WIP

Author: byroot

variable.c

@@ -1679,12 +1679,12 @@ rb_obj_init_too_complex(VALUE obj, st_table *table)
     obj_transition_too_complex(obj, table);
 }
 
+void rb_obj_copy_fields_to_hash_table(VALUE obj, st_table *table);
+
 // Copy all object fields, including ivars and internal object_id, etc
 shape_id_t
 rb_evict_fields_to_hash(VALUE obj)
 {
-    void rb_obj_copy_fields_to_hash_table(VALUE obj, st_table *table);
-
     RUBY_ASSERT(!rb_shape_obj_too_complex_p(obj));
 
     st_table *table = st_init_numtable_with_size(RSHAPE_LEN(RBASIC_SHAPE_ID(obj)));
@@ -1900,18 +1900,99 @@ generic_ivar_set_too_complex_table(VALUE obj, void *data)
 static void
 generic_ivar_set(VALUE obj, ID id, VALUE val)
 {
-    struct gen_fields_lookup_ensure_size fields_lookup = {
-        .obj = obj,
-        .id = id,
-        .resize = false,
-    };
+    const VALUE original_fields_obj = 0;
+    st_table *generic_tbl;
+    bool existing = true;
+
+    RB_VM_LOCKING() {
+        generic_tbl = generic_fields_tbl(obj, id, false);
+        st_lookup(generic_tbl, obj, (st_data_t *)&original_fields_obj);
+    }
+
+    VALUE fields_obj = original_fields_obj;
+    if (!fields_obj) {
+        fields_obj = rb_imemo_fields_new(rb_obj_class(obj), 1);
+        RUBY_ASSERT(RBASIC_SHAPE_ID(obj) == ROOT_SHAPE_ID);
+    }
+
+    shape_id_t current_shape_id = RBASIC_SHAPE_ID(fields_obj);
+    shape_id_t next_shape_id = current_shape_id;
+
+    if (UNLIKELY(rb_shape_too_complex_p(current_shape_id))) {
+        goto too_complex;
+    }
+
+    attr_index_t index;
+    if (!rb_shape_get_iv_index(current_shape_id, id, &index)) {
+        existing = false;
+
+        index = RSHAPE_LEN(current_shape_id);
+        if (index >= SHAPE_MAX_FIELDS) {
+            rb_raise(rb_eArgError, "too many instance variables");
+        }
+
+        next_shape_id = rb_shape_transition_add_ivar(fields_obj, id);
+        if (UNLIKELY(rb_shape_too_complex_p(next_shape_id))) {
+            attr_index_t current_len = RSHAPE_LEN(current_shape_id);
+            fields_obj = rb_imemo_fields_new_complex(rb_obj_class(obj), current_len + 1);
+            if (current_len) {
+                rb_obj_copy_fields_to_hash_table(original_fields_obj, rb_imemo_fields_complex_tbl(fields_obj));
+                RBASIC_SET_SHAPE_ID(fields_obj, next_shape_id);
+            }
+            goto too_complex;
+        }
+
+        attr_index_t next_capacity = RSHAPE_CAPACITY(next_shape_id);
+        attr_index_t current_capacity = RSHAPE_CAPACITY(current_shape_id);
+
+        if (next_capacity != current_capacity) {
+            RUBY_ASSERT(next_capacity > current_capacity);
+
+            fields_obj = rb_imemo_fields_new(rb_obj_class(obj), next_capacity);
+            if (original_fields_obj) {
+                MEMCPY(rb_imemo_fields_ptr(fields_obj), rb_imemo_fields_ptr(original_fields_obj), VALUE, RSHAPE_LEN(current_shape_id));
+            }
+        }
+
+        RUBY_ASSERT(RSHAPE(next_shape_id)->type == SHAPE_IVAR);
+        RUBY_ASSERT(index == (RSHAPE_LEN(next_shape_id) - 1));
+    }
+
+    VALUE *fields = rb_imemo_fields_ptr(fields_obj);
+    RB_OBJ_WRITE(fields_obj, &fields[index], val);
 
-    general_ivar_set(obj, id, val, &fields_lookup,
-                     generic_ivar_set_shape_fields,
-                     generic_ivar_set_shape_resize_fields,
-                     generic_ivar_set_set_shape_id,
-                     generic_ivar_set_transition_too_complex,
-                     generic_ivar_set_too_complex_table);
+    if (!existing) {
+        RBASIC_SET_SHAPE_ID(fields_obj, next_shape_id);
+    }
+
+    if (fields_obj != original_fields_obj) {
+        RB_VM_LOCKING() {
+            st_insert(generic_tbl, obj, fields_obj);
+        }
+        if (!existing) {
+            RBASIC_SET_SHAPE_ID(obj, next_shape_id);
+        }
+    }
+
+    return;
+
+too_complex:
+    {
+        st_table *table = rb_imemo_fields_complex_tbl(fields_obj);
+        existing = st_insert(table, (st_data_t)id, (st_data_t)val);
+        RB_OBJ_WRITTEN(fields_obj, Qundef, val);
+
+        if (fields_obj != original_fields_obj) {
+            RB_VM_LOCKING() {
+                st_insert(generic_tbl, obj, fields_obj);
+            }
+            if (!existing) {
+                RBASIC_SET_SHAPE_ID(obj, next_shape_id);
+            }
+        }
+    }
+
+    return;
 }
 
 static void