Package org.jruby.ext.ffi

Class MemoryIO

java.lang.Object

org.jruby.ext.ffi.MemoryIO

Direct Known Subclasses:

ArrayMemoryIO, InvalidMemoryIO, SwappedMemoryIO

public abstract class MemoryIO
extends Object

Abstracted memory operations.

This abstracts read/write operations to either a native memory area, or a java ByteBuffer.

Field Summary

Fields

Modifier and Type	Field	Description
protected final long	address
protected final boolean	isDirect

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	MemoryIO(boolean direct, long address)

Method Summary

Modifier and Type	Method	Description
final long	address()	Gets the native address of this memory region.
abstract Object	array()
abstract int	arrayLength()
abstract int	arrayOffset()
abstract ByteBuffer	asByteBuffer()	Creates a view of this memory object as a java NIO byte buffer.
abstract MemoryIO	dup()	Duplicates this MemoryIO, including its contents.
abstract void	get(long offset, byte[] dst, int off, int len)	Reads an array of bytes from the memory area at the specified offset.
abstract void	get(long offset, double[] dst, int off, int len)	Reads an array of doubles from the memory area at the specified offset.
abstract void	get(long offset, float[] dst, int off, int len)	Reads an array of floats from the memory area at the specified offset.
abstract void	get(long offset, int[] dst, int off, int len)	Reads an array of ints from the memory area at the specified offset.
abstract void	get(long offset, long[] dst, int off, int len)	Reads an array of longs from the memory area at the specified offset.
abstract void	get(long offset, short[] dst, int off, int len)	Reads an array of shorts from the memory area at the specified offset.
abstract long	getAddress(long offset)	Reads a pointer value at the specified offset within the memory area.
abstract byte	getByte(long offset)	Reads an 8 bit integer value from the memory area.
abstract double	getDouble(long offset)	Reads a double value from the memory area.
abstract float	getFloat(long offset)	Reads a float value from the memory area.
abstract int	getInt(long offset)	Reads a 32 bit integer value from the memory area.
abstract long	getLong(long offset)	Reads a 64 bit integer value from the memory area.
abstract MemoryIO	getMemoryIO(long offset)	Reads a pointer value at the specified offset within the memory area, and wraps it in an abstract memory accessor.
abstract long	getNativeLong(long offset)	Reads a native long integer value from the memory area.
abstract short	getShort(long offset)	Reads a 16 bit integer value from the memory area.
abstract byte[]	getZeroTerminatedByteArray(long offset)	Reads a zero terminated byte array (e.g.
abstract byte[]	getZeroTerminatedByteArray(long offset, int maxlen)	Reads a zero terminated byte array (e.g.
abstract int	indexOf(long offset, byte value)	Gets the first index within the memory area of a particular 8 bit value.
abstract int	indexOf(long offset, byte value, int maxlen)	Gets the first index within the memory area of a particular 8 bit value.
final boolean	isDirect()	Checks if the memory area is a native memory pointer.
final boolean	isNull()	Checks if the memory area is NULL.
abstract ByteOrder	order()	Gets the ByteOrder this MemoryIO instance will read/write values to memory in.
abstract void	put(long offset, byte[] src, int off, int len)	Writes an array of bytes to the memory area at the specified offset.
abstract void	put(long offset, double[] src, int off, int len)	Writes an array of doubles to the memory area at the specified offset.
abstract void	put(long offset, float[] src, int off, int len)	Writes an array of floats to the memory area at the specified offset.
abstract void	put(long offset, int[] src, int off, int len)	Writes an array of ints to the memory area at the specified offset.
abstract void	put(long offset, long[] src, int off, int len)	Writes an array of longs to the memory area at the specified offset.
abstract void	put(long offset, short[] src, int off, int len)	Writes an array of shorts to the memory area at the specified offset.
abstract void	putAddress(long offset, long value)	Writes a pointer value to the memory area at the specified offset.
abstract void	putByte(long offset, byte value)	Writes an 8 bit integer value to the memory area at the specified offset.
abstract void	putDouble(long offset, double value)	Writes a 64 bit float value to the memory area at the specified offset.
abstract void	putFloat(long offset, float value)	Writes a 32 bit float value to the memory area at the specified offset.
abstract void	putInt(long offset, int value)	Writes a 32 bit integer value to the memory area at the specified offset.
abstract void	putLong(long offset, long value)	Writes a 64 bit integer value to the memory area at the specified offset.
abstract void	putMemoryIO(long offset, MemoryIO value)	Writes a pointer value to the memory area at the specified offset.
abstract void	putNativeLong(long offset, long value)	Writes a native long integer value to the memory area at the specified offset.
abstract void	putShort(long offset, short value)	Writes a 16 bit integer value to the memory area at the specified offset.
abstract void	putZeroTerminatedByteArray(long offset, byte[] bytes, int off, int len)	Writes a byte array to memory, and appends a zero terminator
abstract void	setMemory(long offset, long size, byte value)	Sets the contents of the memory area to the value.
abstract MemoryIO	slice(long offset)	Creates a new MemoryIO pointing to a subset of the memory area of this MemoryIO.
abstract MemoryIO	slice(long offset, long size)	Creates a new MemoryIO pointing to a subset of the memory area of this MemoryIO.

