1 files changed, 40 insertions, 10 deletions
diff --git a/java/com/android/dialer/enrichedcall/FuzzyPhoneNumberMatcher.java b/java/com/android/dialer/enrichedcall/FuzzyPhoneNumberMatcher.java
index 250c64313..6f4d97521 100644
--- a/java/com/android/dialer/enrichedcall/FuzzyPhoneNumberMatcher.java
+++ b/java/com/android/dialer/enrichedcall/FuzzyPhoneNumberMatcher.java
@@ -16,20 +16,50 @@
 package com.android.dialer.enrichedcall;
 
 import android.support.annotation.NonNull;
-import com.android.dialer.common.Assert;
 
 /** Utility for comparing phone numbers. */
 public class FuzzyPhoneNumberMatcher {
 
-  /** Returns {@code true} if the given numbers can be interpreted to be the same. */
-  public static boolean matches(@NonNull String a, @NonNull String b) {
-    String aNormalized = Assert.isNotNull(a).replaceAll("[^0-9]", "");
-    String bNormalized = Assert.isNotNull(b).replaceAll("[^0-9]", "");
-    if (aNormalized.length() < 7 || bNormalized.length() < 7) {
-      return false;
+  private static final int REQUIRED_MATCHED_DIGITS = 7;
+
+  /**
+   * Returns {@code true} if the given numbers can be interpreted to be the same.
+   *
+   * <p>This method is called numerous times when rendering the call log. Using string methods is
+   * too slow, so character by character matching is used instead.
+   */
+  public static boolean matches(@NonNull String lhs, @NonNull String rhs) {
+    return lastSevenDigitsCharacterByCharacterMatches(lhs, rhs);
+  }
+
+  /**
+   * This strategy examines the numbers character by character starting from the end. If the last
+   * {@link #REQUIRED_MATCHED_DIGITS} match, it returns {@code true}.
+   */
+  private static boolean lastSevenDigitsCharacterByCharacterMatches(
+      @NonNull String lhs, @NonNull String rhs) {
+    int lhsIndex = lhs.length() - 1;
+    int rhsIndex = rhs.length() - 1;
+
+    int matchedDigits = 0;
+
+    while (lhsIndex >= 0 && rhsIndex >= 0) {
+      if (!Character.isDigit(lhs.charAt(lhsIndex))) {
+        --lhsIndex;
+        continue;
+      }
+      if (!Character.isDigit(rhs.charAt(rhsIndex))) {
+        --rhsIndex;
+        continue;
+      }
+      if (lhs.charAt(lhsIndex) != rhs.charAt(rhsIndex)) {
+        break;
+      }
+      --lhsIndex;
+      --rhsIndex;
+      ++matchedDigits;
     }
-    String aMatchable = aNormalized.substring(aNormalized.length() - 7);
-    String bMatchable = bNormalized.substring(bNormalized.length() - 7);
-    return aMatchable.equals(bMatchable);
+
+    return matchedDigits >= REQUIRED_MATCHED_DIGITS;
   }
 }