libcamera: Move internal headers to include/libcamera/internal/

The libcamera internal headers are located in src/libcamera/include/.
The directory is added to the compiler headers search path with a meson
include_directories() directive, and internal headers are included with
(e.g. for the internal semaphore.h header)

  #include "semaphore.h"

All was well, until libcxx decided to implement the C++20
synchronization library. The __threading_support header gained a

  #include <semaphore.h>

to include the pthread's semaphore support. As include_directories()
adds src/libcamera/include/ to the compiler search path with -I, the
internal semaphore.h is included instead of the pthread version.
Needless to say, the compiler isn't happy.

Three options have been considered to fix this issue:

- Use -iquote instead of -I. The -iquote option instructs gcc to only
  consider the header search path for headers included with the ""
  version. Meson unfortunately doesn't support this option.

- Rename the internal semaphore.h header. This was deemed to be the
  beginning of a long whack-a-mole game, where namespace clashes with
  system libraries would appear over time (possibly dependent on
  particular system configurations) and would need to be constantly
  fixed.

- Move the internal headers to another directory to create a unique
  namespace through path components. This causes lots of churn in all
  the existing source files through the all project.

The first option would be best, but isn't available to us due to missing
support in meson. Even if -iquote support was added, we would need to
fix the problem before a new version of meson containing the required
support would be released.

The third option is thus the only practical solution available. Bite the
bullet, and do it, moving headers to include/libcamera/internal/.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 124 insertions, 0 deletions

diff --git a/include/libcamera/internal/media_object.h b/include/libcamera/internal/media_object.h
new file mode 100644
index 00000000..748eafdc
--- /dev/null
+++ b/include/libcamera/internal/media_object.h
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2018, Google Inc.
+ *
+ * media_object.h - Media Device objects: entities, pads and links.
+ */
+#ifndef __LIBCAMERA_MEDIA_OBJECT_H__
+#define __LIBCAMERA_MEDIA_OBJECT_H__
+
+#include <string>
+#include <vector>
+
+#include <linux/media.h>
+
+namespace libcamera {
+
+class MediaDevice;
+class MediaEntity;
+class MediaPad;
+
+class MediaObject
+{
+public:
+	MediaDevice *device() { return dev_; }
+	unsigned int id() const { return id_; }
+
+protected:
+	friend class MediaDevice;
+
+	MediaObject(MediaDevice *dev, unsigned int id)
+		: dev_(dev), id_(id)
+	{
+	}
+	virtual ~MediaObject() {}
+
+	MediaDevice *dev_;
+	unsigned int id_;
+};
+
+class MediaLink : public MediaObject
+{
+public:
+	MediaPad *source() const { return source_; }
+	MediaPad *sink() const { return sink_; }
+	unsigned int flags() const { return flags_; }
+	int setEnabled(bool enable);
+
+private:
+	friend class MediaDevice;
+
+	MediaLink(const struct media_v2_link *link,
+		  MediaPad *source, MediaPad *sink);
+	MediaLink(const MediaLink &) = delete;
+	~MediaLink() {}
+
+	MediaPad *source_;
+	MediaPad *sink_;
+	unsigned int flags_;
+};
+
+class MediaPad : public MediaObject
+{
+public:
+	unsigned int index() const { return index_; }
+	MediaEntity *entity() const { return entity_; }
+	unsigned int flags() const { return flags_; }
+	const std::vector<MediaLink *> &links() const { return links_; }
+
+	void addLink(MediaLink *link);
+
+private:
+	friend class MediaDevice;
+
+	MediaPad(const struct media_v2_pad *pad, MediaEntity *entity);
+	MediaPad(const MediaPad &) = delete;
+	~MediaPad();
+
+	unsigned int index_;
+	MediaEntity *entity_;
+	unsigned int flags_;
+
+	std::vector<MediaLink *> links_;
+};
+
+class MediaEntity : public MediaObject
+{
+public:
+	const std::string &name() const { return name_; }
+	unsigned int function() const { return function_; }
+	unsigned int flags() const { return flags_; }
+	const std::string &deviceNode() const { return deviceNode_; }
+	unsigned int deviceMajor() const { return major_; }
+	unsigned int deviceMinor() const { return minor_; }
+
+	const std::vector<MediaPad *> &pads() const { return pads_; }
+
+	const MediaPad *getPadByIndex(unsigned int index) const;
+	const MediaPad *getPadById(unsigned int id) const;
+
+	int setDeviceNode(const std::string &deviceNode);
+
+private:
+	friend class MediaDevice;
+
+	MediaEntity(MediaDevice *dev, const struct media_v2_entity *entity,
+		    unsigned int major = 0, unsigned int minor = 0);
+	MediaEntity(const MediaEntity &) = delete;
+	~MediaEntity();
+
+	std::string name_;
+	unsigned int function_;
+	unsigned int flags_;
+	std::string deviceNode_;
+	unsigned int major_;
+	unsigned int minor_;
+
+	std::vector<MediaPad *> pads_;
+
+	void addPad(MediaPad *pad);
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_MEDIA_OBJECT_H__ */