[PATCH 02/10] libcamera: controls: Generate enum value-name maps

[Jacopo Mondi]

Hi Dan

On Fri, Mar 22, 2024 at 01:14:43PM +0000, Daniel Scally wrote:
> Generate maps associating control enumerated control values with a
s/control enumerated control values/enumerated control values/ ?

> string representing that value to provide a central reference for
> them across all pipeline handlers.

As noticed by Kieran, it would be nice to expand a bit on what this
would be used for

>
> Signed-off-by: Daniel Scally <dan.scally at ideasonboard.com>
> ---
>  include/libcamera/control_ids.h.in  |  2 ++
>  include/libcamera/property_ids.h.in |  2 ++
>  utils/gen-controls.py               | 19 +++++++++++++++++++
>  3 files changed, 23 insertions(+)

I like this

The only alternative proposal would be to unify the ControlValue and
the name string into a struct and enumerate them in a single array
to make sure they stay in sync.

But since this is auto-generated and adjusting all users of the *Values
array is probably a big job, I'm not sure it's even worth considering the
alternative proposal.

What you have here is more than fine!

Reviewed-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>

>
> diff --git a/include/libcamera/control_ids.h.in b/include/libcamera/control_ids.h.in
> index d53b1cf7..58dd48e1 100644
> --- a/include/libcamera/control_ids.h.in
> +++ b/include/libcamera/control_ids.h.in
> @@ -10,7 +10,9 @@
>  #pragma once
>
>  #include <array>
> +#include <map>
>  #include <stdint.h>
> +#include <string>
>
>  #include <libcamera/controls.h>
>
> diff --git a/include/libcamera/property_ids.h.in b/include/libcamera/property_ids.h.in
> index 43372c71..f51ba028 100644
> --- a/include/libcamera/property_ids.h.in
> +++ b/include/libcamera/property_ids.h.in
> @@ -9,7 +9,9 @@
>
>  #pragma once
>
> +#include <map>
>  #include <stdint.h>
> +#include <string>
>
>  #include <libcamera/controls.h>
>
> diff --git a/utils/gen-controls.py b/utils/gen-controls.py
> index 6cd5e362..4fe1e705 100755
> --- a/utils/gen-controls.py
> +++ b/utils/gen-controls.py
> @@ -140,6 +140,12 @@ ${description}
>   */''')
>      enum_values_start = string.Template('''extern const std::array<const ControlValue, ${size}> ${name}Values = {''')
>      enum_values_values = string.Template('''\tstatic_cast<int32_t>(${name}),''')
> +    name_value_map_doc = string.Template('''/**
> + * \\var ${name}NameValueMap
> + * \\brief Map of all $name supported value names (in std::string format) to value
> + */''')
> +    name_value_map_start = string.Template('''extern const std::map<std::string, ${type}> ${name}NameValueMap = {''')
> +    name_value_values = string.Template('''\t{ "${name}", ${name} },''')
>
>      ctrls_doc = {}
>      ctrls_def = {}
> @@ -183,6 +189,7 @@ ${description}
>
>              values_info = {
>                  'name': info['name'],
> +                'type': ctrl.type,
>                  'size': num_entries,
>              }
>              target_doc.append(enum_values_doc.substitute(values_info))
> @@ -194,6 +201,15 @@ ${description}
>                  target_def.append(enum_values_values.substitute(value_info))
>              target_def.append("};")
>
> +            target_doc.append(name_value_map_doc.substitute(values_info))
> +            target_def.append(name_value_map_start.substitute(values_info))
> +            for enum in ctrl.enum_values:
> +                value_info = {
> +                    'name': enum.name
> +                }
> +                target_def.append(name_value_values.substitute(value_info))
> +            target_def.append("};")
> +
>          target_doc.append(doc_template.substitute(info))
>          target_def.append(def_template.substitute(info))
>
> @@ -231,6 +247,7 @@ def generate_h(controls, mode, ranges):
>      enum_template_start = string.Template('''enum ${name}Enum {''')
>      enum_value_template = string.Template('''\t${name} = ${value},''')
>      enum_values_template = string.Template('''extern const std::array<const ControlValue, ${size}> ${name}Values;''')
> +    name_value_map_template = string.Template('''extern const std::map<std::string, ${type}> ${name}NameValueMap;''')
>      template = string.Template('''extern const Control<${type}> ${name};''')
>
>      ctrls = {}
> @@ -273,9 +290,11 @@ def generate_h(controls, mode, ranges):
>
>              values_info = {
>                  'name': info['name'],
> +                'type': ctrl.type,
>                  'size': num_entries,
>              }
>              target_ctrls.append(enum_values_template.substitute(values_info))
> +            target_ctrls.append(name_value_map_template.substitute(values_info))
>
>          target_ctrls.append(template.substitute(info))
>          id_value[vendor] += 1
> --
> 2.34.1
>