diff options
| -rw-r--r-- | src/libcamera/include/pipeline_handler.h | 62 | ||||
| -rw-r--r-- | src/libcamera/meson.build | 2 | ||||
| -rw-r--r-- | src/libcamera/pipeline_handler.cpp | 142 |
3 files changed, 206 insertions, 0 deletions
diff --git a/src/libcamera/include/pipeline_handler.h b/src/libcamera/include/pipeline_handler.h new file mode 100644 index 00000000..d70056a1 --- /dev/null +++ b/src/libcamera/include/pipeline_handler.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2018, Google Inc. + * + * pipeline_handler.h - Pipeline handler infrastructure + */ +#ifndef __LIBCAMERA_PIPELINE_HANDLER_H__ +#define __LIBCAMERA_PIPELINE_HANDLER_H__ + +#include <map> +#include <string> +#include <vector> + +#include <libcamera/camera.h> + +namespace libcamera { + +class DeviceEnumerator; +class PipelineHandlerFactory; + +class PipelineHandler +{ +public: + virtual ~PipelineHandler() { }; + + virtual bool match(DeviceEnumerator *enumerator) = 0; + + virtual unsigned int count() = 0; + virtual Camera *camera(unsigned int id) = 0; +}; + +class PipelineHandlerFactory +{ +public: + virtual ~PipelineHandlerFactory() { }; + + virtual PipelineHandler *create() = 0; + + static void registerType(const std::string &name, PipelineHandlerFactory *factory); + static PipelineHandler *create(const std::string &name, DeviceEnumerator *enumerator); + static std::vector<std::string> handlers(); + +private: + static std::map<std::string, PipelineHandlerFactory *> ®istry(); +}; + +#define REGISTER_PIPELINE_HANDLER(handler) \ + class handler##Factory : public PipelineHandlerFactory { \ + public: \ + handler##Factory() \ + { \ + PipelineHandlerFactory::registerType(#handler, this); \ + } \ + virtual PipelineHandler *create() { \ + return new handler(); \ + } \ + }; \ + static handler##Factory global_##handler##Factory; + +} /* namespace libcamera */ + +#endif /* __LIBCAMERA_PIPELINE_HANDLER_H__ */ diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build index 581da1aa..0db648dd 100644 --- a/src/libcamera/meson.build +++ b/src/libcamera/meson.build @@ -3,11 +3,13 @@ libcamera_sources = files([ 'device_enumerator.cpp', 'log.cpp', 'main.cpp', + 'pipeline_handler.cpp', ]) libcamera_headers = files([ 'include/device_enumerator.h', 'include/log.h', + 'include/pipeline_handler.h', 'include/utils.h', ]) diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp new file mode 100644 index 00000000..a737f222 --- /dev/null +++ b/src/libcamera/pipeline_handler.cpp @@ -0,0 +1,142 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2018, Google Inc. + * + * pipeline_handler.cpp - Pipeline handler infrastructure + */ + +#include "device_enumerator.h" +#include "log.h" +#include "pipeline_handler.h" + +/** + * \file pipeline_handler.h + * \brief Create pipelines and cameras from one or more media devices + * + * Each pipeline supported by libcamera needs to be backed by a pipeline + * handler implementation which describes the one or many media devices + * needed for a pipeline to function properly. + * + * The pipeline handler is responsible for providing a description of the + * media devices it requires to operate. Once all media devices can be + * provided the pipeline handler can acquire them and create camera + * devices that utilize the acquired media devices. + * + * To make it a bit less bit complicated to write pipe line handlers a + * macro REGISTER_PIPELINE_HANDLER() is provided which allows a pipeline + * handler implementation to register itself with the library with ease. + */ + +namespace libcamera { + +/** + * \class PipelineHandler + * \brief Find a set of media devices and provide cameras + * + * The responsibility of a PipelineHandler is to describe all media + * devices it would need in order to provide cameras to the system. + */ + +/** + * \class PipelineHandlerFactory + * \brief Keep a registry and create instances of available pipeline handlers + * + * The responsibility of the PipelineHandlerFactory is to keep a list + * of all pipelines in the system. Each pipeline handler should register + * it self with the factory using the REGISTER_PIPELINE_HANDLER() macro. + */ + +/** + * \brief Add a pipeline handler to the global list + * + * \param[in] name Name of the pipeline handler to add + * \param[in] factory Factory to use to construct the pipeline + * + * The caller is responsible to guarantee the uniqueness of the pipeline name. + */ +void PipelineHandlerFactory::registerType(const std::string &name, + PipelineHandlerFactory *factory) +{ + std::map<std::string, PipelineHandlerFactory *> &factories = registry(); + + if (factories.count(name)) { + LOG(Error) << "Registering '" << name << "' pipeline twice"; + return; + } + + factories[name] = factory; +} + +/** + * \brief Create a new pipeline handler and try to match the media devices it requires + * + * \param[in] name Name of the pipeline handler to try + * \param[in] enumerator Device enumerator to search for a match for the handler + * + * Try to match the media devices pipeline \a name requires against the ones + * registered in \a enumerator. + * + * \return Pipeline handler if a match was found, nullptr otherwise + */ +PipelineHandler *PipelineHandlerFactory::create(const std::string &name, + DeviceEnumerator *enumerator) +{ + std::map<std::string, PipelineHandlerFactory *> &factories = registry(); + + auto it = factories.find(name); + if (it == factories.end()) { + LOG(Error) << "Trying to create non-existing pipeline handler " + << name; + return nullptr; + } + + PipelineHandler *pipe = it->second->create(); + + if (pipe->match(enumerator)) + return pipe; + + delete pipe; + return nullptr; +} + +/** + * \brief List all names of piepline handlers from the global list + * + * \return List of registerd pipeline handler names + */ +std::vector<std::string> PipelineHandlerFactory::handlers() +{ + std::map<std::string, PipelineHandlerFactory *> &factories = registry(); + std::vector<std::string> handlers; + + for (auto const &handler : factories) + handlers.push_back(handler.first); + + return handlers; +} + +/** + * \brief Static global list of pipeline handlers + * + * The static factories map is defined inside the function to ensures it gets + * initialized on first use, without any dependency on link order. + * + * \return Global list of pipeline handlers + */ +std::map<std::string, PipelineHandlerFactory *> &PipelineHandlerFactory::registry() +{ + static std::map<std::string, PipelineHandlerFactory *> factories; + return factories; +} + +/** + * \def REGISTER_PIPELINE_HANDLER + * \brief Register a pipeline handler with the global list + * + * \param[in] handler Class name of PipelineHandler derived class to register + * + * Register a specific pipeline handler with the global list and make it + * available to try and match devices. + */ + +} /* namespace libcamera */ |