more TDB

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

@@ -14,16 +14,6 @@
  */
 #include "tdbInt.h"
 
-typedef TD_DLIST_NODE(SPage) SPgListNode;
-struct SPage {
-  pgid_t      pgid;      // page id
-  frame_id_t  frameid;   // frame id
-  SPgListNode freeNode;  // for SPgCache.freeList
-  SPgListNode pghtNode;  // for pght
-  SPgListNode lruNode;   // for LRU
-  uint8_t *   pData;     // real data
-};
-
 typedef TD_DLIST(SPage) SPgList;
 
 struct SPgCache {

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

@@ -15,6 +15,8 @@
 
 #include "tdbInt.h"
 
+static int pgFileRead(SPgFile *pPgFile, pgno_t pgno, uint8_t *pData);
+
 int pgFileOpen(const char *fname, SPgCache *pPgCache, SPgFile **ppPgFile) {
   SPgFile *pPgFile;
 
@@ -80,6 +82,14 @@ SPage *pgFileFetch(SPgFile *pPgFile, pgno_t pgno) {
     // TODO
   } else {
     pPage = pgCacheFetch(pPgCache, pgid);
+    if (1 /*Page is cached, no need to load from file*/) {
+      return pPage;
+    } else {
+      if (pgFileRead(pPgFile, pgno, pPage->pData) < 0) {
+        // todoerr
+      }
+      return pPage;
+    }
   }
 
   return pPage;
@@ -93,4 +103,9 @@ int pgFileRelease(SPage *pPage) {
 int pgFileWrite(SPage *pPage) {
   // TODO
   return 0;
+}
+
+static int pgFileRead(SPgFile *pPgFile, pgno_t pgno, uint8_t *pData) {
+  // TODO
+  return 0;
 }
\ No newline at end of file

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

@@ -34,6 +34,16 @@ int    pgCacheRelease(SPage *pPage);
 
 // SPage
 
+typedef TD_DLIST_NODE(SPage) SPgListNode;
+struct SPage {
+  pgid_t      pgid;      // page id
+  frame_id_t  frameid;   // frame id
+  SPgListNode freeNode;  // for SPgCache.freeList
+  SPgListNode pghtNode;  // for pght
+  SPgListNode lruNode;   // for LRU
+  uint8_t *   pData;     // real data
+};
+
 #ifdef __cplusplus
 }
 #endif