From df2c1f9684c603779436dbe577ae131d3821d62e Mon Sep 17 00:00:00 2001
From: Arbousier1 <elderli@foxmail.com>
Date: Sat, 18 Jul 2026 10:28:13 +0800
Subject: [PATCH] perf(core): specialize string fingerprint fields and inline
 separators

Add a field(String) overload so the hot fingerprint path appends string
fields directly via StringBuilder.append(String) instead of routing
through Objects.toString in the field(Object) overload. Replace the
Objects.toString(value, "") call with an explicit null check to avoid
the wrapper allocation, and inline appendFieldSeparator/finishField so
each field(...) overload emits the separator and flag update in the
same frame. Behavior is unchanged: null fields still append nothing,
non-null fields still append toString(), and raw/entrySeparator keep
their existing semantics.
---
 .../core/DelimitedFingerprintBuilder.java     | 56 +++++++++++--------
 1 file changed, 34 insertions(+), 22 deletions(-)

diff --git a/src/main/java/top/ellan/mahjong/table/core/DelimitedFingerprintBuilder.java b/src/main/java/top/ellan/mahjong/table/core/DelimitedFingerprintBuilder.java
index a675967..d7b1522 100644
--- a/src/main/java/top/ellan/mahjong/table/core/DelimitedFingerprintBuilder.java
+++ b/src/main/java/top/ellan/mahjong/table/core/DelimitedFingerprintBuilder.java
@@ -1,7 +1,5 @@
 package top.ellan.mahjong.table.core;
 
-import java.util.Objects;
-
 public final class DelimitedFingerprintBuilder {
     private final StringBuilder delegate;
     private boolean needsSeparator;
@@ -14,28 +12,53 @@ public static DelimitedFingerprintBuilder create(int capacity) {
         return new DelimitedFingerprintBuilder(capacity);
     }
 
+    public DelimitedFingerprintBuilder field(String value) {
+        if (this.needsSeparator) {
+            this.delegate.append(':');
+        }
+        if (value != null) {
+            this.delegate.append(value);
+        }
+        this.needsSeparator = true;
+        return this;
+    }
+
     public DelimitedFingerprintBuilder field(Object value) {
-        this.appendFieldSeparator();
-        this.delegate.append(Objects.toString(value, ""));
-        return this.finishField();
+        if (this.needsSeparator) {
+            this.delegate.append(':');
+        }
+        if (value != null) {
+            this.delegate.append(value);
+        }
+        this.needsSeparator = true;
+        return this;
     }
 
     public DelimitedFingerprintBuilder field(boolean value) {
-        this.appendFieldSeparator();
+        if (this.needsSeparator) {
+            this.delegate.append(':');
+        }
         this.delegate.append(value);
-        return this.finishField();
+        this.needsSeparator = true;
+        return this;
     }
 
     public DelimitedFingerprintBuilder field(char value) {
-        this.appendFieldSeparator();
+        if (this.needsSeparator) {
+            this.delegate.append(':');
+        }
         this.delegate.append(value);
-        return this.finishField();
+        this.needsSeparator = true;
+        return this;
     }
 
     public DelimitedFingerprintBuilder field(int value) {
-        this.appendFieldSeparator();
+        if (this.needsSeparator) {
+            this.delegate.append(':');
+        }
         this.delegate.append(value);
-        return this.finishField();
+        this.needsSeparator = true;
+        return this;
     }
 
     public DelimitedFingerprintBuilder raw(Object value) {
@@ -49,17 +72,6 @@ public DelimitedFingerprintBuilder entrySeparator() {
         return this;
     }
 
-    private void appendFieldSeparator() {
-        if (this.needsSeparator) {
-            this.delegate.append(':');
-        }
-    }
-
-    private DelimitedFingerprintBuilder finishField() {
-        this.needsSeparator = true;
-        return this;
-    }
-
     @Override
     public String toString() {
         return this.delegate.toString();