Previously this was only done in the is_subset() check but
having it only there brings us into definition-hell where
"1" and "{1}" are subset of each other but not equal.
Fix freeing of partially-inited list value when both values
passed are equal and we want to return a single non-list
value as result. Fixes unit test. Also fix up docs a bit.
https://bugzilla.gnome.org/show_bug.cgi?id=637776
And use it for the fraction comparisons in gstvalue.c instead
of using comparisons by first converting the fractions to double.
Should fix bug #628174.
API: gst_util_fraction_compare()
This is not really necessary here because everything is
initialized from gst_init() already but using G_DEFINE_TYPE()
removes some copy&paste boilerplate code.
This changes some APIs in compatible ways:
- Some functions now take "const char *" arguments, not "char *"
- Some structs now have "conts char *" members, not "char *"
The changes may cause warnings when compiling with the right warning
flags. You've been warned.
Also adds -Wwrite-strings as a warning flag in configure.ac.
https://bugzilla.gnome.org/show_bug.cgi?id=611692
Previous code treated "1/1yourmom" the same as "1/1" and "1wimsmom" the
same as "1". Now the code is stricter and will fail to convert a
fraction when followed by garbage text.
gst_value_list_size and gst_value_list_get_value will do a series of
extra checks due to being public methods.
When we use them from within gstvalue.c we can directly use them without
the extra checks.
gst_util_greatest_common_divisor()
gst_util_double_to_fraction()
gst_util_fraction_to_double()
Using these instead of going over GValue has much lower overhead.
Also add float<->fraction transform functions for GValue.
Add a quick return if two types are the same. Change the check for the
intersection function to be the same as the one used in intersect(). The
later tries both directions.
Don't forbid the empty string "" in generic structures, only in taglists.
Properly allow the NULL string by adding special cases for serialising
and deserialising it. prop1=(string)NULL is the NULL string,
prop1=(string)"NULL" is the actual string with the value "NULL"
This makes the generated code faster since:
* It won't have to read an undirect value (which will most likely be
outside of the L1/L2 cache)
* We know that value never changes (the compiler has no clue that it doesn't).
Small micro-optimisation: look up value table for fundamental types
via an array dedicated to fundamental types instead of going through
a hash table lookup. Since there can be only 255 fundamental types,
the table size/efficiency trade-off should be acceptable, esp. since
the most commonly-used types are all fundamental types. The size of
the table could probably be minimised further if needed by allocating
the table dynamically and only expanding it on demand.
GTypes are not ints and as such are not guaranteed to fit into an int
(with the exception of fundamental types), so we really shouldn't put
them into int variables. Even if a rather unlikely obscure corner case,
this has actually been a problem at some point in the past, see commit
99f16655f4.
Add a GType->GstValueTable hashtable mapping.
Avoid _get_type() multiple times when we can.
Use GSlice for fraction range dynamic memory
Add G_LIKELY when we can
Improve lookup of the value table using the hashtable
Fix some memory leaks shown by the new serialisation/deserialisation unit
test. Split the gst_string_wrap function in gstvalue.c into components and
use them to make gst_string_take_and_wrap, which takes ownership of the
string, avoiding a strdup.
Add some G_LIKELY/UNLIKELY, and clean up some leaks in error paths.
Use string_warp/unwrap to escape delimiters, otherwise deserialisation fails.
Also move GST_ASCII_IS_STRING to private header to avoid keeping it in sync.
Also use '\0' when terminating a string for better readability.
Original commit message from CVS:
* gst/gstvalue.c: (gst_type_is_fixed), (gst_value_is_fixed):
Reorganize some more, be more conservative with the GST_TYPE_ARRAY not
being fixed and inline the trivial check.
Original commit message from CVS:
* gst/gstcaps.c: (gst_caps_copy), (_gst_caps_free),
(gst_caps_merge_structure), (gst_caps_get_structure),
(gst_caps_copy_nth), (gst_caps_set_simple),
(gst_caps_set_simple_valist), (gst_caps_is_fixed),
(gst_caps_is_equal_fixed), (gst_caps_intersect),
(gst_caps_subtract), (gst_caps_normalize), (gst_caps_do_simplify),
(gst_caps_to_string):
Callgrind micro optimisations.
Avoid array bounds checks and force inline of trivial function.
* gst/gstobject.c: (gst_object_set_name_default):
-1 is equivalent to letting glib to the strlen but then there is more
room for optimisations and it's not our fault.
* gst/gststructure.c: (gst_structure_id_empty_new_with_size):
no need to clear the array, we're cool.
* gst/gstvalue.c: (gst_type_is_fixed), (gst_value_is_fixed):
The most common _is_fixed() check is done on fundamental glib base
types so we check this first instead of doing a huge amount of
useless GST_TYPE_ARRAY calls.
Original commit message from CVS:
* gst/gststructure.c: (gst_structure_id_empty_new_with_size):
No need to memset, we can clear the value ourselves.
* gst/gstvalue.c: (gst_type_is_fixed),
(gst_value_get_compare_func):
Some optimisations from a few callgrind sessions:
When checking if a type is fixed, check for trivial fundamental types
first before checking types for which we need to get the type followed
by the heavy duty type checks, this reduces the amount of
g_type_fundamental() calls a lot.
When getting the compare function, first check for our registered types.
If that fails, do the heavy duty g_type_is_a() checks, reduces the
amount of g_type_is_a() considerably.
