MemoryIO.java
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package org.jruby.ext.ffi;
import java.nio.ByteOrder;
/**
* Abstracted memory operations.
* <p>
* This abstracts read/write operations to either a native memory area, or a java
* ByteBuffer.
* </p>
*/
abstract public class MemoryIO {
protected final boolean isDirect;
protected final long address;
protected MemoryIO(boolean direct, long address) {
isDirect = direct;
this.address = address;
}
/**
* Checks if the memory area is NULL.
*
* @return <tt>true</tt> if the memory area is invalid.
*/
public final boolean isNull() {
return address == 0L;
}
/**
* Checks if the memory area is a native memory pointer.
*
* @return <tt>true</tt> if the memory area is a native pointer.
*/
public final boolean isDirect() {
return isDirect;
}
/**
* Gets the native address of this memory region. May return NULL (0) if this is not a direct pointer.
*
* @return A long value containing the native memory address
*/
public final long address() {
return address;
}
abstract public Object array();
abstract public int arrayOffset();
abstract public int arrayLength();
/**
* Gets the {@link ByteOrder} this {@code MemoryIO} instance will read/write
* values to memory in.
*
* @return The current ByteOrder
*/
abstract public ByteOrder order();
/**
* Creates a new MemoryIO pointing to a subset of the memory area of this
* <tt>MemoryIO</tt>.
* @param offset The offset within the existing memory area to start the
* new <tt>MemoryIO</tt> at.
* @return A <tt>MemoryIO</tt> instance.
*/
abstract public MemoryIO slice(long offset);
/**
* Creates a new MemoryIO pointing to a subset of the memory area of this
* <tt>MemoryIO</tt>.
* @param offset The offset within the existing memory area to start the
* new <tt>MemoryIO</tt> at.
* @param size The size of the new slice.
*
* @return A <tt>MemoryIO</tt> instance.
*/
abstract public MemoryIO slice(long offset, long size);
/**
* Duplicates this <tt>MemoryIO</tt>, including its contents.
*
* @return A <tt>MemoryIO</tt> instance.
*/
abstract public MemoryIO dup();
/**
* Creates a view of this memory object as a java NIO byte buffer.
*
* @return A ByteBuffer instance
*/
abstract public java.nio.ByteBuffer asByteBuffer();
/**
* Reads an 8 bit integer value from the memory area.
*
* @param offset The offset within the memory area to read the value.
* @return The 8 bit integer value read from <tt>offset</tt>
*/
abstract public byte getByte(long offset);
/**
* Reads a 16 bit integer value from the memory area.
*
* @param offset The offset within the memory area to read the value.
* @return The 16 bit integer value read from <tt>offset</tt>
*/
abstract public short getShort(long offset);
/**
* Reads a 32 bit integer value from the memory area.
*
* @param offset The offset within the memory area to read the value.
* @return The 32 bit integer value read from <tt>offset</tt>
*/
abstract public int getInt(long offset);
/**
* Reads a 64 bit integer value from the memory area.
*
* @param offset The offset within the memory area to read the value.
* @return The 64 bit integer value read from <tt>offset</tt>
*/
abstract public long getLong(long offset);
/**
* Reads a native long integer value from the memory area.
* <p>
* A native long is 32bits on either ILP32 or LLP64 architectures, and
* 64 bits on an LP64 architecture.
* </p>
* <p>
* 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.
*
* @param offset The offset within the memory area to read the value.
* @return The native long value read from <tt>offset</tt>
*/
abstract public long getNativeLong(long offset);
/**
* Reads a float value from the memory area.
*
* @param offset The offset within the memory area to read the value.
* @return The float value read from <tt>offset</tt>
*/
abstract public float getFloat(long offset);
/**
* Reads a double value from the memory area.
*
* @param offset The offset within the memory area to read the value.
* @return The double value read from <tt>offset</tt>
*/
abstract public double getDouble(long offset);
/**
* Reads a pointer value at the specified offset within the memory area.
