Allow for specifying offset for ecs_delete_empty_tables() function

.gitignore

@@ -1,16 +1,12 @@
-.DS_Store
 bin
-.bake_cache
-.bake
-.vscode
 gcov
-.idea
 *.pdb
 deps
 cmake-build-debug
 bazel-*
 **/CMakeFiles/*
-.vs
 out
 docs/html
 MODULE.bazel.lock
+.*
+.*/*

distr/flecs.c

@@ -23702,13 +23702,14 @@ int32_t ecs_delete_empty_tables(
     ecs_os_perf_trace_push("flecs.delete_empty_tables");
 
     ecs_time_t start = {0}, cur = {0};
-    int32_t delete_count = 0;
     bool time_budget = false;
     int32_t measure_budget_after = 100;
+    int32_t result = 0;
 
     uint16_t clear_generation = desc->clear_generation;
     uint16_t delete_generation = desc->delete_generation;
     double time_budget_seconds = desc->time_budget_seconds;
+    int32_t offset = desc->offset;
 
     if (ECS_NEQZERO(time_budget_seconds) || (ecs_should_log_1() && ecs_os_has_time())) {
         ecs_time_measure(&start);
@@ -23718,13 +23719,34 @@ int32_t ecs_delete_empty_tables(
         time_budget = true;
     }
 
-    int32_t i, count = flecs_sparse_count(&world->store.tables);
+    int32_t count = flecs_sparse_count(&world->store.tables);
+    if (!count) {
+        goto done;
+    }
+
+    if (offset >= count || offset < 0) {
+        offset = 0;
+    }
+
+    int32_t remaining = count;
+    int32_t i = offset;
+
+    while (remaining > 0) {
+        count = flecs_sparse_count(&world->store.tables);
+        if (!count) {
+            break;
+        }
+
+        if (i >= count) {
+            i = 0;
+        }
 
-    for (i = count - 1; i >= 0; i --) {
         ecs_table_t *table = flecs_sparse_get_dense_t(&world->store.tables,
             ecs_table_t, i);
 
         if (table->keep) {
+            i ++;
+            remaining --;
             continue;
         }
 
@@ -23733,31 +23755,42 @@ int32_t ecs_delete_empty_tables(
         if (time_budget && !measure_budget_after) {
             cur = start;
             if (ecs_time_measure(&cur) > time_budget_seconds) {
+                count = flecs_sparse_count(&world->store.tables);
+                result = i + 1;
+                if (result >= count) {
+                    result = 0;
+                }
                 goto done;
             }
 
             measure_budget_after = 100;
         }
 
         if (!table->id || ecs_table_count(table) != 0) {
+            i ++;
+            remaining --;
             continue;
         }
 
         uint16_t gen = ++ table->_->generation;
         if (delete_generation && (gen > delete_generation)) {
             flecs_table_fini(world, table);
-            delete_count ++;
             measure_budget_after = 1;
+            remaining --;
+            continue;
         } else if (clear_generation && (gen > clear_generation)) {
             flecs_table_shrink(world, table);
             measure_budget_after = 1;
         }
+
+        i ++;
+        remaining --;
     }
 
 done:
     ecs_os_perf_trace_pop("flecs.delete_empty_tables");
 
-    return delete_count;
+    return result;
 }
 
 ecs_entities_t ecs_get_entities(

distr/flecs.h

@@ -7727,6 +7727,10 @@ typedef struct ecs_delete_empty_tables_desc_t {
 
     /** Amount of time operation is allowed to spend. */
     double time_budget_seconds;
+
+    /** Table index to start scanning at. The function loops around until it
+     * reaches this offset again, or until the time budget is exceeded. */
+    int32_t offset;
 } ecs_delete_empty_tables_desc_t;
 
 /** Clean up empty tables.
@@ -7754,9 +7758,15 @@ typedef struct ecs_delete_empty_tables_desc_t {
  *
  * The time budget specifies how long the operation should take at most.
  *
+ * The offset parameter specifies the table index at which to start scanning.
+ * The function loops around until it reaches this offset again, or until the
+ * time budget is exceeded.
+ *
  * @param world The world.
  * @param desc Configuration parameters.
- * @return The number of deleted tables.
+ * @return The index + 1 of the table where the function stopped, or 0 if the
+ *         function scanned all tables. The return value can be used as the
+ *         offset for the next call.
  */
 FLECS_API
 int32_t ecs_delete_empty_tables(

include/flecs.h

@@ -2736,6 +2736,10 @@ typedef struct ecs_delete_empty_tables_desc_t {
 
     /** Amount of time operation is allowed to spend. */
     double time_budget_seconds;
+
+    /** Table index to start scanning at. The function loops around until it
+     * reaches this offset again, or until the time budget is exceeded. */
+    int32_t offset;
 } ecs_delete_empty_tables_desc_t;
 
