Copyright	Will Thompson Iñaki García Etxebarria and Jonas Platte
License	LGPL-2.1
Maintainer	Iñaki García Etxebarria (garetxe@gmail.com)
Safe Haskell	None
Language	Haskell2010

GI.GLib.Structs.MappedFile

Contents

Exported types
Methods

Description

The MappedFile represents a file mapping created with mappedFileNew. It has only private members and should not be accessed directly.

Synopsis

newtype MappedFile = MappedFile (ManagedPtr MappedFile)
noMappedFile :: Maybe MappedFile
mappedFileFree :: (HasCallStack, MonadIO m) => MappedFile -> m ()
mappedFileGetBytes :: (HasCallStack, MonadIO m) => MappedFile -> m Bytes
mappedFileGetContents :: (HasCallStack, MonadIO m) => MappedFile -> m Text
mappedFileGetLength :: (HasCallStack, MonadIO m) => MappedFile -> m Word64
mappedFileNew :: (HasCallStack, MonadIO m) => [Char] -> Bool -> m MappedFile
mappedFileNewFromFd :: (HasCallStack, MonadIO m) => Int32 -> Bool -> m MappedFile
mappedFileRef :: (HasCallStack, MonadIO m) => MappedFile -> m MappedFile
mappedFileUnref :: (HasCallStack, MonadIO m) => MappedFile -> m ()

Exported types

newtype MappedFile Source #

Memory-managed wrapper type.

Constructors

MappedFile (ManagedPtr MappedFile)

Instances

BoxedObject MappedFile Source #
Instance details Defined in GI.GLib.Structs.MappedFile Methods boxedType :: MappedFile -> IO GType #

noMappedFile :: Maybe MappedFile Source #

A convenience alias for Nothing :: Maybe MappedFile.

Methods

free

mappedFileFree Source #

Arguments

:: (HasCallStack, MonadIO m)
=> MappedFile	`file`: a `MappedFile`
-> m ()

Deprecated: (Since version 2.22)Use mappedFileUnref instead.

This call existed before MappedFile had refcounting and is currently exactly the same as mappedFileUnref.

Since: 2.8

getBytes

mappedFileGetBytes Source #

Arguments

:: (HasCallStack, MonadIO m)
=> MappedFile	`file`: a `MappedFile`
-> m Bytes	Returns: A newly allocated `Bytes` referencing data from `file`

Creates a new Bytes which references the data mapped from file. The mapped contents of the file must not be modified after creating this bytes object, because a Bytes should be immutable.

Since: 2.34

getContents

mappedFileGetContents Source #

Arguments

:: (HasCallStack, MonadIO m)
=> MappedFile	`file`: a `MappedFile`
-> m Text	Returns: the contents of `file`, or `Nothing`.

Returns the contents of a MappedFile.

Note that the contents may not be zero-terminated, even if the MappedFile is backed by a text file.

If the file is empty then Nothing is returned.

Since: 2.8

getLength

mappedFileGetLength Source #

Arguments

:: (HasCallStack, MonadIO m)
=> MappedFile	`file`: a `MappedFile`
-> m Word64	Returns: the length of the contents of `file`.

Returns the length of the contents of a MappedFile.

Since: 2.8

new

mappedFileNew Source #

Arguments

:: (HasCallStack, MonadIO m)
=> [Char]	`filename`: The path of the file to load, in the GLib filename encoding
-> Bool	`writable`: whether the mapping should be writable
-> m MappedFile	Returns: a newly allocated `MappedFile` which must be unref'd with `mappedFileUnref`, or `Nothing` if the mapping failed. (Can throw `GError`)

Maps a file into memory. On UNIX, this is using the mmap() function.

If writable is True, the mapped buffer may be modified, otherwise it is an error to modify the mapped buffer. Modifications to the buffer are not visible to other processes mapping the same file, and are not written back to the file.

Note that modifications of the underlying file might affect the contents of the MappedFile. Therefore, mapping should only be used if the file will not be modified, or if all modifications of the file are done atomically (e.g. using fileSetContents).

If filename is the name of an empty, regular file, the function will successfully return an empty MappedFile. In other cases of size 0 (e.g. device files such as /dev/null), error will be set to the FileError value G_FILE_ERROR_INVAL.

Since: 2.8

newFromFd

mappedFileNewFromFd Source #

Arguments

:: (HasCallStack, MonadIO m)
=> Int32	`fd`: The file descriptor of the file to load
-> Bool	`writable`: whether the mapping should be writable
-> m MappedFile	Returns: a newly allocated `MappedFile` which must be unref'd with `mappedFileUnref`, or `Nothing` if the mapping failed. (Can throw `GError`)

Maps a file into memory. On UNIX, this is using the mmap() function.

If writable is True, the mapped buffer may be modified, otherwise it is an error to modify the mapped buffer. Modifications to the buffer are not visible to other processes mapping the same file, and are not written back to the file.

Note that modifications of the underlying file might affect the contents of the MappedFile. Therefore, mapping should only be used if the file will not be modified, or if all modifications of the file are done atomically (e.g. using fileSetContents).

Since: 2.32

ref

mappedFileRef Source #

Arguments

:: (HasCallStack, MonadIO m)
=> MappedFile	`file`: a `MappedFile`
-> m MappedFile	Returns: the passed in `MappedFile`.

Increments the reference count of file by one. It is safe to call this function from any thread.

Since: 2.22

unref

mappedFileUnref Source #

Arguments

:: (HasCallStack, MonadIO m)
=> MappedFile	`file`: a `MappedFile`
-> m ()

Decrements the reference count of file by one. If the reference count drops to 0, unmaps the buffer of file and frees it.

It is safe to call this function from any thread.

Since 2.22