Move java api to extras/

[vpp.git] / extras / japi / java / jvpp-registry / io / fd / vpp / jvpp / VppJNIConnection.java

diff --git a/extras/japi/java/jvpp-registry/io/fd/vpp/jvpp/VppJNIConnection.java b/extras/japi/java/jvpp-registry/io/fd/vpp/jvpp/VppJNIConnection.java
new file mode 100644 (file)
index 0000000..6a414f3
--- /dev/null
+++ b/extras/japi/java/jvpp-registry/io/fd/vpp/jvpp/VppJNIConnection.java
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.vpp.jvpp;
+
+import static io.fd.vpp.jvpp.NativeLibraryLoader.loadLibrary;
+import static java.lang.String.format;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * JNI based representation of a management connection to VPP.
+ */
+public final class VppJNIConnection implements VppConnection {
+    private static final Logger LOG = Logger.getLogger(VppJNIConnection.class.getName());
+    private static final String DEFAULT_SHM_PREFIX = "/vpe-api";
+
+    static {
+        final String libName = "libjvpp_registry.so";
+        try {
+            loadLibrary(libName, VppJNIConnection.class);
+        } catch (IOException e) {
+            LOG.log(Level.SEVERE, format("Can't find vpp jni library: %s", libName), e);
+            throw new ExceptionInInitializerError(e);
+        }
+    }
+
+    private ConnectionInfo connectionInfo;
+
+    private final String clientName;
+    private final String shmPrefix;
+    private volatile boolean disconnected = false;
+
+    /**
+     * Create VPPJNIConnection instance for client connecting to VPP.
+     *
+     * @param clientName client name instance to be used for communication. Single connection per clientName is
+     *                   allowed.
+     */
+    public VppJNIConnection(final String clientName) {
+        this.clientName = Objects.requireNonNull(clientName, "Null clientName");
+        this.shmPrefix = DEFAULT_SHM_PREFIX;
+    }
+
+    public VppJNIConnection(final String clientName, final String shmPrefix) {
+        this.clientName = Objects.requireNonNull(clientName, "Null clientName");
+        this.shmPrefix = Objects.requireNonNull(shmPrefix, "Null shmPrefix");
+    }
+
+    /**
+     * Guarded by VppJNIConnection.class
+     */
+    private static final Map<String, VppJNIConnection> connections = new HashMap<>();
+
+    /**
+     * Initiate VPP connection for current instance
+     *
+     * Multiple instances are allowed since this class is not a singleton (VPP allows multiple management connections).
+     *
+     * However only a single connection per clientName is allowed.
+     *
+     * @throws IOException in case the connection could not be established
+     */
+
+    @Override
+    public void connect() throws IOException {
+        _connect(shmPrefix);
+    }
+
+    private void _connect(final String shmPrefix) throws IOException {
+        Objects.requireNonNull(shmPrefix, "Shared memory prefix must be defined");
+
+        synchronized (VppJNIConnection.class) {
+            if (connections.containsKey(clientName)) {
+                throw new IOException("Client " + clientName + " already connected");
+            }
+
+            connectionInfo = clientConnect(shmPrefix, clientName);
+            if (connectionInfo.status != 0) {
+                throw new IOException("Connection returned error " + connectionInfo.status);
+            }
+            connections.put(clientName, this);
+        }
+    }
+
+    @Override
+    public final void checkActive() {
+        if (disconnected) {
+            throw new IllegalStateException("Disconnected client " + clientName);
+        }
+    }
+
+    @Override
+    public final synchronized void close() {
+        if (!disconnected) {
+            disconnected = true;
+            try {
+                clientDisconnect();
+            } finally {
+                synchronized (VppJNIConnection.class) {
+                    connections.remove(clientName);
+                }
+            }
+        }
+    }
+
+    public ConnectionInfo getConnectionInfo() {
+        return connectionInfo;
+    }
+
+    /**
+     * VPP connection information used by plugins to reuse the connection.
+     */
+    public static final class ConnectionInfo {
+        public final long queueAddress;
+        public final int clientIndex;
+        public final int status; // FIXME throw exception instead
+        public final int pid;
+
+        public ConnectionInfo(long queueAddress, int clientIndex, int status, int pid) {
+            this.queueAddress = queueAddress;
+            this.clientIndex = clientIndex;
+            this.status = status;
+            this.pid = pid;
+        }
+    }
+
+    private static native ConnectionInfo clientConnect(String shmPrefix, String clientName);
+
+    private static native void clientDisconnect();
+
+}