[libcamera-devel] [PATCH v3 24/30] py: MappedFrameBuffer: Support non-contextmanager use
Tomi Valkeinen
tomi.valkeinen at ideasonboard.com
Fri May 27 16:44:41 CEST 2022
Implement non-contextmanager use to MappedFrameBuffer so that we can
either:
with MappedFrameBuffer(fb) as mfb:
...
or
mfb = MappedFrameBuffer(fb)
mfb.mmap()
...
mfb.munmap()
While at it, improve the error handling a bit.
Note that the mmap() returns self. In other words, one can do this:
mfb = MappedFrameBuffer(fb).mmap()
...
mfb.munmap()
Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
---
src/py/libcamera/utils/MappedFrameBuffer.py | 22 ++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/src/py/libcamera/utils/MappedFrameBuffer.py b/src/py/libcamera/utils/MappedFrameBuffer.py
index 69315e76..4b20f904 100644
--- a/src/py/libcamera/utils/MappedFrameBuffer.py
+++ b/src/py/libcamera/utils/MappedFrameBuffer.py
@@ -10,8 +10,19 @@ class MappedFrameBuffer:
"""
def __init__(self, fb: libcamera.FrameBuffer):
self.__fb = fb
+ self.__planes = ()
+ self.__maps = ()
def __enter__(self):
+ return self.mmap()
+
+ def __exit__(self, exc_type, exc_value, exc_traceback):
+ self.munmap()
+
+ def mmap(self):
+ if self.__planes:
+ raise RuntimeError('MappedFrameBuffer already mmapped')
+
import os
import mmap
@@ -68,14 +79,23 @@ class MappedFrameBuffer:
return self
- def __exit__(self, exc_type, exc_value, exc_traceback):
+ def munmap(self):
+ if not self.__planes:
+ raise RuntimeError('MappedFrameBuffer not mmapped')
+
for p in self.__planes:
p.release()
for mm in self.__maps:
mm.close()
+ self.__planes = ()
+ self.__maps = ()
+
@property
def planes(self) -> Tuple[memoryview, ...]:
"""memoryviews for the planes"""
+ if not self.__planes:
+ raise RuntimeError('MappedFrameBuffer not mmapped')
+
return self.__planes
--
2.34.1
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