1 files changed, 141 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/database/DeviceLookupService.java b/src/main/java/org/traccar/database/DeviceLookupService.java
new file mode 100644
index 000000000..583b2ae35
--- /dev/null
+++ b/src/main/java/org/traccar/database/DeviceLookupService.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright 2022 Anton Tananaev (anton@traccar.org)
+ *
+ * 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 org.traccar.database;
+
+import io.netty.util.Timeout;
+import io.netty.util.Timer;
+import io.netty.util.TimerTask;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.traccar.config.Config;
+import org.traccar.config.Keys;
+import org.traccar.model.Device;
+import org.traccar.storage.Storage;
+import org.traccar.storage.StorageException;
+import org.traccar.storage.query.Columns;
+import org.traccar.storage.query.Condition;
+import org.traccar.storage.query.Request;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+
+@Singleton
+public class DeviceLookupService {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(DeviceLookupService.class);
+
+    private static final long INFO_TIMEOUT_MS = TimeUnit.MINUTES.toMillis(60);
+    private static final long THROTTLE_MIN_MS = TimeUnit.MINUTES.toMillis(1);
+    private static final long THROTTLE_MAX_MS = TimeUnit.MINUTES.toMillis(30);
+
+    private final Storage storage;
+    private final Timer timer;
+
+    private final boolean throttlingEnabled;
+
+    private static class IdentifierInfo {
+        private long lastQuery;
+        private long delay;
+        private Timeout timeout;
+    }
+
+    private final class IdentifierTask implements TimerTask {
+        private final String uniqueId;
+
+        private IdentifierTask(String uniqueId) {
+            this.uniqueId = uniqueId;
+        }
+
+        @Override
+        public void run(Timeout timeout) {
+            LOGGER.debug("Device lookup expired {}", uniqueId);
+            synchronized (DeviceLookupService.this) {
+                identifierMap.remove(uniqueId);
+            }
+        }
+    }
+
+    private final Map<String, IdentifierInfo> identifierMap = new ConcurrentHashMap<>();
+
+    @Inject
+    public DeviceLookupService(Config config, Storage storage, Timer timer) {
+        this.storage = storage;
+        this.timer = timer;
+        throttlingEnabled = config.getBoolean(Keys.DATABASE_THROTTLE_UNKNOWN);
+    }
+
+    private synchronized boolean isThrottled(String uniqueId) {
+        if (throttlingEnabled) {
+            IdentifierInfo info = identifierMap.get(uniqueId);
+            return info != null && System.currentTimeMillis() < info.lastQuery + info.delay;
+        } else {
+            return false;
+        }
+    }
+
+    private synchronized void lookupSucceeded(String uniqueId) {
+        if (throttlingEnabled) {
+            IdentifierInfo info = identifierMap.remove(uniqueId);
+            if (info != null) {
+                info.timeout.cancel();
+            }
+        }
+    }
+
+    private synchronized void lookupFailed(String uniqueId) {
+        if (throttlingEnabled) {
+            IdentifierInfo info = identifierMap.get(uniqueId);
+            if (info != null) {
+                info.timeout.cancel();
+                info.delay = Math.min(info.delay * 2, THROTTLE_MAX_MS);
+            } else {
+                info = new IdentifierInfo();
+                identifierMap.put(uniqueId, info);
+                info.delay = THROTTLE_MIN_MS;
+            }
+            info.lastQuery = System.currentTimeMillis();
+            info.timeout = timer.newTimeout(new IdentifierTask(uniqueId), INFO_TIMEOUT_MS, TimeUnit.MILLISECONDS);
+            LOGGER.debug("Device lookup {} throttled for {} ms", uniqueId, info.delay);
+        }
+    }
+
+    public Device lookup(String[] uniqueIds) {
+        Device device = null;
+        try {
+            for (String uniqueId : uniqueIds) {
+                if (!isThrottled(uniqueId)) {
+                    device = storage.getObject(Device.class, new Request(
+                            new Columns.All(), new Condition.Equals("uniqueId", uniqueId)));
+                    if (device != null) {
+                        lookupSucceeded(uniqueId);
+                        break;
+                    } else {
+                        lookupFailed(uniqueId);
+                    }
+                } else {
+                    LOGGER.debug("Device lookup throttled {}", uniqueId);
+                }
+            }
+        } catch (StorageException e) {
+            LOGGER.warn("Find device error", e);
+        }
+        return device;
+    }
+
+}