Class VBlob

java.lang.Object

app.photofox.vipsffm.VBlob

public final class VBlob
extends Object

Represents a VipsBlob, which is backed by a contiguous area of off-heap memory

Its constructor is package private to prevent leaking MemorySegments in to the vips-ffm API

Use its static helper methods to create new blobs

Method Summary

Modifier and Type	Method	Description
ByteBuffer	asArenaScopedByteBuffer()	ByteBuffer representation of the data in this blob
ByteBuffer	asClonedByteBuffer()	ByteBuffer representation of the data in this blob
long	byteSize()	Size of the data in this blob
byte[]	getBytes()	byte[] representation of the data in this VipsBlob
MemorySegment	getUnsafeDataAddress()	Not recommended for use, use asArenaScopedByteBuffer() or asClonedByteBuffer() instead
MemorySegment	getUnsafeStructAddress()	Gets the raw MemorySegment (C pointer) for this VipsBlob struct
static VBlob	newFromBytes(Arena arena, byte[] bytes)	Creates a new VBlob from a fixed array of bytes

Methods inherited from class java.lang.Object

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

Method Details

newFromBytes

public static VBlob newFromBytes(Arena arena,
 byte[] bytes)
                          throws VipsError

Creates a new VBlob from a fixed array of bytes

This must copy the data - it's generally more efficient to use VImage.newFromFile(java.lang.foreign.Arena, java.lang.String, app.photofox.vipsffm.VipsOption...), VImage.newFromSource(java.lang.foreign.Arena, app.photofox.vipsffm.VSource, java.lang.String, app.photofox.vipsffm.VipsOption...), and friends

Parameters:

arena - An arena constraining the lifetime of this blob

bytes - The bytes to wrap

Throws:

VipsError

getUnsafeStructAddress

public MemorySegment getUnsafeStructAddress()
                                     throws VipsError

Gets the raw MemorySegment (C pointer) for this VipsBlob struct

You might want the data address instead getUnsafeDataAddress()

The memory address' lifetime is bound to the scope of the arena

Usage of the memory address is strongly discouraged, but it is available if some functionality is missing and you need to use it with VipsHelper

Throws:

VipsError

getUnsafeDataAddress

public MemorySegment getUnsafeDataAddress()
                                   throws VipsError

Not recommended for use, use asArenaScopedByteBuffer() or asClonedByteBuffer() instead

Gets the raw MemorySegment (C pointer) for the data in this blob

Sliced to the length of the data, which isn't always null terminated

Throws:

VipsError

byteSize

public long byteSize()

Size of the data in this blob

asArenaScopedByteBuffer

public ByteBuffer asArenaScopedByteBuffer()

ByteBuffer representation of the data in this blob

Mapped to native memory via DirectByteBuffer, hence does not make a copy, so the data has the same data lifetime as arena

Note that because this is backed by native memory, you cannot use the ByteBuffer.array() method on the resulting buffer. Use asClonedByteBuffer() or getBytes() if you're looking for a full copy of the data.

asClonedByteBuffer

public ByteBuffer asClonedByteBuffer()

ByteBuffer representation of the data in this blob

A full copy of the data is taken, so that its contents are not coupled to the scope of arena

getBytes

public byte[] getBytes()

byte[] representation of the data in this VipsBlob

Useful if you're working with metadata stored on an image, like an ICC profile

Note that a full copy of the data is taken