redirect logging on Win32 & protect from meta file corruption

Win32/MMKV/MMKV.cpp

@@ -48,6 +48,7 @@ static unordered_map<std::string, MMKV *> *g_instanceDic;
 static ThreadLock g_instanceLock;
 static std::wstring g_rootDir;
 static MMKV::ErrorHandler g_errorHandler;
+MMKV::LogHandler g_logHandler;
 
 #define DEFAULT_MMAP_ID "mmkv.default"
 #define SPECIAL_CHARACTER_DIRECTORY_NAME L"specialCharacter"
@@ -1218,6 +1219,21 @@ void MMKV::unRegisetErrorHandler() {
     g_errorHandler = nullptr;
 }
 
+void MMKV::regiserLogHandler(LogHandler handler) {
+    SCOPEDLOCK(g_instanceLock);
+    g_logHandler = handler;
+}
+
+void MMKV::unRegisetLogHandler() {
+    SCOPEDLOCK(g_instanceLock);
+    g_logHandler = nullptr;
+}
+
+void MMKV::setLogLevel(MMKVLogLevel level) {
+    SCOPEDLOCK(g_instanceLock);
+    g_currentLogLevel = level;
+}
+
 static void mkSpecialCharacterFileDirectory() {
     wstring path = g_rootDir + L"/" + SPECIAL_CHARACTER_DIRECTORY_NAME;
     mkPath(path);

Win32/MMKV/MMKV.h

@@ -56,6 +56,14 @@ enum MMKVErrorType : int {
     MMKVFileLength,
 };
 
+enum MMKVLogLevel : int {
+    MMKVLogDebug = 0, // not available for release/product build
+    MMKVLogInfo = 1,  // default level
+    MMKVLogWarning,
+    MMKVLogError,
+    MMKVLogNone, // special level used to disable all log messages
+};
+
 class MMKV {
     std::unordered_map<std::string, mmkv::MMBuffer> m_dic;
     std::string m_mmapID;
@@ -239,6 +247,16 @@ class MMKV {
                                                  MMKVErrorType errorType);
     static void regiserErrorHandler(ErrorHandler handler);
     static void unRegisetErrorHandler();
+
+    typedef void (*LogHandler)(MMKVLogLevel level,
+                               const std::string &file,
+                               int line,
+                               const std::string &function,
+                               const std::string &message);
+    static void regiserLogHandler(LogHandler handler);
+    static void unRegisetLogHandler();
+
+    static void setLogLevel(MMKVLogLevel level);
 };
 
 #endif // MMKV_MMKV_H

Win32/MMKV/MMKV.vcxproj

@@ -209,11 +209,12 @@
     <ClCompile Include="MmapedFile.cpp" />
     <ClCompile Include="MMBuffer.cpp" />
     <ClCompile Include="MMKV.cpp" />
+    <ClCompile Include="MMKVLog.cpp" />
     <ClCompile Include="PBUtility.cpp" />
     <ClCompile Include="pch.cpp" />
     <ClCompile Include="ThreadLock.cpp" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>

Win32/MMKV/MMKV.vcxproj.filters

@@ -149,5 +149,8 @@
     <ClCompile Include="pch.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="MMKVLog.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>

Win32/MMKV/MMKVLog.cpp

@@ -0,0 +1,79 @@
+/*
+ * Tencent is pleased to support the open source community by making
+ * MMKV available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company.
+ * All rights reserved.
+ *
+ * Licensed under the BSD 3-Clause License (the "License"); you may not use
+ * this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ *       https://opensource.org/licenses/BSD-3-Clause
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MMKVLog.h"
+
+#ifdef ENABLE_MMKV_LOG
+
+using namespace std;
+
+#ifndef NDEBUG
+MMKVLogLevel g_currentLogLevel = MMKVLogDebug;
+#else
+MMKVLogLevel g_currentLogLevel = MMKVLogInfo;
+#endif
+
+static const char *MMKVLogLevelDesc(MMKVLogLevel level) {
+    switch (level) {
+        case MMKVLogDebug:
+            return "D";
+        case MMKVLogInfo:
+            return "I";
+        case MMKVLogWarning:
+            return "W";
+        case MMKVLogError:
+            return "E";
+        default:
+            return "N";
+    }
+}
+
+void _MMKVLogWithLevel(
+    MMKVLogLevel level, const char *file, const char *func, int line, const char *format, ...) {
+    if (level >= g_currentLogLevel) {
+        string message;
+        char buffer[16];
+
+        va_list args;
+        va_start(args, format);
+        auto length = std::vsnprintf(buffer, sizeof(buffer), format, args);
+        va_end(args);
+
+        if (length < 0) { // something wrong
+            message = {};
+        } else if (length < sizeof(buffer)) {
+            message = string(buffer, length);
+        } else {
+            message.resize(length, '\0');
+            va_start(args, format);
+            std::vsnprintf(const_cast<char *>(message.data()), length + 1, format, args);
+            va_end(args);
+        }
+
+        if (g_logHandler) {
+            g_logHandler(level, file, line, func, message);
+        } else {
+            printf("[%s] <%s:%d::%s> %s\n", MMKVLogLevelDesc(level), file, line, func,
+                   message.c_str());
+        }
+    }
+}
+
+#endif // ENABLE_MMKV_LOG

