[libvirt] [PATCH 8/8] latency: Update cmdBlkStats to use new API

[Daniel Veillard]

On Mon, Sep 05, 2011 at 04:38:35PM +0800, Osier Yang wrote:
> The modified function fallbacks to use virDomainBlockStats if
> virDomainBlockStatsFlags is not supported by the hypervisor driver.
> If the new API is supported, it will be invoked instead of the
> old API.
> ---
>  tools/virsh.c |  104 ++++++++++++++++++++++++++++++++++++++++++++++-----------
>  1 files changed, 84 insertions(+), 20 deletions(-)
> 
> diff --git a/tools/virsh.c b/tools/virsh.c
> index c7240e5..ea41221 100644
> --- a/tools/virsh.c
> +++ b/tools/virsh.c
> @@ -1070,6 +1070,9 @@ cmdDomblkstat (vshControl *ctl, const vshCmd *cmd)
>      virDomainPtr dom;
>      const char *name = NULL, *device = NULL;
>      struct _virDomainBlockStats stats;
> +    virTypedParameterPtr params = NULL;
> +    int rc, nparams = 0;
> +    bool ret = false;
>  
>      if (!vshConnectionUsability (ctl, ctl->conn))
>          return false;
> @@ -1077,34 +1080,95 @@ cmdDomblkstat (vshControl *ctl, const vshCmd *cmd)
>      if (!(dom = vshCommandOptDomain (ctl, cmd, &name)))
>          return false;
>  
> -    if (vshCommandOptString (cmd, "device", &device) <= 0) {
> -        virDomainFree(dom);
> -        return false;
> -    }
> +    if (vshCommandOptString (cmd, "device", &device) <= 0)
> +        goto cleanup;
>  
> -    if (virDomainBlockStats (dom, device, &stats, sizeof stats) == -1) {
> -        vshError(ctl, _("Failed to get block stats %s %s"), name, device);
> -        virDomainFree(dom);
> -        return false;
> -    }
> +    rc = virDomainBlockStatsFlags(dom, device, NULL, &nparams, 0);
>  
> -    if (stats.rd_req >= 0)
> -        vshPrint (ctl, "%s rd_req %lld\n", device, stats.rd_req);
> +    /* It might fail when virDomainBlockStatsFlags is not
> +     * supported on older libvirt, fallback to use virDomainBlockStats
> +     * then.
> +     */
> +    if (rc < 0) {
> +        if (last_error->code != VIR_ERR_NO_SUPPORT) {
> +            virshReportError(ctl);
> +            goto cleanup;
> +        } else {
> +            virFreeError(last_error);
> +            last_error = NULL;
>  
> -    if (stats.rd_bytes >= 0)
> -        vshPrint (ctl, "%s rd_bytes %lld\n", device, stats.rd_bytes);
> +            if (virDomainBlockStats (dom, device, &stats,
> +                                     sizeof stats) == -1) {
> +                vshError(ctl, _("Failed to get block stats %s %s"),
> +                         name, device);
> +                goto cleanup;
> +            }
> +
> +            if (stats.rd_req >= 0)
> +                vshPrint (ctl, "%s rd_req %lld\n", device, stats.rd_req);
>  
> -    if (stats.wr_req >= 0)
> -        vshPrint (ctl, "%s wr_req %lld\n", device, stats.wr_req);
> +            if (stats.rd_bytes >= 0)
> +                vshPrint (ctl, "%s rd_bytes %lld\n", device, stats.rd_bytes);
>  
> -    if (stats.wr_bytes >= 0)
> -        vshPrint (ctl, "%s wr_bytes %lld\n", device, stats.wr_bytes);
> +            if (stats.wr_req >= 0)
> +                vshPrint (ctl, "%s wr_req %lld\n", device, stats.wr_req);
>  
> -    if (stats.errs >= 0)
> -        vshPrint (ctl, "%s errs %lld\n", device, stats.errs);
> +            if (stats.wr_bytes >= 0)
> +                vshPrint (ctl, "%s wr_bytes %lld\n", device, stats.wr_bytes);
>  
> +            if (stats.errs >= 0)
> +                vshPrint (ctl, "%s errs %lld\n", device, stats.errs);
> +        }
> +    } else {
> +        params = vshMalloc(ctl, sizeof(*params) * nparams);
> +        memset(params, 0, sizeof(*params) * nparams);
> +
> +        if (virDomainBlockStatsFlags (dom, device, params, &nparams, 0) < 0) {
> +            vshError(ctl, _("Failed to get block stats %s %s"), name, device);
> +            goto cleanup;
> +        }
> +
> +        int i;
> +        /* XXX: The output sequence will be different. */
> +        for (i = 0; i < nparams; i++) {
> +            switch(params[i].type) {
> +            case VIR_TYPED_PARAM_INT:
> +                vshPrint (ctl, "%s %s %d\n", device,
> +                          params[i].field, params[i].value.i);
> +                break;
> +            case VIR_TYPED_PARAM_UINT:
> +                vshPrint (ctl, "%s %s %u\n", device,
> +                          params[i].field, params[i].value.ui);
> +                break;
> +            case VIR_TYPED_PARAM_LLONG:
> +                vshPrint (ctl, "%s %s %lld\n", device,
> +                          params[i].field, params[i].value.l);
> +                break;
> +            case VIR_TYPED_PARAM_ULLONG:
> +                vshPrint (ctl, "%s %s %llu\n", device,
> +                          params[i].field, params[i].value.ul);
> +                break;
> +            case VIR_TYPED_PARAM_DOUBLE:
> +                vshPrint (ctl, "%s %s %f\n", device,
> +                          params[i].field, params[i].value.d);
> +                break;
> +            case VIR_TYPED_PARAM_BOOLEAN:
> +                vshPrint (ctl, "%s %s %s\n", device,
> +                          params[i].field, params[i].value.b ? _("yes") : _("no"));
> +                break;
> +            default:
> +                vshError(ctl, _("unimplemented block statistics parameter type"));
> +            }
> +
> +        }
> +    }
> +
> +    ret = true;
> +
> +cleanup:
> +    VIR_FREE(params);
>      virDomainFree(dom);
> -    return true;
> +    return ret;
>  }


  the title should indicate it's only for virsh
I hope the change of order for returned values won't introduce
regressions...

  ACK

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/