[1144:14] static extends: object
Alternate constructors for GVariant. Usage:
GVariantCtors.<name>(...). The primary constructor lives
directly on GVariant.
newArray (object child_type, list children)
Creates a new #GVariant array from @children. @child_type must be non-%NULL if @n_children is zero. Otherwise, the child type is determined by inspecting the first element of the @children array. If @child_type is non-%NULL then it must be a definite type. The items of the array are taken from the @children array. No entry in the @children array may be %NULL. All items in the array must have the same type, which must be the same as @child_type, if given. If the @children are floating references (see g_variant_ref_sink()), the new instance takes ownership of them as if via g_variant_ref_sink().
child_type is the element type of the new array.children is an array of #GVariant pointers, the children.n_children is the length of @children.A new GVariant.newBoolean (bool value)
Creates a new boolean #GVariant instance -- either %TRUE or %FALSE.
value is a #gboolean value.A new GVariant.newByte (int value)
Creates a new byte #GVariant instance.
value is a #guint8 value.A new GVariant.newBytestring (list arg0String)
Creates an array-of-bytes #GVariant with the contents of @string. This function is just like g_variant_new_string() except that the string need not be valid UTF-8. The nul terminator character at the end of the string is stored in the array.
string is a normal nul-terminated string in no particular encoding.A new GVariant.newBytestringArray (list strv)
Constructs an array of bytestring #GVariant from the given array of strings. If @length is -1 then @strv is %NULL-terminated.
strv is an array of strings.length is the length of @strv, or -1.A new GVariant.newDictEntry (object key, object value)
Creates a new dictionary entry #GVariant. @key and @value must be non-%NULL. @key must be a value of a basic type (ie: not a container). If the @key or @value are floating references (see g_variant_ref_sink()), the new instance takes ownership of them as if via g_variant_ref_sink().
key is a basic #GVariant, the key.value is a #GVariant, the value.A new GVariant.newDouble (double value)
Creates a new double #GVariant instance.
value is a #gdouble floating point value.A new GVariant.newFixedArray (object element_type, elements, int n_elements, int element_size)
Constructs a new array #GVariant instance, where the elements are of
type. @elements must be an array with fixed-sized elements. Numeric types are fixed-size as are tuples containing only other fixed-sized types. @element_size must be the size of a single element in the array. For example, if calling this function for an array of 32-bit integers, you might say sizeof(gint32). This value isn't used except for the purpose of a double-check that the form of the serialized data matches the caller's expectation. @n_elements must be the length of thearray.element_type is the #GVariantType of each element.elements is a pointer to the fixed array of contiguous elements.n_elements is the number of elements.element_size is the size of each element.A new GVariant.newFromBytes (object type, object bytes, bool trusted)
Constructs a new serialized-mode #GVariant instance. This is the inner interface for creation of new serialized values that gets called from various functions in gvariant.c. A reference is taken on @bytes. The data in @bytes must be aligned appropriately for the @type being loaded. Otherwise this function will internally create a copy of the memory (since GLib 2.60) or (in older versions) fail and exit the process.
type is a #GVariantType.bytes is a #GBytes.trusted is if the contents of @bytes are trusted.A new GVariant.newFromData (object type, list data, bool trusted, object notify, user_data)
Creates a new #GVariant instance from serialized data. @type is the type of #GVariant instance that will be constructed. The interpretation of
depends on knowing the type. @data is not modified by this function and must remain valid with an unchanging value until such a time asis called with @user_data. If the contents of @data change before that time then the result is undefined. If @data is trusted to be serialized data in normal form then @trusted should be %TRUE. This applies to serialized data created within this process or read from a trusted location on the disk (such as a file installed in /usr/lib alongside your application). You should set trusted to %FALSE if @data is read from the network, a file in the user's home directory, etc. If @data was not stored in this machine's native endianness, any multi-byte numeric values in the returned variant will also be in non-native endianness. g_variant_byteswap() can be used to recover the original values. @notify will be called with @user_data when @data is no longer needed. The exact time of this call is unspecified and might even be before this function returns. Note: @data must be backed by memory that is aligned appropriately for the @type being loaded. Otherwise this function will internally create a copy of the memory (since GLib 2.60) or (in older versions) fail and exit the process.type is a definite #GVariantType.data is the serialized data.size is the size of @data.trusted is %TRUE if @data is definitely in normal form.notify is function to call when @data is no longer needed.user_data is data for @notify.A new GVariant.newHandle (int value)
Creates a new handle #GVariant instance. By convention, handles are indexes into an array of file descriptors that are sent alongside a D-Bus message. If you're not interacting with D-Bus, you probably don't need them.
value is a #gint32 value.A new GVariant.newInt16 (int value)
Creates a new int16 #GVariant instance.
value is a #gint16 value.A new GVariant.newInt32 (int value)
Creates a new int32 #GVariant instance.
value is a #gint32 value.A new GVariant.newInt64 (int value)
Creates a new int64 #GVariant instance.
