Rework external string free operation (#4690)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/api/jerry.c

@@ -2700,9 +2700,9 @@ jerry_create_string_sz (const jerry_char_t *str_p, /**< pointer to string */
  */
 jerry_value_t
 jerry_create_external_string (const jerry_char_t *str_p, /**< pointer to string */
-                              jerry_value_free_callback_t free_cb) /**< free callback */
+                              void *user_p) /**< user pointer passed to the callback when the string is freed */
 {
-  return jerry_create_external_string_sz (str_p, lit_zt_utf8_string_size ((lit_utf8_byte_t *) str_p), free_cb);
+  return jerry_create_external_string_sz (str_p, lit_zt_utf8_string_size ((lit_utf8_byte_t *) str_p), user_p);
 } /* jerry_create_external_string */
 
 /**
@@ -2716,13 +2716,13 @@ jerry_create_external_string (const jerry_char_t *str_p, /**< pointer to string
 jerry_value_t
 jerry_create_external_string_sz (const jerry_char_t *str_p, /**< pointer to string */
                                  jerry_size_t str_size, /**< string size */
-                                 jerry_value_free_callback_t free_cb) /**< free callback */
+                                 void *user_p) /**< user pointer passed to the callback when the string is freed */
 {
   jerry_assert_api_available ();
 
   ecma_string_t *ecma_str_p = ecma_new_ecma_external_string_from_cesu8 ((lit_utf8_byte_t *) str_p,
                                                                         (lit_utf8_size_t) str_size,
-                                                                        free_cb);
+                                                                        user_p);
   return ecma_make_string_value (ecma_str_p);
 } /* jerry_create_external_string_sz */
 
@@ -3107,6 +3107,16 @@ jerry_substring_to_utf8_char_buffer (const jerry_value_t value, /**< input strin
                                              buffer_size);
 } /* jerry_substring_to_utf8_char_buffer */
 
+/**
+ * Sets the global callback which is called when an external string is freed.
+ */
+void
+jerry_string_set_external_string_free_callback (jerry_external_string_free_callback_t callback_p) /**< free
+                                                                                                   *   callback */
+{
+  JERRY_CONTEXT (external_string_free_callback_p) = callback_p;
+} /* jerry_string_set_external_string_free_callback */
+
 /**
  * Checks whether the object or it's prototype objects have the given property.
  *

jerry-core/ecma/base/ecma-globals.h

@@ -1804,8 +1804,8 @@ typedef struct
  */
 typedef struct
 {
-  ecma_long_string_t header;
-  jerry_value_free_callback_t free_cb; /**< free callback */
+  ecma_long_string_t header; /**< long string header */
+  void *user_p; /**< user pointer passed to the callback when the string is freed */
 } ecma_external_string_t;
 
 /**

jerry-core/ecma/base/ecma-helpers-string.c

@@ -19,6 +19,7 @@
 #include "ecma-gc.h"
 #include "ecma-globals.h"
 #include "ecma-helpers.h"
+#include "jcontext.h"
 #include "jrt.h"
 #include "jrt-libc-includes.h"
 #include "lit-char-helpers.h"
@@ -455,7 +456,8 @@ ecma_new_ecma_string_from_utf8_converted_to_cesu8 (const lit_utf8_byte_t *string
 ecma_string_t *
 ecma_new_ecma_external_string_from_cesu8 (const lit_utf8_byte_t *string_p, /**< cesu-8 string */
                                           lit_utf8_size_t string_size, /**< string size */
-                                          jerry_value_free_callback_t free_cb) /**< free callback */
+                                          void *user_p) /**< user pointer passed to the callback
+                                                         *   when the string is freed */
 {
   JERRY_ASSERT (string_p != NULL || string_size == 0);
   JERRY_ASSERT (lit_is_valid_cesu8_string (string_p, string_size));
@@ -465,9 +467,11 @@ ecma_new_ecma_external_string_from_cesu8 (const lit_utf8_byte_t *string_p, /**<
     /* Normal strings are created for short strings. */
     ecma_string_t *string_desc_p = ecma_new_ecma_string_from_utf8 (string_p, string_size);
 
+    jerry_external_string_free_callback_t free_cb = JERRY_CONTEXT (external_string_free_callback_p);
+
     if (free_cb != NULL)
     {
-      free_cb ((void *) string_p);
+      free_cb ((lit_utf8_byte_t *) string_p, string_size, user_p);
     }
     return string_desc_p;
   }
@@ -476,9 +480,11 @@ ecma_new_ecma_external_string_from_cesu8 (const lit_utf8_byte_t *string_p, /**<
 
   if (string_desc_p != NULL)
   {
+    jerry_external_string_free_callback_t free_cb = JERRY_CONTEXT (external_string_free_callback_p);
+
     if (free_cb != NULL)
     {
-      free_cb ((void *) string_p);
+      free_cb ((lit_utf8_byte_t *) string_p, string_size, user_p);
     }
     return string_desc_p;
   }
@@ -491,7 +497,7 @@ ecma_new_ecma_external_string_from_cesu8 (const lit_utf8_byte_t *string_p, /**<
   long_string_p->string_p = string_p;
   long_string_p->size = string_size;
   long_string_p->length = lit_utf8_string_length (string_p, string_size);
-  external_string_p->free_cb = free_cb;
+  external_string_p->user_p = user_p;
 
