|author||David Robillard <firstname.lastname@example.org>||2012-03-03 21:12:15 +0000|
|committer||David Robillard <email@example.com>||2012-03-03 21:12:15 +0000|
Add a warning about the 0 reference problem.
Diffstat (limited to 'lv2/lv2plug.in/ns/ext/atom/forge.h')
1 files changed, 10 insertions, 8 deletions
diff --git a/lv2/lv2plug.in/ns/ext/atom/forge.h b/lv2/lv2plug.in/ns/ext/atom/forge.h
index 82e80eb..2860ab1 100644
@@ -145,14 +145,16 @@ lv2_atom_forge_set_buffer(LV2_Atom_Forge* forge, uint8_t* buf, size_t size)
Set the sink function where @p forge will write output.
- The return value of forge functions is a pointer to the written data, which
- is used for updating parent sizes. To enable this, the sink function must
- return a valid pointer to a contiguous LV2_Atom header. For ringbuffers,
- this should be possible as long as the size of the buffer is a multiple of
- sizeof(LV2_Atom), since atoms are always aligned. When using a ringbuffer,
- the returned pointers may not point to a complete atom (including body).
- The user must take care to only use these return values in a way compatible
- with the sink used.
+ The return value of forge functions is an LV2_Atom_Forge_Ref which is an
+ integer type safe to use as a pointer but is otherwise opaque. The sink
+ function must return a ref that can be dereferenced to access as least
+ sizeof(LV2_Atom) bytes of the written data, so sizes can be updated. For
+ ringbuffers, this should be possible as long as the size of the buffer is a
+ multiple of sizeof(LV2_Atom), since atoms are always aligned.
+ Note that 0 is an invalid reference, so if you are using a buffer offset be
+ sure to offset it such that 0 is never a valid reference. You will get
+ confusing errors otherwise.
static inline void