value is a #gint64 value.A new GVariant.newMaybe (object child_type, object child)
Depending on if @child is %NULL, either wraps @child inside of a maybe container or creates a Nothing instance for the given @type. At least one of @child_type and @child must be non-%NULL. If @child_type is non-%NULL then it must be a definite type. If they are both non-%NULL then
must be the type of @child. If @child is a floating reference (see g_variant_ref_sink()), the new instance takes ownership of @child.child_type is the #GVariantType of the child, or %NULL.child is the child value, or %NULL.A new GVariant.newObjectPath (string object_path)
Creates a D-Bus object path #GVariant with the contents of @object_path.
must be a valid D-Bus object path. Use g_variant_is_object_path() if you're not sure.object_path is a normal C nul-terminated string.A new GVariant.newObjv (list strv)
Constructs an array of object paths #GVariant from the given array of strings. Each string must be a valid #GVariant object path; see g_variant_is_object_path(). If @length is -1 then @strv is %NULL-terminated.
strv is an array of strings.length is the length of @strv, or -1.A new GVariant.newParsed (string format, list varargs)
Parses @format and returns the result. @format must be a text format #GVariant with one extension: at any point that a value may appear in the text, a '%' character followed by a GVariant format string (as per g_variant_new()) may appear. In that case, the same arguments are collected from the argument list as g_variant_new() would have collected. Note that the arguments must be of the correct width for their types specified in @format. This can be achieved by casting them. See the GVariant varargs documentation. Consider this simple example: |[ g_variant_new_parsed ("[('one', 1), ('two', %i), (%s, 3)]", 2, "three"); ]| In the example, the variable argument parameters are collected and filled in as if they were part of the original string to produce the result of |[ [('one', 1), ('two', 2), ('three', 3)] ]| This function is intended only to be used with @format as a string literal. Any parse error is fatal to the calling process. If you want to parse data from untrusted sources, use g_variant_parse(). You may not use this function to return, unmodified, a single #GVariant pointer from the argument list. ie: @format may not solely be anything along the lines of "%*", "%?", "%r", or anything starting with "%@".
format is a text format #GVariant.... is arguments as per @format.A new GVariant.newPrintf (string format_string, list varargs)
Creates a string-type GVariant using printf formatting. This is similar to calling g_strdup_printf() and then g_variant_new_string() but it saves a temporary variable and an unnecessary copy.
format_string is a printf-style format string.... is arguments for @format_string.A new GVariant.newSignature (string signature)
Creates a D-Bus type signature #GVariant with the contents of @string.
must be a valid D-Bus type signature. Use g_variant_is_signature() if you're not sure.signature is a normal C nul-terminated string.A new GVariant.newString (string arg0String)
Creates a string #GVariant with the contents of @string. @string must be valid UTF-8, and must not be %NULL. To encode potentially-%NULL strings, use g_variant_new() with
msas the format string.
string is a normal UTF-8 nul-terminated string.A new GVariant.newStrv (list strv)
Constructs an array of strings #GVariant from the given array of strings. If @length is -1 then @strv is %NULL-terminated.
strv is an array of strings.length is the length of @strv, or -1.A new GVariant.newTakeString (string arg0String)
Creates a string #GVariant with the contents of @string. @string must be valid UTF-8, and must not be %NULL. To encode potentially-%NULL strings, use this with g_variant_new_maybe(). After this call, @string belongs to the #GVariant and may no longer be modified by the caller. The memory of
has to be dynamically allocated and will eventually be freed with g_free(). You must not modify or access @string in any other way after passing it to this function. It is even possible that @string is immediately freed.string is a normal UTF-8 nul-terminated string.A new GVariant.newTuple (list children)
Creates a new tuple #GVariant out of the items in @children. The type is determined from the types of @children. No entry in the @children array may be %NULL. If @n_children is 0 then the unit tuple is constructed. If the @children are floating references (see g_variant_ref_sink()), the new instance takes ownership of them as if via g_variant_ref_sink().
children is the items to make the tuple out of.n_children is the length of @children.A new GVariant.newUint16 (int value)
Creates a new uint16 #GVariant instance.
value is a #guint16 value.A new GVariant.newUint32 (int value)
Creates a new uint32 #GVariant instance.
value is a #guint32 value.A new GVariant.newUint64 (int value)
Creates a new uint64 #GVariant instance.
value is a #guint64 value.A new GVariant.newVariant (object value)
Boxes @value. The result is a #GVariant instance representing a variant containing the original value. If @child is a floating reference (see g_variant_ref_sink()), the new instance takes ownership of @child.
value is a #GVariant instance.A new GVariant.[163:7] extends: object
GVariant is a variant datatype; it can contain one or more values along
with information about the type of the values. A GVariant may contain
simple types, like an integer, or a boolean value; or complex types, like an
array of two strings, or a dictionary of key value pairs. A GVariant is
also immutable: once it’s been created neither its type nor its content can
be modified further. GVariant is useful whenever data needs to be
serialized, for example when sending method parameters in D-Bus, or when
saving settings using GSettings. When
creating a new GVariant, you pass the data you want to store in it along
with a string representing the type of data you wish to pass to it. For
instance, if you want to create a GVariant holding an integer value you can
use: c GVariant *v = g_variant_new ("u", 40); The string u in the
first argument tells GVariant that the data passed to the constructor
(40) is going to be an unsigned integer. More advanced examples of
GVariant in use can be found in documentation for GVariant format
strings. The range of possible values
is determined by the type. The type system used by GVariant is
[type@GLib.VariantType]. GVariant instances always have a type and a value
(which are given at construction time). The type and value of a GVariant
instance can never change other than by the GVariant itself being
destroyed. A GVariant cannot contain a pointer. GVariant is reference
counted using [method@GLib.Variant.ref] and [method@GLib.Variant.unref].