   return (ecma_string_t *) external_string_p;
 } /* ecma_new_ecma_external_string_from_cesu8 */
@@ -961,10 +967,13 @@ ecma_destroy_ecma_string (ecma_string_t *string_p) /**< ecma-string */
       }
 
       ecma_external_string_t *external_string_p = (ecma_external_string_t *) string_p;
+      jerry_external_string_free_callback_t free_cb = JERRY_CONTEXT (external_string_free_callback_p);
 
-      if (external_string_p->free_cb != NULL)
+      if (free_cb != NULL)
       {
-        external_string_p->free_cb ((void *) external_string_p->header.string_p);
+        free_cb ((lit_utf8_byte_t *) external_string_p->header.string_p,
+                 external_string_p->header.size,
+                 external_string_p->user_p);
       }
 
       ecma_dealloc_external_string (external_string_p);

jerry-core/ecma/base/ecma-helpers.h

@@ -303,7 +303,7 @@ ecma_string_t *ecma_new_ecma_string_from_utf8 (const lit_utf8_byte_t *string_p,
 ecma_string_t *ecma_new_ecma_string_from_utf8_converted_to_cesu8 (const lit_utf8_byte_t *string_p,
                                                                   lit_utf8_size_t string_size);
 ecma_string_t *ecma_new_ecma_external_string_from_cesu8 (const lit_utf8_byte_t *string_p, lit_utf8_size_t string_size,
-                                                         jerry_value_free_callback_t free_cb);
+                                                         void *user_p);
 ecma_string_t *ecma_new_ecma_string_from_code_unit (ecma_char_t code_unit);
 #if JERRY_ESNEXT
 ecma_string_t *ecma_new_ecma_string_from_code_units (ecma_char_t first_code_unit, ecma_char_t second_code_unit);

jerry-core/include/jerryscript-core.h

@@ -135,6 +135,7 @@ jerry_size_t jerry_substring_to_utf8_char_buffer (const jerry_value_t value,
                                                   jerry_length_t end_pos,
                                                   jerry_char_t *buffer_p,
                                                   jerry_size_t buffer_size);
+void jerry_string_set_external_string_free_callback (jerry_external_string_free_callback_t callback_p);
 
 /**
  * Functions for array object values.
@@ -188,10 +189,8 @@ jerry_value_t jerry_create_string_from_utf8 (const jerry_char_t *str_p);
 jerry_value_t jerry_create_string_sz_from_utf8 (const jerry_char_t *str_p, jerry_size_t str_size);
 jerry_value_t jerry_create_string (const jerry_char_t *str_p);
 jerry_value_t jerry_create_string_sz (const jerry_char_t *str_p, jerry_size_t str_size);
-jerry_value_t jerry_create_external_string (const jerry_char_t *str_p,
-                                            jerry_value_free_callback_t free_cb);
-jerry_value_t jerry_create_external_string_sz (const jerry_char_t *str_p, jerry_size_t str_size,
-                                               jerry_value_free_callback_t free_cb);
+jerry_value_t jerry_create_external_string (const jerry_char_t *str_p, void *user_p);
+jerry_value_t jerry_create_external_string_sz (const jerry_char_t *str_p, jerry_size_t str_size, void *user_p);
 jerry_value_t jerry_create_symbol (const jerry_value_t value);
 jerry_value_t jerry_create_bigint (const uint64_t *digits_p, uint32_t size, bool sign);
 jerry_value_t jerry_create_undefined (void);

jerry-core/include/jerryscript-types.h

@@ -291,6 +291,12 @@ struct jerry_object_native_info_t;
  */
 typedef void (*jerry_object_native_free_callback_t) (void *native_p, struct jerry_object_native_info_t *info_p);
 
+/**
+ * Free callback for external strings.
+ */
+typedef void (*jerry_external_string_free_callback_t) (jerry_char_t *string_p, jerry_size_t string_size,
+                                                       void *user_p);
+
 /**
  * Decorator callback for Error objects. The decorator can create
  * or update any properties of the newly created Error object.

jerry-core/jcontext/jcontext.h

@@ -158,6 +158,7 @@ struct jerry_context_t
 
   vm_frame_ctx_t *vm_top_context_p; /**< top (current) interpreter context */
   jerry_context_data_header_t *context_data_p; /**< linked list of user-provided context-specific pointers */
+  jerry_external_string_free_callback_t external_string_free_callback_p; /**< free callback for external strings */
   void *error_object_created_callback_user_p; /**< user pointer for error_object_update_callback_p */
   jerry_error_object_created_callback_t error_object_created_callback_p; /**< decorator callback for Error objects */
   size_t ecma_gc_objects_number; /**< number of currently allocated objects */