This introduces a more human friendly syntax to specify nested
structures It does so by using 2 different markers for opening and
closing them instead of abusing quotes which lead to requiring an insane
amount of escaping to match nesting levels.
The brackets (`[` and `]`) have been chosen as they avoid complex
constructions with curly brackets (or lower/higher than signs) where you
could have structures embedded inside arrays (which also use curly
brackets), ie. `s, array=(structure){{struct}}` should be parsed as an
array of structures, but the cast seems to imply something different. We
do not have this issue with brackets as they are currently used for
ranges, which can only be casted to numeric types.
This commit does not make use of that new syntax for serialization as
that would break backward compatibility, so it is basically a 'sugar'
syntax for humans. A notice has been explicitly made in the
documentation to let the user know about it.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/532>
Typing hints can only be passed to gst_value_deserialize()
through the type of the passed-in value. This means deserialization
can only target the desired type for the top-level elements,
making it for example impossible to deserialize an array of
flags to the expected type.
This commit exposes a new function, gst_value_deserialize_full(),
that takes an optional pspec as the extra parameter, and updates
the deserialization code to pass around that pspec, or the
element_spec when recursively parsing the elements of a list-type
value.
This allows for example passing arrays of flags through the
command line or gst_util_set_object_arg, eg:
foo="<bar,bar+baz>"
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/629>
The old code would leave a dangling pointer in oldstr_ptr if two threads
attempted to take the same structure into the same location at the same
time:
1. First "oldstr == newstr" check (before the loop) fails.
2. Compare-and-exchange fails, due to a second thread completing the
same gst_structure_take.
3. Second "oldstr == newstr" check (in the loop) succeeds, loop breaks.
4. "oldstr" check succeeds, old structure gets freed.
5. oldstr_ptr now contains a dangling pointer.
This shouldn't happen in code that handles ownership sanely, so check
that we don't try to do this and complain loudly.
Also simplify the function by using a do-while loop, like
gst_mini_object_take.
https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/413
This tries to inline as much as possible array/list and its contents
in order to avoid double allocation/freeing. This also improves the
locality of data.
The internal value is still API/ABI compatible with the *public*
GArray structure. This allows READ-ONLY backwards compatibility with
any external users that assume that the content of a list/array value
is backed by a GArray.
For all the structure creation using valist/varargs we calculate
the number of fields we will need to store. This ensures all callers
will end up with a single allocation.
Instead of having 3 allocations:
* One for GstStructure
* One for GArray
* One for the array *within* GArray
We try to limit this to a single allocation, inlining everything. This
reduces the number of micro-allocations and improves locality of data
access.
* Making sure that `static inline` function are in the GIR (by first
defining them, and make sure to mark as skiped)
* Do not try to link to unexisting symbols
* Also generate GIR information about gst_tracers
This adds a binding friendly interface to get and set arrays
and list into GstStructure.
New API:
- gst_structure_set_array
- gst_structure_set_list
- gst_structure_get_array
- gst_structure_get_list
https://bugzilla.gnome.org/show_bug.cgi?id=753754
But only when serializing outside of GstStructures, because in case of
GstStructure the type is already preprended to the array/list and the
GstStructure API makes sure that they have the same "generic" type so
deserialization works properly.
This keeps serialization of GstStructures the same as before, and the
GstCaps unit tests already test for that. However when serializing
standalone arrays/lists get the types added now.
Implement GstDynamicTypeFactory as a new registry feature.
GstDynamicTypeFactory provides a way of registering a GType
into the registry, such that it will be registered as a dynamic
type when the registry is loaded, and then automatically loaded
if the type is needed during caps parsing.
This allows using non-core types in pad templates, by loading a
registry feature to create the GType on the fly.
https://bugzilla.gnome.org/show_bug.cgi?id=750079
We use this class to register tracer log entry metadata and build a log
template. With the log template we can serialize log data very efficiently.
This also simplifies the logging code, since that is now a simple varargs
function that is not exposing the implementation details.
Add docs for the new class and basic tests.
Remove the previous log handler.
Fixes#760267
GstFlagSet is a new type designed for negotiating sets
of boolean capabilities flags, consisting of a 32-bit
flags bitfield and 32-bit mask field. The mask field
indicates which of the flags bits an element needs to have
as specific values, and which it doesn't care about.
This allows efficient negotiation of arrays of boolean
capabilities.
The standard serialisation format is FLAGS:MASK, with
flags and mask fields expressed in hexadecimal, however
GstFlagSet has a gst_register_flagset() function, which
associates a new GstFlagSet derived type with an existing
GFlags gtype. When serializing a GstFlagSet with an
associated set of GFlags, it also serializes a human-readable
form of the flags for easier debugging.
It is possible to parse a GFlags style serialisation of a
flagset, without the hex portion on the front. ie,
+flag1/flag2/flag3+flag4, to indicate that
flag1 & flag4 must be set, and flag2/flag3 must be unset,
and any other flags are don't-care.
https://bugzilla.gnome.org/show_bug.cgi?id=746373
TRUE is 1, but every other non-zero value is also considered true. Comparing
for equality with TRUE would only consider 1 but not the others.
Also normalize booleans in a few places.
Support for (nullable) was added to G-I at the same time as nullable
return values. Previous versions of G-I will not mark return values as
nullable, even when an (allow-none) annotation is present, so it is
not necessary to add (allow-none) annotations for compatibility with
older versions of G-I.
https://bugzilla.gnome.org/show_bug.cgi?id=730957
