[libcamera-devel] [PATCH 23/31] libcamera: byte_stream_buffer: Add Span<> support

[Laurent Pinchart]

From: Jacopo Mondi <jacopo at jmondi.org>

Add support to read and write a Span<> from and to the ByteStreamBuffer
class.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 src/libcamera/byte_stream_buffer.cpp       | 18 ++++++++++++++++++
 src/libcamera/include/byte_stream_buffer.h | 17 +++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/src/libcamera/byte_stream_buffer.cpp b/src/libcamera/byte_stream_buffer.cpp
index cd1d8a36d464..40380bf0434a 100644
--- a/src/libcamera/byte_stream_buffer.cpp
+++ b/src/libcamera/byte_stream_buffer.cpp
@@ -232,6 +232,15 @@ int ByteStreamBuffer::skip(size_t size)
  * \retval -ENOSPC no more space is available in the managed memory buffer
  */
 
+/**
+ * \fn template<typename T> int ByteStreamBuffer::read(const Span<T> &data)
+ * \brief Read data from the managed memory buffer into span \a data
+ * \param[out] data Span representing the destination memory
+ * \return 0 on success, a negative error code otherwise
+ * \retval -EACCES attempting to read from a write buffer
+ * \retval -ENOSPC no more space is available in the managed memory buffer
+ */
+
 /**
  * \fn template<typename T> int ByteStreamBuffer::write(const T *t)
  * \brief Write \a t to the managed memory buffer
@@ -241,6 +250,15 @@ int ByteStreamBuffer::skip(size_t size)
  * \retval -ENOSPC no more space is available in the managed memory buffer
  */
 
+/**
+ * \fn template<typename T> int ByteStreamBuffer::write(const Span<T> &data)
+ * \brief Write \a data to the managed memory buffer
+ * \param[in] data The data to write to memory
+ * \return 0 on success, a negative error code otherwise
+ * \retval -EACCES attempting to write to a read buffer
+ * \retval -ENOSPC no more space is available in the managed memory buffer
+ */
+
 int ByteStreamBuffer::read(uint8_t *data, size_t size)
 {
 	if (!read_)
diff --git a/src/libcamera/include/byte_stream_buffer.h b/src/libcamera/include/byte_stream_buffer.h
index b5274c62b85e..17cb0146061e 100644
--- a/src/libcamera/include/byte_stream_buffer.h
+++ b/src/libcamera/include/byte_stream_buffer.h
@@ -10,6 +10,8 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include <libcamera/span.h>
+
 namespace libcamera {
 
 class ByteStreamBuffer
@@ -33,12 +35,27 @@ public:
 	{
 		return read(reinterpret_cast<uint8_t *>(t), sizeof(*t));
 	}
+
+	template<typename T>
+	int read(const Span<T> &data)
+	{
+		return read(reinterpret_cast<uint8_t *>(data.data()),
+			    data.size_bytes());
+	}
+
 	template<typename T>
 	int write(const T *t)
 	{
 		return write(reinterpret_cast<const uint8_t *>(t), sizeof(*t));
 	}
 
+	template<typename T>
+	int write(const Span<T> &data)
+	{
+		return write(reinterpret_cast<const uint8_t *>(data.data()),
+			     data.size_bytes());
+	}
+
 private:
 	ByteStreamBuffer(const ByteStreamBuffer &other) = delete;
 	ByteStreamBuffer &operator=(const ByteStreamBuffer &other) = delete;
-- 
Regards,

Laurent Pinchart