fixed some module/dependency mess by e.g:

* removing SignalInformationPoint from ditto-interna-models-signal (as it pulled in several entity modules); moved funtionality of that interface to Command, Signal, etc. interfaces
* moving HeaderTranslator from ditto-protocol to ditto-base-model
* moving LikeHelper from ditto-rql-query to ditto-base-model
* moved ConciergeForwarderActor and ShardRegions to ditto-edge-api
* moved PolicyEnforcer from ditto-internal-utils-cache-loaders to ditto-policies-enforcement
* created DittoSystemProperties inn ditto-base-model for commonly used system properties in order to avoid dependencies to models where not necessary
* moved ThingCommandEnforcement, LiveSignalEnforcement, etc. from ditto-policies-enforcement to ditto-things-service where they should be located in the end

Signed-off-by: Thomas Jaeckle <thomas.jaeckle@bosch.io>

base/model/src/main/java/org/eclipse/ditto/base/model/common/DittoSystemProperties.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2022 Contributors to the Eclipse Foundation
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.eclipse.ditto.base.model.common;
+
+/**
+ * TODO TJ add javadoc
+ * @since 3.0.0
+ */
+public final class DittoSystemProperties {
+
+    /**
+     * System property name of the property defining the max policy size in bytes.
+     */
+    public static final String DITTO_LIMITS_POLICIES_MAX_SIZE_BYTES = "ditto.limits.policies.max-size";
+
+    /**
+     * System property name of the property defining the max Thing size in bytes.
+     */
+    public static final String DITTO_LIMITS_THINGS_MAX_SIZE_BYTES = "ditto.limits.things.max-size";
+
+    /**
+     * System property name of the property defining the max Message payload size in bytes.
+     */
+    public static final String DITTO_LIMITS_MESSAGES_MAX_SIZE_BYTES = "ditto.limits.messages.max-size";
+
+    private DittoSystemProperties() {
+        throw new AssertionError();
+    }
+}

rql/query/src/main/java/org/eclipse/ditto/rql/query/LikeHelper.java → base/model/src/main/java/org/eclipse/ditto/base/model/common/LikeHelper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Contributors to the Eclipse Foundation
+ * Copyright (c) 2022 Contributors to the Eclipse Foundation
  *
  * See the NOTICE file(s) distributed with this work for additional
  * information regarding copyright ownership.
@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.eclipse.ditto.rql.query;
+package org.eclipse.ditto.base.model.common;
 
 import java.util.regex.Pattern;
 

base/model/src/main/java/org/eclipse/ditto/base/model/entity/id/WithEntityId.java

@@ -16,6 +16,8 @@
 
 import javax.annotation.Nullable;
 
+import org.eclipse.ditto.base.model.signals.Signal;
+
 /**
  * Implementations of this interface are associated to an entity identified by the value
  * returned from {@link #getEntityId()}.
@@ -48,4 +50,41 @@ static <I extends EntityId> Optional<I> getEntityIdOfType(final Class<I> theClas
                 .map(theClass::cast);
     }
 
+    /**
+     * Indicates whether the specified signal argument provides an entity ID.
+     *
+     * @param signal the signal to be checked.
+     * @return {@code true} if {@code signal} provides an entity ID because it implements {@link WithEntityId}.
+     * {@code false} else.
+     * @since 3.0.0
+     */
+    static boolean isWithEntityId(@Nullable final Signal<?> signal) {
+        final boolean result;
+        if (null != signal) {
+            result = WithEntityId.class.isAssignableFrom(signal.getClass());
+        } else {
+            result = false;
+        }
+
+        return result;
+    }
+
+    /**
+     * Returns the {@link EntityId} for the specified signal argument.
+     *
+     * @param signal the signal to get the entity ID from.
+     * @return an {@code Optional} containing the signal's entity ID if it provides one, an empty {@code Optional} else.
+     * @since 3.0.0
+     */
+    static Optional<EntityId> getEntityId(@Nullable final Signal<?> signal) {
+        final Optional<EntityId> result;
+        if (null != signal && WithEntityId.isWithEntityId(signal)) {
+            result = Optional.of(((WithEntityId) signal).getEntityId());
+        } else {
+            result = Optional.empty();
+        }
+
+        return result;
+    }
+
 }

base/model/src/main/java/org/eclipse/ditto/base/model/headers/WithDittoHeaders.java

@@ -12,6 +12,10 @@
  */
 package org.eclipse.ditto.base.model.headers;
 
+import java.util.Optional;
+
+import javax.annotation.Nullable;
+
 /**
  * Common interface for all classes which have {@link org.eclipse.ditto.base.model.headers.DittoHeaders} available.
  */
@@ -24,4 +28,22 @@ public interface WithDittoHeaders {
      */
     DittoHeaders getDittoHeaders();
 
+    /**
+     * Returns the optional correlation ID of the specified argument's headers.
+     *
+     * @param signal the signal to get the optional correlation ID from.
+     * @return the optional correlation ID. The optional is empty if {@code signal} is {@code null}.
+     * @since 3.0.0
+     */
+    static Optional<String> getCorrelationId(@Nullable final WithDittoHeaders signal) {
+        final Optional<String> result;
+        if (null != signal) {
+            final DittoHeaders signalDittoHeaders = signal.getDittoHeaders();
+            result = signalDittoHeaders.getCorrelationId();
+        } else {
+            result = Optional.empty();
+        }
+
+        return result;
+    }
 }

protocol/src/main/java/org/eclipse/ditto/protocol/AbstractHeaderEntryFilter.java → base/model/src/main/java/org/eclipse/ditto/base/model/headers/translator/AbstractHeaderEntryFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Contributors to the Eclipse Foundation
+ * Copyright (c) 2022 Contributors to the Eclipse Foundation
  *
  * See the NOTICE file(s) distributed with this work for additional
  * information regarding copyright ownership.
@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.eclipse.ditto.protocol;
+package org.eclipse.ditto.base.model.headers.translator;
 
 import javax.annotation.Nullable;
 

protocol/src/main/java/org/eclipse/ditto/protocol/CheckExternalFilter.java → base/model/src/main/java/org/eclipse/ditto/base/model/headers/translator/CheckExternalFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Contributors to the Eclipse Foundation
+ * Copyright (c) 2022 Contributors to the Eclipse Foundation
  *
  * See the NOTICE file(s) distributed with this work for additional
  * information regarding copyright ownership.
@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.eclipse.ditto.protocol;
+package org.eclipse.ditto.base.model.headers.translator;
 
 import static org.eclipse.ditto.base.model.common.ConditionChecker.checkNotNull;
 

protocol/src/main/java/org/eclipse/ditto/protocol/DittoAckRequestsFilter.java → base/model/src/main/java/org/eclipse/ditto/base/model/headers/translator/DittoAckRequestsFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Contributors to the Eclipse Foundation
+ * Copyright (c) 2022 Contributors to the Eclipse Foundation
  *
  * See the NOTICE file(s) distributed with this work for additional
  * information regarding copyright ownership.
@@ -10,20 +10,20 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.eclipse.ditto.protocol;
+package org.eclipse.ditto.base.model.headers.translator;
 
 import java.util.Objects;
 
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
+import org.eclipse.ditto.base.model.acks.AcknowledgementLabel;
+import org.eclipse.ditto.base.model.acks.DittoAcknowledgementLabel;
+import org.eclipse.ditto.base.model.headers.DittoHeaderDefinition;
 import org.eclipse.ditto.json.JsonArray;
 import org.eclipse.ditto.json.JsonCollectors;
 import org.eclipse.ditto.json.JsonParseException;
 import org.eclipse.ditto.json.JsonValue;
-import org.eclipse.ditto.base.model.acks.AcknowledgementLabel;
-import org.eclipse.ditto.base.model.acks.DittoAcknowledgementLabel;
-import org.eclipse.ditto.base.model.headers.DittoHeaderDefinition;
 
 /**
  * This {@link HeaderEntryFilter} checks if the given key references {@link DittoHeaderDefinition#REQUESTED_ACKS} and

protocol/src/main/java/org/eclipse/ditto/protocol/HeaderEntryFilter.java → base/model/src/main/java/org/eclipse/ditto/base/model/headers/translator/HeaderEntryFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Contributors to the Eclipse Foundation
+ * Copyright (c) 2022 Contributors to the Eclipse Foundation
  *
  * See the NOTICE file(s) distributed with this work for additional
  * information regarding copyright ownership.
@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.eclipse.ditto.protocol;
+package org.eclipse.ditto.base.model.headers.translator;
 
 import static org.eclipse.ditto.base.model.common.ConditionChecker.checkNotNull;
 

protocol/src/main/java/org/eclipse/ditto/protocol/HeaderEntryFilters.java → base/model/src/main/java/org/eclipse/ditto/base/model/headers/translator/HeaderEntryFilters.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Contributors to the Eclipse Foundation
+ * Copyright (c) 2022 Contributors to the Eclipse Foundation
  *
  * See the NOTICE file(s) distributed with this work for additional
  * information regarding copyright ownership.
@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.eclipse.ditto.protocol;
+package org.eclipse.ditto.base.model.headers.translator;
 
 import java.util.Map;
 

protocol/src/main/java/org/eclipse/ditto/protocol/HeaderTranslator.java → base/model/src/main/java/org/eclipse/ditto/base/model/headers/translator/HeaderTranslator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 Contributors to the Eclipse Foundation
+ * Copyright (c) 2022 Contributors to the Eclipse Foundation
  *
  * See the NOTICE file(s) distributed with this work for additional
  * information regarding copyright ownership.
@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.eclipse.ditto.protocol;
+package org.eclipse.ditto.base.model.headers.translator;
 
 import static org.eclipse.ditto.base.model.common.ConditionChecker.checkNotNull;
 
@@ -34,6 +34,8 @@
  * <p>
  * Does so by applying blocking based on {@link HeaderDefinition}s.
  * </p>
+ * @since 3.0.0
+ * TODO TJ can we make HeaderTranslator internal??
  */
 @Immutable
 public final class HeaderTranslator {

protocol/src/main/java/org/eclipse/ditto/protocol/ReadJsonArrayHeadersFilter.java → base/model/src/main/java/org/eclipse/ditto/base/model/headers/translator/ReadJsonArrayHeadersFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Contributors to the Eclipse Foundation
+ * Copyright (c) 2022 Contributors to the Eclipse Foundation
  *
  * See the NOTICE file(s) distributed with this work for additional
  * information regarding copyright ownership.
@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.eclipse.ditto.protocol;
+package org.eclipse.ditto.base.model.headers.translator;
 
 import static org.eclipse.ditto.base.model.common.ConditionChecker.checkNotNull;
 
@@ -22,14 +22,14 @@
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
+import org.eclipse.ditto.base.model.headers.HeaderDefinition;
 import org.eclipse.ditto.json.JsonArray;
 import org.eclipse.ditto.json.JsonCollectors;
 import org.eclipse.ditto.json.JsonParseException;
 import org.eclipse.ditto.json.JsonValue;
-import org.eclipse.ditto.base.model.headers.HeaderDefinition;
 
 /**
- * This {@link org.eclipse.ditto.protocol.HeaderEntryFilter} reads headers which are of {@code serializationType}
+ * This {@link HeaderEntryFilter} reads headers which are of {@code serializationType}
  * {@code JsonArray} as comma-separated list of values so that the read header entry does not need to be in the JSON
  * representation of a JSON array (that would be: {@code "\"["foo","bar"]\""}), but instead simply: {@code "foo,bar"}.
  *

base/model/src/main/java/org/eclipse/ditto/base/model/signals/Signal.java

@@ -12,11 +12,15 @@
  */
 package org.eclipse.ditto.base.model.signals;
 
-import org.eclipse.ditto.json.JsonField;
-import org.eclipse.ditto.json.JsonObject;
+import javax.annotation.Nullable;
+
+import org.eclipse.ditto.base.model.headers.DittoHeaders;
 import org.eclipse.ditto.base.model.headers.DittoHeadersSettable;
+import org.eclipse.ditto.base.model.headers.WithDittoHeaders;
 import org.eclipse.ditto.base.model.headers.WithManifest;
 import org.eclipse.ditto.base.model.json.Jsonifiable;
+import org.eclipse.ditto.json.JsonField;
+import org.eclipse.ditto.json.JsonObject;
 
 /**
  * A service message that incites to action or conveys notice or warning.
@@ -26,6 +30,18 @@
 public interface Signal<T extends Signal<T>> extends Jsonifiable.WithPredicate<JsonObject, JsonField>,
         DittoHeadersSettable<T>, WithManifest, WithType, WithName, WithResource {
 
+    /**
+     * TODO TJ doc
+     * @since 3.0.0
+     */
+    String CHANNEL_LIVE = "live";
+
+    /**
+     * TODO TJ doc
+     * @since 3.0.0
+     */
+    String CHANNEL_TWIN = "twin";
+
     /**
      * Returns the name of the signal. This is gathered by the type of the signal by default.
      *
@@ -36,4 +52,41 @@ default String getName() {
         return getType().contains(":") ? getType().split(":")[1] : getType();
     }
 
+    /**
+     * TODO TJ doc - moved from SignalInformationPoint
+     * @param signal
+     * @param typePrefix
+     * @return
+     * @since 3.0.0
+     */
+    static boolean hasTypePrefix(@Nullable final WithType signal, final String typePrefix) {
+        final boolean result;
+        if (null != signal) {
+            final String signalType = signal.getType();
+            result = signalType.startsWith(typePrefix);
+        } else {
+            result = false;
+        }
+        return result;
+    }
+
+    /**
+     * Indicates whether the headers of the specified signal argument contain channel {@value CHANNEL_LIVE}.
+     *
+     * @param signal the signal to be checked.
+     * @return {@code true} if the headers of {@code signal} contain the channel {@value CHANNEL_LIVE}.
+     * @since 3.0.0
+     */
+    static boolean isChannelLive(@Nullable final WithDittoHeaders signal) {
+        final boolean result;
+        if (null != signal) {
+            final DittoHeaders dittoHeaders = signal.getDittoHeaders();
+            result = dittoHeaders.getChannel().filter(CHANNEL_LIVE::equals).isPresent();
+        } else {
+            result = false;
+        }
+
+        return result;
+    }
+
 }