Firestore: use Integer.compare() and Long.compare() instead Firestore bespoke implementations

firebase-firestore/CHANGELOG.md

@@ -2,6 +2,9 @@
 * [fixed] Further improved performance of UTF-8 string ordering logic,
   which had degraded in v25.1.2 and received some improvements in v25.1.3.
   [#7053](//github.com/firebase/firebase-android-sdk/issues/7053)
+* [changed] Use the `compare()` methods defined in standard `Integer`, `Long`, and `Character`
+  classes instead of Firestore's bespoke implementations.
+  [#7109](//github.com/firebase/firebase-android-sdk/pull/7109)
 
 
 # 25.1.4

firebase-firestore/src/main/java/com/google/cloud/datastore/core/number/NumberComparisonHelper.java

@@ -50,7 +50,7 @@ public static int firestoreCompareDoubleWithLong(double doubleValue, long longVa
     }
 
     long doubleAsLong = (long) doubleValue;
-    int cmp = compareLongs(doubleAsLong, longValue);
+    int cmp = Long.compare(doubleAsLong, longValue);
     if (cmp != 0) {
       return cmp;
     }
@@ -60,11 +60,6 @@ public static int firestoreCompareDoubleWithLong(double doubleValue, long longVa
     return firestoreCompareDoubles(doubleValue, longAsDouble);
   }
 
-  /** Compares longs. */
-  public static int compareLongs(long leftLong, long rightLong) {
-    return Long.compare(leftLong, rightLong);
-  }
-
   /**
    * Compares doubles with Firestore query semantics: NaN precedes all other numbers and equals
    * itself, all zeroes are equal.

firebase-firestore/src/main/java/com/google/firebase/firestore/core/View.java

@@ -17,7 +17,6 @@
 import static com.google.firebase.firestore.core.Query.LimitType.LIMIT_TO_FIRST;
 import static com.google.firebase.firestore.core.Query.LimitType.LIMIT_TO_LAST;
 import static com.google.firebase.firestore.util.Assert.hardAssert;
-import static com.google.firebase.firestore.util.Util.compareIntegers;
 
 import androidx.annotation.Nullable;
 import com.google.firebase.database.collection.ImmutableSortedMap;
@@ -301,7 +300,7 @@ public ViewChange applyChanges(
     Collections.sort(
         viewChanges,
         (DocumentViewChange o1, DocumentViewChange o2) -> {
-          int typeComp = compareIntegers(View.changeTypeOrder(o1), View.changeTypeOrder(o2));
+          int typeComp = Integer.compare(View.changeTypeOrder(o1), View.changeTypeOrder(o2));
           if (typeComp != 0) {
             return typeComp;
           }

firebase-firestore/src/main/java/com/google/firebase/firestore/local/DocumentReference.java

@@ -14,8 +14,6 @@
 
 package com.google.firebase.firestore.local;
 
-import static com.google.firebase.firestore.util.Util.compareIntegers;
-
 import com.google.firebase.firestore.model.DocumentKey;
 import java.util.Comparator;
 
@@ -60,12 +58,12 @@ int getId() {
           return keyComp;
         }
 
-        return compareIntegers(o1.targetOrBatchId, o2.targetOrBatchId);
+        return Integer.compare(o1.targetOrBatchId, o2.targetOrBatchId);
       };
 
   static final Comparator<DocumentReference> BY_TARGET =
       (o1, o2) -> {
-        int targetComp = compareIntegers(o1.targetOrBatchId, o2.targetOrBatchId);
+        int targetComp = Integer.compare(o1.targetOrBatchId, o2.targetOrBatchId);
 
         if (targetComp != 0) {
           return targetComp;

firebase-firestore/src/main/java/com/google/firebase/firestore/local/SQLiteMutationQueue.java

@@ -30,7 +30,6 @@
 import com.google.firebase.firestore.model.mutation.MutationBatch;
 import com.google.firebase.firestore.remote.WriteStream;
 import com.google.firebase.firestore.util.Consumer;
-import com.google.firebase.firestore.util.Util;
 import com.google.protobuf.ByteString;
 import com.google.protobuf.InvalidProtocolBufferException;
 import com.google.protobuf.MessageLite;
@@ -324,7 +323,7 @@ public List<MutationBatch> getAllMutationBatchesAffectingDocumentKeys(
       Collections.sort(
           result,
           (MutationBatch lhs, MutationBatch rhs) ->
-              Util.compareIntegers(lhs.getBatchId(), rhs.getBatchId()));
+              Integer.compare(lhs.getBatchId(), rhs.getBatchId()));
     }
     return result;
   }

firebase-firestore/src/main/java/com/google/firebase/firestore/model/BasePath.java

@@ -100,7 +100,7 @@ public int compareTo(@NonNull B o) {
       }
       i++;
     }
-    return Util.compareIntegers(myLength, theirLength);
+    return Integer.compare(myLength, theirLength);
   }
 
   private static int compareSegments(String lhs, String rhs) {

firebase-firestore/src/main/java/com/google/firebase/firestore/model/Values.java

@@ -214,7 +214,7 @@ public static int compare(Value left, Value right) {
     int rightType = typeOrder(right);
 
     if (leftType != rightType) {
-      return Util.compareIntegers(leftType, rightType);
+      return Integer.compare(leftType, rightType);
     }
 
     switch (leftType) {
@@ -291,7 +291,7 @@ private static int compareNumbers(Value left, Value right) {
     } else if (left.getValueTypeCase() == Value.ValueTypeCase.INTEGER_VALUE) {
       long leftLong = left.getIntegerValue();
       if (right.getValueTypeCase() == Value.ValueTypeCase.INTEGER_VALUE) {
-        return Util.compareLongs(leftLong, right.getIntegerValue());
+        return Long.compare(leftLong, right.getIntegerValue());
       } else if (right.getValueTypeCase() == Value.ValueTypeCase.DOUBLE_VALUE) {
         return -1 * Util.compareMixed(right.getDoubleValue(), leftLong);
       }
@@ -301,11 +301,11 @@ private static int compareNumbers(Value left, Value right) {
   }
 
