dispose: physically destory db

Author: wulei

c_src/elmdb_nif.c

@@ -197,6 +197,16 @@ static ERL_NIF_TERM elmdb_close(ErlNifEnv* env, int argc, const ERL_NIF_TERM arg
         return enif_raise_exception(env, enif_make_string(env, "closed lmdb", ERL_NIF_LATIN1));\
     }
 
+static ERL_NIF_TERM elmdb_path(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {
+    __UNUSED(argc);
+    lmdb_env_t *handle = NULL;
+    CHECKOUT_ARG_FOR_DB(handle);
+    const char* path;
+    mdb_env_get_path(handle->env, &path);
+    DBG("path: %s",path);
+    return enif_make_string(env, path, ERL_NIF_LATIN1);
+}
+
 static ERL_NIF_TERM elmdb_drop(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {
     __UNUSED(argc);
     lmdb_env_t *handle = NULL;
@@ -912,6 +922,7 @@ static ErlNifFunc nif_funcs[] = {
     {"init",        1, elmdb_init,      ERL_NIF_DIRTY_JOB_IO_BOUND},
     {"close",       1, elmdb_close,     ERL_NIF_DIRTY_JOB_IO_BOUND},
     {"drop",        2, elmdb_drop,      ERL_NIF_DIRTY_JOB_IO_BOUND},
+    {"db_path",     1, elmdb_path,      0},
     {"count",       2, elmdb_count,     0},
     {"put",         3, elmdb_put,       0},
     {"get",         2, elmdb_get,       0},

src/elmdb.erl

@@ -4,6 +4,7 @@
 -export([to_map/2]).
 
 -export([open/1]).
+-export([dispose/1]).
 -export([close/1]).
 -export([drop/2]).
 -export([count/2]).
@@ -55,6 +56,16 @@ init(_) ->
 close(_) ->
 	erlang:nif_error({not_loaded, ?MODULE}).
 
+db_path(_) ->
+	erlang:nif_error({not_loaded, ?MODULE}).
+
+-spec dispose(reference()) -> ok | {error, term()}.
+dispose(LmdbRes) ->
+    Dir = db_path(LmdbRes),
+    ok = close(LmdbRes),
+    [file:delete(F) || F <- filelib:wildcard(Dir ++ "*")],
+    file:del_dir(Dir).
+
 -spec drop(reference(), string()) -> ok | {error, any()}.
 drop(_LmdbRes, _Layer) ->
 	erlang:nif_error({not_loaded, ?MODULE}).

test/elmdb_foldl_test.erl

@@ -13,9 +13,7 @@ teardown(D) ->
     [elmdb:drop(D, L) || L <- elmdb:ls(D)],
     %%ok = elmdb:close(D),
 
-    Dir = "./mytestdb2/",
-    [file:delete(F) || F <- filelib:wildcard(Dir ++ "*")],
-    file:del_dir(Dir).
+    elmdb:dispose(D).
 
 fold_db(D) ->
     [fold_normal_db(D), fold_empty_db(D)].

test/elmdb_test.erl

@@ -11,11 +11,10 @@ startup() ->
 
 teardown(D) ->
     [elmdb:drop(D, L) || L <- elmdb:ls(D)],
-    ok = elmdb:close(D),
+    Dir0 = elmdb:dispose(D),
     Dir = "./mytestdb1/",
-    ?debugFmt("teardown.......... @dir=~ts", [Dir]),
-    [file:delete(F) || F <- filelib:wildcard(Dir ++ "*")],
-    file:del_dir(Dir).
+    ?debugFmt("teardown.......... @path=~ts", [Dir0]),
+    ok.
 
 
 list_db(D) ->