bdb test

contrib/test/bdb/bdbTest.c

@@ -5,25 +5,65 @@
 
 // refer: https://docs.oracle.com/cd/E17076_05/html/gsg/C/BerkeleyDB-Core-C-GSG.pdf
 
+// Access Methods:
+// 1. BTree
+// 2. Hash
+// 3. Queue
+// 4. Recno
+
+#define USE_ENV 0
+
 int main(int argc, char const *argv[]) {
-  DB *      dbp;
+  DB *      dbp = NULL;
+  u_int32_t db_flags;
+  DB_ENV *  envp = NULL;
+  u_int32_t env_flags;
   int       ret;
-  u_int32_t flags;
-  DBT       key, value;
+  DBT       key, value;  // Database records
 
-  ret = db_create(&dbp, NULL, 0);
+#if USE_ENV
+  // Initialize an env object and open it for
+  ret = db_env_create(&envp, 0);
+  if (ret != 0) {
+    fprintf(stderr, "Error creating env handle: %s\n", db_strerror(ret));
+    return -1;
+  }
+
+  env_flags = DB_CREATE | DB_INIT_MPOOL;
+
+  ret = envp->open(envp, "./meta", env_flags, 0);
+  if (ret != 0) {
+    fprintf(stderr, "Error opening env handle: %s\n", db_strerror(ret));
+    return -1;
+  }
+#endif
+
+  // Initialize a DB handle and open the DB
+  ret = db_create(&dbp, envp, 0);
   if (ret != 0) {
     exit(1);
   }
 
-  flags = DB_CREATE;
-
-  ret = dbp->open(dbp, NULL, "meta.db", NULL, DB_BTREE, flags, 0);
+  db_flags = DB_CREATE;
+  ret = dbp->open(dbp,       /* DB structure pointer */
+                  NULL,      /* Transaction pointer */
+                  "meta.db", /* On-disk file that holds the database */
+                  NULL,      /* Optional logical database name */
+                  DB_BTREE,  /* Database access method */
+                  db_flags,  /* Open flags */
+                  0);        /* File mode */
   if (ret != 0) {
     exit(1);
   }
 
-  dbp->close(dbp, 0);
+  // Close the database
+  if (dbp != NULL) {
+    dbp->close(dbp, 0);
+  }
+
+  if (envp != NULL) {
+    envp->close(envp, 0);
+  }
 
   return 0;
 }