more TDB

source/libs/tdb/src/db/tdb.c

@@ -65,6 +65,7 @@ int tdbOpen(TDB *pDb, const char *fname, const char *dbname, TENV *pEnv) {
   SBTree *  pBt;
   bool      fileExist;
   size_t    dbNameLen;
+  pgno_t    dbRootPgno;
   char      dbfname[128];  // TODO: make this as a macro or malloc on the heap
 
   ASSERT(pDb != NULL);
@@ -104,10 +105,19 @@ int tdbOpen(TDB *pDb, const char *fname, const char *dbname, TENV *pEnv) {
   }
 
   // TODO: open the database (an existing or a new one)
-  // Search the page file master DB to check if the db exists
-  // If DB exists, get the root page number
-  // If DB not exists, create a new DB
+  if (0) {
+    // Search the page file master DB to check if the db exists
+    // If exists, run this branch (TODO)
+  } else {
+    ret = pgFileAllocatePage(pPgFile, &dbRootPgno);
+    if (ret != 0) {
+      // TODO: handle error
+    }
+  }
+
+  pDb->pBt->root = dbRootPgno;
 
+  // register
   pDb->pPgFile = pPgFile;
   tdbEnvRgstDB(pEnv, pDb);
   pDb->pEnv = pEnv;

source/libs/tdb/src/db/tdbPgFile.c

@@ -110,6 +110,19 @@ int pgFileWrite(SPage *pPage) {
   return 0;
 }
 
+int pgFileAllocatePage(SPgFile *pPgFile, pgno_t *pPgno) {
+  pgno_t pgno;
+
+  if (0) {
+    // TODO: allocate from the free list
+  } else {
+    pgno = ++pPgFile->dbNewSize;
+  }
+
+  *pPgno = pgno;
+  return 0;
+}
+
 static int pgFileRead(SPgFile *pPgFile, pgno_t pgno, uint8_t *pData) {
   pgsz_t   pgSize;
   ssize_t  rsize;

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

@@ -46,10 +46,12 @@ struct SPgFile {
 int pgFileOpen(SPgFile **ppPgFile, const char *fname, TENV *pEnv);
 int pgFileClose(SPgFile *pPgFile);
 
+
 SPage *pgFileFetch(SPgFile *pPgFile, pgno_t pgno);
 int    pgFileRelease(SPage *pPage);
 
 int pgFileWrite(SPage *pPage);
+int pgFileAllocatePage(SPgFile *pPgFile, pgno_t *pPgno);
 
 #ifdef __cplusplus
 }