GVariant also has floating reference counts — see
[method@GLib.Variant.ref_sink]. GVariant is completely threadsafe. A
GVariant instance can be concurrently accessed in any way from any number
of threads without problems. GVariant is heavily optimised for dealing with
data in serialized form. It works particularly well with data located in
memory-mapped files. It can perform nearly all deserialization operations in
a small constant time, usually touching only a single memory page. Serialized
GVariant data can also be sent over the network. GVariant is largely
compatible with D-Bus. Almost all types of GVariant instances can be sent
over D-Bus. See [type@GLib.VariantType] for exceptions. (However,
GVariant’s serialization format is not the same as the serialization format
of a D-Bus message body: use GDBusMessage,
in the GIO library, for those.) For space-efficiency, the GVariant
serialization format does not automatically include the variant’s length,
type or endianness, which must either be implied from context (such as
knowledge that a particular file format always contains a little-endian
G_VARIANT_TYPE_VARIANT which occupies the whole length of the file) or
supplied out-of-band (for instance, a length, type and/or endianness
indicator could be placed at the beginning of a file, network message or
network stream). A GVariant’s size is limited mainly by any lower level
operating system constraints, such as the number of bits in gsize. For
example, it is reasonable to have a 2GB file mapped into memory with
[struct@GLib.MappedFile], and call [ctor@GLib.Variant.new_from_data] on it.
For convenience to C programmers, GVariant features powerful varargs-based
value construction and destruction. This feature is designed to be embedded
in other libraries. There is a Python-inspired text language for describing
GVariant values. GVariant includes a printer for this language and a
parser with type inferencing. ## Memory Use GVariant tries to be quite
efficient with respect to memory use. This section gives a rough idea of how
much memory is used by the current implementation. The information here is
subject to change in the future. The memory allocated by GVariant can be
grouped into 4 broad purposes: memory for serialized data, memory for the
type information cache, buffer management memory and memory for the
GVariant structure itself. ## Serialized Data Memory This is the memory
that is used for storing GVariant data in serialized form. This is what
would be sent over the network or what would end up on disk, not counting any
indicator of the endianness, or of the length or type of the top-level
variant. The amount of memory required to store a boolean is 1 byte. 16, 32
and 64 bit integers and double precision floating point numbers use their
‘natural’ size. Strings (including object path and signature strings) are
stored with a nul terminator, and as such use the length of the string plus 1
byte. ‘Maybe’ types use no space at all to represent the value and use the
same amount of space (sometimes plus one byte) as the equivalent
non-maybe-typed value to represent the non-null case. Arrays use the amount
of space required to store each of their members, concatenated. Additionally,
if the items stored in an array are not of a fixed-size (ie: strings, other
arrays, etc) then an additional framing offset is stored for each item. The
size of this offset is either 1, 2 or 4 bytes depending on the overall size
of the container. Additionally, extra padding bytes are added as required for
alignment of child values. Tuples (including dictionary entries) use the
amount of space required to store each of their members, concatenated, plus
one framing offset (as per arrays) for each non-fixed-sized item in the
tuple, except for the last one. Additionally, extra padding bytes are added
as required for alignment of child values. Variants use the same amount of
space as the item inside of the variant, plus 1 byte, plus the length of the
type string for the item inside the variant. As an example, consider a
dictionary mapping strings to variants. In the case that the dictionary is
empty, 0 bytes are required for the serialization. If we add an item ‘width’
that maps to the int32 value of 500 then we will use 4 bytes to store the
int32 (so 6 for the variant containing it) and 6 bytes for the string. The
variant must be aligned to 8 after the 6 bytes of the string, so that’s 2
extra bytes. 6 (string) + 2 (padding) + 6 (variant) is 14 bytes used for the
dictionary entry. An additional 1 byte is added to the array as a framing
offset making a total of 15 bytes. If we add another entry, ‘title’ that maps
to a nullable string that happens to have a value of null, then we use 0
bytes for the value (and 3 bytes for the variant to contain it along with its
type string) plus 6 bytes for the string. Again, we need 2 padding bytes.
That makes a total of 6 + 2 + 3 = 11 bytes. We now require extra padding
between the two items in the array. After the 14 bytes of the first item,
that’s 2 bytes required. We now require 2 framing offsets for an extra two
bytes. 14 + 2 + 11 + 2 = 29 bytes to encode the entire two-item dictionary.