*
* @param offset The offset within the memory area to read the value.
* @return A <tt>long</tt> value that represents the address.
*/
abstract public long getAddress(long offset);
/**
* Reads a pointer value at the specified offset within the memory area, and
* wraps it in an abstract memory accessor.
*
* @param offset The offset within the memory area to read the value.
* @return A <tt>DirectMemoryIO</tt> accessor that can be used to access the memory
* pointed to by the address.
*/
abstract public MemoryIO getMemoryIO(long offset);
/**
* Writes an 8 bit integer value to the memory area at the specified offset.
*
* @param offset The offset within the memory area to write the value.
* @param value The 8 bit integer value to write to the memory location.
*/
abstract public void putByte(long offset, byte value);
/**
* Writes a 16 bit integer value to the memory area at the specified offset.
*
* @param offset The offset within the memory area to write the value.
* @param value The 16 bit integer value to write to the memory location.
*/
abstract public void putShort(long offset, short value);
/**
* Writes a 32 bit integer value to the memory area at the specified offset.
*
* @param offset The offset within the memory area to write the value.
* @param value The 32 bit integer value to write to the memory location.
*/
abstract public void putInt(long offset, int value);
/**
* Writes a 64 bit integer value to the memory area at the specified offset.
*
* @param offset The offset within the memory area to write the value.
* @param value The 64 bit integer value to write to the memory location.
*/
abstract public void putLong(long offset, long value);
/**
* Writes a native long integer value to the memory area at the specified offset.
*
* @param offset The offset within the memory area to write the value.
* @param value The native long integer value to write to the memory location.
*/
abstract public void putNativeLong(long offset, long value);
/**
* Writes a 32 bit float value to the memory area at the specified offset.
*
* @param offset The offset within the memory area to write the value.
* @param value The 32 bit float value to write to the memory location.
*/
abstract public void putFloat(long offset, float value);
/**
* Writes a 64 bit float value to the memory area at the specified offset.
*
* @param offset The offset within the memory area to write the value.
* @param value The 64 bit float value to write to the memory location.
*/
abstract public void putDouble(long offset, double value);
/**
* Writes a pointer value to the memory area at the specified offset.
*
* @param offset The offset within the memory area to write the value.
* @param value The pointer value to write to the memory location.
*/
abstract public void putMemoryIO(long offset, MemoryIO value);
/**
* Writes a pointer value to the memory area at the specified offset.
*
* @param offset The offset within the memory area to write the value.
* @param value The pointer value to write to the memory location.
*/
abstract public void putAddress(long offset, long value);
/**
* Reads an array of bytes from the memory area at the specified offset.
*
* @param offset The offset within the memory area to read the bytes.
* @param dst The output byte array to place the data.
* @param off The offset within the byte array to start copying.
* @param len The length of data to read.
*/
abstract public void get(long offset, byte[] dst, int off, int len);
/**
* Writes an array of bytes to the memory area at the specified offset.
*
* @param offset The offset within the memory area to start writing the bytes.
* @param src The byte array to write to the memory area.
* @param off The offset within the byte array to start copying.
* @param len The length of data to write.
*/
abstract public void put(long offset, byte[] src, int off, int len);
/**
* Reads an array of shorts from the memory area at the specified offset.
*
* @param offset The offset within the memory area to read the shorts.
* @param dst The output array to place the data in.
* @param off The offset within the array to start copying.
* @param len The number of shorts to read.
*/
abstract public void get(long offset, short[] dst, int off, int len);
/**
* Writes an array of shorts to the memory area at the specified offset.
*
* @param offset The offset within the memory area to start writing the shorts.
* @param src The array to write to the memory area.
* @param off The offset within the array to start copying.
* @param len The number of shorts to write.
*/
abstract public void put(long offset, short[] src, int off, int len);
/**
* Reads an array of ints from the memory area at the specified offset.
*
* @param offset The offset within the memory area to read the ints.
* @param dst The output array to place the data in.
* @param off The offset within the array to start copying.
