Copyright | Will Thompson Iñaki García Etxebarria and Jonas Platte |
---|---|
License | LGPL-2.1 |
Maintainer | Iñaki García Etxebarria |
Safe Haskell | None |
Language | Haskell2010 |
A simple refcounted data type representing an immutable sequence of zero or more bytes from an unspecified origin.
The purpose of a Bytes
is to keep the memory region that it holds
alive for as long as anyone holds a reference to the bytes. When
the last reference count is dropped, the memory is released. Multiple
unrelated callers can use byte data in the Bytes
without coordinating
their activities, resting assured that the byte data will not change or
move while they hold a reference.
A Bytes
can come from many different origins that may have
different procedures for freeing the memory region. Examples are
memory from malloc
, from memory slices, from a MappedFile
or
memory from other allocators.
Bytes
work well as keys in HashTable
. Use bytesEqual
and
bytesHash
as parameters to g_hash_table_new()
or g_hash_table_new_full()
.
Bytes
can also be used as keys in a Tree
by passing the bytesCompare
function to g_tree_new()
.
The data pointed to by this bytes must not be modified. For a mutable
array of bytes see ByteArray
. Use bytesUnrefToArray
to create a
mutable array for a Bytes
sequence. To create an immutable Bytes
from
a mutable ByteArray
, use the byteArrayFreeToBytes
function.
Since: 2.32
Synopsis
- newtype Bytes = Bytes (ManagedPtr Bytes)
- bytesCompare :: (HasCallStack, MonadIO m) => Bytes -> Bytes -> m Int32
- bytesEqual :: (HasCallStack, MonadIO m) => Bytes -> Bytes -> m Bool
- bytesGetData :: (HasCallStack, MonadIO m) => Bytes -> m (Maybe ByteString)
- bytesGetSize :: (HasCallStack, MonadIO m) => Bytes -> m Word64
- bytesHash :: (HasCallStack, MonadIO m) => Bytes -> m Word32
- bytesNew :: (HasCallStack, MonadIO m) => Maybe ByteString -> m Bytes
- bytesNewFromBytes :: (HasCallStack, MonadIO m) => Bytes -> Word64 -> Word64 -> m Bytes
- bytesNewTake :: (HasCallStack, MonadIO m) => Maybe ByteString -> m Bytes
- bytesRef :: (HasCallStack, MonadIO m) => Bytes -> m Bytes
- bytesUnref :: (HasCallStack, MonadIO m) => Bytes -> m ()
- bytesUnrefToArray :: (HasCallStack, MonadIO m) => Bytes -> m ByteString
- bytesUnrefToData :: (HasCallStack, MonadIO m) => Bytes -> m ByteString
Exported types
Memory-managed wrapper type.
Instances
Eq Bytes Source # | |
IsGValue Bytes Source # | Convert |
ManagedPtrNewtype Bytes Source # | |
Defined in GI.GLib.Structs.Bytes toManagedPtr :: Bytes -> ManagedPtr Bytes # | |
TypedObject Bytes Source # | |
Defined in GI.GLib.Structs.Bytes | |
GBoxed Bytes Source # | |
Defined in GI.GLib.Structs.Bytes | |
HasParentTypes Bytes Source # | |
Defined in GI.GLib.Structs.Bytes | |
type ParentTypes Bytes Source # | |
Defined in GI.GLib.Structs.Bytes |
Methods
Overloaded methods
compare
:: (HasCallStack, MonadIO m) | |
=> Bytes |
|
-> Bytes |
|
-> m Int32 | Returns: a negative value if |
Compares the two Bytes
values.
This function can be used to sort GBytes instances in lexicographical order.
If bytes1
and bytes2
have different length but the shorter one is a
prefix of the longer one then the shorter one is considered to be less than
the longer one. Otherwise the first byte where both differ is used for
comparison. If bytes1
has a smaller value at that position it is
considered less, otherwise greater than bytes2
.
Since: 2.32
equal
getData
:: (HasCallStack, MonadIO m) | |
=> Bytes |
|
-> m (Maybe ByteString) | Returns:
a pointer to the byte data, or |
Get the byte data in the Bytes
. This data should not be modified.
This function will always return the same pointer for a given Bytes
.
Nothing
may be returned if size
is 0. This is not guaranteed, as the Bytes
may represent an empty string with data
non-Nothing
and size
as 0. Nothing
will
not be returned if size
is non-zero.
Since: 2.32
getSize
:: (HasCallStack, MonadIO m) | |
=> Bytes |
|
-> m Word64 | Returns: the size |
hash
:: (HasCallStack, MonadIO m) | |
=> Bytes |
|
-> m Word32 | Returns: a hash value corresponding to the key. |
new
:: (HasCallStack, MonadIO m) | |
=> Maybe ByteString |
|
-> m Bytes | Returns: a new |
newFromBytes
:: (HasCallStack, MonadIO m) | |
=> Bytes |
|
-> Word64 |
|
-> Word64 |
|
-> m Bytes | Returns: a new |
Creates a Bytes
which is a subsection of another Bytes
. The offset
+
length
may not be longer than the size of bytes
.
A reference to bytes
will be held by the newly created Bytes
until
the byte data is no longer needed.
Since 2.56, if offset
is 0 and length
matches the size of bytes
, then
bytes
will be returned with the reference count incremented by 1. If bytes
is a slice of another Bytes
, then the resulting Bytes
will reference
the same Bytes
instead of bytes
. This allows consumers to simplify the
usage of Bytes
when asynchronously writing to streams.
Since: 2.32
newTake
:: (HasCallStack, MonadIO m) | |
=> Maybe ByteString |
|
-> m Bytes | Returns: a new |
Creates a new Bytes
from data
.
After this call, data
belongs to the bytes and may no longer be
modified by the caller. free
will be called on data
when the
bytes is no longer in use. Because of this data
must have been created by
a call to malloc
, malloc0
or realloc
or by one of the many
functions that wrap these calls (such as g_new()
, strdup
, etc).
For creating Bytes
with memory from other allocators, see
g_bytes_new_with_free_func()
.
data
may be Nothing
if size
is 0.
Since: 2.32
ref
Increase the reference count on bytes
.
Since: 2.32
unref
:: (HasCallStack, MonadIO m) | |
=> Bytes |
|
-> m () |
Releases a reference on bytes
. This may result in the bytes being
freed. If bytes
is Nothing
, it will return immediately.
Since: 2.32
unrefToArray
:: (HasCallStack, MonadIO m) | |
=> Bytes |
|
-> m ByteString | Returns: a new mutable |
Unreferences the bytes, and returns a new mutable ByteArray
containing
the same byte data.
As an optimization, the byte data is transferred to the array without copying
if this was the last reference to bytes and bytes was created with
bytesNew
, bytesNewTake
or byteArrayFreeToBytes
. In all
other cases the data is copied.
Since: 2.32
unrefToData
:: (HasCallStack, MonadIO m) | |
=> Bytes |
|
-> m ByteString | Returns: a pointer to the same byte data, which should be
freed with |
Unreferences the bytes, and returns a pointer the same byte data contents.
As an optimization, the byte data is returned without copying if this was
the last reference to bytes and bytes was created with bytesNew
,
bytesNewTake
or byteArrayFreeToBytes
. In all other cases the
data is copied.
Since: 2.32