GVariant type that currently exists inthe program a type information structure is kept in the type information
cache. The type information structure is required for rapid deserialization.
Continuing with the above example, if a GVariant exists with the type
a{sv} then a type information struct will exist for a{sv}, {sv}, s,
and v. Multiple uses of the same type will share the same type information.
Additionally, all single-digit types are stored in read-only static memory
and do not contribute to the writable memory footprint of a program using
GVariant. Aside from the type information structures stored in read-only
memory, there are two forms of type information. One is used for container
types where there is a single element type: arrays and maybe types. The other
is used for container types where there are multiple element types: tuples
and dictionary entries. Array type info structures are 6 * sizeof (void *),
plus the memory required to store the type string itself. This means that on
32-bit systems, the cache entry for a{sv} would require 30 bytes of memory
(plus allocation overhead). Tuple type info structures are 6 * sizeof (void *), plus 4 * sizeof (void *) for each item in the tuple, plus the memory
required to store the type string itself. A 2-item tuple, for example, would
have a type information structure that consumed writable memory in the size
of 14 * sizeof (void *) (plus type string) This means that on 32-bit
systems, the cache entry for {sv} would require 61 bytes of memory (plus
allocation overhead). This means that in total, for our a{sv} example, 91
bytes of type information would be allocated. The type information cache,
additionally, uses a [struct@GLib.HashTable] to store and look up the cached
items and stores a pointer to this hash table in static storage. The hash
table is freed when there are zero items in the type cache. Although these
sizes may seem large it is important to remember that a program will probably
only have a very small number of different types of values in it and that
only one type information structure is required for many different values of
the same type. ## Buffer Management Memory GVariant uses an internal buffer
management structure to deal with the various different possible sources of
serialized data that it uses. The buffer is responsible for ensuring that the
correct call is made when the data is no longer in use by GVariant. This
may involve a [func@GLib.free] or even [method@GLib.MappedFile.unref]. One
buffer management structure is used for each chunk of serialized data. The
size of the buffer management structure is 4 * (void *). On 32-bit systems,
that’s 16 bytes. ## GVariant structure The size of a GVariant structure is
6 * (void *). On 32-bit systems, that’s 24 bytes. GVariant structures
only exist if they are explicitly created with API calls. For example, if a
GVariant is constructed out of serialized data for the example given above
(with the dictionary) then although there are 9 individual values that
comprise the entire dictionary (two keys, two values, two variants containing
the values, two dictionary entries, plus the dictionary itself), only 1
GVariant instance exists — the one referring to the dictionary. If calls
are made to start accessing the other values then GVariant instances will
exist for those values only for as long as they are in use (ie: until you
call [method@GLib.Variant.unref]). The type information is shared. The
serialized data and the buffer management structure for that serialized data
is shared by the child. ## Summary To put the entire example together, for
our dictionary mapping strings to variants (with two entries, as given
above), we are using 91 bytes of memory for type information, 29 bytes of
memory for the serialized data, 16 bytes for buffer management and 24 bytes
for the GVariant instance, or a total of 160 bytes, plus allocation
overhead. If we were to use [method@GLib.Variant.get_child_value] to access
the two dictionary entries, we would use an additional 48 bytes. If we were
to have other dictionaries of the same type, we would use more memory for the
serialized data and buffer management for those dictionaries, but the type
information would be shared.
GVariant (format_string = null, ___ = null)
Creates a new #GVariant instance. Think of this function as an analogue to g_strdup_printf(). The type of the created instance and the arguments that are expected by this function are determined by @format_string. See the section on GVariant format strings. Please note that the syntax of the format string is very likely to be extended in the future. The first character of the format string must not be '*' '?' '@' or 'r'; in essence, a new #GVariant must always be constructed by this function (and not merely passed through it unmodified). Note that the arguments must be of the correct width for their types specified in @format_string. This can be achieved by casting them. See the GVariant varargs documentation. |[ MyFlags some_flags = FLAG_ONE | FLAG_TWO; const gchar *some_strings[] = { "a", "b", "c", NULL }; GVariant *new_variant; new_variant = g_variant_new ("(t^as)", // This cast is required. (guint64) some_flags, some_strings); ]|
format_string is a #GVariant format string.___ is arguments, as per @format_string.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 exposinghandle(), or null. Returns null when the argument carries no pointer.
Source is the raw handle, raw buffer, wrapper, or null.A raw pointer carrier or null when no pointer is present.getLib ()
Returns the opened native library for this generated wrapper.
The opened native library.handle ()
Returns the wrapped NativeHandle.
The wrapped NativeHandle.isNull ()
Returns true when the wrapped handle is null.
A bool.describe ()
Returns a small string for debugging generated wrappers.
