more TDB

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

@@ -49,21 +49,11 @@ int tdbDbOpen(const char *fname, int keyLen, int valLen, FKeyComparator keyCmprF
 
   ASSERT(pFile != NULL);
 
-  // TODO: Search if the DB already in the file
+  ret = tdbPFileOpenDB(pFile, &pgno, true);
-  if (1 /*todo: db should be created*/) {
-    ret = tdbPFileAllocPage(pFile, &pPage, &pgno);
   if (ret < 0) {
     return -1;
   }
 
-    ret = tdbPFileWrite(pFile, pPage);
-    if (ret < 0) {
-      return -1;
-    }
-  } else {
-    ASSERT(0);
-  }
-
   // pDb->pBt
   ret = tdbBtreeOpen(pgno, keyLen, valLen, pFile, keyCmprFn, &(pDb->pBt));
   if (ret < 0) {

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

@@ -31,6 +31,10 @@ struct SPFile {
   u8       inTran;
 };
 
+typedef struct {
+  /* TODO */
+} SFileHdr;
+
 static int tdbPFileReadPage(SPFile *pFile, SPage *pPage);
 
 int tdbPFileOpen(SPCache *pCache, const char *fileName, SPFile **ppFile) {
@@ -87,6 +91,33 @@ int tdbPFileClose(SPFile *pFile) {
   return 0;
 }
 
+int tdbPFileOpenDB(SPFile *pFile, SPgno *ppgno, bool toCreate) {
+  SPgno  pgno;
+  SPage *pPage;
+  int    ret;
+
+  {
+    // TODO: try to search the main DB to get the page number
+    pgno = 0;
+  }
+
+  if (pgno == 0 && toCreate) {
+    ret = tdbPFileAllocPage(pFile, &pPage, &pgno);
+    if (ret < 0) {
+      return -1;
+    }
+
+    // tdbPFileZeroPage(pPage);
+    ret = tdbPFileWrite(pFile, pPage);
+    if (ret < 0) {
+      return -1;
+    }
+  }
+
+  *ppgno = pgno;
+  return 0;
+}
+
 SPage *tdbPFileGet(SPFile *pFile, SPgno pgno) {
   SPgid  pgid;
   SPage *pPage;

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

@@ -24,6 +24,7 @@ typedef struct SPFile SPFile;
 
 int    tdbPFileOpen(SPCache *pCache, const char *fileName, SPFile **ppFile);
 int    tdbPFileClose(SPFile *pFile);
+int    tdbPFileOpenDB(SPFile *pFile, SPgno *ppgno, bool toCreate);
 SPage *tdbPFileGet(SPFile *pFile, SPgno pgno);
 int    tdbPFileWrite(SPFile *pFile, SPage *pPage);
 int    tdbPFileAllocPage(SPFile *pFile, SPage **ppPage, SPgno *ppgno);