* @param len The number of ints to read.
*/
abstract public void get(long offset, int[] dst, int off, int len);
/**
* Writes an array of ints to the memory area at the specified offset.
*
* @param offset The offset within the memory area to start writing the ints.
* @param src The array to write to the memory area.
* @param off The offset within the array to start copying.
* @param len The number of ints to write.
*/
abstract public void put(long offset, int[] src, int off, int len);
/**
* Reads an array of longs from the memory area at the specified offset.
*
* @param offset The offset within the memory area to read the longs.
* @param dst The output array to place the data in.
* @param off The offset within the array to start copying.
* @param len The number of longs to read.
*/
abstract public void get(long offset, long[] dst, int off, int len);
/**
* Writes an array of longs to the memory area at the specified offset.
*
* @param offset The offset within the memory area to start writing the longs.
* @param src The array to write to the memory area.
* @param off The offset within the array to start copying.
* @param len The number of longs to write.
*/
abstract public void put(long offset, long[] src, int off, int len);
/**
* Reads an array of floats from the memory area at the specified offset.
*
* @param offset The offset within the memory area to read the floats.
* @param dst The output array to place the data in.
* @param off The offset within the array to start copying.
* @param len The number of floats to read.
*/
abstract public void get(long offset, float[] dst, int off, int len);
/**
* Writes an array of floats to the memory area at the specified offset.
*
* @param offset The offset within the memory area to start writing the floats.
* @param src The array to write to the memory area.
* @param off The offset within the array to start copying.
* @param len The number of floats to write.
*/
abstract public void put(long offset, float[] src, int off, int len);
/**
* Reads an array of doubles from the memory area at the specified offset.
*
* @param offset The offset within the memory area to read the doubles.
* @param dst The output array to place the data in.
* @param off The offset within the array to start copying.
* @param len The number of doubles to read.
*/
abstract public void get(long offset, double[] dst, int off, int len);
/**
* Writes an array of doubles to the memory area at the specified offset.
*
* @param offset The offset within the memory area to start writing the doubles.
* @param src The array to write to the memory area.
* @param off The offset within the array to start copying.
* @param len The number of doubles to write.
*/
abstract public void put(long offset, double[] src, int off, int len);
/**
* Gets the first index within the memory area of a particular 8 bit value.
*
* @param offset The offset within the memory area to start searching.
* @param value The value to search for.
*
* @return The index of the value, relative to offset.
*/
abstract public int indexOf(long offset, byte value);
/**
* Gets the first index within the memory area of a particular 8 bit value.
*
* @param offset The offset within the memory area to start searching.
* @param value The value to search for.
*
* @return The index of the value, relative to offset.
*/
abstract public int indexOf(long offset, byte value, int maxlen);
/**
* Sets the contents of the memory area to the value.
*
* @param offset The offset within the memory area to start writing.
* @param size The number of bytes to set to the value.
* @param value The value to set each byte to.
*/
abstract public void setMemory(long offset, long size, byte value);
/**
* Reads a zero terminated byte array (e.g. an ascii or utf-8 string)
*
* @param offset The offset within the memory area of the start of the string.
* @return A byte array containing a copy of the data.
*/
abstract public byte[] getZeroTerminatedByteArray(long offset);
/**
* Reads a zero terminated byte array (e.g. an ascii or utf-8 string)
*
* @param offset The offset within the memory area of the start of the string.
* @param maxlen The maximum length to search for the zero byte terminator.
* @return A byte array containing a copy of the data.
*/
abstract public byte[] getZeroTerminatedByteArray(long offset, int maxlen);
/**
* Writes a byte array to memory, and appends a zero terminator
*
* @param offset The offset within the memory area of the start of the string.
* @param bytes The byte array to write to the memory.
* @param off The offset with the byte array to start copying.
* @param maxlen The number of bytes of the byte array to write to the memory area. (not including zero byte)
*/
abstract public void putZeroTerminatedByteArray(long offset, byte[] bytes, int off, int len);
}