A string.byteswap ()
Performs a byteswapping operation on the contents of @value. The result is that all multi-byte numeric data contained in @value is byteswapped. That includes 16, 32, and 64bit signed and unsigned integers as well as file handles and double precision floating point values. This function is an identity mapping on any value that does not contain multi-byte numeric data. That include strings, booleans, bytes and containers containing only these things (recursively). While this function can safely handle untrusted, non-normal data, it is recommended to check whether the input is in normal form beforehand, using g_variant_is_normal_form(), and to reject non-normal inputs if your application can be strict about what inputs it rejects. The returned value is always in normal form and is marked as trusted. A full, not floating, reference is returned.
the byteswapped form of @value.check_format_string (string format_string, bool copy_only)
Checks if calling g_variant_get() with @format_string on @value would be valid from a type-compatibility standpoint. @format_string is assumed to be a valid format string (from a syntactic standpoint). If @copy_only is %TRUE then this function additionally checks that it would be safe to call g_variant_unref() on @value immediately after the call to g_variant_get() without invalidating the result. This is only possible if deep copies are made (ie: there are no pointers to the data inside of the soon-to-be-freed #GVariant instance). If this check fails then a g_critical() is printed and %FALSE is returned. This function is meant to be used by functions that wish to provide varargs accessors to #GVariant values of uncertain values (eg: g_variant_lookup() or g_menu_model_get_item_attribute()).
format_string is a valid #GVariant format string.copy_only is %TRUE to ensure the format string makes deep copies.%TRUE if @format_string is safe to use.classify ()
Classifies @value according to its top-level type.
the #GVariantClass of @value.compare (object two)
Compares @one and @two. The types of @one and @two are #gconstpointer only to allow use of this function with #GTree, #GPtrArray, etc. They must each be a #GVariant. Comparison is only defined for basic types (ie: booleans, numbers, strings). For booleans, %FALSE is less than %TRUE. Numbers are ordered in the usual way. Strings are in ASCII lexographical order. It is a programmer error to attempt to compare container values or two values that have types that are not exactly equal. For example, you cannot compare a 32-bit signed integer with a 32-bit unsigned integer. Also note that this function is not particularly well-behaved when it comes to comparison of doubles; in particular, the handling of incomparable values (ie: NaN) is undefined. If you only require an equality comparison, g_variant_equal() is more general.
two is a #GVariant instance of the same type.negative value if a < b; zero if a = b; positive value if a > b..dup_bytestring ()
Similar to g_variant_get_bytestring() except that instead of returning a constant string, the string is duplicated. The return value must be freed using g_free().
length is a pointer to a #gsize, to store the length (not including the nul terminator).a newly allocated string.dup_bytestring_array ()
Gets the contents of an array of array of bytes #GVariant. This call makes a deep copy; the return result should be released with g_strfreev(). If @length is non-%NULL then the number of elements in the result is stored there. In any case, the resulting array will be %NULL-terminated. For an empty array, @length will be set to 0 and a pointer to a %NULL pointer will be returned.
length is the length of the result, or %NULL.an array of strings.dup_objv ()
Gets the contents of an array of object paths #GVariant. This call makes a deep copy; the return result should be released with g_strfreev(). If
is non-%NULL then the number of elements in the result is stored there. In any case, the resulting array will be %NULL-terminated. For an empty array, @length will be set to 0 and a pointer to a %NULL pointer will be returned.length is the length of the result, or %NULL.an array of strings.dup_string ()
Similar to g_variant_get_string() except that instead of returning a constant string, the string is duplicated. The string will always be UTF-8 encoded. The return value must be freed using g_free().
length is a pointer to a #gsize, to store the length.a newly allocated string, UTF-8 encoded.dup_strv ()
Gets the contents of an array of strings #GVariant. This call makes a deep copy; the return result should be released with g_strfreev(). If
is non-%NULL then the number of elements in the result is stored there. In any case, the resulting array will be %NULL-terminated. For an empty array, @length will be set to 0 and a pointer to a %NULL pointer will be returned.length is the length of the result, or %NULL.an array of strings.equal (object two)
Checks if @one and @two have the same type and value. The types of @one and @two are #gconstpointer only to allow use of this function with #GHashTable. They must each be a #GVariant.
two is a #GVariant instance.%TRUE if @one and @two are equal.get (string format_string, list varargs)
Deconstructs a #GVariant instance. Think of this function as an analogue to scanf(). The arguments that are expected by this function are entirely determined by @format_string. @format_string also restricts the permissible types of @value. It is an error to give a value with an incompatible type. See the section on GVariant format strings. Please note that the syntax of the format string is very likely to be extended in the future.
determines the C types that are used for unpacking the values and also determines if the values are copied or borrowed, see the section on GVariant format strings.format_string is a #GVariant format string.... is arguments, as per @format_string.None.get_boolean ()
Returns the boolean value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_BOOLEAN.