Win32/MMKV/MMKVLog.h

@@ -21,6 +21,7 @@
 #ifndef MMKV_MMKVLOG_H
 #define MMKV_MMKVLOG_H
 
+#include "MMKV.h"
 #include <cstdio>
 #include <cstring>
 
@@ -29,20 +30,28 @@
 
 #ifdef ENABLE_MMKV_LOG
 
-#define APPNAME "MMKV"
+extern MMKVLogLevel g_currentLogLevel;
+extern MMKV::LogHandler g_logHandler;
 
-#define __NEW_LINE "\n"
+#define __filename__ (strrchr(__FILE__, '\\') + 1)
 
-#define MMKVError(format, ...) ::printf(format __NEW_LINE, ##__VA_ARGS__)
-#define MMKVWarning(format, ...) ::printf(format __NEW_LINE, ##__VA_ARGS__)
-#define MMKVInfo(format, ...) ::printf(format __NEW_LINE, ##__VA_ARGS__)
+#define MMKVError(format, ...)                                                                     \
+    _MMKVLogWithLevel(MMKVLogError, __filename__, __func__, __LINE__, format, ##__VA_ARGS__)
+#define MMKVWarning(format, ...)                                                                   \
+    _MMKVLogWithLevel(MMKVLogWarning, __filename__, __func__, __LINE__, format, ##__VA_ARGS__)
+#define MMKVInfo(format, ...)                                                                      \
+    _MMKVLogWithLevel(MMKVLogInfo, __filename__, __func__, __LINE__, format, ##__VA_ARGS__)
 
 #ifndef NDEBUG
-#define MMKVDebug(format, ...) ::printf(format __NEW_LINE, ##__VA_ARGS__)
+#define MMKVDebug(format, ...)                                                                     \
+    _MMKVLogWithLevel(MMKVLogDebug, __filename__, __func__, __LINE__, format, ##__VA_ARGS__)
 #else
 #define MMKVDebug(format, ...)                                                                     \
     {}
-#endif
+#endif // NDEBUG
+
+void _MMKVLogWithLevel(
+    MMKVLogLevel level, const char *file, const char *func, int line, const char *format, ...);
 
 #else
 

Win32/MMKV/MmapedFile.cpp

@@ -20,9 +20,11 @@
 
 #include "pch.h"
 
+#include "InterProcessLock.h"
 #include "MMBuffer.h"
 #include "MMKVLog.h"
 #include "MmapedFile.h"
+#include "ScopedLock.hpp"
 
 using namespace std;
 
@@ -47,6 +49,10 @@ MmapedFile::MmapedFile(const std::wstring &path, size_t size)
     if (m_file == INVALID_HANDLE_VALUE) {
         MMKVError("fail to open:%ws, %d", m_name.c_str(), GetLastError());
     } else {
+        FileLock fileLock(m_file);
+        InterProcessLock lock(&fileLock, ExclusiveLockType);
+        SCOPEDLOCK(lock);
+
         getfilesize(m_file, m_segmentSize);
         if (m_segmentSize < DEFAULT_MMAP_SIZE) {
             m_segmentSize = static_cast<size_t>(DEFAULT_MMAP_SIZE);

Win32/Win32Demo/Win32Demo.cpp

@@ -165,13 +165,39 @@ void processTest() {
     cout << "total count of process_test: " << mmkv->count() << endl;
 }
 
+static void LogHandler(MMKVLogLevel level,
+                       const std::string &file,
+                       int line,
+                       const std::string &function,
+                       const std::string &message) {
+
+    auto desc = [level] {
+        switch (level) {
+            case MMKVLogDebug:
+                return "D";
+            case MMKVLogInfo:
+                return "I";
+            case MMKVLogWarning:
+                return "W";
+            case MMKVLogError:
+                return "E";
+            default:
+                return "N";
+        }
+    }();
+    printf("redirecting-[%s] <%s:%d::%s> %s\n", desc, file.c_str(), line, function.c_str(),
+           message.c_str());
+}
+
 int main() {
     locale::global(locale(""));
     wcout.imbue(locale(""));
     srand(GetTickCount());
 
     wstring rootDir = getAppDataRoaming(L"Tencent", L"΢ÐÅ-MMKV");
     MMKV::initializeMMKV(rootDir);
+    //MMKV::setLogLevel(MMKVLogNone);
+    MMKV::regiserLogHandler(LogHandler);
 
     auto mmkv = MMKV::defaultMMKV();
     functionalTest(mmkv, false);