1 files changed, 112 insertions, 0 deletions
diff --git a/src/com/android/providers/contacts/aggregation/util/ContactAggregatorHelper.java b/src/com/android/providers/contacts/aggregation/util/ContactAggregatorHelper.java
new file mode 100644
index 0000000..983cd60
--- /dev/null
+++ b/src/com/android/providers/contacts/aggregation/util/ContactAggregatorHelper.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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 com.android.providers.contacts.aggregation.util;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Multimap;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Helper class for contacts aggregation.
+ */
+public class ContactAggregatorHelper {
+
+    private ContactAggregatorHelper() {}
+
+    /**
+     * If two connected components have disjoint accounts, merge them.
+     * If there is any uncertainty, keep them separate.
+     */
+    @VisibleForTesting
+    public static void mergeComponentsWithDisjointAccounts(Set<Set<Long>> connectedRawContactSets,
+            Map<Long, Long> rawContactsToAccounts) {
+        // Index to rawContactIds mapping
+        final Map<Integer, Set<Long>> rawContactIds = new HashMap<>();
+        // AccountId to indices mapping
+        final Map<Long, Set<Integer>> accounts = new HashMap<>();
+
+        int index = 0;
+        for (Set<Long> rIds : connectedRawContactSets) {
+            rawContactIds.put(index, rIds);
+            for (Long rId : rIds) {
+                long acctId = rawContactsToAccounts.get(rId);
+                Set<Integer> s = accounts.get(acctId);
+                if (s == null) {
+                    s = new HashSet<Integer>();
+                }
+                s.add(index);
+                accounts.put(acctId, s);
+            }
+            index++;
+        }
+        final Set<Long> mergedSet = new HashSet<>();
+        connectedRawContactSets.clear();
+        for (Long accountId : accounts.keySet()) {
+            final Set<Integer> s = accounts.get(accountId);
+            if (s.size() > 1) {
+                for (Integer i : s) {
+                    final Set<Long> rIdSet = rawContactIds.get(i);
+                    if (rIdSet != null) {
+                        connectedRawContactSets.add(rawContactIds.get(i));
+                        rawContactIds.remove(i);
+                    }
+                }
+            } else {
+                Set<Long> ids = rawContactIds.get(Iterables.getOnlyElement(s));
+                if (ids != null) {
+                    mergedSet.addAll(ids);
+                }
+            }
+        }
+        connectedRawContactSets.add(mergedSet);
+    }
+
+    /**
+     * Given a set of raw contact ids {@code rawContactIdSet} and the connection among them
+     * {@code matchingRawIdPairs}, find the connected components.
+     */
+    @VisibleForTesting
+    public static Set<Set<Long>> findConnectedComponents(Set<Long> rawContactIdSet, Multimap<Long,
+            Long> matchingRawIdPairs) {
+        Set<Set<Long>> connectedRawContactSets = new HashSet<>();
+        Set<Long> visited = new HashSet<>();
+        for (Long id : rawContactIdSet) {
+            if (!visited.contains(id)) {
+                Set<Long> set = new HashSet<>();
+                findConnectedComponentForRawContact(matchingRawIdPairs, visited, id, set);
+                connectedRawContactSets.add(set);
+            }
+        }
+        return connectedRawContactSets;
+    }
+
+    private static void findConnectedComponentForRawContact(Multimap<Long, Long> connections,
+            Set<Long> visited, Long rawContactId, Set<Long> results) {
+        visited.add(rawContactId);
+        results.add(rawContactId);
+        for (long match : connections.get(rawContactId)) {
+            if (!visited.contains(match)) {
+                findConnectedComponentForRawContact(connections, visited, match, results);
+            }
+        }
+    }
+}