%TRUE or %FALSE.get_byte ()
Returns the byte value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_BYTE.
a #guint8.get_bytestring ()
Returns the string value of a #GVariant instance with an array-of-bytes type. The string has no particular encoding. If the array does not end with a nul terminator character, the empty string is returned. For this reason, you can always trust that a non-%NULL nul-terminated string will be returned by this function. If the array contains a nul terminator character somewhere other than the last byte then the returned string is the string, up to the first such nul character. g_variant_get_fixed_array() should be used instead if the array contains arbitrary data that could not be nul-terminated or could contain nul bytes. It is an error to call this function with a @value that is not an array of bytes. The return value remains valid as long as @value exists.
the constant string.get_bytestring_array ()
Gets the contents of an array of array of bytes #GVariant. This call makes a shallow copy; the return result should be released with g_free(), but the individual strings must not be modified. If @length is non-%NULL then the number of elements in the result is stored there. In any case, the resulting array will be %NULL-terminated. For an empty array, @length will be set to 0 and a pointer to a %NULL pointer will be returned.
length is the length of the result, or %NULL.an array of constant strings.get_child (int index_, string format_string, list varargs)
Reads a child item out of a container #GVariant instance and deconstructs it according to @format_string. This call is essentially a combination of g_variant_get_child_value() and g_variant_get(). @format_string determines the C types that are used for unpacking the values and also determines if the values are copied or borrowed, see the section on
GVariantformat strings.
index_ is the index of the child to deconstruct.format_string is a #GVariant format string.... is arguments, as per @format_string.None.get_child_value (int index_)
Reads a child item out of a container #GVariant instance. This includes variants, maybes, arrays, tuples and dictionary entries. It is an error to call this function on any other type of #GVariant. It is an error if
is greater than the number of child items in the container. See g_variant_n_children(). The returned value is never floating. You should free it with g_variant_unref() when you're done with it. Note that values borrowed from the returned child are not guaranteed to still be valid after the child is freed even if you still hold a reference to @value, ifhas not been serialized at the time this function is called. To avoid this, you can serialize @value by calling g_variant_get_data() and optionally ignoring the return value. There may be implementation specific restrictions on deeply nested values, which would result in the unit tuple being returned as the child value, instead of further nested children. #GVariant is guaranteed to handle nesting up to at least 64 levels. This function is O(1).index_ is the index of the child to fetch.the child at the specified index.get_data ()
Returns a pointer to the serialized form of a #GVariant instance. The returned data may not be in fully-normalised form if read from an untrusted source. The returned data must not be freed; it remains valid for as long as @value exists. If @value is a fixed-sized value that was deserialized from a corrupted serialized container then %NULL may be returned. In this case, the proper thing to do is typically to use the appropriate number of nul bytes in place of @value. If @value is not fixed-sized then %NULL is never returned. In the case that @value is already in serialized form, this function is O(1). If the value is not already in serialized form, serialization occurs implicitly and is approximately O(n) in the size of the result. To deserialize the data returned by this function, in addition to the serialized data, you must know the type of the #GVariant, and (if the machine might be different) the endianness of the machine that stored it. As a result, file formats or network messages that incorporate serialized #GVariants must include this information either implicitly (for instance "the file always contains a %G_VARIANT_TYPE_VARIANT and it is always in little-endian order") or explicitly (by storing the type and/or endianness in addition to the serialized data).
the serialized form of @value, or %NULL.get_data_as_bytes ()
Returns a pointer to the serialized form of a #GVariant instance. The semantics of this function are exactly the same as g_variant_get_data(), except that the returned #GBytes holds a reference to the variant data.
A new #GBytes representing the variant data.get_double ()
Returns the double precision floating point value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_DOUBLE.
a #gdouble.get_fixed_array (int element_size)
Provides access to the serialized data for an array of fixed-sized items.
must be an array with fixed-sized elements. Numeric types are fixed-size, as are tuples containing only other fixed-sized types.must be the size of a single element in the array, as given by the section on serialized data memory. In particular, arrays of these fixed-sized types can be interpreted as an array of the given C type, with @element_size set to the size the appropriate type: - %G_VARIANT_TYPE_INT16 (etc.): #gint16 (etc.) - %G_VARIANT_TYPE_BOOLEAN: #guchar (not #gboolean!) - %G_VARIANT_TYPE_BYTE: #guint8 - %G_VARIANT_TYPE_HANDLE: #guint32 - %G_VARIANT_TYPE_DOUBLE: #gdouble For example, if calling this function for an array of 32-bit integers, you might say sizeof(gint32). This value isn't used except for the purpose of a double-check that the form of the serialized data matches the caller's expectation. @n_elements, which must be non-%NULL, is set equal to the number of items in the array.n_elements is a pointer to the location to store the number of items.element_size is the size of each element.a pointer to the fixed array.get_handle ()
Returns the 32-bit signed integer value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_HANDLE. By convention, handles are indexes into an array of file descriptors that are sent alongside a D-Bus message. If you're not interacting with D-Bus, you probably don't need them.
a #gint32.get_int16 ()
Returns the 16-bit signed integer value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_INT16.
a #gint16.get_int32 ()
Returns the 32-bit signed integer value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_INT32.
a #gint32.get_int64 ()
Returns the 64-bit signed integer value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_INT64.
a #gint64.get_maybe ()
Given a maybe-typed #GVariant instance, extract its value. If the value is Nothing, then this function returns %NULL.
