Package org.gnome.gio

Class MemoryOutputStream

java.lang.Object

org.javagi.base.ProxyInstance

org.gnome.gobject.TypeInstance

org.gnome.gobject.GObject

org.gnome.gio.OutputStream

org.gnome.gio.MemoryOutputStream

All Implemented Interfaces:

AutoCloseable, PollableOutputStream, Seekable, Proxy, AutoCloseable

@Generated("io.github.jwharm.JavaGI")
public class MemoryOutputStream
extends OutputStream
implements PollableOutputStream, Seekable

GMemoryOutputStream is a class for using arbitrary memory chunks as output for GIO streaming output operations.

As of GLib 2.34, GMemoryOutputStream trivially implements PollableOutputStream: it always polls as ready.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MemoryOutputStream.Builder<B extends MemoryOutputStream.Builder<B>>	Inner class implementing a builder pattern to construct a GObject with properties.
static class	MemoryOutputStream.MemoryOutputStreamClass

Nested classes/interfaces inherited from class org.gnome.gio.OutputStream

OutputStream.OutputStream$Impl, OutputStream.OutputStreamClass

Nested classes/interfaces inherited from class org.gnome.gobject.GObject

GObject.NotifyCallback, GObject.ObjectClass

Nested classes/interfaces inherited from interface org.gnome.gio.PollableOutputStream

PollableOutputStream.PollableOutputStream$Impl, PollableOutputStream.PollableOutputStreamInterface

Nested classes/interfaces inherited from interface org.gnome.gio.Seekable

Seekable.Seekable$Impl, Seekable.SeekableIface

Constructor Summary

Constructors

Constructor	Description
MemoryOutputStream()	Creates a new MemoryOutputStream.
MemoryOutputStream(@Nullable MemorySegment data, long size, @Nullable ReallocFunc reallocFunction)	Creates a new GMemoryOutputStream.
MemoryOutputStream(MemorySegment address)	Create a MemoryOutputStream proxy instance for the provided memory address.

Method Summary

Modifier and Type	Method	Description
protected MemoryOutputStream	asParent()	Returns this instance as if it were its parent type.
static MemoryOutputStream.Builder<? extends MemoryOutputStream.Builder>	builder()	A MemoryOutputStream.Builder object constructs a MemoryOutputStream with the specified properties.
@Nullable MemorySegment	getData()	Gets any loaded data from the ostream.
long	getDataSize()	Returns the number of bytes from the start up to including the last byte written in the stream that has not been truncated away.
static MemoryLayout	getMemoryLayout()	The memory layout of the native struct.
long	getSize()	Gets the size of the currently allocated data area (available from g_memory_output_stream_get_data()).
static @Nullable Type	getType()	Get the GType of the MemoryOutputStream class
static OutputStream	resizable()	Creates a new GMemoryOutputStream, using g_realloc() and g_free() for memory allocation.
byte[]	stealAsBytes()	Returns data from the this MemoryOutputStream as a GBytes.
@Nullable MemorySegment	stealData()	Gets any loaded data from the ostream. Ownership of the data is transferred to the caller; when no longer needed it must be freed using the free function set in ostream's GMemoryOutputStream:destroy-function property.

Methods inherited from class org.gnome.gio.OutputStream

clearPending, close, closeAsync, closeFinish, closeFn, flush, flushAsync, flushFinish, hasPending, isClosed, isClosing, printf, setPending, splice, splice, spliceAsync, spliceAsync, spliceFinish, write, writeAll, writeAllAsync, writeAllFinish, writeAsync, writeBytes, writeBytesAsync, writeBytesFinish, writeFinish, writev, writevAll, writevAllAsync, writevAllFinish, writevAsync, writevFinish

Methods inherited from class org.gnome.gobject.GObject

addToggleRef, addWeakPointer, bindProperty, bindProperty, bindProperty, bindPropertyFull, bindPropertyFull, bindPropertyWithClosures, bindPropertyWithClosures, compatControl, connect, connect, connect, constructed, disconnect, dispatchPropertiesChanged, dispose, dupData, dupQdata, emit, emitNotify, finalize_, forceFloating, freezeNotify, get, getData, getProperty, getProperty, getProperty, getQdata, getv, interfaceFindProperty, interfaceInstallProperty, interfaceListProperties, isFloating, newInstance, newInstance, newv, notify, notify, notifyByPspec, onNotify, ref, refSink, removeToggleRef, removeWeakPointer, replaceData, replaceQdata, runDispose, set, setData, setDataFull, setProperty, setProperty, setProperty, setQdata, setQdataFull, setv, stealData, stealQdata, takeRef, thawNotify, unref, watchClosure, weakRef, weakUnref, withProperties

Methods inherited from class org.gnome.gobject.TypeInstance

callParent, callParent, cast, getPrivate, readGClass, writeGClass

Methods inherited from class org.javagi.base.ProxyInstance

equals, handle, hashCode

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.javagi.gio.AutoCloseable

close

Methods inherited from interface org.gnome.gio.PollableOutputStream

canPoll, createSource, isWritable, writeNonblocking, writevNonblocking

Methods inherited from interface org.javagi.base.Proxy

handle

Methods inherited from interface org.gnome.gio.Seekable

canSeek, canTruncate, seek, tell, truncate

Constructor Details

MemoryOutputStream

public MemoryOutputStream(MemorySegment address)

Create a MemoryOutputStream proxy instance for the provided memory address.

