[pulseaudio-discuss] [PATCH RFCv3 04/51] tagstruct: Add type _APPENDED

[Peter Meerwald]

Hello David,

> > add 128 bytes of storage in each tagstruct that will initially
> > be used; if this storage is exceeded the type changes to _DYNAMIC
> >
> > v2: (thanks Alexander Patrakov)
> > * replace constant 100 with GROW_TAG_SIZE (the increment in with a dynamic
> tagstruct grows when extend()ed)
> >
> > Signed-off-by: Peter Meerwald <pmeerw at pmeerw.net>
> > ---
> >   src/pulsecore/tagstruct.c | 22 +++++++++++++++++-----
> >   1 file changed, 17 insertions(+), 5 deletions(-)
> >
> > diff --git a/src/pulsecore/tagstruct.c b/src/pulsecore/tagstruct.c
> > index 834a972..a504be8 100644
> > --- a/src/pulsecore/tagstruct.c
> > +++ b/src/pulsecore/tagstruct.c
> > @@ -41,6 +41,8 @@
> >   #include "tagstruct.h"
> >
> >   #define MAX_TAG_SIZE (64*1024)
> > +#define MAX_APPENDED_SIZE 128
> > +#define GROW_TAG_SIZE 100
> >
> >   struct pa_tagstruct {
> >       uint8_t *data;
> > @@ -50,17 +52,21 @@ struct pa_tagstruct {
> >       enum {
> >           PA_TAGSTRUCT_FIXED,
> >           PA_TAGSTRUCT_DYNAMIC,
> > +        PA_TAGSTRUCT_APPENDED,
> 
> How about adding comments like this:
> 
>   PA_TAGSTRUCT_FIXED, /* The tagstruct does not own the data, buffer was 
> provided by caller */
>   PA_TAGSTRUCT_DYNAMIC, /* Buffer owned by tagstruct, data must be freed */
>   PA_TAGSTRUCT_APPENDED, /* Data points to per_type.appended minibuffer, 
> used for small tagstructs. Will change to dynamic if needed */

good idea!
will do for the next revision

thanks, p.
 
> >       } type;
> > +    union {
> > +        uint8_t appended[MAX_APPENDED_SIZE];
> > +    } per_type;
> >   };
> >
> >   pa_tagstruct *pa_tagstruct_new(void) {
> >       pa_tagstruct*t;
> >
> >       t = pa_xnew(pa_tagstruct, 1);
> > -    t->data = NULL;
> > -    t->allocated = t->length = 0;
> > -    t->rindex = 0;
> > -    t->type = PA_TAGSTRUCT_DYNAMIC;
> > +    t->data = t->per_type.appended;
> > +    t->allocated = MAX_APPENDED_SIZE;
> > +    t->length = t->rindex = 0;
> > +    t->type = PA_TAGSTRUCT_APPENDED;
> >
> >       return t;
> >   }
> > @@ -94,7 +100,13 @@ static void extend(pa_tagstruct*t, size_t l) {
> >       if (t->length+l <= t->allocated)
> >           return;
> >
> > -    t->data = pa_xrealloc(t->data, t->allocated = t->length+l+100);
> > +    if (t->type == PA_TAGSTRUCT_DYNAMIC)
> > +        t->data = pa_xrealloc(t->data, t->allocated = t->length + l +
> GROW_TAG_SIZE);
> > +    else if (t->type == PA_TAGSTRUCT_APPENDED) {
> > +        t->type = PA_TAGSTRUCT_DYNAMIC;
> > +        t->data = pa_xmalloc(t->allocated = t->length + l + GROW_TAG_SIZE);
> > +        memcpy(t->data, t->per_type.appended, t->length);
> > +    }
> >   }
> >
> >   void pa_tagstruct_puts(pa_tagstruct*t, const char *s) {
> >
> 
> 

-- 

Peter Meerwald
+43-664-2444418 (mobile)