[libcamera-devel] [PATCH v2 3/5] libcamera: file: Use Flags<> class for map flags

[Laurent Pinchart]

Hi Jacopo,

On Mon, Jul 26, 2021 at 11:52:24AM +0200, Jacopo Mondi wrote:
> On Sun, Jul 25, 2021 at 08:18:25PM +0300, Laurent Pinchart wrote:
> > Use the newly introduced Flags<> class to store a bitfield of
> > File::MapFlag in a type-safe way.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> > ---
> > Changes since v1:
> >
> > - Use an unscoped enum
> > ---
> >  include/libcamera/base/file.h | 5 ++++-
> >  src/libcamera/base/file.cpp   | 7 ++++++-
> >  2 files changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/libcamera/base/file.h b/include/libcamera/base/file.h
> > index 7dd1559d2285..452a658b409f 100644
> > --- a/include/libcamera/base/file.h
> > +++ b/include/libcamera/base/file.h
> > @@ -15,6 +15,7 @@
> >  #include <libcamera/base/private.h>
> >
> >  #include <libcamera/base/class.h>
> > +#include <libcamera/base/flags.h>
> >  #include <libcamera/base/span.h>
> >
> >  namespace libcamera {
> > @@ -27,6 +28,8 @@ public:
> >  		MapPrivate = (1 << 0),
> >  	};
> >
> > +	using MapFlags = Flags<MapFlag>;
> > +
> 
> Shouldn't you enable bitwise operations for this type ?

Not for Flags<>, that's handled by the Flags class itself. It's only
operators for the base Flag that need to be enabled, and only when the
base Flag is a scoped enum. As File uses unscoped enums, it's not needed
here. This is changed in 5/5.

> >  	enum OpenMode {
> >  		NotOpen = 0,
> >  		ReadOnly = (1 << 0),
> > @@ -57,7 +60,7 @@ public:
> >  	ssize_t write(const Span<const uint8_t> &data);
> >
> >  	Span<uint8_t> map(off_t offset = 0, ssize_t size = -1,
> > -			  MapFlag flags = MapNoOption);
> > +			  MapFlags flags = MapNoOption);
> >  	bool unmap(uint8_t *addr);
> >
> >  	static bool exists(const std::string &name);
> > diff --git a/src/libcamera/base/file.cpp b/src/libcamera/base/file.cpp
> > index 073666fa6f66..e180c5479098 100644
> > --- a/src/libcamera/base/file.cpp
> > +++ b/src/libcamera/base/file.cpp
> > @@ -52,6 +52,11 @@ LOG_DEFINE_CATEGORY(File)
> >   * the file constents
> >   */
> >
> > +/**
> > + * \typedef File::MapFlags
> > + * \brief An OR combination of File::MapFlag values
> 
> Why a type is an OR combination ?

Maybe "A bitwise combination of File::MapFlag values" would be better ?

> > + */
> > +
> >  /**
> >   * \enum File::OpenMode
> >   * \brief Mode in which a file is opened
> > @@ -371,7 +376,7 @@ ssize_t File::write(const Span<const uint8_t> &data)
> >   *
> >   * \return The mapped memory on success, or an empty span otherwise
> >   */
> > -Span<uint8_t> File::map(off_t offset, ssize_t size, enum File::MapFlag flags)
> > +Span<uint8_t> File::map(off_t offset, ssize_t size, File::MapFlags flags)
> >  {
> >  	if (!isOpen()) {
> >  		error_ = -EBADF;

-- 
Regards,

Laurent Pinchart