From 2204597cfef8767472f2dd25a6e6972fd45845c7 Mon Sep 17 00:00:00 2001
From: WangZengrui <joeywang98@outlook.com>
Date: Sat, 9 Oct 2021 16:49:49 +0800
Subject: [PATCH] add FunctionOSKernelVersion

---
 .../registerFunctionsMiscellaneous.cpp        |  2 ++
 src/Functions/serverConstants.cpp             | 24 ++++++++++++++
 src/Interpreters/getOSKernelVersion.cpp       | 31 -------------------
 src/Interpreters/getOSKernelVersion.h         | 21 -------------
 4 files changed, 26 insertions(+), 52 deletions(-)
 delete mode 100644 src/Interpreters/getOSKernelVersion.cpp
 delete mode 100644 src/Interpreters/getOSKernelVersion.h

diff --git a/src/Functions/registerFunctionsMiscellaneous.cpp b/src/Functions/registerFunctionsMiscellaneous.cpp
index dfd986c5f82..8fc084b3d1a 100644
--- a/src/Functions/registerFunctionsMiscellaneous.cpp
+++ b/src/Functions/registerFunctionsMiscellaneous.cpp
@@ -81,6 +81,7 @@ void registerFunctionQueryID(FunctionFactory & factory);
 void registerFunctionInitialQueryID(FunctionFactory & factory);
 void registerFunctionServerUUID(FunctionFactory &);
 void registerFunctionZooKeeperSessionUptime(FunctionFactory &);
+void registerFunctionOSKernelVersion(FunctionFactory &);
 
 #if USE_ICU
 void registerFunctionConvertCharset(FunctionFactory &);
@@ -162,6 +163,7 @@ void registerFunctionsMiscellaneous(FunctionFactory & factory)
     registerFunctionInitialQueryID(factory);
     registerFunctionServerUUID(factory);
     registerFunctionZooKeeperSessionUptime(factory);
+    registerFunctionOSKernelVersion(factory);
 
 #if USE_ICU
     registerFunctionConvertCharset(factory);
diff --git a/src/Functions/serverConstants.cpp b/src/Functions/serverConstants.cpp
index 9a53a5cf582..170f4cb86ee 100644
--- a/src/Functions/serverConstants.cpp
+++ b/src/Functions/serverConstants.cpp
@@ -7,6 +7,10 @@
 #include <Common/DNSResolver.h>
 #include <base/DateLUT.h>
 
+#if defined(OS_LINUX)
+#    include <Poco/Environment.h>
+#endif
+
 #if !defined(ARCADIA_BUILD)
 #    include <Common/config_version.h>
 #endif
@@ -93,6 +97,17 @@ namespace
         explicit FunctionZooKeeperSessionUptime(ContextPtr context) : FunctionConstantBase(context, context->getZooKeeperSessionUptime()) {}
         static FunctionPtr create(ContextPtr context) { return std::make_shared<FunctionZooKeeperSessionUptime>(context); }
     };
+
+#if defined(OS_LINUX)
+    class FunctionOSKernelVersion : public FunctionConstantBase<FunctionOSKernelVersion, String, DataTypeString>
+    {
+    public:
+        static constexpr auto name = "OSKernelVersion";
+        explicit FunctionOSKernelVersion(ContextPtr context) : FunctionConstantBase(context, Poco::Environment::osName() + " " + Poco::Environment::osVersion()) {}
+        static FunctionPtr create(ContextPtr context) { return std::make_shared<FunctionOSKernelVersion>(context); }
+    };
+#endif
+
 }
 
 
@@ -140,5 +155,14 @@ void registerFunctionZooKeeperSessionUptime(FunctionFactory & factory)
     factory.registerFunction<FunctionZooKeeperSessionUptime>();
 }
 
+
+void registerFunctionOSKernelVersion(FunctionFactory & factory)
+{
+#if defined(OS_LINUX)
+    factory.registerFunction<FunctionOSKernelVersion>();
+#endif
+}
+
+
 }
 
diff --git a/src/Interpreters/getOSKernelVersion.cpp b/src/Interpreters/getOSKernelVersion.cpp
deleted file mode 100644
index c4b4564f46e..00000000000
--- a/src/Interpreters/getOSKernelVersion.cpp
+++ /dev/null
@@ -1,31 +0,0 @@
-#if defined(OS_LINUX)
-#include <Interpreters/getOSKernelVersion.h>
-
-
-namespace DB
-{
-
-namespace ErrorCodes
-{
-    extern const int SYSTEM_ERROR;
-}
-    
-String getOSKernelVersion()
-{
-    struct utsname os_kernel_info;
-    int buf = uname(&os_kernel_info);
-    if (buf < 0)
-    {
-        throw Exception(
-            "EFAULT buffer is not valid.",
-            ErrorCodes::SYSTEM_ERROR);
-    }
-    else
-    {
-        return String(os_kernel_info.sysname) + " " + String(os_kernel_info.release);
-    }
-}
-
-}
-
-#endif
\ No newline at end of file
diff --git a/src/Interpreters/getOSKernelVersion.h b/src/Interpreters/getOSKernelVersion.h
deleted file mode 100644
index fc3c7583aef..00000000000
--- a/src/Interpreters/getOSKernelVersion.h
+++ /dev/null
@@ -1,21 +0,0 @@
-#pragma once
-#if defined(OS_LINUX)
-
-#include <Common/typeid_cast.h>
-
-#include <string>
-#include <sys/utsname.h>
-
-namespace DB
-{
-
-/// Returns String with OS Kernel version.
-/* To get name and information about current kernel.
-   For simplicity, the function can be implemented only for Linux. 
-*/
-    
-String getOSKernelVersion();
-
-}
-
-#endif
\ No newline at end of file