From 32433af35e2ff0ebee3ffc6413c243a4fa0148eb Mon Sep 17 00:00:00 2001
From: sunshine7058 <2564255161@qq.com>
Date: Sat, 11 May 2024 18:04:59 +0800
Subject: [PATCH] =?UTF-8?q?feat:=E7=BC=96=E5=86=99=E6=B5=8B=E8=AF=95?=
 =?UTF-8?q?=E7=B1=BB=E4=BF=A1=E6=81=AF?=
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---
 .../java/com/lijie/ByteBufferCompare.java     | 64 +++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 muyu-modules/muyu-data-source/muyu-data-source-server/src/test/java/com/lijie/ByteBufferCompare.java

diff --git a/muyu-modules/muyu-data-source/muyu-data-source-server/src/test/java/com/lijie/ByteBufferCompare.java b/muyu-modules/muyu-data-source/muyu-data-source-server/src/test/java/com/lijie/ByteBufferCompare.java
new file mode 100644
index 0000000..d6f838d
--- /dev/null
+++ b/muyu-modules/muyu-data-source/muyu-data-source-server/src/test/java/com/lijie/ByteBufferCompare.java
@@ -0,0 +1,64 @@
+package com.lijie;
+
+import java.nio.ByteBuffer;
+
+/**
+ * 直接内存 与 堆内存的比较
+ */
+public class ByteBufferCompare {
+
+    public static void main(String[] args) {
+        allocateCompare();   //分配比较
+        operateCompare();    //读写比较
+    }
+
+    /**
+     * 直接内存 和 堆内存的 分配空间比较
+     */
+    public static void allocateCompare() {
+        int time = 10000000;    //操作次数
+        long st = System.currentTimeMillis();
+        for (int i = 0; i < time; i++) {
+
+            ByteBuffer buffer = ByteBuffer.allocate(2);      //非直接内存分配申请
+        }
+        long et = System.currentTimeMillis();
+        System.out.println("在进行" + time + "次分配操作时，堆内存：分配耗时:" + (et - st) + "ms");
+        long st_heap = System.currentTimeMillis();
+        for (int i = 0; i < time; i++) {
+            ByteBuffer buffer = ByteBuffer.allocateDirect(2); //直接内存分配申请
+        }
+        long et_direct = System.currentTimeMillis();
+        System.out.println("在进行" + time + "次分配操作时，直接内存：分配耗时:" + (et_direct - st_heap) + "ms");
+    }
+
+    /**
+     * 直接内存 和 堆内存的 读写性能比较
+     */
+    public static void operateCompare() {
+        //如果报错修改这里，把数字改小一点
+        int time = 1000000000;
+        ByteBuffer buffer = ByteBuffer.allocate(2 * time);
+        long st = System.currentTimeMillis();
+        for (int i = 0; i < time; i++) {
+            buffer.putChar('a');
+        }
+        buffer.flip();
+        for (int i = 0; i < time; i++) {
+            buffer.getChar();
+        }
+        long et = System.currentTimeMillis();
+        System.out.println("在进行" + time + "次读写操作时，堆内存：读写耗时：" + (et - st) + "ms");
+        ByteBuffer buffer_d = ByteBuffer.allocateDirect(2 * time);
+        long st_direct = System.currentTimeMillis();
+        for (int i = 0; i < time; i++) {
+            buffer_d.putChar('a');
+        }
+        buffer_d.flip();
+        for (int i = 0; i < time; i++) {
+            buffer_d.getChar();
+        }
+        long et_direct = System.currentTimeMillis();
+        System.out.println("在进行" + time + "次读写操作时，直接内存：读写耗时:" + (et_direct - st_direct) + "ms");
+    }
+}