[libcamera-devel] [PATCH 03/12] libcamera: deviceenumerator: add DeviceInfo class

[Jacopo Mondi]

Hi Niklas,

On Sun, Dec 23, 2018 at 12:00:32AM +0100, Niklas S??derlund wrote:
> Provide a DeviceInfo class which holds all information from the initial
> enumeration of a media device. Not all information available at a media
> device is stored, only the information needed for a pipeline handler to
> find a specific device.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> ---
>  src/libcamera/deviceenumerator.cpp       | 78 ++++++++++++++++++++++++
>  src/libcamera/include/deviceenumerator.h | 44 +++++++++++++
>  src/libcamera/meson.build                |  2 +
>  3 files changed, 124 insertions(+)
>  create mode 100644 src/libcamera/deviceenumerator.cpp
>  create mode 100644 src/libcamera/include/deviceenumerator.h
>
> diff --git a/src/libcamera/deviceenumerator.cpp b/src/libcamera/deviceenumerator.cpp
> new file mode 100644
> index 0000000000000000..7c44a65b45472ef3
> --- /dev/null
> +++ b/src/libcamera/deviceenumerator.cpp
> @@ -0,0 +1,78 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2018, Google Inc.
> + *
> + * deviceenumerator.cpp - Enumeration and matching
> + */
> +
> +#include "deviceenumerator.h"
> +#include "log.h"
> +
> +namespace libcamera {
> +
> +/* -----------------------------------------------------------------------------
> + * DeviceInfo
> + */
> +
> +DeviceInfo::DeviceInfo(const std::string &devnode, const struct media_device_info &info,
> +		       const std::map<std::string, std::string> &entities)
> +	: acquired_(false), devnode_(devnode), info_(info), entities_(entities)
> +{
> +	for (const auto &entity : entities_)
> +		LOG(Info) << "Device: " << devnode_ << " Entity: '" << entity.first << "' -> " << entity.second;
> +}
> +
> +int DeviceInfo::acquire()
> +{
> +	if (acquired_)
> +		return -EBUSY;
> +
> +	acquired_ = true;
> +
> +	return 0;
> +}
> +
> +void DeviceInfo::release()
> +{
> +	acquired_ = false;
> +}
> +
> +bool DeviceInfo::busy() const
> +{
> +	return acquired_;
> +}
> +
> +const std::string &DeviceInfo::devnode() const
> +{
> +	return devnode_;
> +}
> +
> +const struct media_device_info &DeviceInfo::info() const
> +{
> +	return info_;
> +}
> +
> +std::vector<std::string> DeviceInfo::entities() const
> +{
> +	std::vector<std::string> entities;
> +
> +	for (const auto &entity : entities_)
> +		entities.push_back(entity.first);
> +
> +	return entities;

Are you returning (by copy) a variable with local scope?
Why coldn't you just return (as const reference maybe) entities_ ?

> +}
> +
> +bool DeviceInfo::lookup(const std::string &name, std::string &devnode) const
> +{
> +	auto it = entities_.find(name);
> +
> +	if (it == entities_.end()) {
> +		LOG(Error) << "Trying to lookup entity '" << name << "' which do not exist";

nit: "does not exist"

> +		return false;
> +	}
> +
> +	devnode = it->second;
> +	return true;
> +}
> +
> +} /* namespace libcamera */
> diff --git a/src/libcamera/include/deviceenumerator.h b/src/libcamera/include/deviceenumerator.h
> new file mode 100644
> index 0000000000000000..0136ed6ea23bf65e
> --- /dev/null
> +++ b/src/libcamera/include/deviceenumerator.h
> @@ -0,0 +1,44 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2018, Google Inc.
> + *
> + * deviceenumerator.h - API to enumerate and find media devices
> + */
> +#ifndef __LIBCAMERA_DEVICEENUMERATE_H__
> +#define __LIBCAMERA_DEVICEENUMERATE_H__
> +
> +#include <map>
> +#include <string>
> +#include <vector>
> +
> +#include <linux/media.h>
> +
> +namespace libcamera {
> +
> +class DeviceInfo
> +{
> +public:
> +	DeviceInfo(const std::string &devnode, const struct media_device_info &info,
> +		   const std::map<std::string, std::string> &entities);
> +
> +	int acquire();
> +	void release();
> +	bool busy() const;

Trivial methods might be inlined here.

> +
> +	const std::string &devnode() const;
> +	const struct media_device_info &info() const;
> +	std::vector<std::string> entities() const;
> +
> +	bool lookup(const std::string &name, std::string &devnode) const;
> +
> +private:
> +	bool acquired_;
> +
> +	std::string devnode_;
> +	struct media_device_info info_;
> +	std::map<std::string, std::string> entities_;
> +};
> +
> +} /* namespace libcamera */
> +
> +#endif	/* __LIBCAMERA_DEVICEENUMERATE_H__ */
> diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> index 52b556a8ed4050cb..17cdf06dd2bedfb3 100644
> --- a/src/libcamera/meson.build
> +++ b/src/libcamera/meson.build
> @@ -1,10 +1,12 @@
>  libcamera_sources = files([
>      'camera.cpp',
> +    'deviceenumerator.cpp',
>      'log.cpp',
>      'main.cpp',
>  ])
>
>  libcamera_headers = files([
> +    'include/deviceenumerator.h',
>      'include/log.h',
>      'include/utils.h',
>  ])
> --
> 2.20.1
>
> _______________________________________________
> libcamera-devel mailing list
> libcamera-devel at lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel
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