   private static int compareTimestamps(Timestamp left, Timestamp right) {
-    int cmp = Util.compareLongs(left.getSeconds(), right.getSeconds());
+    int cmp = Long.compare(left.getSeconds(), right.getSeconds());
     if (cmp != 0) {
       return cmp;
     }
-    return Util.compareIntegers(left.getNanos(), right.getNanos());
+    return Integer.compare(left.getNanos(), right.getNanos());
   }
 
   private static int compareReferences(String leftPath, String rightPath) {
@@ -319,7 +319,7 @@ private static int compareReferences(String leftPath, String rightPath) {
         return cmp;
       }
     }
-    return Util.compareIntegers(leftSegments.length, rightSegments.length);
+    return Integer.compare(leftSegments.length, rightSegments.length);
   }
 
   private static int compareGeoPoints(LatLng left, LatLng right) {
@@ -338,7 +338,7 @@ private static int compareArrays(ArrayValue left, ArrayValue right) {
         return cmp;
       }
     }
-    return Util.compareIntegers(left.getValuesCount(), right.getValuesCount());
+    return Integer.compare(left.getValuesCount(), right.getValuesCount());
   }
 
   private static int compareMaps(MapValue left, MapValue right) {
@@ -372,7 +372,7 @@ private static int compareVectors(MapValue left, MapValue right) {
     ArrayValue rightArrayValue = rightMap.get(Values.VECTOR_MAP_VECTORS_KEY).getArrayValue();
 
     int lengthCompare =
-        Util.compareIntegers(leftArrayValue.getValuesCount(), rightArrayValue.getValuesCount());
+        Integer.compare(leftArrayValue.getValuesCount(), rightArrayValue.getValuesCount());
     if (lengthCompare != 0) {
       return lengthCompare;
     }

firebase-firestore/src/main/java/com/google/firebase/firestore/util/Util.java

@@ -73,20 +73,6 @@ public static int compareBooleans(boolean b1, boolean b2) {
     }
   }
 
-  /**
-   * Utility function to compare integers. Note that we can't use Integer.compare because it's only
-   * available after Android 19.
-   */
-  public static int compareIntegers(int i1, int i2) {
-    if (i1 < i2) {
-      return -1;
-    } else if (i1 > i2) {
-      return 1;
-    } else {
-      return 0;
-    }
-  }
-
   /** Compare strings in UTF-8 encoded byte order */
   public static int compareUtf8Strings(String left, String right) {
     // noinspection StringEquality
@@ -119,7 +105,7 @@ public static int compareUtf8Strings(String left, String right) {
       final char rightChar = right.charAt(i);
       if (leftChar != rightChar) {
         return (isSurrogate(leftChar) == isSurrogate(rightChar))
-            ? Util.compareIntegers(leftChar, rightChar)
+            ? Character.compare(leftChar, rightChar)
             : isSurrogate(leftChar) ? 1 : -1;
       }
     }
@@ -129,14 +115,6 @@ public static int compareUtf8Strings(String left, String right) {
     return Integer.compare(left.length(), right.length());
   }
 
-  /**
-   * Utility function to compare longs. Note that we can't use Long.compare because it's only
-   * available after Android 19.
-   */
-  public static int compareLongs(long i1, long i2) {
-    return NumberComparisonHelper.compareLongs(i1, i2);
-  }
-
   /** Utility function to compare doubles (using Firestore semantics for NaN). */
   public static int compareDoubles(double i1, double i2) {
     return NumberComparisonHelper.firestoreCompareDoubles(i1, i2);
@@ -274,7 +252,7 @@ public static int compareByteArrays(byte[] left, byte[] right) {
       }
       // Byte values are equal, continue with comparison
     }
-    return Util.compareIntegers(left.length, right.length);
+    return Integer.compare(left.length, right.length);
   }
 
   public static int compareByteStrings(ByteString left, ByteString right) {
@@ -290,7 +268,7 @@ public static int compareByteStrings(ByteString left, ByteString right) {
       }
       // Byte values are equal, continue with comparison
     }
-    return Util.compareIntegers(left.size(), right.size());
+    return Integer.compare(left.size(), right.size());
   }
 
   public static StringBuilder repeatSequence(

firebase-firestore/src/test/java/com/google/firebase/firestore/util/UtilTest.java

@@ -108,7 +108,7 @@ public void compareUtf8StringsShouldReturnCorrectValue() {
       ByteString b2 = ByteString.copyFromUtf8(s2);
       int expected = Util.compareByteStrings(b1, b2);
 
-      if (actual == expected) {
+      if (Integer.signum(actual) == Integer.signum(expected)) {
         passCount++;
       } else {
         errors.add(
@@ -117,9 +117,12 @@ public void compareUtf8StringsShouldReturnCorrectValue() {
                 + "\", s2=\""
                 + s2
                 + "\") returned "
+                + signName(actual)
+                + " ("
                 + actual
+                + ")"
                 + ", but expected "
-                + expected
+                + signName(expected)
                 + " (i="
                 + i
                 + ", s1.length="
@@ -142,6 +145,16 @@ public void compareUtf8StringsShouldReturnCorrectValue() {
     }
   }
 
+  private static String signName(int value) {
+    if (value < 0) {
+      return "a negative value";
+    } else if (value > 0) {
+      return "a positive value";
+    } else {
+      return "0";
+    }
+  }
+
   private static class StringPairGenerator {
 
     private final StringGenerator stringGenerator;