Methods inherited from class java.lang.Object

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

Field Details

isDirect

protected final boolean isDirect

address

protected final long address

Constructor Details

MemoryIO

protected MemoryIO(boolean direct,
 long address)

Method Details

isNull

public final boolean isNull()

Checks if the memory area is NULL.

Returns:

true if the memory area is invalid.

isDirect

public final boolean isDirect()

Checks if the memory area is a native memory pointer.

Returns:

true if the memory area is a native pointer.

address

public final long address()

Gets the native address of this memory region. May return NULL (0) if this is not a direct pointer.

Returns:

A long value containing the native memory address

array

public abstract Object array()

arrayOffset

public abstract int arrayOffset()

arrayLength

public abstract int arrayLength()

order

public abstract ByteOrder order()

Gets the ByteOrder this MemoryIO instance will read/write values to memory in.

Returns:

The current ByteOrder

slice

public abstract MemoryIO slice(long offset)

Creates a new MemoryIO pointing to a subset of the memory area of this MemoryIO.

Parameters:

offset - The offset within the existing memory area to start the new MemoryIO at.

Returns:

A MemoryIO instance.

slice

public abstract MemoryIO slice(long offset,
 long size)

Creates a new MemoryIO pointing to a subset of the memory area of this MemoryIO.

Parameters:

offset - The offset within the existing memory area to start the new MemoryIO at.

size - The size of the new slice.

Returns:

A MemoryIO instance.

dup

public abstract MemoryIO dup()

Duplicates this MemoryIO, including its contents.

Returns:

A MemoryIO instance.

asByteBuffer

public abstract ByteBuffer asByteBuffer()

Creates a view of this memory object as a java NIO byte buffer.

Returns:

A ByteBuffer instance

getByte

public abstract byte getByte(long offset)

Reads an 8 bit integer value from the memory area.

Parameters:

offset - The offset within the memory area to read the value.

Returns:

The 8 bit integer value read from offset

getShort

public abstract short getShort(long offset)

Reads a 16 bit integer value from the memory area.

Parameters:

offset - The offset within the memory area to read the value.

Returns:

The 16 bit integer value read from offset

getInt

public abstract int getInt(long offset)

Reads a 32 bit integer value from the memory area.

Parameters:

offset - The offset within the memory area to read the value.

Returns:

The 32 bit integer value read from offset

getLong

public abstract long getLong(long offset)

Reads a 64 bit integer value from the memory area.

Parameters:

offset - The offset within the memory area to read the value.

Returns:

The 64 bit integer value read from offset

getNativeLong

public abstract long getNativeLong(long offset)

Reads a native long integer value from the memory area.

A native long is 32bits on either ILP32 or LLP64 architectures, and 64 bits on an LP64 architecture.

This means that it will always read a 32bit value on Windows, but on Unix systems such as MacOS or Linux, it will read a 32bit value on 32bit systems, and a 64bit value on 64bit systems.

Parameters:

offset - The offset within the memory area to read the value.

Returns:

The native long value read from offset

getFloat

public abstract float getFloat(long offset)

Reads a float value from the memory area.

Parameters:

offset - The offset within the memory area to read the value.

Returns:

The float value read from offset

getDouble

public abstract double getDouble(long offset)

Reads a double value from the memory area.

Parameters:

offset - The offset within the memory area to read the value.

Returns:

The double value read from offset

getAddress

public abstract long getAddress(long offset)

Reads a pointer value at the specified offset within the memory area.

Parameters:

offset - The offset within the memory area to read the value.

Returns:

A long value that represents the address.

getMemoryIO

public abstract MemoryIO getMemoryIO(long offset)

Reads a pointer value at the specified offset within the memory area, and wraps it in an abstract memory accessor.

Parameters:

offset - The offset within the memory area to read the value.

Returns:

A DirectMemoryIO accessor that can be used to access the memory pointed to by the address.

putByte

public abstract void putByte(long offset,
 byte value)

Writes an 8 bit integer value to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to write the value.

value - The 8 bit integer value to write to the memory location.

putShort

public abstract void putShort(long offset,
 short value)

Writes a 16 bit integer value to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to write the value.

value - The 16 bit integer value to write to the memory location.

putInt

public abstract void putInt(long offset,
 int value)

Writes a 32 bit integer value to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to write the value.

value - The 32 bit integer value to write to the memory location.

putLong

public abstract void putLong(long offset,
 long value)

Writes a 64 bit integer value to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to write the value.

value - The 64 bit integer value to write to the memory location.

putNativeLong

public abstract void putNativeLong(long offset,
 long value)

Writes a native long integer value to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to write the value.

value - The native long integer value to write to the memory location.

putFloat

public abstract void putFloat(long offset,
 float value)

Writes a 32 bit float value to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to write the value.

value - The 32 bit float value to write to the memory location.

putDouble

public abstract void putDouble(long offset,
 double value)