the contents of @value, or %NULL.get_normal_form ()
Gets a #GVariant instance that has the same value as @value and is trusted to be in normal form. If @value is already trusted to be in normal form then a new reference to @value is returned. If @value is not already trusted, then it is scanned to check if it is in normal form. If it is found to be in normal form then it is marked as trusted and a new reference to it is returned. If @value is found not to be in normal form then a new trusted #GVariant is created with the same value as @value. The non-normal parts of @value will be replaced with default values which are guaranteed to be in normal form. It makes sense to call this function if you've received #GVariant data from untrusted sources and you want to ensure your serialized output is definitely in normal form. If @value is already in normal form, a new reference will be returned (which will be floating if @value is floating). If it is not in normal form, the newly created #GVariant will be returned with a single non-floating reference. Typically, g_variant_take_ref() should be called on the return value from this function to guarantee ownership of a single non-floating reference to it.
a trusted #GVariant.get_objv ()
Gets the contents of an array of object paths #GVariant. This call makes a shallow copy; the return result should be released with g_free(), but the individual strings must not be modified. If @length is non-%NULL then the number of elements in the result is stored there. In any case, the resulting array will be %NULL-terminated. For an empty array, @length will be set to 0 and a pointer to a %NULL pointer will be returned.
length is the length of the result, or %NULL.an array of constant strings.get_size ()
Determines the number of bytes that would be required to store @value with g_variant_store(). If @value has a fixed-sized type then this function always returned that fixed size. In the case that @value is already in serialized form or the size has already been calculated (ie: this function has been called before) then this function is O(1). Otherwise, the size is calculated, an operation which is approximately O(n) in the number of values involved.
the serialized size of @value.get_string ()
Returns the string value of a #GVariant instance with a string type. This includes the types %G_VARIANT_TYPE_STRING, %G_VARIANT_TYPE_OBJECT_PATH and %G_VARIANT_TYPE_SIGNATURE. The string will always be UTF-8 encoded, will never be %NULL, and will never contain nul bytes. If @length is non-%NULL then the length of the string (in bytes) is returned there. For trusted values, this information is already known. Untrusted values will be validated and, if valid, a strlen() will be performed. If invalid, a default value will be returned — for %G_VARIANT_TYPE_OBJECT_PATH, this is
"/", and for other types it is the empty string. It is an error to call this function with a @value of any type other than those three. The return value remains valid as long as @value exists.
length is a pointer to a #gsize, to store the length.the constant string, UTF-8 encoded.get_strv ()
Gets the contents of an array of strings #GVariant. This call makes a shallow copy; the return result should be released with g_free(), but the individual strings must not be modified. If @length is non-%NULL then the number of elements in the result is stored there. In any case, the resulting array will be %NULL-terminated. For an empty array, @length will be set to 0 and a pointer to a %NULL pointer will be returned.
length is the length of the result, or %NULL.an array of constant strings.get_type ()
Determines the type of @value. The return value is valid for the lifetime of @value and must not be freed.
a #GVariantType.get_type_string ()
Returns the type string of @value. Unlike the result of calling g_variant_type_peek_string(), this string is nul-terminated. This string belongs to #GVariant and must not be freed.
the type string for the type of @value.get_uint16 ()
Returns the 16-bit unsigned integer value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_UINT16.
a #guint16.get_uint32 ()
Returns the 32-bit unsigned integer value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_UINT32.
a #guint32.get_uint64 ()
Returns the 64-bit unsigned integer value of @value. It is an error to call this function with a @value of any type other than %G_VARIANT_TYPE_UINT64.
a #guint64.get_variant ()
Unboxes @value. The result is the #GVariant instance that was contained in @value.
the item contained in the variant.hash ()
Generates a hash value for a #GVariant instance. The output of this function is guaranteed to be the same for a given value only per-process. It may change between different processor architectures or even different versions of GLib. Do not use this function as a basis for building protocols or file formats. The type of @value is #gconstpointer only to allow use of this function with #GHashTable. @value must be a #GVariant.
a hash value corresponding to @value.is_container ()
Checks if @value is a container.
%TRUE if @value is a container.is_floating ()
Checks whether @value has a floating reference count. This function should only ever be used to assert that a given variant is or is not floating, or for debug purposes. To acquire a reference to a variant that might be floating, always use g_variant_ref_sink() or g_variant_take_ref(). See g_variant_ref_sink() for more information about floating reference counts.
whether @value is floating.is_normal_form ()
Checks if @value is in normal form. The main reason to do this is to detect if a given chunk of serialized data is in normal form: load the data into a #GVariant using g_variant_new_from_data() and then use this function to check. If @value is found to be in normal form then it will be marked as being trusted. If the value was already marked as being trusted then this function will immediately return %TRUE. There may be implementation specific restrictions on deeply nested values. GVariant is guaranteed to handle nesting up to at least 64 levels.