Parameters:

address - the memory address of the native object

MemoryOutputStream

public MemoryOutputStream(@Nullable MemorySegment data,
 long size,
 @Nullable ReallocFunc reallocFunction)

Creates a new GMemoryOutputStream.

In most cases this is not the function you want. See g_memory_output_stream_new_resizable() instead.

If data is non-null, the stream will use that for its internal storage.

If reallocFn is non-null, it will be used for resizing the internal storage when necessary and the stream will be considered resizable. In that case, the stream will start out being (conceptually) empty. size is used only as a hint for how big data is. Specifically, seeking to the end of a newly-created stream will seek to zero, not size. Seeking past the end of the stream and then writing will introduce a zero-filled gap.

If reallocFn is null then the stream is fixed-sized. Seeking to the end will seek to size exactly. Writing past the end will give an 'out of space' error. Attempting to seek past the end will fail. Unlike the resizable case, seeking to an offset within the stream and writing will preserve the bytes passed in as data before that point and will return them as part of g_memory_output_stream_steal_data(). If you intend to seek you should probably therefore ensure that data is properly initialised.

It is probably only meaningful to provide data and size in the case that you want a fixed-sized stream. Put another way: if reallocFn is non-null then it makes most sense to give data as null and size as 0 (allowing GMemoryOutputStream to do the initial allocation for itself).

// a stream that can grow
 stream = g_memory_output_stream_new (NULL, 0, realloc, free);

 // another stream that can grow
 stream2 = g_memory_output_stream_new (NULL, 0, g_realloc, g_free);

 // a fixed-size stream
 data = malloc (200);
 stream3 = g_memory_output_stream_new (data, 200, NULL, free);
 

Parameters:

data - pointer to a chunk of memory to use, or null

size - the size of data

reallocFunction - a function with realloc() semantics (like g_realloc()) to be called when data needs to be grown, or null

MemoryOutputStream

public MemoryOutputStream()

Creates a new MemoryOutputStream.

Method Details

getType

public static @Nullable Type getType()

Get the GType of the MemoryOutputStream class

Returns:

the GType

getMemoryLayout

public static MemoryLayout getMemoryLayout()

The memory layout of the native struct.

Returns:

the memory layout

asParent

protected MemoryOutputStream asParent()

Returns this instance as if it were its parent type. This is mostly synonymous to the Java super keyword, but will set the native typeclass function pointers to the parent type. When overriding a native virtual method in Java, "chaining up" with super.methodName() doesn't work, because it invokes the overridden function pointer again. To chain up, call asParent().methodName(). This will call the native function pointer of this virtual method in the typeclass of the parent type.

Overrides:

asParent in class OutputStream

resizable

public static OutputStream resizable()

Creates a new GMemoryOutputStream, using g_realloc() and g_free() for memory allocation.

Since:

2.36

getData

public @Nullable MemorySegment getData()

Gets any loaded data from the ostream.

Note that the returned pointer may become invalid on the next write or truncate operation on the stream.

Returns:

pointer to the stream's data, or null if the data has been stolen

getDataSize

public long getDataSize()

Returns the number of bytes from the start up to including the last byte written in the stream that has not been truncated away.

Returns:

the number of bytes written to the stream

Since:

2.18

getSize

public long getSize()

Gets the size of the currently allocated data area (available from g_memory_output_stream_get_data()).

You probably don't want to use this function on resizable streams. See g_memory_output_stream_get_data_size() instead. For resizable streams the size returned by this function is an implementation detail and may be change at any time in response to operations on the stream.

If the stream is fixed-sized (ie: no realloc was passed to g_memory_output_stream_new()) then this is the maximum size of the stream and further writes will return IOErrorEnum.NO_SPACE.

In any case, if you want the number of bytes currently written to the stream, use g_memory_output_stream_get_data_size().

Returns:

the number of bytes allocated for the data buffer

stealAsBytes

public byte[] stealAsBytes()

Returns data from the this MemoryOutputStream as a GBytes. this MemoryOutputStream must be closed before calling this function.

Returns:

the stream's data

Since:

2.34

stealData

public @Nullable MemorySegment stealData()

Gets any loaded data from the ostream. Ownership of the data is transferred to the caller; when no longer needed it must be freed using the free function set in ostream's GMemoryOutputStream:destroy-function property.

this MemoryOutputStream must be closed before calling this function.

Returns:

the stream's data, or null if it has previously been stolen

Since:

2.26

builder

public static MemoryOutputStream.Builder<? extends MemoryOutputStream.Builder> builder()

A MemoryOutputStream.Builder object constructs a MemoryOutputStream with the specified properties. Use the various set...() methods to set properties, and finish construction with MemoryOutputStream.Builder.build().

Returns:

the builder object