libcamera: proxy: add default linux IPA proxy

Add a skeletal default linux IPA proxy. It currently lacks the IPA proxy
protocol itself.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/proxy/worker/ipa_proxy_linux_worker.cpp

@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * ipa_proxy_linux_worker.cpp - Default Image Processing Algorithm proxy worker for Linux
+ */
+
+#include <iostream>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <libcamera/camera_manager.h>
+#include <libcamera/event_dispatcher.h>
+#include <libcamera/ipa/ipa_interface.h>
+#include <libcamera/logging.h>
+
+#include "ipa_module.h"
+#include "ipc_unixsocket.h"
+#include "log.h"
+#include "utils.h"
+
+using namespace libcamera;
+
+LOG_DEFINE_CATEGORY(IPAProxyLinuxWorker)
+
+void readyRead(IPCUnixSocket *ipc)
+{
+	IPCUnixSocket::Payload message;
+	int ret;
+
+	ret = ipc->receive(&message);
+	if (ret) {
+		LOG(IPAProxyLinuxWorker, Error)
+			<< "Receive message failed: " << ret;
+		return;
+	}
+
+	LOG(IPAProxyLinuxWorker, Debug) << "Received a message!";
+}
+
+int main(int argc, char **argv)
+{
+	/* Uncomment this for debugging. */
+#if 0
+	std::string logPath = "/tmp/libcamera.worker." +
+			      std::to_string(getpid()) + ".log";
+	logSetFile(logPath.c_str());
+#endif
+
+	if (argc < 3) {
+		LOG(IPAProxyLinuxWorker, Debug)
+			<< "Tried to start worker with no args";
+		return EXIT_FAILURE;
+	}
+
+	int fd = std::stoi(argv[2]);
+	LOG(IPAProxyLinuxWorker, Debug)
+		<< "Starting worker for IPA module " << argv[1]
+		<< " with IPC fd = " << fd;
+
+	std::unique_ptr<IPAModule> ipam = utils::make_unique<IPAModule>(argv[1]);
+	if (!ipam->isValid() || !ipam->load()) {
+		LOG(IPAProxyLinuxWorker, Error)
+			<< "IPAModule " << argv[1] << " should be valid but isn't";
+		return EXIT_FAILURE;
+	}
+
+	IPCUnixSocket socket;
+	if (socket.bind(fd) < 0) {
+		LOG(IPAProxyLinuxWorker, Error) << "IPC socket binding failed";
+		return EXIT_FAILURE;
+	}
+	socket.readyRead.connect(&readyRead);
+
+	std::unique_ptr<IPAInterface> ipa = ipam->createInstance();
+	if (!ipa) {
+		LOG(IPAProxyLinuxWorker, Error) << "Failed to create IPA interface";
+		return EXIT_FAILURE;
+	}
+
+	LOG(IPAProxyLinuxWorker, Debug) << "Proxy worker successfully started";
+
+	/* \todo upgrade listening loop */
+	EventDispatcher *dispatcher = CameraManager::instance()->eventDispatcher();
+	while (1)
+		dispatcher->processEvents();
+
+	return 0;
+}

src/libcamera/proxy/worker/meson.build

@@ -0,0 +1,16 @@
+ipa_proxy_sources = [
+    ['ipa_proxy_linux', 'ipa_proxy_linux_worker.cpp']
+]
+
+proxy_install_dir = join_paths(get_option('libexecdir'), 'libcamera')
+
+foreach t : ipa_proxy_sources
+    proxy = executable(t[0], t[1],
+                       include_directories : libcamera_internal_includes,
+                       install : true,
+                       install_dir : proxy_install_dir,
+                       dependencies : libcamera_dep)
+endforeach
+
+config_h.set('IPA_PROXY_DIR',
+             '"' + join_paths(get_option('prefix'), proxy_install_dir) + '"')