class: GSeekable

[22:7] extends: object

GSeekable is implemented by streams (implementations of [class@Gio.InputStream] or [class@Gio.OutputStream]) that support seeking. Seekable streams largely fall into two categories: resizable and fixed-size. GSeekable on fixed-sized streams is approximately the same as POSIX lseek() on a block device (for example: attempting to seek past the end of the device is an error). Fixed streams typically cannot be truncated. GSeekable on resizable streams is approximately the same as POSIX lseek() on a normal file. Seeking past the end and writing data will usually cause the stream to resize by introducing zero bytes.

Members

handleObj
lib
retainedCallbacks
signalHandlerNames
signalSetterHandlers

Methods

GSeekable (Handle = null)

Creates a new Seekable by wrapping a native handle or another wrapper.
- @p Handle is the native handle or another wrapper whose handle to adopt.
toNativeHandle (Source)

Normalizes a constructor argument into a raw pointer carrier. Accepts a raw NativeHandle, a raw NativeBuffer returned from fn.call(...), another generated wrapper exposing handle(), or null. Returns null when the argument carries no pointer.
- @p Source is the raw handle, raw buffer, wrapper, or null.
- @r A raw pointer carrier or null when no pointer is present.
getLib ()

Returns the opened native library for this generated wrapper.
- @r The opened native library.
handle ()

Returns the wrapped NativeHandle.
- @r The wrapped NativeHandle.
isNull ()

Returns true when the wrapped handle is null.
- @r A bool.
describe ()

Returns a small string for debugging generated wrappers.
- @r A string.
can_seek ()

Tests if the stream supports the #GSeekableIface.
- @r %TRUE if @seekable can be seeked. %FALSE otherwise..
can_truncate ()

Tests if the length of the stream can be adjusted with g_seekable_truncate().
- @r %TRUE if the stream can be truncated, %FALSE otherwise..
seek (int offset, string type, object cancellable)

Seeks in the stream by the given @offset, modified by @type. Attempting to seek past the end of the stream will have different results depending on if the stream is fixed-sized or resizable. If the stream is resizable then seeking past the end and then writing will result in zeros filling the empty space. Seeking past the end of a resizable stream and reading will result in EOF. Seeking past the end of a fixed-sized stream will fail. Any operation that would result in a negative offset will fail. If
- @cancellable is not %NULL, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
- @p offset is a #goffset..
- @p type is a #GSeekType..
- @p cancellable is optional #GCancellable object, %NULL to ignore..
- @r %TRUE if successful. If an error has occurred, this function will return %FALSE and set @error appropriately if present..
tell ()

Tells the current position within the stream.
- @r the (positive or zero) offset from the beginning of the buffer, zero if the target is not seekable..
truncate (int offset, object cancellable)

Sets the length of the stream to @offset. If the stream was previously larger than @offset, the extra data is discarded. If the stream was previously shorter than @offset, it is extended with NUL ('\0') bytes. If
- @cancellable is not %NULL, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error %G_IO_ERROR_CANCELLED will be returned. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.
- @p offset is new length for @seekable, in bytes..
- @p cancellable is optional #GCancellable object, %NULL to ignore..
- @r %TRUE if successful. If an error has occurred, this function will return %FALSE and set @error appropriately if present..