[libcamera-devel] [PATCH 02/12] android: Introduce CameraBuffer interface

[Jacopo Mondi]

In order to provide support for different memory backends,
move the MappedCamera3Buffer class definition outside of the
CameraDevice class to its own file.

The interface defined in camera_buffer.h will be implemented by
different backends that will be placed in the src/android/mm
subdirectory.

Provide a first implementation for the 'generic android' backend which
matches the existing one.

The MappedCamera3Buffer interface will be renamed in CameraBuffer
in the next patch to match the name of the file and not in this patch
to ease review.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/android/camera_buffer.h               | 21 ++++++++++
 src/android/camera_device.cpp             | 30 --------------
 src/android/camera_device.h               |  7 +---
 src/android/meson.build                   |  2 +
 src/android/mm/android_generic_buffer.cpp | 48 +++++++++++++++++++++++
 src/android/mm/meson.build                |  6 +++
 6 files changed, 78 insertions(+), 36 deletions(-)
 create mode 100644 src/android/camera_buffer.h
 create mode 100644 src/android/mm/android_generic_buffer.cpp
 create mode 100644 src/android/mm/meson.build

diff --git a/src/android/camera_buffer.h b/src/android/camera_buffer.h
new file mode 100644
index 000000000000..a1fb97a3c6db
--- /dev/null
+++ b/src/android/camera_buffer.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * camera_buffer.h - Frame buffer handling interface definition
+ */
+#ifndef __ANDROID_CAMERA_BUFFER_H__
+#define __ANDROID_CAMERA_BUFFER_H__
+
+#include <hardware/camera3.h>
+
+#include <libcamera/internal/buffer.h>
+
+class MappedCamera3Buffer : public libcamera::MappedBuffer
+{
+public:
+	MappedCamera3Buffer(const buffer_handle_t camera3buffer, int flags);
+	~MappedCamera3Buffer();
+};
+
+#endif /* __ANDROID_CAMERA_BUFFER_H__ */
diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index 16cb8c6d2b84..a7a5b7986aa4 100644
--- a/src/android/camera_device.cpp
+++ b/src/android/camera_device.cpp
@@ -257,36 +257,6 @@ void sortCamera3StreamConfigs(std::vector<Camera3StreamConfig> &unsortedConfigs,
 
 } /* namespace */
 
-MappedCamera3Buffer::MappedCamera3Buffer(const buffer_handle_t camera3buffer,
-					 int flags)
-{
-	maps_.reserve(camera3buffer->numFds);
-	error_ = 0;
-
-	for (int i = 0; i < camera3buffer->numFds; i++) {
-		if (camera3buffer->data[i] == -1)
-			continue;
-
-		off_t length = lseek(camera3buffer->data[i], 0, SEEK_END);
-		if (length < 0) {
-			error_ = -errno;
-			LOG(HAL, Error) << "Failed to query plane length";
-			break;
-		}
-
-		void *address = mmap(nullptr, length, flags, MAP_SHARED,
-				     camera3buffer->data[i], 0);
-		if (address == MAP_FAILED) {
-			error_ = -errno;
-			LOG(HAL, Error) << "Failed to mmap plane";
-			break;
-		}
-
-		maps_.emplace_back(static_cast<uint8_t *>(address),
-				   static_cast<size_t>(length));
-	}
-}
-
 /*
  * \struct Camera3RequestDescriptor
  *
diff --git a/src/android/camera_device.h b/src/android/camera_device.h
index 9cbfcad38433..e6c192c2100b 100644
--- a/src/android/camera_device.h
+++ b/src/android/camera_device.h
@@ -24,17 +24,12 @@
 #include "libcamera/internal/log.h"
 #include "libcamera/internal/message.h"
 
+#include "camera_buffer.h"
 #include "camera_metadata.h"
 #include "camera_stream.h"
 #include "camera_worker.h"
 #include "jpeg/encoder.h"
 
-class MappedCamera3Buffer : public libcamera::MappedBuffer
-{
-public:
-	MappedCamera3Buffer(const buffer_handle_t camera3buffer, int flags);
-};
-
 class CameraDevice : protected libcamera::Loggable
 {
 public:
diff --git a/src/android/meson.build b/src/android/meson.build
index a13ce63b1d58..fd41c74f78ef 100644
--- a/src/android/meson.build
+++ b/src/android/meson.build
@@ -57,6 +57,8 @@ android_hal_sources = files([
     'yuv/post_processor_yuv.cpp'
 ])
 
+subdir('mm')
+
 android_camera_metadata_sources = files([
     'metadata/camera_metadata.c',
 ])
diff --git a/src/android/mm/android_generic_buffer.cpp b/src/android/mm/android_generic_buffer.cpp
new file mode 100644
index 000000000000..2504d9276e9e
--- /dev/null
+++ b/src/android/mm/android_generic_buffer.cpp
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * android_generic_buffer.cpp - Generic Android frame buffer backend
+ */
+
+#include "../camera_buffer.h"
+
+#include "libcamera/internal/log.h"
+
+using namespace libcamera;
+
+LOG_DECLARE_CATEGORY(HAL)
+
+MappedCamera3Buffer::MappedCamera3Buffer(const buffer_handle_t camera3buffer,
+					 int flags)
+{
+	maps_.reserve(camera3buffer->numFds);
+	error_ = 0;
+
+	for (int i = 0; i < camera3buffer->numFds; i++) {
+		if (camera3buffer->data[i] == -1)
+			continue;
+
+		off_t length = lseek(camera3buffer->data[i], 0, SEEK_END);
+		if (length < 0) {
+			error_ = -errno;
+			LOG(HAL, Error) << "Failed to query plane length";
+			break;
+		}
+
+		void *address = mmap(nullptr, length, flags, MAP_SHARED,
+				     camera3buffer->data[i], 0);
+		if (address == MAP_FAILED) {
+			error_ = -errno;
+			LOG(HAL, Error) << "Failed to mmap plane";
+			break;
+		}
+
+		maps_.emplace_back(static_cast<uint8_t *>(address),
+				   static_cast<size_t>(length));
+	}
+}
+
+MappedCamera3Buffer::~MappedCamera3Buffer()
+{
+}
diff --git a/src/android/mm/meson.build b/src/android/mm/meson.build
new file mode 100644
index 000000000000..39be8fec8567
--- /dev/null
+++ b/src/android/mm/meson.build
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: CC0-1.0
+
+memory_backend = get_option('android_memory_backend')
+if memory_backend == 'android_generic'
+    android_hal_sources += files(['android_generic_buffer.cpp'])
+endif
-- 
2.30.0