fix(JSONReader): Add reference detection disable flag

wenshao · wenshao · commit a632e14b37cf · 2025-02-21T10:26:05.000+08:00
Add support for disabling reference detection via a new feature flag (MASK_DISABLE_REFERENCE_DETECT). This improves performance in cases where reference tracking is unnecessary.
diff --git a/benchmark/src/test/java/com/alibaba/fastjson2/benchmark/eishay/EishayParseUTF8BytesTest.java b/benchmark/src/test/java/com/alibaba/fastjson2/benchmark/eishay/EishayParseUTF8BytesTest.java
@@ -16,6 +16,8 @@ public static void fastjson2() {
             // zulu8.62.0.19 : 703 746 710 706 700 682 717 698 526 500 474 445 425
             // zulu11.52.13 : 579 565 552 541 554 553 554 538 420 424 434 370
             // zulu17.40.19 : 600 604 597 593 578 567 447 420 380 379
+            // zulu21.37.17 : 364
+            // graalvm 21+35.1 : 403
         }
     }
 
diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONReader.java b/core/src/main/java/com/alibaba/fastjson2/JSONReader.java
@@ -2432,8 +2432,13 @@ public Map<String, Object> readObject() {
                     break;
                 case '{':
                     if (isReference()) {
-                        addResolveTask(object, name, JSONPath.of(readReference()));
-                        val = null;
+                        String path = readReference();
+                        if (path.startsWith("$") || path.equals("..") || path.equals(".")) {
+                            addResolveTask(object, name, JSONPath.of(path));
+                            val = null;
+                        } else {
+                            val = path;
+                        }
                     } else {
                         val = readObject();
                     }
@@ -4328,6 +4333,7 @@ public void config(Feature feature, boolean state) {
 
     protected static final long MASK_TRIM_STRING = 1L << 14;
     protected static final long MASK_EMPTY_STRING_AS_NULL = 1L << 27;
+    protected static final long MASK_DISABLE_REFERENCE_DETECT = 1L << 33;
 
     public enum Feature {
         FieldBased(1),
@@ -4456,7 +4462,12 @@ public enum Feature {
         /**
          * @since 2.0.53
          */
-        UseDoubleForDecimals(1L << 32L);
+        UseDoubleForDecimals(1L << 32L),
+
+        /**
+         * @since 2.0.56
+         */
+        DisableReferenceDetect(MASK_DISABLE_REFERENCE_DETECT);
 
         public final long mask;
 
diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONReaderUTF16.java b/core/src/main/java/com/alibaba/fastjson2/JSONReaderUTF16.java
@@ -387,6 +387,9 @@ public final byte[] readHex() {
     }
 
     public final boolean isReference() {
+        if ((context.features & MASK_DISABLE_REFERENCE_DETECT) != 0) {
+            return false;
+        }
         // should be codeSize <= FreqInlineSize 325, current is 276
         final char[] chars = this.chars;
         char ch = this.ch;
diff --git a/core/src/main/java/com/alibaba/fastjson2/JSONReaderUTF8.java b/core/src/main/java/com/alibaba/fastjson2/JSONReaderUTF8.java
@@ -6855,6 +6855,9 @@ public final byte[] readHex() {
     @Override
     public final boolean isReference() {
         // should be codeSize <= FreqInlineSize 325, current : 284
+        if ((context.features & MASK_DISABLE_REFERENCE_DETECT) != 0) {
+            return false;
+        }
         final byte[] bytes = this.bytes;
         int ch = this.ch;
         if (ch != '{') {
diff --git a/core/src/test/java/com/alibaba/fastjson2/issues_3300/Issue3347.java b/core/src/test/java/com/alibaba/fastjson2/issues_3300/Issue3347.java
@@ -0,0 +1,15 @@
+package com.alibaba.fastjson2.issues_3300;
+
+import com.alibaba.fastjson2.JSON;
+import com.alibaba.fastjson2.JSONObject;
+import com.alibaba.fastjson2.JSONReader;
+import org.junit.jupiter.api.Test;
+
+public class Issue3347 {
+    @Test
+    public void test() {
+        String json2 = "{\"*/*\":{\"schema\":{\"$ref\":\"Error-ModelName{namespace='javax.servlet.http', name='HttpServletResponse'}\"}}}";
+        System.out.println(json2);
+        JSONObject jsonObject4 = JSON.parseObject(json2, JSONReader.Feature.DisableReferenceDetect);
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -16,6 +16,8 @@ public static void fastjson2() {`
`16`	`16`	`// zulu8.62.0.19 : 703 746 710 706 700 682 717 698 526 500 474 445 425`
`17`	`17`	`// zulu11.52.13 : 579 565 552 541 554 553 554 538 420 424 434 370`
`18`	`18`	`// zulu17.40.19 : 600 604 597 593 578 567 447 420 380 379`
	`19`	`+ // zulu21.37.17 : 364`
	`20`	`+ // graalvm 21+35.1 : 403`
`19`	`21`	`}`
`20`	`22`	`}`
`21`	`23`
Original file line number	Diff line number	Diff line change
`@@ -387,6 +387,9 @@ public final byte[] readHex() {`
`387`	`387`	`}`
`388`	`388`
`389`	`389`	`public final boolean isReference() {`
	`390`	`+ if ((context.features & MASK_DISABLE_REFERENCE_DETECT) != 0) {`
	`391`	`+ return false;`
	`392`	`+ }`
`390`	`393`	`// should be codeSize <= FreqInlineSize 325, current is 276`
`391`	`394`	`final char[] chars = this.chars;`
`392`	`395`	`char ch = this.ch;`