1 files changed, 46 insertions, 3 deletions

diff --git a/src/libcamera/pipeline/rpi/common/rpi_stream.cpp b/src/libcamera/pipeline/rpi/common/rpi_stream.cpp
index 7319f510..ee827a86 100644
--- a/src/libcamera/pipeline/rpi/common/rpi_stream.cpp
+++ b/src/libcamera/pipeline/rpi/common/rpi_stream.cpp
@@ -6,6 +6,10 @@
  */
 #include "rpi_stream.h"
 
+#include <algorithm>
+#include <tuple>
+#include <utility>
+
 #include <libcamera/base/log.h>
 
 /* Maximum number of buffer slots to allocate in the V4L2 device driver. */
@@ -17,8 +21,13 @@ LOG_DEFINE_CATEGORY(RPISTREAM)
 
 namespace RPi {
 
+const BufferObject Stream::errorBufferObject{ nullptr, false };
+
 void Stream::setFlags(StreamFlags flags)
 {
+	/* We don't want dynamic mmapping. */
+	ASSERT(!(flags & StreamFlag::RequiresMmap));
+
 	flags_ |= flags;
 
 	/* Import streams cannot be external. */
@@ -27,6 +36,9 @@ void Stream::setFlags(StreamFlags flags)
 
 void Stream::clearFlags(StreamFlags flags)
 {
+	/* We don't want dynamic mmapping. */
+	ASSERT(!(flags & StreamFlag::RequiresMmap));
+
 	flags_ &= ~flags;
 }
 
@@ -56,7 +68,7 @@ void Stream::resetBuffers()
 void Stream::setExportedBuffers(std::vector<std::unique_ptr<FrameBuffer>> *buffers)
 {
 	for (auto const &buffer : *buffers)
-		bufferMap_.emplace(++id_, buffer.get());
+		bufferEmplace(++id_, buffer.get());
 }
 
 const BufferMap &Stream::getBuffers() const
@@ -71,7 +83,7 @@ unsigned int Stream::getBufferId(FrameBuffer *buffer) const
 
 	/* Find the buffer in the map, and return the buffer id. */
 	auto it = std::find_if(bufferMap_.begin(), bufferMap_.end(),
-			       [&buffer](auto const &p) { return p.second == buffer; });
+			       [&buffer](auto const &p) { return p.second.buffer == buffer; });
 
 	if (it == bufferMap_.end())
 		return 0;
@@ -81,7 +93,7 @@ unsigned int Stream::getBufferId(FrameBuffer *buffer) const
 
 void Stream::setExportedBuffer(FrameBuffer *buffer)
 {
-	bufferMap_.emplace(++id_, buffer);
+	bufferEmplace(++id_, buffer);
 }
 
 int Stream::prepareBuffers(unsigned int count)
@@ -180,6 +192,27 @@ void Stream::returnBuffer(FrameBuffer *buffer)
 	}
 }
 
+const BufferObject &Stream::getBuffer(unsigned int id)
+{
+	auto const &it = bufferMap_.find(id);
+	if (it == bufferMap_.end())
+		return errorBufferObject;
+
+	return it->second;
+}
+
+const BufferObject &Stream::acquireBuffer()
+{
+	/* No id provided, so pick up the next available buffer if possible. */
+	if (availableBuffers_.empty())
+		return errorBufferObject;
+
+	unsigned int id = getBufferId(availableBuffers_.front());
+	availableBuffers_.pop();
+
+	return getBuffer(id);
+}
+
 int Stream::queueAllBuffers()
 {
 	int ret;
@@ -204,6 +237,16 @@ void Stream::releaseBuffers()
 	clearBuffers();
 }
 
+void Stream::bufferEmplace(unsigned int id, FrameBuffer *buffer)
+{
+	if (flags_ & StreamFlag::RequiresMmap)
+		bufferMap_.emplace(std::piecewise_construct, std::forward_as_tuple(id),
+				   std::forward_as_tuple(buffer, true));
+	else
+		bufferMap_.emplace(std::piecewise_construct, std::forward_as_tuple(id),
+				   std::forward_as_tuple(buffer, false));
+}
+
 void Stream::clearBuffers()
 {
 	availableBuffers_ = std::queue<FrameBuffer *>{};