From: George Dunlap <George.Dunlap@citrix.com>
To: Nick Rosbrook <rosbrookn@gmail.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
Nick Rosbrook <rosbrookn@ainfosec.com>,
Ian Jackson <iwj@xenproject.org>, Wei Liu <wl@xen.org>
Subject: Re: [RESEND PATCH 08/12] golang/xenlight: add functional options to configure Context
Date: Fri, 18 Jun 2021 14:44:15 +0000 [thread overview]
Message-ID: <EF069373-26FC-4151-9CD9-6B8C48D9AEB0@citrix.com> (raw)
In-Reply-To: <dc5cd6728e8477c9eb3ba75a55c7128da46a86ef.1621887506.git.rosbrookn@ainfosec.com>
> On May 24, 2021, at 9:36 PM, Nick Rosbrook <rosbrookn@gmail.com> wrote:
>
> Add a ContextOption type to support functional options in NewContext.
> Then, add a variadic ContextOption parameter to NewContext, which allows
> callers to specify 0 or more configuration options.
>
> For now, just add the WithLogLevel option so that callers can set the
> log level of the Context's xentoollog_logger. Future configuration
> options can be created by adding an appropriate field to the
> contextOptions struct and creating a With<OptionName> function to return
> a ContextOption
>
> Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
> ---
> tools/golang/xenlight/xenlight.go | 44 +++++++++++++++++++++++++++++--
> 1 file changed, 42 insertions(+), 2 deletions(-)
>
> diff --git a/tools/golang/xenlight/xenlight.go b/tools/golang/xenlight/xenlight.go
> index f68d7b6e97..65f93abe32 100644
> --- a/tools/golang/xenlight/xenlight.go
> +++ b/tools/golang/xenlight/xenlight.go
> @@ -136,7 +136,7 @@ func sigchldHandler(ctx *Context) {
> }
>
> // NewContext returns a new Context.
> -func NewContext() (ctx *Context, err error) {
> +func NewContext(opts ...ContextOption) (ctx *Context, err error) {
> ctx = &Context{}
>
> defer func() {
> @@ -146,8 +146,19 @@ func NewContext() (ctx *Context, err error) {
> }
> }()
>
> + // Set the default context options. These fields may
> + // be modified by the provided opts.
> + copts := &contextOptions{
> + logLevel: LogLevelError,
> + }
> +
> + for _, opt := range opts {
> + opt.apply(copts)
> + }
> +
> // Create a logger
> - ctx.logger = C.xtl_createlogger_stdiostream(C.stderr, C.XTL_ERROR, 0)
> + ctx.logger = C.xtl_createlogger_stdiostream(C.stderr,
> + C.xentoollog_level(copts.logLevel), 0)
>
> // Allocate a context
> ret := C.libxl_ctx_alloc(&ctx.ctx, C.LIBXL_VERSION, 0,
> @@ -201,6 +212,35 @@ func (ctx *Context) Close() error {
> return nil
> }
>
> +type contextOptions struct {
> + logLevel LogLevel
> +}
> +
> +// ContextOption is used to configure options for a Context.
> +type ContextOption interface {
> + apply(*contextOptions)
> +}
> +
> +type funcContextOption struct {
> + f func(*contextOptions)
> +}
> +
> +func (fco *funcContextOption) apply(c *contextOptions) {
> + fco.f(c)
> +}
Why all this convolution with interfaces and such, rather than just defining ContextOption as a function pointer? Is it just to keep contextOptions out of the documentation page?
-George
next prev parent reply other threads:[~2021-06-18 14:44 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-24 20:36 [RESEND PATCH 00/12] golang/xenlight: domain life cycle support Nick Rosbrook
2021-05-24 20:36 ` [RESEND PATCH 01/12] golang/xenlight: update generated code Nick Rosbrook
2021-06-18 10:30 ` George Dunlap
2021-05-24 20:36 ` [RESEND PATCH 02/12] golang/xenlight: fix StringList toC conversion Nick Rosbrook
2021-06-18 10:51 ` George Dunlap
2021-05-24 20:36 ` [RESEND PATCH 03/12] golang/xenlight: fix string conversion in generated toC functions Nick Rosbrook
2021-06-18 11:00 ` George Dunlap
2021-06-21 16:11 ` Nick Rosbrook
2021-07-01 14:09 ` George Dunlap
2021-07-07 19:29 ` Nick Rosbrook
2021-05-24 20:36 ` [RESEND PATCH 04/12] golang/xenlight: export keyed union interface types Nick Rosbrook
2021-06-18 11:19 ` George Dunlap
2021-05-24 20:36 ` [RESEND PATCH 05/12] golang/xenlight: use struct pointers in keyed union fields Nick Rosbrook
2021-06-18 11:26 ` George Dunlap
2021-05-24 20:36 ` [RESEND PATCH 06/12] golang/xenlight: rename Ctx receivers to ctx Nick Rosbrook
2021-06-18 11:39 ` George Dunlap
2021-05-24 20:36 ` [RESEND PATCH 07/12] golang/xenlight: add logging conveniences for within xenlight Nick Rosbrook
2021-06-18 13:17 ` George Dunlap
2021-06-18 13:21 ` George Dunlap
2021-06-18 15:26 ` Nick Rosbrook
2021-06-18 16:30 ` George Dunlap
2021-06-18 15:17 ` Nick Rosbrook
2021-06-18 16:28 ` George Dunlap
2021-05-24 20:36 ` [RESEND PATCH 08/12] golang/xenlight: add functional options to configure Context Nick Rosbrook
2021-06-18 14:44 ` George Dunlap [this message]
2021-06-18 15:08 ` Nick Rosbrook
2021-06-18 16:18 ` George Dunlap
2021-06-18 17:00 ` Nick Rosbrook
2021-06-18 18:12 ` George Dunlap
2021-05-24 20:36 ` [RESEND PATCH 09/12] golang/xenlight: add DomainDestroy wrapper Nick Rosbrook
2021-06-18 14:47 ` George Dunlap
2021-05-24 20:36 ` [RESEND PATCH 10/12] golang/xenlight: add SendTrigger wrapper Nick Rosbrook
2021-06-18 14:54 ` George Dunlap
2021-05-24 20:36 ` [RESEND PATCH 11/12] golang/xenlight: do not negate ret when converting to Error Nick Rosbrook
2021-06-18 15:13 ` George Dunlap
2021-06-18 15:32 ` Nick Rosbrook
2021-05-24 20:36 ` [RESEND PATCH 12/12] golang/xenlight: add NotifyDomainDeath method to Context Nick Rosbrook
2021-06-18 18:28 ` George Dunlap
2021-06-18 19:31 ` George Dunlap
2021-06-21 21:41 ` Nick Rosbrook
2021-06-17 15:29 ` [RESEND PATCH 00/12] golang/xenlight: domain life cycle support Nick Rosbrook
2021-06-21 15:53 ` George Dunlap
2021-06-21 16:19 ` Nick Rosbrook
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