 /** Clean up empty tables.
@@ -2763,9 +2767,15 @@ typedef struct ecs_delete_empty_tables_desc_t {
  *
  * The time budget specifies how long the operation should take at most.
  *
+ * The offset parameter specifies the table index at which to start scanning.
+ * The function loops around until it reaches this offset again, or until the
+ * time budget is exceeded.
+ *
  * @param world The world.
  * @param desc Configuration parameters.
- * @return The number of deleted tables.
+ * @return The index + 1 of the table where the function stopped, or 0 if the
+ *         function scanned all tables. The return value can be used as the
+ *         offset for the next call.
  */
 FLECS_API
 int32_t ecs_delete_empty_tables(

src/world.c

@@ -1696,13 +1696,14 @@ int32_t ecs_delete_empty_tables(
     ecs_os_perf_trace_push("flecs.delete_empty_tables");
 
     ecs_time_t start = {0}, cur = {0};
-    int32_t delete_count = 0;
     bool time_budget = false;
     int32_t measure_budget_after = 100;
+    int32_t result = 0;
 
     uint16_t clear_generation = desc->clear_generation;
     uint16_t delete_generation = desc->delete_generation;
     double time_budget_seconds = desc->time_budget_seconds;
+    int32_t offset = desc->offset;
 
     if (ECS_NEQZERO(time_budget_seconds) || (ecs_should_log_1() && ecs_os_has_time())) {
         ecs_time_measure(&start);
@@ -1712,13 +1713,34 @@ int32_t ecs_delete_empty_tables(
         time_budget = true;
     }
 
-    int32_t i, count = flecs_sparse_count(&world->store.tables);
+    int32_t count = flecs_sparse_count(&world->store.tables);
+    if (!count) {
+        goto done;
+    }
+
+    if (offset >= count || offset < 0) {
+        offset = 0;
+    }
+
+    int32_t remaining = count;
+    int32_t i = offset;
+
+    while (remaining > 0) {
+        count = flecs_sparse_count(&world->store.tables);
+        if (!count) {
+            break;
+        }
+
+        if (i >= count) {
+            i = 0;
+        }
 
-    for (i = count - 1; i >= 0; i --) {
         ecs_table_t *table = flecs_sparse_get_dense_t(&world->store.tables,
             ecs_table_t, i);
 
         if (table->keep) {
+            i ++;
+            remaining --;
             continue;
         }
 
@@ -1727,31 +1749,42 @@ int32_t ecs_delete_empty_tables(
         if (time_budget && !measure_budget_after) {
             cur = start;
             if (ecs_time_measure(&cur) > time_budget_seconds) {
+                count = flecs_sparse_count(&world->store.tables);
+                result = i + 1;
+                if (result >= count) {
+                    result = 0;
+                }
                 goto done;
             }
 
             measure_budget_after = 100;
         }
 
         if (!table->id || ecs_table_count(table) != 0) {
+            i ++;
+            remaining --;
             continue;
         }
 
         uint16_t gen = ++ table->_->generation;
         if (delete_generation && (gen > delete_generation)) {
             flecs_table_fini(world, table);
-            delete_count ++;
             measure_budget_after = 1;
+            remaining --;
+            continue;
         } else if (clear_generation && (gen > clear_generation)) {
             flecs_table_shrink(world, table);
             measure_budget_after = 1;
         }
+
+        i ++;
+        remaining --;
     }
 
 done:
     ecs_os_perf_trace_pop("flecs.delete_empty_tables");
 
-    return delete_count;
+    return result;
 }
 
 ecs_entities_t ecs_get_entities(

test/core/project.json

@@ -2798,7 +2798,11 @@
                 "add_dont_fragment_after_pair_query",
                 "add_can_toggle_after_pair_query",
                 "add_traversable_after_pair_query",
-                "set_component_after_in_use"
+                "set_component_after_in_use",
+                "delete_empty_tables_w_offset",
+                "delete_empty_tables_w_offset_out_of_range",
+                "delete_empty_tables_w_offset_wrap_around",
+                "delete_empty_tables_return_value"
             ]
         }, {
             "id": "ExclusiveAccess",