[libcamera-devel] [PATCH v2 1/5] libcamera: Add Buffer and BufferPool classes

[Kieran Bingham]

From: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Provide classes that represent frame buffers and pools of frame buffers.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

---
Kieran
 - Fix checkstyle.py diff
---
 include/libcamera/buffer.h    |  55 ++++++++++++++++++
 include/libcamera/libcamera.h |   1 +
 include/libcamera/meson.build |   1 +
 src/libcamera/buffer.cpp      | 102 ++++++++++++++++++++++++++++++++++
 src/libcamera/meson.build     |   1 +
 5 files changed, 160 insertions(+)
 create mode 100644 include/libcamera/buffer.h
 create mode 100644 src/libcamera/buffer.cpp

diff --git a/include/libcamera/buffer.h b/include/libcamera/buffer.h
new file mode 100644
index 000000000000..97c8025d9e77
--- /dev/null
+++ b/include/libcamera/buffer.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2018, Google Inc.
+ *
+ * buffer.h - Buffer handling
+ */
+#ifndef __LIBCAMERA_BUFFER_H__
+#define __LIBCAMERA_BUFFER_H__
+
+#include <vector>
+
+namespace libcamera {
+
+class Buffer
+{
+public:
+	Buffer();
+	~Buffer();
+
+	int dmabuf() const { return fd_; };
+	int setDmabuf(int fd);
+
+	int mmap();
+	void munmap();
+
+private:
+	int fd_;
+};
+
+class BufferPool
+{
+public:
+	enum Memory {
+		Internal,
+		External,
+	};
+
+	BufferPool(Memory memory);
+	virtual ~BufferPool();
+
+	int allocate(unsigned int count);
+	void free();
+
+	unsigned int count() const { return buffers_.size(); };
+
+private:
+	virtual int allocateMemory() = 0;
+
+	BufferPool::Memory memory_;
+	std::vector<Buffer *> buffers_;
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_BUFFER_H__ */
diff --git a/include/libcamera/libcamera.h b/include/libcamera/libcamera.h
index 272dfd5e4a67..8167e8099ac0 100644
--- a/include/libcamera/libcamera.h
+++ b/include/libcamera/libcamera.h
@@ -7,6 +7,7 @@
 #ifndef __LIBCAMERA_LIBCAMERA_H__
 #define __LIBCAMERA_LIBCAMERA_H__
 
+#include <libcamera/buffer.h>
 #include <libcamera/camera.h>
 #include <libcamera/camera_manager.h>
 #include <libcamera/event_dispatcher.h>
diff --git a/include/libcamera/meson.build b/include/libcamera/meson.build
index 54a680787e5c..8c14423bc444 100644
--- a/include/libcamera/meson.build
+++ b/include/libcamera/meson.build
@@ -1,4 +1,5 @@
 libcamera_api = files([
+    'buffer.h',
     'camera.h',
     'camera_manager.h',
     'event_dispatcher.h',
diff --git a/src/libcamera/buffer.cpp b/src/libcamera/buffer.cpp
new file mode 100644
index 000000000000..6dfebfc6bb28
--- /dev/null
+++ b/src/libcamera/buffer.cpp
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2018, Google Inc.
+ *
+ * buffer.cpp - Buffer handling
+ */
+
+#include <errno.h>
+#include <unistd.h>
+
+#include <libcamera/buffer.h>
+
+/**
+ * \file buffer.h
+ * \brief Buffer handling
+ */
+
+namespace libcamera {
+
+/**
+ * \class Buffer
+ * \brief A memory buffer to store a frame
+ *
+ * The Buffer class represents a memory buffer used to store a frame.
+ */
+Buffer::Buffer()
+	: fd_(-1)
+{
+}
+
+Buffer::~Buffer()
+{
+	if (fd_ != -1)
+		close(fd_);
+}
+
+/**
+ * \fn Buffer::dmabuf()
+ * \brief Get the dmabuf file handle backing the buffer
+ */
+
+/**
+ * \brief Set the dmabuf file handle backing the buffer
+ *
+ * The \a fd dmabuf file handle is duplicated and stored.
+ */
+int Buffer::setDmabuf(int fd)
+{
+	if (fd_ != -1) {
+		close(fd_);
+		fd_ = -1;
+	}
+
+	if (fd != -1)
+		return 0;
+
+	fd_ = dup(fd);
+	if (fd_ == -1)
+		return -errno;
+
+	return 0;
+}
+
+/**
+ * \class BufferPool
+ * \brief A pool of buffers
+ */
+BufferPool::BufferPool(BufferPool::Memory memory)
+	: memory_(memory)
+{
+}
+
+BufferPool::~BufferPool()
+{
+	free();
+}
+
+int BufferPool::allocate(unsigned int count)
+{
+	for (unsigned int i = 0; i < count; ++i) {
+		Buffer *buffer = new Buffer();
+		buffers_.push_back(buffer);
+	}
+
+	if (memory_ == Memory::Internal) {
+		int ret = allocateMemory();
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+void BufferPool::free()
+{
+	for (Buffer *buffer : buffers_)
+		delete buffer;
+
+	buffers_.clear();
+}
+
+} /* namespace libcamera */
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index 9f6ff99eebe2..a4e9cc8f936c 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -1,4 +1,5 @@
 libcamera_sources = files([
+    'buffer.cpp',
     'camera.cpp',
     'camera_manager.cpp',
     'device_enumerator.cpp',
-- 
2.19.1