refactor(NumberUtils, Scientific): Finalize fields and update multiplication logic

wenshao · wenshao · commit 2c59dd2861dd · 2025-02-21T00:42:12.000+08:00
Finalized `output` and `count` fields in `Scientific` class to improve immutability. Updated multiplication logic in `NumberUtils` to use `MULTIPLY_HIGH` method consistently.
diff --git a/core/src/main/java/com/alibaba/fastjson2/util/NumberUtils.java b/core/src/main/java/com/alibaba/fastjson2/util/NumberUtils.java
@@ -595,7 +595,7 @@ public static Scientific floatToScientific(float floatValue) {
 
         if (accurate) {
             // If we pursue performance, we can return it here, but it may return a non-shortest sequence of numbers (the result is correct)
-            // rawOutput = EnvUtils.JDK_AGENT_INSTANCE.multiplyHighKaratsuba(rawOutput, 0x6b5fca6af2bd215fL) >> 22; // rawOutput / 10000000;
+            // rawOutput = MULTIPLY_HIGH.multiplyHigh(rawOutput, 0x6b5fca6af2bd215fL) >> 22; // rawOutput / 10000000;
             // if (adl == 7) {
             //     --adl;
             //     rawOutput = (rawOutput + 5) / 10; // rawOutput = rawOutput / 10 + ((rawOutput % 10) >= 5 ? 1 : 0);
@@ -604,7 +604,7 @@ public static Scientific floatToScientific(float floatValue) {
         }
 
         if (rawOutput < 1000000000) {
-            return new Scientific(rawOutput / 10000000, 2, e10);
+            return new Scientific(MULTIPLY_HIGH.multiplyHigh(rawOutput, 0x6b5fca6af2bd215fL) >> 22, 2, e10); // rawOutput / 10000000
         }
         long div = MULTIPLY_HIGH.multiplyHigh(rawOutput, 0x44b82fa09b5a52ccL) >> 28; // rawOutput / 1000000000;
         long rem = rawOutput - div * 1000000000;
diff --git a/core/src/main/java/com/alibaba/fastjson2/util/Scientific.java b/core/src/main/java/com/alibaba/fastjson2/util/Scientific.java
@@ -5,8 +5,8 @@
  * Created by wangyc
  */
 public class Scientific {
-    public long output;
-    public int count;
+    public final long output;
+    public final int count;
     public final int e10;
     public final boolean b;
 
@@ -23,6 +23,8 @@ public Scientific(long output, int count, int e10) {
     public Scientific(int e10, boolean b) {
         this.e10 = e10;
         this.b = b;
+        this.output = 0;
+        this.count = 0;
     }
 
     @Override
