Merge pull request atomvm#1461 from TheSobkiewicz/thesobkiewicz/nifs/ets/refactor_delete

Add `ets:delete/1`, `ets:delete` refactor

See also atomvm#1509

- Added ets:delete/1.
- Extracted helper functions for ets:delete that will be used in future
function implementations.
Based on atomvm#1405.

The new helper functions can be utilized in the following ETS operations to
reduce code duplication:
- ets:take/2
- ets:delete_object/2

These changes are made under both the "Apache 2.0" and the "GNU Lesser General
Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later

Author: bettio

CHANGELOG.md

@@ -27,6 +27,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Support for `float/1` BIF.
 - Added `erlang:get/0` and `erlang:erase/0`.
 - Added `erlang:unique_integer/0` and `erlang:unique_integer/1`
+- Added support for 'ets:delete/1'.
 
 ### Fixed
 - ESP32: improved sntp sync speed from a cold boot.

libs/estdlib/src/ets.erl

@@ -29,6 +29,7 @@
     insert/2,
     lookup/2,
     lookup_element/3,
+    delete/1,
     delete/2,
     update_counter/3,
     update_counter/4
@@ -141,3 +142,12 @@ update_counter(_Table, _Key, _Params) ->
 ) -> integer().
 update_counter(_Table, _Key, _Params, _Default) ->
     erlang:nif_error(undefined).
+%%-----------------------------------------------------------------------------
+%% @param   Table a reference to the ets table
+%% @returns true;
+%% @doc Delete an ets table.
+%% @end
+%%-----------------------------------------------------------------------------
+-spec delete(Table :: table()) -> true.
+delete(_Table) ->
+    erlang:nif_error(undefined).

src/libAtomVM/ets.c

@@ -426,27 +426,57 @@ EtsErrorCode ets_lookup_element_maybe_gc(term name_or_ref, term key, size_t pos,
     return EtsOk;
 }
 
-EtsErrorCode ets_delete(term name_or_ref, term key, term *ret, Context *ctx)
+static EtsErrorCode ets_table_delete(struct EtsTable *ets_table, term key, term *ret, Context *ctx)
 {
-    struct EtsTable *ets_table = term_is_atom(name_or_ref) ? ets_get_table_by_name(&ctx->global->ets, name_or_ref, TableAccessRead) : ets_get_table_by_ref(&ctx->global->ets, term_to_ref_ticks(name_or_ref), TableAccessRead);
-    if (ets_table == NULL) {
-        return EtsTableNotFound;
-    }
-
     if (ets_table->access_type != EtsAccessPublic && ets_table->owner_process_id != ctx->process_id) {
-        SMP_UNLOCK(ets_table);
         return EtsPermissionDenied;
     }
 
     bool _res = ets_hashtable_remove(ets_table->hashtable, key, ets_table->keypos, ctx->global);
     UNUSED(_res);
 
-    SMP_UNLOCK(ets_table);
     *ret = TRUE_ATOM;
+    return EtsOk;
+}
 
+EtsErrorCode ets_drop_table(term name_or_ref, term *ret, Context *ctx)
+{
+    struct EtsTable *ets_table = term_is_atom(name_or_ref)
+        ? ets_get_table_by_name(&ctx->global->ets, name_or_ref, TableAccessWrite)
+        : ets_get_table_by_ref(&ctx->global->ets, term_to_ref_ticks(name_or_ref), TableAccessWrite);
+    if (IS_NULL_PTR(ets_table)) {
+        return EtsTableNotFound;
+    }
+    if (ets_table->access_type != EtsAccessPublic && ets_table->owner_process_id != ctx->process_id) {
+        return EtsPermissionDenied;
+    }
+
+    struct ListHead *ets_tables_list = synclist_wrlock(&ctx->global->ets.ets_tables);
+    UNUSED(ets_tables_list);
+    list_remove(&ets_table->head);
+    SMP_UNLOCK(ets_table);
+    ets_table_destroy(ets_table, ctx->global);
+    synclist_unlock(&ctx->global->ets.ets_tables);
+
+    *ret = TRUE_ATOM;
     return EtsOk;
 }
 
