] array of length getBytesWritten().
protected long	writeOffset(int writeBytes)

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.oracle.graal.compiler.common.util.TypeWriter

putS2, putS4, putS8, putSV, putUV

Field Detail

MIN_CHUNK_LENGTH

private static final int MIN_CHUNK_LENGTH

See Also:

Constant Field Values

MAX_CHUNK_LENGTH

private static final int MAX_CHUNK_LENGTH

See Also:

Constant Field Values

firstChunk

protected final UnsafeArrayTypeWriter.Chunk firstChunk

writeChunk

protected UnsafeArrayTypeWriter.Chunk writeChunk

totalSize

protected int totalSize

Constructor Detail

UnsafeArrayTypeWriter

protected UnsafeArrayTypeWriter()

Method Detail

create

public static UnsafeArrayTypeWriter create(boolean supportsUnalignedMemoryAccess)

getBytesWritten

public final long getBytesWritten()

Description copied from interface: TypeWriter

Returns the number of bytes that have been written, i.e., the byte index of the next byte to be written.

Specified by:

getBytesWritten in interface TypeWriter

toArray

public final byte[] toArray(byte[] result)

Copies the buffer into the provided byte[] array of length getBytesWritten().

putS1

public final void putS1(long value)

Description copied from interface: TypeWriter

Writes a signed 1 byte value.

Specified by:

putS1 in interface TypeWriter

putU1

public final void putU1(long value)

Description copied from interface: TypeWriter

Writes an unsigned 1 byte value.

Specified by:

putU1 in interface TypeWriter

putU2

public final void putU2(long value)

Description copied from interface: TypeWriter

Writes an unsigned 2 byte value.

Specified by:

putU2 in interface TypeWriter

putU4

public final void putU4(long value)

Description copied from interface: TypeWriter

Writes an unsigned 4 byte value.

Specified by:

putU4 in interface TypeWriter

writeOffset

protected long writeOffset(int writeBytes)