Re: [PATCH 11/19] rust/qobject: add from/to JSON bindings for QObject

[Markus Armbruster <armbru@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> These are used by tests.  However it could even be an idea to use
> serde_json + transcoding and get rid of the C version...

Tell me more!

> Co-authored-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  rust/util/wrapper.h          |  1 +
>  rust/util/src/qobject/mod.rs | 17 +++++++++++++++++
>  2 files changed, 18 insertions(+)
>
> diff --git a/rust/util/wrapper.h b/rust/util/wrapper.h
> index 0907dd59142..c88820a5e5b 100644
> --- a/rust/util/wrapper.h
> +++ b/rust/util/wrapper.h
> @@ -37,3 +37,4 @@ typedef enum memory_order {
>  #include "qobject/qobject.h"
>  #include "qobject/qlist.h"
>  #include "qobject/qdict.h"
> +#include "qobject/qjson.h"
> diff --git a/rust/util/src/qobject/mod.rs b/rust/util/src/qobject/mod.rs
> index e896aba5f3a..292a3c9c238 100644
> --- a/rust/util/src/qobject/mod.rs
> +++ b/rust/util/src/qobject/mod.rs
> @@ -23,6 +23,7 @@
>  use common::assert_field_type;
>  pub use deserializer::from_qobject;
>  pub use error::{Error, Result};
> +use foreign::prelude::*;
>  pub use serializer::to_qobject;
>  
>  use crate::bindings;
> @@ -111,6 +112,22 @@ fn refcnt(&self) -> &AtomicUsize {
>          let qobj = self.0.get();
>          unsafe { AtomicUsize::from_ptr(addr_of_mut!((*qobj).base.refcnt)) }
>      }
> +
> +    pub fn to_json(&self) -> String {
> +        let qobj = self.0.get();
> +        unsafe {
> +            let json = bindings::qobject_to_json(qobj);
> +            glib_sys::g_string_free(json, glib_sys::GFALSE).into_native()
> +        }
> +    }
> +
> +    pub fn from_json(json: &str) -> std::result::Result<Self, crate::Error> {
> +        let c_json = std::ffi::CString::new(json)?;
> +        unsafe {
> +            crate::Error::with_errp(|errp| bindings::qobject_from_json(c_json.as_ptr(), errp))
> +                .map(|qobj| QObject::from_raw(qobj))
> +        }
> +    }
>  }
>  
>  impl From<()> for QObject {