+EtsErrorCode ets_delete(term name_or_ref, term key, term *ret, Context *ctx)
+{
+    struct EtsTable *ets_table = term_is_atom(name_or_ref)
+        ? ets_get_table_by_name(&ctx->global->ets, name_or_ref, TableAccessRead)
+        : ets_get_table_by_ref(&ctx->global->ets, term_to_ref_ticks(name_or_ref), TableAccessRead);
+    if (IS_NULL_PTR(ets_table)) {
+        return EtsTableNotFound;
+    }
+
+    EtsErrorCode res = ets_table_delete(ets_table, key, ret, ctx);
+
+    SMP_UNLOCK(ets_table);
+    return res;
+}
+
 static bool operation_to_tuple4(term operation, size_t default_pos, term *position, term *increment, term *threshold, term *set_value)
 {
     if (term_is_integer(operation)) {

src/libAtomVM/ets.h

@@ -79,6 +79,7 @@ EtsErrorCode ets_lookup_maybe_gc(term ref, term key, term *ret, Context *ctx);
 EtsErrorCode ets_lookup_element_maybe_gc(term ref, term key, size_t pos, term *ret, Context *ctx);
 EtsErrorCode ets_delete(term ref, term key, term *ret, Context *ctx);
 EtsErrorCode ets_update_counter_maybe_gc(term ref, term key, term value, term pos, term *ret, Context *ctx);
+EtsErrorCode ets_drop_table(term ref, term *ret, Context *ctx);
 #ifdef __cplusplus
 }
 #endif

src/libAtomVM/nifs.c

@@ -3314,15 +3314,17 @@ static term nif_ets_lookup_element(Context *ctx, int argc, term argv[])
 
 static term nif_ets_delete(Context *ctx, int argc, term argv[])
 {
-    UNUSED(argc);
-
     term ref = argv[0];
     VALIDATE_VALUE(ref, is_ets_table_id);
-
-    term key = argv[1];
-
     term ret = term_invalid_term();
-    EtsErrorCode result = ets_delete(ref, key, &ret, ctx);
+    EtsErrorCode result;
+    if (argc == 2) {
+        term key = argv[1];
+        result = ets_delete(ref, key, &ret, ctx);
+    } else {
+        result = ets_drop_table(ref, &ret, ctx);
+    }
+
     switch (result) {
         case EtsOk:
             return ret;

src/libAtomVM/nifs.gperf

@@ -131,6 +131,7 @@ ets:new/2, &ets_new_nif
 ets:insert/2, &ets_insert_nif
 ets:lookup/2, &ets_lookup_nif
 ets:lookup_element/3, &ets_lookup_element_nif
+ets:delete/1, &ets_delete_nif
 ets:delete/2, &ets_delete_nif
 ets:update_counter/3, &ets_update_counter_nif
 ets:update_counter/4, &ets_update_counter_nif

tests/erlang_tests/test_ets.erl

@@ -33,6 +33,7 @@ start() ->
     ok = test_lookup_element(),
     ok = test_insert_list(),
     ok = test_update_counter(),
+    ok = test_delete_table(),
     0.
 
 test_basic() ->
@@ -386,3 +387,16 @@ test_update_counter() ->
     10 = ets:update_counter(Tid, patatas, {3, 10, 10, 0}),
     0 = ets:update_counter(Tid, patatas, {3, 10, 10, 0}),
     ok.
+
+test_delete_table() ->
+    Tid = ets:new(test_delete_table, []),
+    true = ets:delete(Tid),
+    ok = expect_failure(
+        fun() -> ets:insert(Tid, {gnu, gnat}) end
+    ),
+    Ntid = ets:new(test_delete_table, []),
+    true = ets:delete(Ntid),
+    ok = expect_failure(fun() -> ets:delete(Ntid) end),
+    ok = expect_failure(fun() -> ets:delete(Tid) end),
+    ok = expect_failure(fun() -> ets:delete(non_existent) end),
+    ok.