Re: [libvirt] [PATCH] Allow to dynamically set the size of the debug buffer
On Tue, Mar 08, 2011 at 03:43:50PM +0000, Daniel P. Berrange wrote:
On Tue, Mar 08, 2011 at 06:44:56PM +0800, Daniel Veillard wrote:
> diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
> index 452566c..d3631ec 100644
> --- a/daemon/libvirtd.c
> +++ b/daemon/libvirtd.c
> @@ -2720,11 +2720,16 @@ qemudSetLogging(struct qemud_server *server, virConfPtr
conf,
> const char *filename)
> {
> int log_level = 0;
> + int log_buffer_size = -2;
> char *log_filters = NULL;
> char *log_outputs = NULL;
> char *log_file = NULL;
> int ret = -1;
>
> + GET_CONF_INT (conf, filename, log_buffer_size);
> + if (log_buffer_size != -2)
> + virLogSetBufferSize(log_buffer_size);
The possible values here seem a little odd.
> 0 -> sets the log buffer size
== 0 -> disables
== -2 -> leave at the default
< 0 -> disables
-2 was just a trick to try to get from GET_CONF_INT whether
the configuration file had that setting set or not. I tried to
hint at the problem in the comment to my patch but this just led
to confusion apparently.
I will just default log_buffer_size to 64 as indicated in
libvirtd.conf and fix the macro to actually get the information out.
> /**
> + * virLogSetBufferSize:
> + * @size: size of the buffer in kilobytes or 0 to deactivate
> + *
> + * Dynamically set the size or desactivate the logging buffer used to keep
> + * a trace of all recent debug output. Note that the content of the buffer
> + * is lost if it gets reallocated.
> + *
> + * Return -1 in case of failure or 0 in case of success
> + */
> +extern int
> +virLogSetBufferSize(int size) {
> + int ret = 0;
> + int oldsize;
> + char *oldLogBuffer;
> +
> + if (size < 0)
> + size = 0;
IMHO size should just be 'size_t'. We don't need to have -ve
values, since '0' already indicates disabled.
I dislike using size_t for kilobytes as it tend to carry the meaning
that the value is a lenght in byte :
"This type is used to represent the size of an object."
this is a very good way to get people confused, and we have had byte/kb
confusion in the past already.
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
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