From 8f6781a7bb0a884a7abab33ab3c907ff3bbcc680 Mon Sep 17 00:00:00 2001
From: Hongze Cheng <hzcheng@taosdata.com>
Date: Wed, 16 Feb 2022 07:32:34 +0000
Subject: [PATCH] more TDB

---
 source/libs/tdb/src/db/tdb.c       |  2 +-
 source/libs/tdb/src/db/tdbPgFile.c | 33 +++++++++++++++++++++++++++---
 source/libs/tdb/src/db/tdbUtil.c   | 14 +++++++++++--
 source/libs/tdb/src/inc/tdbUtil.h  |  2 +-
 4 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/source/libs/tdb/src/db/tdb.c b/source/libs/tdb/src/db/tdb.c
index e79313d1ca..6fcb2686fd 100644
--- a/source/libs/tdb/src/db/tdb.c
+++ b/source/libs/tdb/src/db/tdb.c
@@ -115,7 +115,7 @@ int tdbOpen(TDB *pDb, const char *fname, const char *dbname, TENV *pEnv) {
     }
   }
 
-  pDb->pBt->root = dbRootPgno;
+  // pDb->pBt->root = dbRootPgno;
 
   // register
   pDb->pPgFile = pPgFile;
diff --git a/source/libs/tdb/src/db/tdbPgFile.c b/source/libs/tdb/src/db/tdbPgFile.c
index d6223a5788..030f57de4c 100644
--- a/source/libs/tdb/src/db/tdbPgFile.c
+++ b/source/libs/tdb/src/db/tdbPgFile.c
@@ -30,6 +30,7 @@ int pgFileOpen(SPgFile **ppPgFile, const char *fname, TENV *pEnv) {
   SPgFile * pPgFile;
   SPgCache *pPgCache;
   size_t    fnameLen;
+  pgno_t    fsize;
 
   *ppPgFile = NULL;
 
@@ -55,6 +56,28 @@ int pgFileOpen(SPgFile **ppPgFile, const char *fname, TENV *pEnv) {
   }
 
   tdbGnrtFileID(fname, pPgFile->fileid, false);
+  tdbGetFileSize(fname, tdbEnvGetPageSize(pEnv), &fsize);
+
+  pPgFile->fsize = fsize;
+  pPgFile->lsize = fsize;
+
+  if (pPgFile->fsize == 0) {
+    // A created file
+    pgno_t pgno;
+    pgid_t pgid;
+
+    pgFileAllocatePage(pPgFile, &pgno);
+
+    ASSERT(pgno == 1);
+
+    memcpy(pgid.fileid, pPgFile->fileid, TDB_FILE_ID_LEN);
+    pgid.pgno = pgno;
+
+    pgCacheFetch(pPgCache, pgid);
+    // Need to allocate the first page as a description page
+  } else {
+    // An existing file
+  }
 
   /* TODO: other open operations */
 
@@ -122,10 +145,14 @@ int pgFileWrite(SPage *pPage) {
 int pgFileAllocatePage(SPgFile *pPgFile, pgno_t *pPgno) {
   pgno_t pgno;
 
-  if (0) {
-    // TODO: allocate from the free list
-  } else {
+  if (pPgFile->lsize == 0) {
     pgno = ++(pPgFile->lsize);
+  } else {
+    if (0) {
+      // TODO: allocate from the free list
+    } else {
+      pgno = ++(pPgFile->lsize);
+    }
   }
 
   *pPgno = pgno;
diff --git a/source/libs/tdb/src/db/tdbUtil.c b/source/libs/tdb/src/db/tdbUtil.c
index 591e7eedd4..fa9a3297da 100644
--- a/source/libs/tdb/src/db/tdbUtil.c
+++ b/source/libs/tdb/src/db/tdbUtil.c
@@ -51,7 +51,17 @@ int tdbCheckFileAccess(const char *pathname, int mode) {
   return access(pathname, flags);
 }
 
-int64_t tdbGetFileSize(const char *fname) {
-  // TODO
+int tdbGetFileSize(const char *fname, pgsz_t pgSize, pgno_t *pSize) {
+  struct stat st;
+  int         ret;
+
+  ret = stat(fname, &st);
+  if (ret != 0) {
+    return -1;
+  }
+
+  ASSERT(st.st_size % pgSize == 0);
+
+  *pSize = st.st_size / pgSize;
   return 0;
 }
\ No newline at end of file
diff --git a/source/libs/tdb/src/inc/tdbUtil.h b/source/libs/tdb/src/inc/tdbUtil.h
index f3e00a5ba5..8108e5aba6 100644
--- a/source/libs/tdb/src/inc/tdbUtil.h
+++ b/source/libs/tdb/src/inc/tdbUtil.h
@@ -35,7 +35,7 @@ int tdbGnrtFileID(const char *fname, uint8_t *fileid, bool unique);
 #define TDB_W_OK 0x4
 int tdbCheckFileAccess(const char *pathname, int mode);
 
-int64_t tdbGetFileSize(const char *fname);
+int tdbGetFileSize(const char *fname, pgsz_t pgSize, pgno_t *pSize);
 
 #ifdef __cplusplus
 }