Module org.freedesktop.cairo

Package org.freedesktop.cairo

Interface ReadFunc

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface ReadFunc

ReadFunc is the type of function which is called when a backend needs to read data from an input stream. It is passed the closure which was specified by the user at the time the read function was registered, the buffer to read the data into and the length of the data in bytes. The read function should throw IOException if all the data was not successfully read.

Since:

1.0

Method Summary

Modifier and Type	Method	Description
byte[]	read(int length)	The function to implement as callback in a read operation from an input stream.
default MemorySegment	toCallback(Arena arena)	Generates an upcall stub, a C function pointer that will call upcall(java.lang.foreign.MemorySegment, java.lang.foreign.MemorySegment, int).
default int	upcall(MemorySegment closure, MemorySegment data, int length)	The callback that is executed by native code.

Method Details

read

byte[] read(int length)
     throws IOException

The function to implement as callback in a read operation from an input stream.

Parameters:

length - the amount of data to read

Returns:

data the data read from the input stream

Throws:

IOException - to be thrown when an error occurs during the read operation

Since:

1.0

upcall

default int upcall(MemorySegment closure,
 MemorySegment data,
 int length)

The callback that is executed by native code. This method marshals the parameters and calls read(int).

Parameters:

closure - ignored

data - the buffer into which to read the data

length - the amount of data to read

Returns:

Status.SUCCESS on success, or Status.READ_ERROR if an IOException occured or 0 bytes (or null) was returned from read().

Since:

1.0

toCallback

default MemorySegment toCallback(Arena arena)

Generates an upcall stub, a C function pointer that will call upcall(java.lang.foreign.MemorySegment, java.lang.foreign.MemorySegment, int).

Parameters:

arena - the arena in which the upcall stub will be allocated

Returns:

the function pointer of the upcall stub

Since:

1.0