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<GBytes>
A simple refcounted data type representing an immutable sequence of zero or more bytes from an unspecified origin.
The purpose of a GBytes 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 GBytes without coordinating their activities, resting assured that the byte data will not change or move while they hold a reference.
A GBytes can come from many different origins that may have
different procedures for freeing the memory region. Examples are
memory from g_malloc()
, from memory slices, from a GMappedFile or
memory from other allocators.
GBytes work well as keys in GHashTable. Use g_bytes_equal()
and
g_bytes_hash()
as parameters to g_hash_table_new()
or g_hash_table_new_full()
.
GBytes can also be used as keys in a GTree by passing the g_bytes_compare()
function to g_tree_new()
.
The data pointed to by this bytes must not be modified. For a mutable
array of bytes see GByteArray. Use g_bytes_unref_to_array()
to create a
mutable array for a GBytes sequence. To create an immutable GBytes from
a mutable GByteArray, use the g_byte_array_free_to_bytes()
function.
(define-values (%return) (bytes:compare self bytes2))
Compares the two GBytes 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
.
(define-values (%return) (bytes:equal? self bytes2))
Compares the two GBytes values being pointed to and returns
TRUE
if they are equal.
This function can be passed to g_hash_table_new()
as the key_equal_func
parameter, when using non-NULL
GBytes pointers as keys in a GHashTable.
(define-values (%return size) (bytes:get-data self))
Get the byte data in the GBytes. This data should not be modified.
This function will always return the same pointer for a given GBytes.
NULL
may be returned if size
is 0. This is not guaranteed, as the GBytes
may represent an empty string with data
non-NULL
and size
as 0. NULL
will
not be returned if size
is non-zero.
(define-values (%return) (bytes:get-region self element-size offset n-elements))
Undocumented
(define-values (%return) (bytes:get-size self))
Get the size of the byte data in the GBytes.
This function will always return the same value for a given GBytes.
(define-values (%return) (bytes:hash self))
Creates an integer hash code for the byte data in the GBytes.
This function can be passed to g_hash_table_new()
as the key_hash_func
parameter, when using non-NULL
GBytes pointers as keys in a GHashTable.
(define-values (%return) (bytes:new-from-bytes self offset length))
Creates a GBytes which is a subsection of another GBytes. The offset
+
length
may not be longer than the size of bytes
.
A reference to bytes
will be held by the newly created GBytes 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 GBytes, then the resulting GBytes will reference
the same GBytes instead of bytes
. This allows consumers to simplify the
usage of GBytes when asynchronously writing to streams.
(define-values () (bytes:unref self))
Releases a reference on bytes
. This may result in the bytes being
freed. If bytes
is NULL
, it will return immediately.
(define-values (%return) (bytes:unref-to-array self))
Unreferences the bytes, and returns a new mutable GByteArray 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
g_bytes_new()
, g_bytes_new_take()
or g_byte_array_free_to_bytes()
. In all
other cases the data is copied.
(define-values (%return size) (bytes:unref-to-data self))
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 g_bytes_new()
,
g_bytes_new_take()
or g_byte_array_free_to_bytes()
. In all other cases the
data is copied.