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/ipa_proxy_linux.cpp

@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * ipa_proxy_linux.cpp - Default Image Processing Algorithm proxy for Linux
+ */
+
+#include <vector>
+
+#include <libcamera/ipa/ipa_interface.h>
+#include <libcamera/ipa/ipa_module_info.h>
+
+#include "ipa_module.h"
+#include "ipa_proxy.h"
+#include "ipc_unixsocket.h"
+#include "log.h"
+#include "process.h"
+
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(IPAProxy)
+
+class IPAProxyLinux : public IPAProxy
+{
+public:
+	IPAProxyLinux(IPAModule *ipam);
+	~IPAProxyLinux();
+
+	int init();
+
+private:
+	void readyRead(IPCUnixSocket *ipc);
+
+	Process *proc_;
+
+	IPCUnixSocket *socket_;
+};
+
+int IPAProxyLinux::init()
+{
+	LOG(IPAProxy, Debug) << "initializing IPA via dummy proxy!";
+
+	return 0;
+}
+
+IPAProxyLinux::IPAProxyLinux(IPAModule *ipam)
+{
+	LOG(IPAProxy, Debug)
+		<< "initializing dummy proxy: loading IPA from "
+		<< ipam->path();
+
+	std::vector<int> fds;
+	std::vector<std::string> args;
+	args.push_back(ipam->path());
+	const std::string path = resolvePath("ipa_proxy_linux");
+	if (path.empty()) {
+		LOG(IPAProxy, Error)
+			<< "Failed to get proxy worker path";
+		return;
+	}
+
+	socket_ = new IPCUnixSocket();
+	int fd = socket_->create();
+	if (fd < 0) {
+		LOG(IPAProxy, Error)
+			<< "Failed to create socket";
+		return;
+	}
+	socket_->readyRead.connect(this, &IPAProxyLinux::readyRead);
+	args.push_back(std::to_string(fd));
+	fds.push_back(fd);
+
+	proc_ = new Process();
+	int ret = proc_->start(path, args, fds);
+	if (ret) {
+		LOG(IPAProxy, Error)
+			<< "Failed to start proxy worker process";
+		return;
+	}
+
+	valid_ = true;
+}
+
+IPAProxyLinux::~IPAProxyLinux()
+{
+	delete proc_;
+	delete socket_;
+}
+
+void IPAProxyLinux::readyRead(IPCUnixSocket *ipc)
+{
+}
+
+REGISTER_IPA_PROXY(IPAProxyLinux)
+
+}; /* namespace libcamera */