Writes a 64 bit float value to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to write the value.

value - The 64 bit float value to write to the memory location.

putMemoryIO

public abstract void putMemoryIO(long offset,
 MemoryIO value)

Writes a pointer value to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to write the value.

value - The pointer value to write to the memory location.

putAddress

public abstract void putAddress(long offset,
 long value)

Writes a pointer value to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to write the value.

value - The pointer value to write to the memory location.

get

public abstract void get(long offset,
 byte[] dst,
 int off,
 int len)

Reads an array of bytes from the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to read the bytes.

dst - The output byte array to place the data.

off - The offset within the byte array to start copying.

len - The length of data to read.

put

public abstract void put(long offset,
 byte[] src,
 int off,
 int len)

Writes an array of bytes to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to start writing the bytes.

src - The byte array to write to the memory area.

off - The offset within the byte array to start copying.

len - The length of data to write.

get

public abstract void get(long offset,
 short[] dst,
 int off,
 int len)

Reads an array of shorts from the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to read the shorts.

dst - The output array to place the data in.

off - The offset within the array to start copying.

len - The number of shorts to read.

put

public abstract void put(long offset,
 short[] src,
 int off,
 int len)

Writes an array of shorts to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to start writing the shorts.

src - The array to write to the memory area.

off - The offset within the array to start copying.

len - The number of shorts to write.

get

public abstract void get(long offset,
 int[] dst,
 int off,
 int len)

Reads an array of ints from the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to read the ints.

dst - The output array to place the data in.

off - The offset within the array to start copying.

len - The number of ints to read.

put

public abstract void put(long offset,
 int[] src,
 int off,
 int len)

Writes an array of ints to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to start writing the ints.

src - The array to write to the memory area.

off - The offset within the array to start copying.

len - The number of ints to write.

get

public abstract void get(long offset,
 long[] dst,
 int off,
 int len)

Reads an array of longs from the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to read the longs.

dst - The output array to place the data in.

off - The offset within the array to start copying.

len - The number of longs to read.

put

public abstract void put(long offset,
 long[] src,
 int off,
 int len)

Writes an array of longs to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to start writing the longs.

src - The array to write to the memory area.

off - The offset within the array to start copying.

len - The number of longs to write.

get

public abstract void get(long offset,
 float[] dst,
 int off,
 int len)

Reads an array of floats from the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to read the floats.

dst - The output array to place the data in.

off - The offset within the array to start copying.

len - The number of floats to read.

put

public abstract void put(long offset,
 float[] src,
 int off,
 int len)

Writes an array of floats to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to start writing the floats.

src - The array to write to the memory area.

off - The offset within the array to start copying.

len - The number of floats to write.

get

public abstract void get(long offset,
 double[] dst,
 int off,
 int len)

Reads an array of doubles from the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to read the doubles.

dst - The output array to place the data in.

off - The offset within the array to start copying.

len - The number of doubles to read.

put

public abstract void put(long offset,
 double[] src,
 int off,
 int len)

Writes an array of doubles to the memory area at the specified offset.

Parameters:

offset - The offset within the memory area to start writing the doubles.

src - The array to write to the memory area.

off - The offset within the array to start copying.

len - The number of doubles to write.

indexOf

public abstract int indexOf(long offset,
 byte value)

Gets the first index within the memory area of a particular 8 bit value.

Parameters:

offset - The offset within the memory area to start searching.

value - The value to search for.

Returns:

The index of the value, relative to offset.

indexOf

public abstract int indexOf(long offset,
 byte value,
 int maxlen)

Gets the first index within the memory area of a particular 8 bit value.

Parameters:

offset - The offset within the memory area to start searching.

value - The value to search for.

Returns:

The index of the value, relative to offset.

setMemory

public abstract void setMemory(long offset,
 long size,
 byte value)

Sets the contents of the memory area to the value.

Parameters:

offset - The offset within the memory area to start writing.

size - The number of bytes to set to the value.

value - The value to set each byte to.

getZeroTerminatedByteArray

public abstract byte[] getZeroTerminatedByteArray(long offset)

Reads a zero terminated byte array (e.g. an ascii or utf-8 string)

Parameters:

offset - The offset within the memory area of the start of the string.

Returns:

A byte array containing a copy of the data.

getZeroTerminatedByteArray

public abstract byte[] getZeroTerminatedByteArray(long offset,
 int maxlen)

Reads a zero terminated byte array (e.g. an ascii or utf-8 string)

Parameters:

offset - The offset within the memory area of the start of the string.

maxlen - The maximum length to search for the zero byte terminator.

Returns:

A byte array containing a copy of the data.

putZeroTerminatedByteArray

public abstract void putZeroTerminatedByteArray(long offset,
 byte[] bytes,
 int off,
 int len)

Writes a byte array to memory, and appends a zero terminator

Parameters:

offset - The offset within the memory area of the start of the string.

bytes - The byte array to write to the memory.

off - The offset with the byte array to start copying.

len - The number of bytes of the byte array to write to the memory area. (not including zero byte)