design dbc api

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

@@ -90,4 +90,19 @@ int tdbDbInsert(STDB *pDb, const void *pKey, int keyLen, const void *pVal, int v
 
 int tdbDbGet(STDB *pDb, const void *pKey, int kLen, void **ppVal, int *vLen) {
   return tdbBtreeGet(pDb->pBt, pKey, kLen, ppVal, vLen);
+}
+
+int tdbDbcOpen(STDB *pDb, STDBC **ppTDbc) {
+  // TODO
+  return 0;
+}
+
+int tdbDbNext(STDBC *pDbc, void **ppKey, int *kLen, void **ppVal, int *vLen) {
+  // TODO
+  return 0;
+}
+
+int tdbDbcClose(STDBC *pDbc) {
+  // TODO
+  return 0;
 }
\ No newline at end of file

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

@@ -21,14 +21,20 @@ extern "C" {
 #endif
 
 typedef struct STDB  STDB;
-typedef struct STDbC STDbC;
+typedef struct STDBC STDBC;
 
+// STDB
 int tdbDbOpen(const char *fname, int keyLen, int valLen, FKeyComparator keyCmprFn, STEnv *pEnv, STDB **ppDb);
 int tdbDbClose(STDB *pDb);
 int tdbDbDrop(STDB *pDb);
 int tdbDbInsert(STDB *pDb, const void *pKey, int keyLen, const void *pVal, int valLen);
 int tdbDbGet(STDB *pDb, const void *pKey, int kLen, void **ppVal, int *vLen);
 
+// STDBC
+int tdbDbcOpen(STDB *pDb, STDBC **ppTDbc);
+int tdbDbNext(STDBC *pDbc, void **ppKey, int *kLen, void **ppVal, int *vLen);
+int tdbDbcClose(STDBC *pDbc);
+
 #ifdef __cplusplus
 }
 #endif

source/libs/tdb/test/tdbTest.cpp

@@ -48,9 +48,28 @@ TEST(tdb_test, simple_test) {
       TDB_FREE(pVal);
     }
 
-    {  // Loop to query the data
-       // STDbC *pDBC;
-       // tdbDBNext(pDBC, p)
+    {  // Iterate to query the DB data
+      STDBC *pDBC;
+      void  *pKey = NULL;
+      void  *pVal = NULL;
+      int    vLen, kLen;
+      int    count = 0;
+
+      ret = tdbDbcOpen(pDb, &pDBC);
+      GTEST_ASSERT_EQ(ret, 0);
+
+      for (;;) {
+        ret = tdbDbNext(pDBC, &pKey, &kLen, &pVal, &vLen);
+        if (ret < 0) break;
+        count++;
+      }
+
+      GTEST_ASSERT_EQ(count, nData);
+
+      tdbDbcClose(pDBC);
+
+      TDB_FREE(pKey);
+      TDB_FREE(pVal);
     }
   }