%TRUE if @value is in normal form.is_of_type (object type)
Checks if a value has a type matching the provided type.
type is a #GVariantType.%TRUE if the type of @value matches @type.iter_new ()
Creates a heap-allocated #GVariantIter for iterating over the items in
Use g_variant_iter_free() to free the return value when you no longer need it. A reference is taken to @value and will be released only when g_variant_iter_free() is called.a new heap-allocated #GVariantIter.lookup (string key, string format_string, list varargs)
Looks up a value in a dictionary #GVariant. This function is a wrapper around g_variant_lookup_value() and g_variant_get(). In the case that %NULL would have been returned, this function returns %FALSE. Otherwise, it unpacks the returned value and returns %TRUE. @format_string determines the C types that are used for unpacking the values and also determines if the values are copied or borrowed, see the section on
GVariantformat strings. This function is currently implemented with a linear scan. If you plan to do many lookups then #GVariantDict may be more efficient.
key is the key to look up in the dictionary.format_string is a GVariant format string.... is the arguments to unpack the value into.%TRUE if a value was unpacked.lookup_value (string key, object expected_type)
Looks up a value in a dictionary #GVariant. This function works with dictionaries of the type
a{s*}(and equally well with typea{o*}), but we only further discuss the string case for sake of clarity). In the event that @dictionary has the typea{sv}, the @expected_type string specifies what type of value is expected to be inside of the variant. If the value inside the variant has a different type then %NULL is returned. In the event that @dictionary has a value type other than v then
must directly match the value type and it is used to unpack the value directly or an error occurs. In either case, if @key is not found in @dictionary, %NULL is returned. If the key is found and the value has the correct type, it is returned. If @expected_type was specified then any non-%NULL return value will have this type. This function is currently implemented with a linear scan. If you plan to do many lookups then [struct@VariantDict] may be more efficient.key is the key to look up in the dictionary.expected_type is a #GVariantType, or %NULL.the value of the dictionary key, or %NULL.n_children ()
Determines the number of children in a container #GVariant instance. This includes variants, maybes, arrays, tuples and dictionary entries. It is an error to call this function on any other type of #GVariant. For variants, the return value is always 1. For values with maybe types, it is always zero or one. For arrays, it is the length of the array. For tuples it is the number of tuple items (which depends only on the type). For dictionary entries, it is always 2 This function is O(1).
the number of children in the container.print (bool type_annotate)
Pretty-prints @value in the format understood by g_variant_parse(). The format is described here. If @type_annotate is %TRUE, then type information is included in the output.
type_annotate is %TRUE if type information should be included in the output.a newly-allocated string holding the result..print_string (object arg1String, bool type_annotate)
Behaves as g_variant_print(), but operates on a #GString. If @string is non-%NULL then it is appended to and returned. Else, a new empty #GString is allocated and it is returned.
string is a #GString, or %NULL.type_annotate is %TRUE if type information should be included in the output.a #GString containing the string.ref ()
Increases the reference count of @value.
the same @value.ref_sink ()
#GVariant uses a floating reference count system. All functions with names starting with
g_variant_new_return floating references. Calling g_variant_ref_sink() on a #GVariant with a floating reference will convert the floating reference into a full reference. Calling g_variant_ref_sink() on a non-floating #GVariant results in an additional normal reference being added. In other words, if the @value is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference. If the @value is not floating, then this call adds a new normal reference increasing the reference count by one. All calls that result in a #GVariant instance being inserted into a container will call g_variant_ref_sink() on the instance. This means that if the value was just created (and has only its floating reference) then the container will assume sole ownership of the value at that point and the caller will not need to unreference it. This makes certain common styles of programming much easier while still maintaining normal refcounting semantics in situations where values are not floating.
the same @value.store (data)
Stores the serialized form of @value at @data. @data should be large enough. See g_variant_get_size(). The stored data is in machine native byte order but may not be in fully-normalised form if read from an untrusted source. See g_variant_get_normal_form() for a solution. As with g_variant_get_data(), to be able to deserialize the serialized variant successfully, its type and (if the destination machine might be different) its endianness must also be available. This function is approximately O(n) in the size of @data.
data is the location to store the serialized data at.None.take_ref ()
If @value is floating, sink it. Otherwise, do nothing. Typically you want to use g_variant_ref_sink() in order to automatically do the correct thing with respect to floating or non-floating references, but there is one specific scenario where this function is helpful. The situation where this function is helpful is when creating an API that allows the user to provide a callback function that returns a #GVariant. We certainly want to allow the user the flexibility to return a non-floating reference from this callback (for the case where the value that is being returned already exists). At the same time, the style of the #GVariant API makes it likely that for newly-created #GVariant instances, the user can be saved some typing if they are allowed to return a #GVariant with a floating reference. Using this function on the return value of the user's callback allows the user to do whichever is more convenient for them. The caller will always receives exactly one full reference to the value: either the one that was returned in the first place, or a floating reference that has been converted to a full reference. This function has an odd interaction when combined with g_variant_ref_sink() running at the same time in another thread on the same #GVariant instance. If g_variant_ref_sink() runs first then the result will be that the floating reference is converted to a hard reference. If g_variant_take_ref() runs first then the result will be that the floating reference is converted to a hard reference and an additional reference on top of that one is added. It is best to avoid this situation.
the same @value.unref ()
Decreases the reference count of @value. When its reference count drops to 0, the memory used by the variant is freed.
None.
