From 8630cc09933db9b6816a530ba2d2345f54f1d006 Mon Sep 17 00:00:00 2001
From: zjncs <18910855655@163.com>
Date: Fri, 4 Sep 2026 12:36:41 +0800
Subject: [PATCH] fix(common): parse +Inf/-Inf as real infinity in
 StrBuffer.parseDouble

StrBuffer.parseDouble returned the raw IEEE-754 bit-pattern constants
0x7FF0000000000000L / 0xFFF0000000000000L widened to double
(9.2e18 / -4.5e15) instead of real infinities for the Prometheus
text format special values +inf/-inf. OnlineParser.toDouble already
maps them to Double.POSITIVE_INFINITY/NEGATIVE_INFINITY; align
StrBuffer (used by TextParser) with that behavior and drop the
+/-Inf exclusion from the cross-parser test that papered over the
divergence.

Signed-off-by: zjncs <18910855655@163.com>
---
 .../collect/prometheus/parser/OnlineParserTest.java       | 7 ++-----
 .../java/org/apache/hertzbeat/common/util/StrBuffer.java  | 4 ++--
 .../org/apache/hertzbeat/common/util/StrBufferTest.java   | 8 ++++----
 3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/hertzbeat-collector/hertzbeat-collector-basic/src/test/java/org/apache/hertzbeat/collector/collect/prometheus/parser/OnlineParserTest.java b/hertzbeat-collector/hertzbeat-collector-basic/src/test/java/org/apache/hertzbeat/collector/collect/prometheus/parser/OnlineParserTest.java
index 370ac9a3bd..51ca94a5e5 100644
--- a/hertzbeat-collector/hertzbeat-collector-basic/src/test/java/org/apache/hertzbeat/collector/collect/prometheus/parser/OnlineParserTest.java
+++ b/hertzbeat-collector/hertzbeat-collector-basic/src/test/java/org/apache/hertzbeat/collector/collect/prometheus/parser/OnlineParserTest.java
@@ -108,11 +108,8 @@ class OnlineParserTest {
             MetricFamily metricFamily1 = metricFamilyMap1.get(metricFamilyName);
             Set<Double> metricValueSet = metricFamily2.getMetricList().stream().map(MetricFamily.Metric::getValue).collect(Collectors.toSet());
             metricFamily1.getMetricList().forEach(metric -> {
-                // this is for something different between two algorithms above, and both of them is current on this parsing behavior.
-                if (!(metric.getValue() == Double.POSITIVE_INFINITY || metric.getValue() == Double.NEGATIVE_INFINITY)) {
-                    if (!metricValueSet.contains(metric.getValue())) {
-                        fail();
-                    }
+                if (!metricValueSet.contains(metric.getValue())) {
+                    fail();
                 }
             });
         });
diff --git a/hertzbeat-common-core/src/main/java/org/apache/hertzbeat/common/util/StrBuffer.java b/hertzbeat-common-core/src/main/java/org/apache/hertzbeat/common/util/StrBuffer.java
index c15bc33594..d58fe09a11 100644
--- a/hertzbeat-common-core/src/main/java/org/apache/hertzbeat/common/util/StrBuffer.java
+++ b/hertzbeat-common-core/src/main/java/org/apache/hertzbeat/common/util/StrBuffer.java
@@ -153,9 +153,9 @@ public class StrBuffer {
      */
     public static double parseDouble(String s) {
         if (POSITIVE_INF.equalsIgnoreCase(s)) {
-            return POSITIVE_INF_VALUE;
+            return Double.POSITIVE_INFINITY;
         } else if (NEGATIVE_INF.equalsIgnoreCase(s)) {
-            return NEGATIVE_INF_VALUE;
+            return Double.NEGATIVE_INFINITY;
         }
         return Double.parseDouble(s);
     }
diff --git a/hertzbeat-common-core/src/test/java/org/apache/hertzbeat/common/util/StrBufferTest.java b/hertzbeat-common-core/src/test/java/org/apache/hertzbeat/common/util/StrBufferTest.java
index 98a5a93341..0bade03c1d 100644
--- a/hertzbeat-common-core/src/test/java/org/apache/hertzbeat/common/util/StrBufferTest.java
+++ b/hertzbeat-common-core/src/test/java/org/apache/hertzbeat/common/util/StrBufferTest.java
@@ -91,10 +91,10 @@ class StrBufferTest {
         assertEquals(123.45, buffer.toDouble());
 
         buffer = new StrBuffer("+inf");
-        assertEquals(POSITIVE_INF_VALUE, buffer.toDouble());
+        assertEquals(Double.POSITIVE_INFINITY, buffer.toDouble());
 
         buffer = new StrBuffer("-inf");
-        assertEquals(NEGATIVE_INF_VALUE, buffer.toDouble());
+        assertEquals(Double.NEGATIVE_INFINITY, buffer.toDouble());
     }
 
     @Test
@@ -144,8 +144,8 @@ class StrBufferTest {
     void testParseDouble() {
 
         assertEquals(123.45, StrBuffer.parseDouble("123.45"));
-        assertEquals(POSITIVE_INF_VALUE, StrBuffer.parseDouble("+inf"));
-        assertEquals(NEGATIVE_INF_VALUE, StrBuffer.parseDouble("-inf"));
+        assertEquals(Double.POSITIVE_INFINITY, StrBuffer.parseDouble("+inf"));
+        assertEquals(Double.NEGATIVE_INFINITY, StrBuffer.parseDouble("-inf"));
     }
 
 }