Re: [Xen-devel] [PATCH] libxl: add support for yajl 2.x

[Roger Pau Monnà <roger.pau@xxxxxxxxxxxxx>]

2012/1/3 Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>:
> Roger Pau Monne writes ("[Xen-devel] [PATCH] libxl: add support for yajl 
> 2.x"):
>> This patch adds support for yajl versions 2.x, while retaining 1.x
>> compatibility. This patch adds quite a lot of #ifdefs all over the
>> json code, so I'm open to suggestions if there's a better way to
>> handle this.
>
> I have some suggestions. ÂThe basic idea would be to try to put all of
> the ifdefs in one place in libxl_json.h.
>
>> +#ifdef HAVE_YAJL_V2
>> +static int json_callback_number(void *opaque, const char *s, size_t len)
>> +#else
>> Âstatic int json_callback_number(void *opaque, const char *s, unsigned int 
>> len)
>> +#endif
>
> So how about:
>
> Â/* libxl_json.h */
>
> Â#ifdef HAVE_YAJL_V2
> Âtypedef size_t libxl_yajl_length;
> Â...
> Â#else
> Âtypedef unsigned int libxl_yajl_length;
> Â...
> Â#endif
>
>
> Â/* libxl_json.c */
>
> Âstatic int json_callback_number(void *opaque, const char *s,
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âlibxl_yajl_length len) {
> Â Â ...
>
>> +#ifdef HAVE_YAJL_V2
>> + Â Â Â Âyajl_ctx.hand = yajl_alloc(&callbacks, NULL, &yajl_ctx);
>> +#else
>> Â Â Â Â Âyajl_parser_config cfg = {
>> Â Â Â Â Â Â Â.allowComments = 1,
>> Â Â Â Â Â Â Â.checkUTF8 = 1,
>> Â Â Â Â Â};
>> Â Â Â Â Âyajl_ctx.hand = yajl_alloc(&callbacks, &cfg, NULL, &yajl_ctx);
>> +#endif
> ...
>> Â Â Âstatus = yajl_parse(yajl_ctx.hand, (const unsigned char *)s, strlen(s));
>> Â Â Âif (status != yajl_status_ok)
>> Â Â Â Â Âgoto out;
>> +
>
> Â/* libxl_json.h */
>
> Â#ifdef HAVE_YAJL_V2
> Â...
> Âstatic inline int libxl_yajl_alloc(...) { return yajl_alloc .... }
> Â...
> Â#else
> Â...
> Âstatic inline int libxl_yajl_alloc(...) { [version with cfg] }
> Â#define yajl_complete_parse yajl_parse_complete
> Â...
> Â#endif
>
> etc.

I haven't really though of this anymore, but this seems much more
appropriate and less intrusive.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel