+++ /dev/null
-/*
- * Sone - IdentityChangeDetector.java - Copyright © 2013–2019 David Roden
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-package net.pterodactylus.sone.freenet.wot;
-
-import java.util.*;
-import java.util.Map.*;
-import java.util.function.*;
-import java.util.stream.*;
-
-import com.google.common.collect.*;
-
-/**
- * Detects changes between two lists of {@link Identity}s. The detector can find
- * added and removed identities, and for identities that exist in both list
- * their contexts and properties are checked for added, removed, or (in case of
- * properties) changed values.
- */
-public class IdentityChangeDetector {
-
- private final Map<String, Identity> oldIdentities;
- private IdentityProcessor onNewIdentity;
- private IdentityProcessor onRemovedIdentity;
- private IdentityProcessor onChangedIdentity;
- private IdentityProcessor onUnchangedIdentity;
-
- public IdentityChangeDetector(Collection<? extends Identity> oldIdentities) {
- this.oldIdentities = convertToMap(oldIdentities);
- }
-
- public void onNewIdentity(IdentityProcessor onNewIdentity) {
- this.onNewIdentity = onNewIdentity;
- }
-
- public void onRemovedIdentity(IdentityProcessor onRemovedIdentity) {
- this.onRemovedIdentity = onRemovedIdentity;
- }
-
- public void onChangedIdentity(IdentityProcessor onChangedIdentity) {
- this.onChangedIdentity = onChangedIdentity;
- }
-
- public void onUnchangedIdentity(IdentityProcessor onUnchangedIdentity) {
- this.onUnchangedIdentity = onUnchangedIdentity;
- }
-
- public void detectChanges(final Collection<? extends Identity> newIdentities) {
- notifyForRemovedIdentities(oldIdentities.values().stream().filter(notContainedIn(newIdentities)).collect(Collectors.toList()));
- notifyForNewIdentities(newIdentities.stream().filter(notContainedIn(oldIdentities.values())).collect(Collectors.toList()));
- notifyForChangedIdentities(newIdentities.stream().filter(containedIn(oldIdentities)).filter(hasChanged(oldIdentities)).collect(Collectors.toList()));
- notifyForUnchangedIdentities(newIdentities.stream().filter(containedIn(oldIdentities)).filter(hasChanged(oldIdentities).negate()).collect(Collectors.toList()));
- }
-
- private void notifyForRemovedIdentities(Iterable<Identity> identities) {
- notify(onRemovedIdentity, identities);
- }
-
- private void notifyForNewIdentities(Iterable<? extends Identity> newIdentities) {
- notify(onNewIdentity, newIdentities);
- }
-
- private void notifyForChangedIdentities(Iterable<? extends Identity> identities) {
- notify(onChangedIdentity, identities);
- }
-
- private void notifyForUnchangedIdentities(Iterable<? extends Identity> identities) {
- notify(onUnchangedIdentity, identities);
- }
-
- private void notify(IdentityProcessor identityProcessor, Iterable<? extends Identity> identities) {
- if (identityProcessor == null) {
- return;
- }
- for (Identity identity : identities) {
- identityProcessor.processIdentity(identity);
- }
- }
-
- private static Predicate<Identity> hasChanged(final Map<String, Identity> oldIdentities) {
- return identity -> (identity != null) && identityHasChanged(oldIdentities.get(identity.getId()), identity);
- }
-
- private static boolean identityHasChanged(Identity oldIdentity, Identity newIdentity) {
- return identityHasNewContexts(oldIdentity, newIdentity)
- || identityHasRemovedContexts(oldIdentity, newIdentity)
- || identityHasNewProperties(oldIdentity, newIdentity)
- || identityHasRemovedProperties(oldIdentity, newIdentity)
- || identityHasChangedProperties(oldIdentity, newIdentity);
- }
-
- private static boolean identityHasNewContexts(Identity oldIdentity, Identity newIdentity) {
- return newIdentity.getContexts().stream().anyMatch(notAContextOf(oldIdentity));
- }
-
- private static boolean identityHasRemovedContexts(Identity oldIdentity, Identity newIdentity) {
- return oldIdentity.getContexts().stream().anyMatch(notAContextOf(newIdentity));
- }
-
- private static boolean identityHasNewProperties(Identity oldIdentity, Identity newIdentity) {
- return newIdentity.getProperties().entrySet().stream().anyMatch(notAPropertyOf(oldIdentity));
- }
-
- private static boolean identityHasRemovedProperties(Identity oldIdentity, Identity newIdentity) {
- return oldIdentity.getProperties().entrySet().stream().anyMatch(notAPropertyOf(newIdentity));
- }
-
- private static boolean identityHasChangedProperties(Identity oldIdentity, Identity newIdentity) {
- return oldIdentity.getProperties().entrySet().stream().anyMatch(hasADifferentValueThanIn(newIdentity));
- }
-
- private static Predicate<Identity> containedIn(final Map<String, Identity> identities) {
- return identity -> (identity != null) && identities.containsKey(identity.getId());
- }
-
- private static Predicate<String> notAContextOf(final Identity identity) {
- return context -> (identity != null) && !identity.getContexts().contains(context);
- }
-
- private static Predicate<Identity> notContainedIn(final Collection<? extends Identity> newIdentities) {
- return identity -> (identity != null) && !newIdentities.contains(identity);
- }
-
- private static Predicate<Entry<String, String>> notAPropertyOf(final Identity identity) {
- return property -> (property != null) && !identity.getProperties().containsKey(property.getKey());
- }
-
- private static Predicate<Entry<String, String>> hasADifferentValueThanIn(final Identity newIdentity) {
- return property -> (property != null) && !newIdentity.getProperty(property.getKey()).equals(property.getValue());
- }
-
- private static Map<String, Identity> convertToMap(Collection<? extends Identity> identities) {
- ImmutableMap.Builder<String, Identity> mapBuilder = ImmutableMap.builder();
- for (Identity identity : identities) {
- mapBuilder.put(identity.getId(), identity);
- }
- return mapBuilder.build();
- }
-
- public interface IdentityProcessor {
-
- void processIdentity(Identity identity);
-
- }
-
-}
projects / Sone.git / blobdiff