tdb/write: new tdbPWriteFile api for commit and prep async to maindb

include/os/osFile.h

@@ -88,6 +88,7 @@ int32_t taosFsyncFile(TdFilePtr pFile);
 int64_t taosReadFile(TdFilePtr pFile, void *buf, int64_t count);
 int64_t taosPReadFile(TdFilePtr pFile, void *buf, int64_t count, int64_t offset);
 int64_t taosWriteFile(TdFilePtr pFile, const void *buf, int64_t count);
+int64_t taosPWriteFile(TdFilePtr pFile, const void *buf, int64_t count, int64_t offset);
 void    taosFprintfFile(TdFilePtr pFile, const char *format, ...);
 
 int64_t taosGetLineFile(TdFilePtr pFile, char **__restrict ptrBuf);

source/libs/tdb/src/inc/tdbOs.h

@@ -52,6 +52,7 @@ typedef TdFilePtr tdb_fd_t;
 #define tdbOsRead                taosReadFile
 #define tdbOsPRead               taosPReadFile
 #define tdbOsWrite               taosWriteFile
+#define tdbOsPWrite              taosPWriteFile
 #define tdbOsFSync               taosFsyncFile
 #define tdbOsLSeek               taosLSeekFile
 #define tdbOsRemove              remove

source/os/src/osFile.c

@@ -491,6 +491,28 @@ int64_t taosWriteFile(TdFilePtr pFile, const void *buf, int64_t count) {
   return count;
 }
 
+int64_t taosPWriteFile(TdFilePtr pFile, const void *buf, int64_t count, int64_t offset) {
+  if (pFile == NULL) {
+    return 0;
+  }
+#if FILE_WITH_LOCK
+  taosThreadRwlockWrlock(&(pFile->rwlock));
+#endif
+  assert(pFile->fd >= 0);  // Please check if you have closed the file.
+#ifdef WINDOWS
+  size_t pos = _lseeki64(pFile->fd, 0, SEEK_CUR);
+  _lseeki64(pFile->fd, offset, SEEK_SET);
+  int64_t ret = _write(pFile->fd, buf, count);
+  _lseeki64(pFile->fd, pos, SEEK_SET);
+#else
+  int64_t ret = pwrite(pFile->fd, buf, count, offset);
+#endif
+#if FILE_WITH_LOCK
+  taosThreadRwlockUnlock(&(pFile->rwlock));
+#endif
+  return ret;
+}
+
 int64_t taosLSeekFile(TdFilePtr pFile, int64_t offset, int32_t whence) {
 #if FILE_WITH_LOCK
   taosThreadRwlockRdlock(&(pFile->rwlock));