Re: [PATCH 12/20] migration: introduce new constructors for QEMUFile

[Dr. David Alan Gilbert]

* Daniel P. Berrangé (berrange@redhat.com) wrote:
> Prepare for the elimination of QEMUFileOps by introducing a pair of new
> constructors. This lets us distinguish between an input and output file
> object explicitly rather than via the existance of specific callbacks.
> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  migration/qemu-file-channel.c |  4 ++--
>  migration/qemu-file.c         | 18 ++++++++++++++++--
>  migration/qemu-file.h         |  3 ++-
>  3 files changed, 20 insertions(+), 5 deletions(-)
> 
> diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c
> index ce8eced417..5cb8ac93c0 100644
> --- a/migration/qemu-file-channel.c
> +++ b/migration/qemu-file-channel.c
> @@ -184,11 +184,11 @@ static const QEMUFileOps channel_output_ops = {
>  QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
>  {
>      object_ref(OBJECT(ioc));
> -    return qemu_fopen_ops(ioc, &channel_input_ops);
> +    return qemu_file_new_input(ioc, &channel_input_ops);
>  }
>  
>  QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
>  {
>      object_ref(OBJECT(ioc));
> -    return qemu_fopen_ops(ioc, &channel_output_ops);
> +    return qemu_file_new_output(ioc, &channel_output_ops);
>  }
> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> index ea1e8da0cb..5548e1abf3 100644
> --- a/migration/qemu-file.c
> +++ b/migration/qemu-file.c
> @@ -38,6 +38,7 @@ struct QEMUFile {
>      const QEMUFileOps *ops;
>      const QEMUFileHooks *hooks;
>      QIOChannel *ioc;
> +    bool is_writable;
>  
>      /*
>       * Maximum amount of data in bytes to transfer during one
> @@ -111,7 +112,9 @@ bool qemu_file_mode_is_not_valid(const char *mode)
>      return false;
>  }
>  
> -QEMUFile *qemu_fopen_ops(QIOChannel *ioc, const QEMUFileOps *ops)
> +static QEMUFile *qemu_file_new_impl(QIOChannel *ioc,
> +                                    const QEMUFileOps *ops,
> +                                    bool is_writable)
>  {
>      QEMUFile *f;
>  
> @@ -119,10 +122,21 @@ QEMUFile *qemu_fopen_ops(QIOChannel *ioc, const 
> QEMUFileOps *ops)
>  
>      f->ioc = ioc;
>      f->ops = ops;
> +    f->is_writable = is_writable;
>  
>      return f;
>  }
>  
> +QEMUFile *qemu_file_new_output(QIOChannel *ioc, const QEMUFileOps *ops)
> +{
> +    return qemu_file_new_impl(ioc, ops, true);
> +}
> +
> +QEMUFile *qemu_file_new_input(QIOChannel *ioc, const QEMUFileOps *ops)
> +{
> +    return qemu_file_new_impl(ioc, ops, false);
> +}
> +
>  
>  void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks)
>  {
> @@ -181,7 +195,7 @@ void qemu_file_set_error(QEMUFile *f, int ret)
>  
>  bool qemu_file_is_writable(QEMUFile *f)
>  {
> -    return f->ops->writev_buffer;
> +    return f->is_writable;
>  }
>  
>  static void qemu_iovec_release_ram(QEMUFile *f)
> diff --git a/migration/qemu-file.h b/migration/qemu-file.h
> index 0458b1d3b6..07c86bfea3 100644
> --- a/migration/qemu-file.h
> +++ b/migration/qemu-file.h
> @@ -118,7 +118,8 @@ typedef struct QEMUFileHooks {
>      QEMURamSaveFunc *save_page;
>  } QEMUFileHooks;
>  
> -QEMUFile *qemu_fopen_ops(QIOChannel *ioc, const QEMUFileOps *ops);
> +QEMUFile *qemu_file_new_input(QIOChannel *ioc, const QEMUFileOps *ops);
> +QEMUFile *qemu_file_new_output(QIOChannel *ioc, const QEMUFileOps *ops);
>  void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
>  int qemu_get_fd(QEMUFile *f);
>  int qemu_fclose(QEMUFile *f);
> -- 
> 2.36.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK