[libcamera-devel] [PATCH 4/7] android: Add CameraHalConfig class

[Niklas Söderlund]

Hi Jacopo,

On 2021-03-29 16:23:08 +0200, Jacopo Mondi wrote:
> Hi Niklas,
> 
> On Thu, Mar 25, 2021 at 11:33:31PM +0100, Niklas Söderlund wrote:
> > Hi Jacopo,
> >
> > Thanks for your work.
> >
> > On 2021-03-24 12:25:24 +0100, Jacopo Mondi wrote:
> > > Add a CameraHalConfig class to the Android Camera3 HAL layer.
> > >
> > > Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> >
> > There are a few small nits below but I think this is a great step in the
> > right direction.
> >
> > Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> >
> > > ---
> > >  src/android/camera_hal_config.cpp | 385 ++++++++++++++++++++++++++++++
> > >  src/android/camera_hal_config.h   |  54 +++++
> > >  src/android/meson.build           |   1 +
> > >  3 files changed, 440 insertions(+)
> > >  create mode 100644 src/android/camera_hal_config.cpp
> > >  create mode 100644 src/android/camera_hal_config.h
> > >
> > > diff --git a/src/android/camera_hal_config.cpp b/src/android/camera_hal_config.cpp
> > > new file mode 100644
> > > index 000000000000..7e33dfb750ff
> > > --- /dev/null
> > > +++ b/src/android/camera_hal_config.cpp
> > > @@ -0,0 +1,385 @@
> > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > > +/*
> > > + * Copyright (C) 2021, Google Inc.
> > > + *
> > > + * camera_hal_config.cpp - Camera HAL configuration file manager
> > > + */
> > > +#include "camera_hal_config.h"
> > > +
> > > +#include <stdio.h>
> > > +#include <stdlib.h>
> > > +#include <string.h>
> > > +
> > > +#include "libcamera/internal/file.h"
> > > +#include "libcamera/internal/log.h"
> > > +
> > > +using namespace libcamera;
> > > +
> > > +LOG_DEFINE_CATEGORY(HALConfig)
> > > +
> > > +const std::string CameraHalConfig::CameraBlock::toString() const
> > > +{
> > > +	std::stringstream ss;
> > > +
> > > +	ss << "\'" << name << "\'"
> > > +	   << " model: " << model
> > > +	   << "(" << location << ")[" << rotation << "]";
> >
> > nit: The usage of the pattern "key: <value>" have been discouraged in
> > the core, do we extend the same to the HAL?
> >
> 
> Not sure what you mean here -.-

Sorry, I just noticed that the pattern of

    << " model: " << model 

Have been discouraged in the core in favor of

    << " model " << model 

> 
> > > +
> > > +	return ss.str();
> > > +}
> > > +
> > > +CameraHalConfig::CameraHalConfig()
> > > +{
> > > +	if (!yaml_parser_initialize(&parser_))
> > > +		LOG(HALConfig, Error) << "Failed to initialize yaml parser";
> >
> > Fatal?
> >
> > > +}
> > > +
> > > +CameraHalConfig::~CameraHalConfig()
> > > +{
> > > +	yaml_parser_delete(&parser_);
> > > +}
> > > +
> > > +/*
> > > + * Configuration files can be stored in system paths, which are identified
> > > + * through the build configuration.
> > > + *
> > > + * However, when running uninstalled - the source location takes precedence.
> > > + */
> > > +const std::string CameraHalConfig::findFilePath(const std::string &filename)
> > > +{
> > > +	static std::array<std::string, 2> searchPaths = {
> > > +		LIBCAMERA_SYSCONF_DIR,
> > > +		LIBCAMERA_DATA_DIR,
> > > +	};
> > > +
> > > +	if (File::exists(filename))
> > > +		return filename;
> > > +
> > > +	std::string root = utils::libcameraSourcePath();
> > > +	if (!root.empty()) {
> > > +		std::string configurationPath = root + "data/" + filename;
> > > +
> > > +		if (File::exists(configurationPath))
> > > +			return configurationPath;
> > > +	}
> > > +
> > > +	for (std::string &path : searchPaths) {
> > > +		std::string configurationPath = path + "/" + filename;
> > > +		if (File::exists(configurationPath))
> > > +			return configurationPath;
> > > +	}
> > > +
> > > +	return "";
> > > +}
> > > +
> > > +/*
> > > + * \brief Open the HAL configuration file and validate its content
> > > + * \return 0 on success, a negative error code otherwise
> >
> > nit: We don't Doxygen the HAL is it not confusing to use it mark up here
> > then?
> >
> > > + */
> > > +int CameraHalConfig::open()
> > > +{
> > > +	int ret;
> > > +
> > > +	const std::string configPath = "camera_hal.yaml";
> >
> > s/configPath/configFile/ ?
> >
> > > +	const std::string filePath = findFilePath(configPath);
> >
> > As this is the only call site would it make sens to have findFilePath()
> > return a FILE * to get compartmentalizing of the error paths?
> >
> > > +	if (filePath.empty()) {
> > > +		LOG(HALConfig, Warning)
> > > +			<< "File: \"" << configPath << "\" not found";
> > > +		return -ENOENT;
> > > +	}
> > > +
> > > +	FILE *fh = fopen(filePath.c_str(), "r");
> > > +	if (!fh) {
> > > +		ret = -errno;
> > > +		LOG(HALConfig, Error) << "Failed to open file " << filePath
> > > +				      << ": " << strerror(-ret);
> > > +		return ret;
> > > +	}
> > > +
> > > +	yaml_parser_set_input_file(&parser_, fh);
> > > +
> > > +	LOG(HALConfig, Debug) << "Reading configuration from " << filePath;
> > > +
> > > +	ret = parseConfigFile();
> > > +	fclose(fh);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	LOG(HALConfig, Info) << "Device model: " << model_;
> > > +	LOG(HALConfig, Info) << "Device maker: " << maker_;
> > > +	for (const auto &c : cameras_) {
> > > +		const CameraBlock camera = c.second;
> > > +		LOG(HALConfig, Info) << camera.toString();
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +const std::string &CameraHalConfig::cameraLocation(const std::string &camera) const
> > > +{
> > > +	static const std::string empty("");
> > > +	const auto &it = cameras_.find(camera);
> > > +	if (it == cameras_.end()) {
> > > +		LOG(HALConfig, Error)
> > > +			<< "Camera '" << camera
> > > +			<< "' not described in the HAL configuration file";
> > > +		return empty;
> > > +	}
> > > +
> > > +	const CameraBlock &cam = it->second;
> > > +	return cam.location;
> > > +}
> > > +
> > > +unsigned int CameraHalConfig::cameraRotation(const std::string &camera) const
> > > +{
> > > +	static const std::string empty("");
> >
> > empty not used.
> >
> 
> Ouch, leftover
> 
> > > +	const auto &it = cameras_.find(camera);
> > > +	if (it == cameras_.end()) {
> > > +		LOG(HALConfig, Error)
> > > +			<< "Camera '" << camera
> > > +			<< "' not described in the HAL configuration file";
> > > +		return 0;
> > > +	}
> > > +
> > > +	const CameraBlock &cam = it->second;
> > > +	return cam.rotation;
> > > +}
> > > +
> > > +const std::string &CameraHalConfig::cameraModel(const std::string &camera) const
> > > +{
> > > +	static const std::string empty("");
> > > +	const auto &it = cameras_.find(camera);
> > > +	if (it == cameras_.end()) {
> > > +		LOG(HALConfig, Error)
> > > +			<< "Camera '" << camera
> > > +			<< "' not described in the HAL configuration file";
> > > +		return empty;
> > > +	}
> > > +
> > > +	const CameraBlock &cam = it->second;
> > > +	return cam.model;
> > > +}
> > > +
> > > +std::string CameraHalConfig::parseValue(yaml_token_t &token)
> > > +{
> > > +	/* Make sure the token type is a value and get its content. */
> > > +	yaml_parser_scan(&parser_, &token);
> > > +	if (token.type != YAML_VALUE_TOKEN) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +		return "";
> > > +	}
> > > +	yaml_token_delete(&token);
> > > +
> > > +	yaml_parser_scan(&parser_, &token);
> > > +	if (token.type != YAML_SCALAR_TOKEN) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +		return "";
> > > +	}
> > > +
> > > +	char *scalar = reinterpret_cast<char *>(token.data.scalar.value);
> > > +	std::string value(scalar, token.data.scalar.length);
> > > +	yaml_token_delete(&token);
> > > +
> > > +	return value;
> > > +}
> > > +
> > > +std::string CameraHalConfig::parseKey(yaml_token_t &token)
> > > +{
> > > +	/* Make sure the token type is a key and get its value. */
> > > +	yaml_parser_scan(&parser_, &token);
> > > +	if (token.type != YAML_KEY_TOKEN) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +		return "";
> > > +	}
> > > +	yaml_token_delete(&token);
> > > +
> > > +	yaml_parser_scan(&parser_, &token);
> > > +	if (token.type != YAML_SCALAR_TOKEN) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +		return "";
> > > +	}
> > > +
> > > +	char *scalar = reinterpret_cast<char *>(token.data.scalar.value);
> > > +	std::string key(scalar, token.data.scalar.length);
> > > +	yaml_token_delete(&token);
> > > +
> > > +	return key;
> > > +}
> > > +
> > > +int CameraHalConfig::parseCameraBlock(yaml_token_t &token)
> > > +{
> > > +	/* The 'camera' block is a VALUE token type. */
> > > +	yaml_parser_scan(&parser_, &token);
> > > +	if (token.type != YAML_VALUE_TOKEN) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +		return -EINVAL;
> > > +	}
> > > +	yaml_token_delete(&token);
> > > +
> > > +	/*
> > > +	 * Parse the content of the camera block until we have an unbalanced
> > > +	 * BLOCK_END_TOKEN which closes the camera block.
> > > +	 *
> > > +	 * Add a safety counter to make sure we don't loop indefinitely in case
> > > +	 * the configuration file is malformed.
> > > +	 */
> > > +	unsigned int sentinel = 100;
> > > +	CameraBlock cameraBlock{};
> > > +	int blockCounter = 0;
> > > +	do {
> > > +		yaml_parser_scan(&parser_, &token);
> > > +		switch (token.type) {
> > > +		case YAML_BLOCK_ENTRY_TOKEN:
> > > +			yaml_token_delete(&token);
> > > +			blockCounter++;
> > > +			break;
> > > +		case YAML_BLOCK_END_TOKEN:
> > > +			yaml_token_delete(&token);
> > > +			blockCounter--;
> > > +			break;
> > > +		case YAML_BLOCK_MAPPING_START_TOKEN: {
> > > +			yaml_token_delete(&token);
> > > +
> > > +			std::string key = parseKey(token);
> > > +			std::string value = parseValue(token);
> > > +			if (key.empty() || value.empty()) {
> > > +				LOG(HALConfig, Error)
> > > +					<< "Configuration file is not valid";
> > > +				return -EINVAL;
> > > +			}
> > > +
> > > +			/* Validate that the parsed key is valid. */
> > > +			if (key == "location") {
> > > +				if (value != "front" && value != "back" &&
> > > +				    value != "external") {
> > > +					LOG(HALConfig, Error)
> > > +						<< "Unknown location: " << value;
> > > +					return -EINVAL;
> > > +				}
> > > +				cameraBlock.location = value;
> > > +			} else if (key == "rotation") {
> > > +				cameraBlock.rotation = strtoul(value.c_str(),
> > > +							       NULL, 10);
> > > +				if (cameraBlock.rotation < 0) {
> > > +					LOG(HALConfig, Error)
> > > +						<< "Unknown rotation: "
> > > +						<< cameraBlock.rotation;
> > > +					return -EINVAL;
> > > +				}
> > > +			} else if (key == "name") {
> > > +				cameraBlock.name = value;
> > > +			} else if (key == "model") {
> > > +				cameraBlock.model = value;
> > > +			} else {
> > > +				LOG(HALConfig, Error)
> > > +					<< "Configuration file is not valid "
> > > +					<< "unknown key: " << key;
> > > +				return -EINVAL;
> > > +			}
> > > +			break;
> > > +		}
> > > +		default:
> > > +			yaml_token_delete(&token);
> > > +			break;
> > > +		}
> > > +		--sentinel;
> > > +	} while (blockCounter >= 0 && sentinel);
> > > +	if (!sentinel) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid ";
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	cameras_[cameraBlock.name] = cameraBlock;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +int CameraHalConfig::parseEntryBlock(yaml_token_t &token)
> > > +{
> > > +	int ret;
> > > +
> > > +	yaml_parser_scan(&parser_, &token);
> > > +	if (token.type != YAML_BLOCK_MAPPING_START_TOKEN) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +		return -EINVAL;
> > > +	}
> > > +	yaml_token_delete(&token);
> > > +
> > > +	std::string key = parseKey(token);
> > > +	if (key.empty()) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	if (key == "camera") {
> > > +		yaml_token_delete(&token);
> > > +		ret = parseCameraBlock(token);
> > > +		if (ret)
> > > +			return ret;
> > > +	} else if (key == "manufacturer") {
> > > +		yaml_token_delete(&token);
> > > +		maker_ = parseValue(token);
> > > +		if (maker_.empty()) {
> > > +			LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +			return -EINVAL;
> > > +		}
> > > +	} else if (key == "model") {
> > > +		yaml_token_delete(&token);
> > > +		model_ = parseValue(token);
> > > +		if (model_.empty()) {
> > > +			LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +			return -EINVAL;
> > > +		}
> > > +	} else {
> > > +		yaml_token_delete(&token);
> > > +		LOG(HALConfig, Error) << "Unknown key " << key;
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +int CameraHalConfig::parseConfigFile()
> > > +{
> > > +	yaml_token_t token;
> > > +	int ret;
> > > +
> > > +	yaml_parser_scan(&parser_, &token);
> > > +	if (token.type != YAML_STREAM_START_TOKEN) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +		return EINVAL;
> > > +	}
> > > +	yaml_token_delete(&token);
> > > +
> > > +	/*
> > > +	 * Start parsing the content of the configuration file which
> > > +	 * starts as with sequence block.
> > > +	 */
> > > +	yaml_parser_scan(&parser_, &token);
> > > +	if (token.type != YAML_BLOCK_SEQUENCE_START_TOKEN) {
> > > +		LOG(HALConfig, Error) << "Configuration file is not valid";
> > > +		return -EINVAL;
> > > +	}
> > > +	yaml_token_delete(&token);
> > > +
> > > +	/* Parse the single entry blocks. */
> > > +	do {
> > > +		yaml_parser_scan(&parser_, &token);
> > > +		switch (token.type) {
> > > +		case YAML_BLOCK_ENTRY_TOKEN:
> > > +			yaml_token_delete(&token);
> > > +			ret = parseEntryBlock(token);
> > > +			break;
> > > +		case YAML_STREAM_END_TOKEN:
> > > +			/* Resources are released after the loop exit. */
> > > +			break;
> > > +		default:
> > > +			/* Release resources before re-parsing. */
> > > +			yaml_token_delete(&token);
> > > +			break;
> > > +		}
> > > +	} while (token.type != YAML_STREAM_END_TOKEN && ret >= 0);
> > > +	yaml_token_delete(&token);
> > > +
> > > +	return ret;
> > > +}
> > > diff --git a/src/android/camera_hal_config.h b/src/android/camera_hal_config.h
> > > new file mode 100644
> > > index 000000000000..69d42658e90a
> > > --- /dev/null
> > > +++ b/src/android/camera_hal_config.h
> > > @@ -0,0 +1,54 @@
> > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > > +/*
> > > + * Copyright (C) 2021, Google Inc.
> > > + *
> > > + * camera_hal_config.h - Camera HAL configuration file manager
> > > + */
> > > +#ifndef __ANDROID_CAMERA_HAL_CONFIG_H__
> > > +#define __ANDROID_CAMERA_HAL_CONFIG_H__
> > > +
> > > +#include <map>
> > > +#include <string>
> > > +#include <yaml.h>
> > > +
> > > +class CameraHalConfig
> > > +{
> > > +public:
> > > +	CameraHalConfig();
> > > +	~CameraHalConfig();
> > > +
> > > +	int open();
> > > +
> > > +	const std::string &deviceModel() const { return model_; }
> > > +	const std::string &deviceMaker() const { return maker_; }
> > > +
> > > +	const std::string &cameraLocation(const std::string &camera) const;
> > > +	unsigned int cameraRotation(const std::string &camera) const;
> > > +	const std::string &cameraModel(const std::string &camera) const;
> > > +
> > > +private:
> > > +	yaml_parser_t parser_;
> > > +
> > > +	std::string model_;
> > > +	std::string maker_;
> > > +	class CameraBlock
> > > +	{
> > > +	public:
> > > +		std::string name;
> > > +		std::string location;
> > > +		std::string model;
> > > +		unsigned int rotation;
> > > +
> > > +		const std::string toString() const;
> > > +	};
> > > +	std::map<std::string, CameraBlock> cameras_;
> > > +
> > > +	const std::string findFilePath(const std::string &filename);
> > > +	std::string parseValue(yaml_token_t &token);
> > > +	std::string parseKey(yaml_token_t &token);
> > > +	int parseCameraBlock(yaml_token_t &token);
> > > +	int parseEntryBlock(yaml_token_t &token);
> > > +	int parseConfigFile();
> > > +};
> > > +
> > > +#endif /* __ANDROID_CAMERA_HAL_CONFIG_H__ */
> > > diff --git a/src/android/meson.build b/src/android/meson.build
> > > index 19f94a4073f1..34e5c494a492 100644
> > > --- a/src/android/meson.build
> > > +++ b/src/android/meson.build
> > > @@ -44,6 +44,7 @@ android_hal_sources = files([
> > >      'camera3_hal.cpp',
> > >      'camera_hal_manager.cpp',
> > >      'camera_device.cpp',
> > > +    'camera_hal_config.cpp',
> > >      'camera_metadata.cpp',
> > >      'camera_ops.cpp',
> > >      'camera_stream.cpp',
> > > --
> > > 2.30.0
> > >
> > > _______________________________________________
> > > libcamera-devel mailing list
> > > libcamera-devel at lists.libcamera.org
> > > https://lists.libcamera.org/listinfo/libcamera-devel
> >
> > --
> > Regards,
> > Niklas Söderlund

-- 
Regards,
Niklas Söderlund